Heart Rate Monitor ~ chest strap v.s. wrist sensor??

What heart rate monitor is good for hiking?

Chest-strap heart rate sensor

Embedded wrist heart rate sensor

There are a lot of devices which have heart rate sensors!!

Running devices, activity tracker, Apple watch and so on!

A several years ago, most of heart rate sensor for running was chest strap type.

Now, it is getting popular to use embedded heart rate sensor in a device.

I had a comparison about the accuracy!

Offset of measured heart rate between a chest-strap sensor and embedded wrist sensor

Offset of measured heart rate

I collected heart rate data based on my regular running exercise for a month.  I was wearing the both type of heart rate sensors, a chest-strap type and an embedded wrist sensor when I ran.

The chart above is the offset of the both measurements.  More than 90% of samples are within 4 (bpm).    This shows the embedded sensor is probably accurate enough for running and hiking.

Here is an example which has larger offset:

An example of larger offset 

The orange color is a data captured by a chest-strap sensor (with Garmin Forerunner 910XT).
In the middle of chart, there are some portion where the offset is bigger.  However the reading is more than 180 (bpm) which is probably way bigger for mild jog.  Therefore, I assume this data captured by a chest-strap sensor might be something wrong.

Another example is the the following:

Another bad example with larger offset

The blue color is captured by an embedded writ sensor (Garmin Vivosmart HR).  The early part, there are some spikes.  This data captured by an exercise using StarMaster in a gym.  It is hard to believe there is such spike during the exercise since the type of exercise won't introduce such narrow heart rate spikes.  Therefore, I assume this would be wrong reading by the embedded sensors.

Conclusion:The both sensors might have some wrong reading!

The both example shows there might be some wrong reading for the both sensors.  It is hard to identify the reason why the reading gets some offset.  Overall reading is matched well.   I think as long as contact between the sensor and body is good, the reading can be accurate.
My best guess is that if the contact is getting loose or dislocate a proper position to the body, the reading might be offsetting.

When people using a chest-strap sensor, it is probably easy to dislocate position due to a backpack.  I think that would be one of issue when I use the chest-strap type sensor during hiking.
Therefore, I would recommend embedded wrist sensor for hiking!

 

This device is with GPS function and it can track where you hike.

 

This device has pulse oximeter function, but no GPS.
It might be good to see your oxygen saturation which might be a good index for your body reaction of elevation!

A good partner for hiking! ~ Easy hiking in high elevation!

Monitoring your heart rate duing hiking helps to manage your walking pace!
This is one of a good way to manage your walking pace.

For experienced hiker, they know their best pace for hiking.  They won't get exhausted based on optimal pace.  Many seriour climbers who climed Himalaya mountains, they understand what the reaction of their body in higher elevation.

However, for many hikiers who do not have a lot of experience more than 10,000 feet. It is hard to tell what is going on for your body.   It is almost no sign for impacts of high elevation.  As a result, you may be exhausted.   Your experience of the hiking won't be great if you really exhausted.

Monitoring heart rate and manage your walking pace will help to keep an optimal pace for you and you will have a great experience for your big desstination like Mt. Whitney which is the highest mountain in lower 48 states in the United States.

Let's get a device which can monitor your heart rate during hiking!

The lowest cost solution!

Hiking season is coming!

In the US, Memorial Day weekend is coming!   It is starting a nice hiking season this summer!

Mt. Whitney which is the highest mountain in Calfornia. 

It is the highest mountain in the lower 48 states in the United States.

Due to the "highest mountain" in the main portion of the United States, 

Mt. Whitney is very popular destination for many hikers.

High Altitude Sickness

Do you know "High Altitude Sickness"?

Due to low oxigen environment in highe elevation, many people feels some symptoms when they hike more than 10,000 feet.  It is sometimes headache, dehydration and others.

If you spend more time in higher elevation, human body will adopt the altitude slowly in many cases.  However, it is hard to avoid in short term. 

Many hiking might be done within a few days and it would be too short to adopt the altitude.

Pace management in high elevation

The pace management for a hiking in higer elevation, which is above 10,000 feet, is probably very difficult for most of people.  Because almost all people could not feel the impact in the early stage of high altitude sickness where the elevation around 10,000 feet.  At this stage, you do not feel anything different from a typical hiking in lower elevation.

However, if you monitor your heart rate, you will see the difference.  Even if you walked a similar pace when you hikin in lower elevation, the heart rate is getting much higher in higher elevation.  This means you do not feel anything special, but there is sign for the high altitude sickness already.

What happens?

Since you cannot recognize any impact of the elevation in the early stage of high altitude sickness, your walking pace is eventually "over pacing".  Then it will gets worse quickly and you will be exhausted in a short time.

Most of destination for hikers is somewhere around 14,000 feet and you may be able to reach the summit without any special thing for the altitude.  But you may be exhausted and your experience might not be great.

Monitor Heart rate helps your experience!

One of a good solution for the high altitude sickness is monitoring heart rate and manage your pace based on heart rate.

It used to be not easy since there is not very good way to monitor your heart rate in real time during hiking.   However, it is getting much easier nowadays.  Since there are many devices which can monitor real time heart rate just waring a watch!

A good solution is using activity tracker during hiking!

There are many activitiy tracker devices in the market.  Also, running is getting very popular for people's health, there are many running devices with GPS function.  Those are all good devices to monitor your heart rate duing hiking!

The following device is called "Garming vivoactive 3".

This device also capable to trace where you go as your record with GPS. 

This is a very good fit for many hikers to keep tracking where you go and how much time you took.

In terms of the cost, I would recomend this device for trcking your heart rate during hiking.

Nice device with GPS function!

The next device is "Garmin fenix 5".  This is a bit expensive.  However due to a updated model is introduced this price is getting lower and now it is a bit expensive but affordable range now.

A good thing for this device is more nice features for hikers.  Longer battery life, built in compas and more profile for many other spots to track your activity.   I have been using the previous modle "fenix 3 HR" and it is really nice gear for hiking.

If you can affort this price, I would recomend this device!

More outdoor feature!

I will post how to manage you hiking pace in the next post!

(To be continue)

Mt. Whitney Hiking 2018 (4) ~ SPO2 value and Heart rate at 12000 feet

SPO2 value and Heart rate at Trail Camp on Mt. Whitney Trail

SPO2 value at 12,000 feet

Elevation of Trail Camp on Mt. Whitney Trail is about 12,000 feet (3,600m) where many people have some symptom of high altitude sickness.
I majored SPO2 value with a pulse oximeter before, however it was very hard to determine which value would be a real value since the majored value kept changed in a wide range.

For this hiking, I carried a one which is used for monitoring SPO2 during sleeping to understand a situation of sleep apnea.  It can measure SPO2 continuously what it looks like when I am in the tent.
Almost all time, SPO2 value was below 90% and the range of the measured range is huge.  It depends on how I breath and what I am doing such as walking and lay down.  This is expected based on the previous measurement with real time measurement.  The range is roughly 70 ~90%.

Overall, the average SPO2 value when I awake is somewhere around 85%.  However it is getting lower when I slept, the value was somewhere 75%.  This is probably due to lower breathing rate when I slept.  As long as I am awake, I might be able to control how I breath intentionally.  However once I fell into sleep, then it is very hard to control.  Also, the range of the measured value during sleeping is probably much smaller than when I am awake.

For heart rate, it is also wide range comparing data in lower elevation and it might be related to SPO 2 value I guess.

Without acclimatization

Based on this data, SPO2 value might be getting lower when people sleep.  I guess it is probably possible to get worse when people sleep in higher elevation without acclimatization.   The reason I woke up often during the night would be one of symptoms of high altitude sickness.

Unfortunately,  this is only data I have now and I do not have any other data to compare, it is very difficult to conclude what happens.   I need to collect more data such as multiple nights with longer stay.  Then I can find out more.

One think I can tell is probably SPO2 range when people is not acclimatized.  It is probably hard to determine what would be the value in this situation.  We might need to find some average during some period.

Data during sleeping at home last night

As a reference, I show a data when I was sleeping at home last night.  SPO2 value and the heart late are much more stable than a data at 12,000 feet.  The heart rate is below 60 bpm and SPO2 value is around 95% overall during night.

I think it is very clear, the data shows impact to human body who is in higher elevation.  I do not see any sign for acclimatization.   I guess it is getting much more stable when people get acclimatized.

It is clearly the range of the change for heart rate is much smaller and it might be a better index for hiking in my opinion.

(To be continue)

Mt. Whitney Hiking 2018 (3) ~ From Trail Camp to Summit -- Fastest time !!

Heart Rate trend from Trail Camp to the Summit of Mt.Whitney

Day2 2018

Here is a data analysis report from Trail Camp to the summit of Mt. Whitney.

The total time is 3 hours 7 minutes including 4 minutes of resting.  Actually I did not take any break, therefore the resting time is just stop walking in a short period to adjust breathing.  That is the 4 minutes shows in the tracking data.
This is the fastest time from Trail Camp in my past hiking.  The previous record was 197 minutes in 2015.  The other years were between 200 minutes and 250 minutes.  So that it is 10 minutes faster than the previous record.  It is really fast for me.
As usual, I started walking around 3:40 am.   The strategy was trying not to take a break and the target heart rate was keeping less than 140 bpm.

Walking Speed

On the way to Trail Crest, I was passed by other party in 99-switch back section, however, I did not take any break.  As a result I reached the summit a little earlier than them.  Since it was low temperature early in the morning before Sun rise, I might need to ware a jacket to keep warm when I take a break.  However, I did not take any break and just walking slowly, I did not have to worry about such thing.  It was really easy!!

心拍ゾーンの分布

Slowly is better!?


The average walking speed is about 0.6 m / sec, 36 m / min.  This is really slow pace.  However, the overall it was not too bad comparing with the other parties.   The heart rate zone was also stayed below Zone 1.  I did not feel hard at all.  It was really easy!
 
I think my fitness level was getting worse than 2015 due to my age.  Even though the total time is the best record for the section from Trail Camp to the summit.   I think this is a good indication for the pace management based on the heart rate.  It is really good method for hiking in higher elevation.

I think it is very hard to keep this slow pace if I do not see my heart rate.  It is really good indication to define a better walking pace where many people feel some symptoms of high altitude sickness.

The key is "Do not push your self".  This is really trick to have a better experience for such hiking.

The next posting is looking into heart rate other than walking.  I got some heart rate / SPO2 data in a camp site this time.

(To be continue)

Mt. Whitney Hiking 2018 (2) ~ Data analysis for the first day

Heart Rate trend for the day 1

Walking Speed trend for day 1

Elevation trend for day 1

Data for the first day

As I always do for each hiking, I captured GPS / HR data by a GPS running watch.  Here is the analysis result for the first day of the hiking to Mt. Whitney this year.
As a result, the total time from the trail head (Whitney Portal) to Trail Camp where I camped was:

• Total Time:    271    minutes (including resting time)
• Resting Time   14.2 minutes

The distance based on the GPS data is 7.4 miles (11.9 km).
To compare data from different years, some reference point (location) is picked from a map with latitude and longitude.  Based on the location data, a program looks for the GPS data entries within 50m from the reference point.  Then, the program will check the minimum duration for each section.  Since GPS and distance calculation in the GPS device has some error, the measured distances are not the same for each year.  The average distance of this section (Trail head - Trail Camp) in the past years is about 6.5 mils (10.5 km) .  So that the distance measured this year is about a mile longer than the average.  However, this is not an important parameter for this comparison.  This comparison is focusing on the total duration, therefore it is not a problem.

The following is the past duration in the same section:

• 2011: 264 (min) (Resting: 56 min)
• 2014: 276 (min) (Resting: 65 min)
• 2015: 266 (min) (Resting: 64 min)
• 2016: 310 (min) (Resting: 81 min)
• 2018: 271 (min) (Resting: 14 min)

(*) Note: The definition of resting time is the walking speed is less than 20 m / min.

Based on this data, this year is 3rd fastest after 2011 and 2015.  The big difference is much less resting time this year.

Actual feeling?

Here is what I felt during hiking this year.  Overall, my condition was pretty good.  I had 4 hours sleep at home before left home.  Just thinking about long driving during night, this would be a better than other years and it was not too bad at all!

However.......

When I started walking from the trail head, the heart rate jumped to more than 160 bpm right away even if the walking pace was not so fast.  I guess this is probably due to lack of training for ascending before the hiking.  I think my muscle strength was not enough and it was easy to increase the heart rate.  Therefore, I was very carefully manage the heart rate with slower pace from the beginning of this hiking.  The target range I set was somewhere around 140 ~ 155 bpm. 

Duration for each key section

Let's look into more detail!  A section from Whitney Portal to a branch to Lone Pine Lake, I took about 103 minutes.  I thought I was walking very slowly.  However it is very similar time as year 2014, 102 minutes  which was the fastest duration in the past.  The difference between the years are resting time, it was 12 minutes in 2014, but only 6 minutes this year.  It is the half of 2014.

The next section is from Lone Pine Lake branch to Outpost Camp.  It is relatively flat section and the fastest duration in the past was 28 minutes in 2011 which includes 3 minutes resting time.  This year was 30 minutes without any resting time.

The next section is probably the most tough section in the first day which is from Outpost Camp to Trail Camp.  The best duration in the past was 125 minutes in 2015 with 37 minutes resting time.  This year was 132 minutes with 9 minutes resting time.

Please note, the sum of duration for each section does not match the total time I showed in the beginning.  This is because, each reference location is defined within 50 m range and calculated the duration with the shortest duration between each reference point.  This means the moving time with in the 50 m range for each section does not include the time.  Thus, this is not an error.

Distribution of heart rate zones

The heart rate zone distribution for the first day, almost 80% of time, it was less than Zone 2.  Except 2012, that I hiked a friend who did not have a lot of experience in high elevation, therefore the overall pace was significantly slowing down.  The rest of years, Zone 3 distribution was more than Zone 2.  That is the major difference for this hiking.   This is a similar experience from Trail Camp to Summit in the other years that I kept my heart late below Zone 2 and I did not have to take resting time a lot.  I think if I keep my heart late below Zone 2, I could move without much resting for long time.

Overall, the total duration was not taking long time I originally thought during the hiking even if the walking pace was relatively slower than the other years since the resting time was significantly shorter than the other years.  Also, I felt it was one of easy hiking comparing the other years.

Summary of the first day

I think I am pretty sure that walking pace management based on the heart rate is really efficient method to manage the pace during hiking especially in higher elevation.
This year, the heart rate was much higher than usual and I intentionally kept slow pace and it helps overall duration in day 1.

(To be continue)

Help to minimize resting!

99-Switch back on Mt. Whitney Trail

Better to avoid resting in some sections

During hiking, there might be some sections where we'd better to avoid resting.  It might be hard to find out a good safe place to take some rest during hiking.   One of example is 99-switch back on Mt. Whitney Trail.  This section is steep and it might be hard to find out wide enough safe place.  In this case, one of options is to avoid resting such section.

I think to manage the pace with heart rate helps to minimize resting time.

Total Time from Trail Camp ~ the summit

This is chart shows walking time and resting time in a section from Trail Camp to the summit.  This section includes 99-switch back I mentioned above.
In 2011, I walked as fast as I can and I really exhausted.  In 2012, I walked very slowly to wait a friend who did not have much experience of hiking.  So it took the longest from Trail Camp to the summit.  In 2014, I also walked slowly since a friends got some symptoms of a mild high altitude sickness.  In 2015 and 2016, I intentionally walked very slowly to minimize the resting.  However the total time is probably similar or smaller than 2011.  Even I walked slowly, the total time could be the same or shorter.  That is one of interesting data from my hiking.

In 2012 and 2014, since the pace was very slow for me, I did not feel it was hard at all.  However, in 2011, I was really exhausted.   Unfortunately, I do not have heart rate data in 2011.  But I have heart rate data for other years.

Distribution of Heart rate zone

(From Trail Camp to Trail Crest) 

This data is a distribution of heart rate zone from Trail Camp to Trail Crest where is the most steep portion between Trail Camp and the summit.  As you can see, in 2012, I walked in zone 1 for the most of time.  In 2014, zone 1 is more time than zone 2.  In 2016, my condition was not very good and I walked in zone 2 for the most of time.  Even though, I took more time than 2015.  But the time difference is very small (about 10 minutes).   Also, I did not feel it was hard.
So as long as I can maintain the heart rate zone less than zone 2 (or zone 1).  I did not feel it was hard.  So the key is keep the heart rate less than zone 2, then I might not need resting much.

The actual walking pace was very slow.  I felt I could walk much faster, but I watched my heart rate and I kept the pace based on the heart rate.  I guess I might walk much faster if I had not monitored the heart rate.  So it is probably beneficial to monitor and manage the pace.  Just using "feeling", it might be hard to keep a good pace for hiking.

This is another good example to use heart rate to manage the pace.

Smart Hiking (9) ~ Target heart rate

What is the target HR?

Based on the past data from my hiking, it is possible to manage walking pace by heart rate.  However, the question is what heart rate would be a good target to manage the pace.   That was a big question when I apply this method to hiking.

It is slightly different from running.  Because many runner has a goal or target time for a specific distance.  So many people probably look for a pace to maximize the performance.  However, hiking is not competition and it does not have to be maximize someone's performance.  Probably 30 minutes difference might not be a big deal.  So I stared "try & error" approach.

Try & Error!

I started to pick an average HR during a running activities.   I think I mentioned this before.  A typical average during running activities, my average HR is somewhere around 160 bpm.  So I picked 160 bpm as a threshold to slow down the working pace.  Since I can continue to run with this HR up to 3 hours.  Therefore, I think I can walk to manage HR below 160 bpm.  The answer was, yes, I could do it.  But it was really tough.  It was probably possible to continue, but it was not easy.  I did not have much room to enjoy the hiking.

Then, the next year, I set the target as 155 bpm.  It was a little bit lower than I can maintain.  It was much easier than the previous year and I had some time to enjoy the hiking.  But it was getting harder in the end of a day.  So I found out it might be better to set a little more lower.  Then, I picked 150 bpm the next hiking.  It seems to be an optimized pace for hiking.  It was not really hard and not too easy.  Also, the total time which included the resting time was very similar as using 160bpm or 155bpm.   Slower pace helped to reduce the resting time and the total time to the same destination is almost the same.

This was how I found out my target heart rate for hiking.  It works well for me.  However, this number could change especially my age (around 50 years old).  The fitness level is probably getting worse year by year.  So I was looking for a better method.

(To be continue)

Smart Hiking (8) ~ Strength of activity for hiking

Example of heart rate trend

(Whitney Portal ~ Trail Camp in 2015) 

Impact of elevation

The above chart is an example of heart rate trend in higher elevation.   As you can see, the heart rate except resting above 9,000 feet (3,000 m) is more than 150 bpm.  This is a sort of high side.  Here is another data as a reference.

 Heart Rate during long run

This is a data when I ran for 3 hours.  The pace is not very fast, but the average heart rate is somewhere around 150 bpm.  To compare those two activity is not really easy.  During hiking, I had a backpack with all camping gears, however, the walking pace was really slow.  The strength is probably higher than the long run.   The heart rate is close to 160 bpm in some part.

What I try to say here is the impact of elevation, or lower oxygen environment, is probably much higher than people think.  The key is we need to understand this impact of elevation and manage the heart rate (pace) is really helping for better experience during hiking.

Also, the running example shows that I can run longer if I can maintain the heart rate somewhere around 150 bpm.

(To be continue)

Smart Hiking (7) ~ Pace and resting time

Total time from Trail Camp to the summit of Mt. Whitney

This is another interesting data from my experience.  This is break down for walking time (moving time) and resting time (time not to move).  Again, in 2012, I hiked there with a friend who did not have much hiking experience and I need to stop and wait the friend often.  Therefore the total time is taking more time.  In terms of walking pace, in 2011, it was fastest.  In 2014, it is probably moderate.  In 2015 and 2016 were slower than the other years.

Especially in 2015 and 2016, I tried to maintain the heart rate less than 145 bpm.  Then, I did not have to take a rest or stop so often.  Then the total time to the summit is much less than the other years.

This section is above 3,700m.  The summit is close to 4,500m.  Therefore even if just a little faster pace is a cause of increasing the heart rate.  To lower the heart rate, I needed to stop or slow down the pace.  If I can maintain the heart rate lower than 145 bpm.  I did not have to do that.

In 2011, I felt really exhausted.  However, in 2012, since the pace is so slow and I felt it was really easy.   I had a similar feeling in 2015 and 2016.  Probably around 140~145bpm is probably my optimized pace.   The pace in 2015 and 2016, I thought it was really slow.  But it was a right pace in the elevation.  However it might be a little difficult to maintain such slow pace without knowing the heart rate.  I probably tend to walk faster if I do not have such indication.

This is one of good example of pace management with heart rate in higher elevation.

(To be continue)

Smart Hiking (6) ~ Total Time with different pace

Total time from Whitney Porta (Trailhead) to Trail Camp

I went hiking to Mt. Whitney a several times in the past years.  I hiked some different pace on Mt. Whitney Trail.  Trail Camp is one of major camp sites on the trail.  From the trail head, the distance to Trail Camp is about 6+ miles.   The total duration in this section is 264 ~ 346 minutes.  Actual walking time which excludes the resting time is from 202~243 minutes.

In 2012, I went there with a friend who did not have much experience for hiking.  Therefore the overall pace is very slow and we took longer resting.  The other years, the actual walking time is probably very similar 202 ~ 229 minutes.   However, the feeling was very different.  In 2011, it was obviously over pace and I felt very exhausted.  However, the rest of years, I did not feel exhausted at all.  I felt something much easier than 2011.  Primary difference between 2011 and the other years was walking pace.

In 2011, I tried to maintain the original pace as well as I can.  However, I could not keep the same pace due to high altitude sickness and I was slowing down significantly and it was very very slow near Trail Camp and I was really exhausted.   However in 2015, the total time was almost the same as 2011, but this year I did not feel exhausted at all.  After 2014, I tried to set a target heart rate and tried to maintain my heart rate below the target.   In 2014, the target was somewhere around 160 bpm, in 2015 somewhere around 155 and in 2016 somewhere around 150.

This is very interesting data I found from my records.   Yes, it is much easy to slow down the pace.  However, it does not seem that there is not much difference for the total time and the feeling is very different.   So, I realized there is a way to "optimize" the pace.

(To be continue)

Smart Hiking (5) ~ Heart rate base training

Running Watch (device) with GPS and Heart Rate Monitor

I wrote about relationship between elevation and heart rate in the previous post.   Today, I am talking about heart rate base training in running world.  This is slightly different topic from hiking, but it is better to know the concept of heart rate training.

Running device

Many runners use a running device which has GPS, heart rate monitor and other nice function nowadays.  It is really convenient to track all activities with a lot of data during the activities such as where they ran, distance of running, pace, heart rate and etc.  It also help to tell actual pace when they run in real time.

Since such device is getting very popular in running world, many people using the device to manage running pace and training.  There are so many training menu using heart rate since depending on what performance people try to improve, the intensity of the training is different.   For example to burn fat in the body, the intensity should not be high.  Low intensity with longer time of running would be much more efficient to burn body fat.  However to improve speed and lactate threshold, it usually require high intensity like interval training.  To set a target, "pace" was used in old days, something like 6 minutes per mile x 5.  However, it is hard to set a right pace for many people who is not really serious athletes.  Then the strength / intensity might be too high and it is due to an injury.  Or it is too easy to improve the performance old days.
Now many training many using "target heart rate" instead of "target pace".   It is much easier for many people to set a reasonable goal based on heart rate.

Heart rate zone
To set a target heart rate, there is a definition called "heart rate zone" which is a range of heart rates based on the maximum heart rate, sometime maximum heart rate with the resting (minimum) heart rate.  As long as people knows the maximum (and resting ) heart rate, it is easy to tell which heart rate range people need to maintain for each training.

One of simple example is based on ratio of the maximum heart rate:
- Zone 5 - 90% of the maximum heart rate ~ maximum heart rate
- Zone 4 - 80% ~ 70%
- Zone 3 - 70% ~ 60%
- Zone 2 - 60% ~ 50%
- Zone 1 - 50% ~ or less

Then to burn the body fat, zone 2 would be a good zone.  Typical marathon pace for many people is probably zone 3 or zone 2.   Many interval training can be zone 4 something like that.

The maximum heart rate can be find in a real high intensity activities or using an equation to estimate the maximum heart rate by age.  (A popular formula is "220 - age" [bpm])

Based on such heart rate zone definition, it is hard to maintain zone 4 for a long time.   Even zone 3, it is probably possible to maintain the range longer than zone 4.  But it is probably not easy to maintain zone 3 very long time.  To continue to maintain for very long time, it is probably better to stay in zone 2.   That is the idea.

Based on my experience, it is similar in hiking.  If the heart rate reaches zone 4, it is obviously impossible to maintain such high heart rate for long time.  Therefore, if we can maintain a pace in hiking based on this heart rate zone.  I think we can find a better pace for hiking.

This is the concept for "smart hiking" in higher elevation with heart rate.

(To be continue)

Smart Hiking (4) ~ Example Heart Rate data on Mt. Whitney Trail

Heart Rate trend in 2015

(Whitney Portal ~ Trail Camp)

Here is one of examples for heart rate and elevation.
The chart above shows heart rate trend from Trail Head (Whitney Portal) to Trail Camp.  Since I took some rests on the way to Trail Camp, there are some drips.  However the overall trend is increasing the heart rate significantly.

Walking Speed trend in 2015

(Whitney Portal ~ Trail Camp)

This is a trend for walking speed.  Since resting, there are drops as well.  However, the overall trend is decreasing the speed.

Slope (Elevation / Distance)

Slope of the trail is close to linear.  It is probably okay to assume the slope is almost constant in the section.  The weight in the backpack is also almost the same from trail head to Trail Camp.
Those three chart shows that the heart rate is increasing even if the walking pace is slowing down.  The rest of factor might impact, which are slope of trail and weight of the backpack would be very similar.   The only factor would be elevation.

Elevation of trail head is around 2,500m and Trail Camp is about 3,657m.   The biggest depth on the heart rate and the speed is Outpost Camp where is about 3,170m.  Roughly, below Outpost Camp, the peaks are reached a similar speed.  However after Outpost Camp, the peak speed is clearly much slower than the lower parts.  Also, I did not feel any clear symptom I can recognize below Outpost Camp.  Based on the data above, here is what I found:

• Blew Outpost Camp, I did not feel any clear symptoms for high altitude sickness
• Blew Outpost Camp, I was able to maintain a similar speed as I hike lower elevation.
• Blew Outpost Camp, heart rate is getting higher even if the speed is a similar.
• Above Outpost Camp, I cannot maintain the same speed as lower portion
• Above Outpost Camp, the speed is getting lower

This experience shows even I was not aware of any impact of high altitude sickness, the heart rate stats getting higher somewhere near 3,000 m (or 9,000 feet).  Also, above 3,000m (or 9,000 feet), the heart rate gets higher even if the speed is dropped.  Clearly, heart rate could be a good factor to see an impact of elevation.

Heart rate in running

When I am running, the heart rate I can run for longer distance / time would be below somewhere around 150~160 [bpm].  If the heart rate beyond the point, it is hard to continue or maintain the pace for longer.   That is typical maximum marathon pace I am usually targeting.   The chart clearly shows, the heart rate after Outpost Camp (or 3,000m / 9,000 feet) is higher than this.  Therefore it is considered as "over pace" in running world.

Apply to hiking for pace management

From the running experience, I think we can apply a similar concept to hiking.  That is where the idea is coming from.

(Continue)

Smart Hiking (3) ~ How to recognize "sign"

Difference between casual hiking in high elevation and Himalaya expedition?

One thing I can tell is that there is some difference between a casual hiking in high elevation, which is somewhere around 9,000 ~ 15,000 feet and mountains in Himalaya.
A major factor is "duration".   In general, those expeditions can be long enough to acclimatize the altitude up to some elevation.   However most of casual hiking could be done within a few days.   I think it is probably not long enough to acclimatize the elevation.   This means some symptoms for high altitude sickness is probably given and I think the key is probably to minimize the impact of the elevation.  That is a big difference.

On the other hand, most of strategy people believe is a similar way as those expeditions.  Something like staying higher altitude in a previous night....   However, I personally do not believe it helps a lot.  Based on my experience, I did not really realized that I was getting some symptoms until I really have obvious symptoms.  I think that is difficulty of such hiking.

Need some clear factor to quantify the impact to human body

Especially in early stage or the elevation is probably not high enough to see very clear symptom of high altitude sickness, most of people think "I am good".  Then people tend to walk a regular pace as lower elevation based on their experience.   People who has a lot of experience in that elevation, they might have a better idea how they can manage the pace with the elevation.  In this case, it is probably less problem.  The problem is many people do not have a lot of experience above 10,000 feet.   Therefore, they might walk over pace and exhausted.

If people can have a good factor to recognize the impact, it might help to adjust the pace.

One of popular factor for high altitude hiking / climbing is probably SPO2 (Peripheral Oxygen Saturation).   The value can be measured by pulse oximeter and many expedition might use it as a reference for altitude acclimatization.   If people measure SPO2 in lower elevation like lower than 1000 feet, then the value is typically more than 95%.  However if people is getting higher elevation, this value is getting lower.  Based on my experience, SPO2 valur in 14,000 feet was sometimes less than 80% which is really low value.   It is probably a good factor to show some impact to human body in higher elevation.  This value could be lower once people acclimatize the elevation and it is a good factor for acclimatization.   It is probably very useful for the expeditions.  But it is probably a little hard to use for hiking in a short period.

Another one is probably heart rate.  I am also runner and using a running device (watch) with GPS to track all race and training data.  Many devices nowadays can capture heart rate during the activities.  I also collect heart rate data during hiking to Mt. Whitney which is more than 14,000 feet.  I realize that the heart rate is getting higher if I am in higher altitude even waling pace is slower.
Also, heart rate is one of very good factor to manage the strength of a training and manage running pace in running world.   Therefore, I believe a similar idea can be applied to hiking.   That is the idea to manage walking pace in higher altitude during hiking.

I will show some examples which indicates some impact of higher elevation.

(To be continue)

Smart hiking (2) ~ Hiking over 9,000 feet

Hiking over 9,000 feet

When people hike over 9,000 feet, they might start feel some symptoms for high altitude sickness.  There are some popular destinations over 9,000 feet, such as Mt. Fuji in Japan, Mt. Whitney in California / USA, Mont-Blanc and etc.   Depending on seasons, but it is probably not so difficult in summer time and many hikers are there.  The symptom is typically not really serious in many cases for those destinations, I guess it is something wrong / different for many people and they might be able to reach the summit and come back without major problems.

However, many people feel this is different from hiking in lower elevation.  Therefore there might be some tips such as stay higher elevation in the previous night, walking slowly and etc.  They might be coming from strategy from expedition to mountains in Himalaya.   Basic idea is taking more time to acclimatize the elevation.

My experience on Mt. Whitney trail

I had a several experiences to hike to Mt. Whitney in past years.  I also tried to stay higher elevation in a previous night like many articles suggested.   However, I did not feel any clear difference.  On the other hand, I had very different feeling in a few different hiking.  I felt really exhausted once, but I felt really easy in other.  The major difference is probably walking pace.   It seems to be common sense if people walk slowly, it must be easy.   However, after I collect heart rate data during hiking, I think there is a better way to manage the walking pace.  Obviously, it might be impossible to avoid any symptoms for high altitude sickness, but I believe there might be a way to optimize the pace to minimize the impact of high altitude sickness.

This is the topic I will post as a series to this blog.  I wrote a book about this experience in Japanese and I plan to publish English edition after this series.  After publish the Japanese Edition, I got some extra data / thought, therefore I will reorganize the contents and post in this blog.

(To be continue)

Garmin Forerunner 645

Forerunner 645

Forerunner645 is available!

I have not checked Garmin web site for a while and I found out Forerunner 645 is available. The price is USD $399.99.  The feature is probably between Forerunner 935 and 735.  Battery life is shorter than Forerunner 935.  Forerunner 645 is up to 7 days as a smart watch,  14 hours with GPS.

Overall, it is probably good enough for regular running and hiking purpose.   Major difference between 935 and 645 is "Training Stauts" and "Training Load" features that fenix 5 also has.

I have fenix 3 HR which does not have those features, but I do not believe they are really important features.  It is probably "nice to have" features.

Based on the price, price for Forerunner 735 is reduce to USD $349.99.  So 735 is attractive for price point of view. 

The other feature I found is this has "Garmin Pay".  It seems that it is a similar feature like "Apple Pay".  Garmin watch really becomes "smart watch" now.  For most of people, Apple watch might have more "nice feature", however for runners / hikers, I guess Garmin watch is probably better due to longer battery life.

For now, fenix 3 HR is probably good enough for me and I do not plan to replace any new product.  However, people who look for a GPS watch, it is probably worth to look around the new products.

Recent VO2max trend

VO2max Trend (last 6 months)

VO2max Trend last 6 months

    In February, I got a little pain on my left leg and it seemed be a symptom of shin splint.  Therefore I stopped running about a months and just walking and indoor biking (station bike).  It was a middle of a full marathon training (level 1 from Garmin Connect).

   In march I resumed running 7 km every other days.   I have not started any training menu yet and I have not done any high intensity training like "interval training" last 2 months.   Since I was monitoring VO2max and lactate threshold as a factor of training effort.   Here is the recent trend of my VO2max.   (I have not hit to detect lactate threshold last 2 months since no high intensity training).

   Since there is no running in February, my VO2max was dropped in February.   Once I resume running, it is improved month by month.  February value is 40 [ml/kg/min] and the last value is 45 [ml/kg/min].   I just run 7 km every other day (build-up) and I can see a better improvement.  The average pace is improved.  Overall heart rate zone during the training is staying zone 2.

   At least, just running in zoon 2, even I just run 7km with out really high intensity effort, VO2max value is improved.   It shows the key is running regular basis.  I am not sure what my lactate threshold looks like since there is no recent data.  So the next step is to resume some high intensity training once a week.

Pace management with heart rate (4) ~ Heart rate during hiking

   The previous post was talking about required endurance for hiking.   Without enough endurance, it might be hard to achieve some hard hiking just managing the pace.   Today, I assume a person has enough endurance for a hiking, then how he / she can manage the pace for hiking.

   First of all, a target heart rate which is the upper limit of heart rate during hiking needs to be set.  As the previous posts are talking about heart rate zones to define a target heart rate zone.   Of course, the idea is to maintain the heart rate below the target, however there are some tips.  It is probably better to set an actual target 5 ~ 10 bpm lower than the upper limit since it is typically increasing the heart rate slowly even if a person walking with a similar pace.  In many cases, the intensity of hiking is typically high and it is probably hard to maintain a similar heart rate even if he / she walk a similar case.  Also, the trail slope can be vary and it is hard to maintain the heart rate in some steep sections.  It is probably better to have some extra margin not to reach the upper limit based on my past experience.
   It is also better to slow down significantly or stop if the heart rate reaches close to the upper limit or beyond the limit.  Once it is not immediately lower the heart rate with slowing down / stopped, then it is a time to take a rest with completely stop walking.  You may need to take a rest till the heart rate is get lower than "zone 1".  If it is not getting into "zone 1" in a short period of resting, it is probably better to lower the elevation if you hike higher elevation more than 12,000 feet in general.  If you want to walk without taking reset for a long time, you might need to set the actual threshold to adjust the heart rate much lower.  If your target zone is "zone 2", you might need to close to be lower threshold of zone 2 or zone 1.
   Another tip is to try keeping a constant heart rate as well as you can for easy hiking.   If your heart rate range during hiking is big, it is typically really high intensity when the heart rate in upper side.  In this case, you might feel hard in many cases.

(This is a summary for pace management with heart rate)

For detail, I will be almost ready to publish a Kindle Book about this topic very soon.  It is under review now.   I try to complete this this months and I will be announce it when it is ready.

Pace management for hiking with heart rate (1)

Garmin fenix 3 HR

   Although I am still working on the English edition of heart rate based pace management for hiking, I started thinking about how we can really set the target heart rate for hiking.  I did not post about this topic in the English blog.  However, I published a book in Japanese and posted to the Japanese blog in the past.   The basic idea of this concept is trying keep the heart rate in heart rate zone 2 ~ 3 during hiking.  That is one of my conclusion based on my past hiking data to Mt. Whitney.   This works very well at least my case.   On the other hand, I got some feedback that it might not work some people especially who do not training regular basis.  That is why I am looking into this topic again and looking for a better method.

   I think the concept is still valid and works.  However, the problem is probably those people might not be ready for some hiking or they might not be good enough fitness condition for a particular hiking.   It is a similar idea that running a full marathon.   I think pacing is key to finish full marathon and it is probably true.   However, it is also true that people need to have enough strength to finish a full marathon.  So they need to prepare or train to improve their fitness situation.   Without such effort it is probably hard to finish a full marathon.   I think a similar concept may apply for hiking as well.   If it is a short hiking like up to a few hours walking, then I guess many people might be able to achieve the hiking without training for hiking.   However, if it is a several hours or more, then people might need to prepare for the hiking to achieve.

   Here is what I found out from my training and its data in the past.   If I stopped training for a while especially due to an injury, then I felt it was heard when I resumed training.  After really bad injury like stress fracture on my leg, I had to stop training for more than several months.  Then it was getting really hard when I resumed a training.   Even if I started really slow pace, the heart rate was getting high in a short time and it was also hard to continue running as well.   However it was getting better after a few months if I was continue to train.   The heart rate was getting more stable and I could maintain a similar heart rate if the pace is reasonable.

   So if people who do not do training regular basis, they might not be able to maintain their heart rate in a reasonable range for long time.   Therefore even if we can estimate their heart rate zone from their age, it might be heard to keep the heart rate within the range during hiking.  The heart rate might getting really high in a short time and they need to take a rest to recover from such heart rate.  Therefore, the key is not only finding a target heart rate, but they also need to do some training to prepare their body for a hiking.

  Therefore what I am looking for is:

1. Sets a target heart rate first either based on age or training data
2. Tries the target heart rate for a reasonable period to understand their fitness situation
3. Do some training to prepare a target hiking destination

   The problem is I might not have a good sample data to show.  But I tried to propose a reasonable process based on some my experience.  If anybody give me some feedback for the method I will try to introduce, it would be really helpful for this procedure.

Resting Heart Rate and Training Progress

Resting Heart Rate last 6 mounts

   I posted about relationship training progress and VO2max and Lactate threshold.   I also think the resting heart late has some relationship with training progress as well.

    It is obvious that resting heart rate shows some conditions in short term.   For long term, it also show the training progress.  The plot above is average resting heart rate trend last 6 mounts.  When I resume the training the resting heart rate is getting lower.   Estimated VO2max and Lactate threshold, I only have data past 12 months since this is a new feature (data) in fenix 3 HR.  Previously, I did not have any device to get such data.   However, regarding heart rate, I had Vivosmart HR and I have a little more data than the others.  Based on my experience, the long term resting heart rate is probably a good factor to watch to see the training progress.

   Last a few years, including Apple watch, those "smart devices" are getting much better and collect various our body data to see many things in different aspect.   As I keep posting, they are good to to monitor our training activities, helping hiking, monitoring the progress, our body conditions and etc.
   I think even some low-end model has various monitoring features and they might be good enough to get some basic data for our daily training and supporting hiking.

   I really want to see what else we can utilize the devices.  I keep watching / looking for more useful way for those devices!

Assessment of Full-Marathon Level 1 Training Plan ~ Using VO2max

Estimated VO2max last 12 months

Full Marathon Training Plan Level 1 is almost the end

I started this training plan in August after I recovered an injury in April.  It is 16 week plan and it is in 14th week now.   Since the current running device I am using for my regular running has a feature to estimate VO2max from the training data and I want to know the relationship between the training progress and VO2max number.  The best number last 12 months was 43 [ml/kg/min] in April which is before the injury.  Then I got injured in the end of April and I stopped training about 6 weeks after the injury.   The number was dropped to 38 [ml/kg/min] when I resumed training in June.

Once resumed training the number was slightly getting better.  It was 40 [ml/kg/min] in July.   

The number was dropped to 38 [ml/kg/min] in August again.  There are a couple possible reasons:

• I took a rest about 10 days due to traveling to Japan in the end of July.
• I started a training plan from Garmin, Full Marathon Level 1 and the initial menu was probably too easy.

 I think I mentioned the reasons in my past posting.  Now the training plan is in 14th week and the number is 41[ml/kg/min].

Previous history of the estimated VO2max

When I got Garmin fenix 3 HR was October last year.  At that time, I was in a middle of the same training plan Full-Marathon Level 1 from Garmin and the number in October in 2016 was 39 [ml/kg/min].   The plan was completed in December and the number was 41[ml/kg/min].  So that the current number is the same as what I have right now.   After that, I moved to Full-Marathon Level 2 which was January to April in 2017.   Then, I got injured right before Level 2 plan was completed.  The number right before the injury was 43 [ml/kg/min] as I mentioned earlier in this post.

Based on the history of the data, it seems that my VO2max number is improved by the training plan.  Also, as I mentioned in some previous posts, the number is probably linked with the training.

Also, the pace (speed) for a similar running is improved as well, especially "Long Run" which is more than 90 minutes.  In the level 1 menu, the long run is combination of walking and running.  So the overall pace including walking is more than 8 minutes / km in the beginning.  The last 2 long run which is more than 120 minutes were better which is around 7:30 ~ 7:40 / km.

The training plan I picked is heart rate based training and the strength is managed by heart rate zone.  So the pace is not how fast I can run.  It is based on a similar heart rate and how fast I could do.  So 8:00 / km is very slow pace, but if I ran faster, then the heart rate is out of suggested range.   So I have to slow down the pace.  Even the training is after the injury, so far I did not see any injury after the recovery and I believe this is a good method for older people.

The data indicates, once people get injured and stop the workout, then the fitness level is getting lower and it is hard to recover the same as before the injury.   The key for older people like me, it is how we can avoid injury due to over  training.  The big problem is even if I do over  training in a short time, I may be able to do without serious injury.   But it may be a cause of injury for long term.  It is very different from serious athletes.  I think serious athletes may need to do high intensity training to improve the performance, but for general people, it might not be very good idea especially older people like me which is over 50 years old.

Last time I switched to Full-Marathon level 2 after Level.   However, I probably want to continue Level 1 menu after the current plan is end.   Even if I take the same plan, it is based on heart rate to define the strength, therefore, if I follow the instruction, I may still be able to get a right level of training.  Maybe in the beginning, it might be too easy again.  But overall, it might be getting some improvement.  Let's see how it goes.  I will continue to report my data and own analysis.