Garmin fenix HR feature ~ Estimating Lactate Threshold / VO2max

Lactate Threshold Pace (Last 6 months)

Lactate Threshold HR (Last 6 months)

VO2max (Last 6 months)

Lactate Threshold Estimation on Garmin High-End Running device

   The last posting was talking about VO2 max for a factor of training progress.  Garmin started supporting this estimating feature most of running devices (above Forerunner 35).   My device, fenix 3 HR, supports to estimate Lactate Threshold (LT) as well.

   The devices shows LT with LT Heart rate and LT pace.   I did not have very good idea how I use the both data.  I did not have enough data to talk about my analysis before.  Now I have probably enough data to talk about LT feature.  As I explained my training activities last 6 months in my previous posting:

• April: Just finished "Full marathon level 2" training -- Good fitness condition
• May:  Due to injury late in April, I stopped running about 4 weeks
• June:  Resumed training, but stopped again due to FRU for 3 weeks
• July:   Resumed training, every other days 5km - 10km, rested for 1 week in the last week
• August - September: Started "Full marathon level 1", 3 times a week
• September -- my health condition is not very well last a several days

   Since last a several days in September, my health condition has not been very well, but I did not take a rest.  Therefore, my performance was not very well.  That is why I do see most of factors are dropped in September.

LT Heart Rate

   The range of LT Heart rate last 6 months is 163-167 [bpm].  The delta between the minimum and the maximum is only 4 [bpm].   My opinion, this is not much difference, but I think slightly improved due to the training a little.  Even if I stopped training, it was not really getting worse.  As long as I tried to do something regular basis, this might not change a lot.  Maybe people who does not have training for a long time, it may be improved with some regular based training.

LT Pace

   The range of LT pace last 6 months is 5:31 ~ 6:23 [MM:SS].   The delta is close to 1 minute.  If I stopped the training, the number was getting worse and once I resumed running, it was getting better slowly.  The trend is very similar as VO2max.

My analysis

   I think LT HR is probably not much change as long as people continue to training for long time　and LT Pace and VO2max could be a good factor to see the progress.  Either one could be used to measure the progress of the training.  Many models support VO2max estimation, but LT estimation is limited only some high-end model.   The high-end models have more nice features and the prices is much higher than other low-mid class models.   So if you just need a basic features, I think Forerunner 35/235 would be good.   Also 735 price is getting lower due to some other new models.

   The other factors, VO2max estimates works with the embedded heart rate sensor.  However for LT estimation, chest-strap heart rate sensor is requires.   Also, to estimate LT, people need to do relatively hard workout than VO2max estimation.  VO2 max estimation can be done with a light workout.  I am not sure how it is accurate.  But even I ran slowly, the value is a similar number as I did heard work out.   So with those factors, I would think VO2 max is probably more convenient in my opinion.

Example to for VO2max estimation in Garmin Running device

最近の最大酸素摂取量の推移

　今日の話題は、ガーミン社のランニング用のデバイスの活用方法の紹介の続きです。以前から私の利用法について投稿していますが、今日は、最近のガーミン社のランニング用のモデルではついている物が多くなった最大酸素摂取量（VO2max）の推定機能についてです。

最大酸素摂取量

　最大酸素摂取量は有酸素運動のパフォーマンスの指標として用いられる値の一つで、厳密な測定では、トレッドミルで負荷を増加しながら呼吸量、酸素量、二酸化炭素量を測定する事が必要です。ただし、簡易的に行われる物として、クーパーテスト（12分間走）などでも推定値を知る事ができるとされています。最近のランニング用のデバイスではこうした推定値を各アクティビティのデータを基に推定する機能がついています。

　以前にも紹介していますが、fenix 3 HRにもその機能がサポートされていて、実際に行ったアクティビティのデータで概算の最大酸素摂取量を推定してくれます。今回、故障や風などでトレーニングができない期間がこの数か月の間に何回かあったので、その影響がこの値にどのように影響するかを知る事ができたのでその結果を投稿する事にしました。

過去5ヶ月のデータ

　冒頭のグラフが過去5ヶ月の私の最大酸素摂取量の推移です。4月の43[ml/kg/min]をピークに下降傾向というのがわかります。この期間のトレーニング状況ですが、4月はガーミン社のトレーニングプラン、フルマラソンのレベル２を終了した直後で、トレーニングの効果もあり、VO2maxの値が徐々に改善し、最近の最高値に達していました。ところが、4月の下旬に左足を負傷して、約1ヶ月の間トレーニングを休むことになってしまいました。その後トレーニングを2週間ほど再開した後、6月に入って風邪をひいてしまい、さらに3週間トレーニングを休んだために38[ml/kg/min]まで低下してしまいました。7月はトレーニングを再開して、40[ml/kg/min]まで回復しましたが、日本に行っていた約1週間の間トレーニングを休んだためまた、38[ml/kg/min]に戻ってしまいました。その後8月はトレーニングを再開しましたが、今回は急にトレーニングを再開した事による負傷を防ぐために、トレーニングプランをフルマラソンのレベル１に戻って再開したため、トレーニング初期段階の負荷が軽くなった事もあってまだ改善が見られていません。ここ数日は体調を崩してペースが上がらないため、値はやや下降気味になっているというのが最近のトレーニング状況です。

データの考察

　この結果を見ると、トレーニング状況とその負荷が値に大きく影響していると見る事ができるかと思います。特に改善のスピードは緩やかですが、下降は少しトレーニングを休んだり、負荷を落とすとすぐに値が落ちてしまう様です。

　7月は約1日おきにマラソンペース（心拍ゾーンのレベル３）で5kmから始めて10kmまで徐々に距離を延ばすのを約1ヶ月続けたところ、ある程度の改善がありましたが、8月に再開した際は、フルマラソン　レベル１の最初の部分で比較的負荷も軽く、週3回の実施と言うことで、7月に比べてトレーニング頻度が落ちている事もあって、改善の度合いは殆どmられていません。

　このデータを見ると、VO2maxの値は、トレーニング状況が比較的すぐに数値として表れるようで、トレーニングの状況を見るのには都合の良い値だと考える事ができます。今後は、トレーニングプランの負荷が徐々に上がって来ると思うのでそれがどの様に値に影響してくるかがポイントになるかと思います。

　クーパーテストを行うのもVO2maxを知る手法になると思いますが、こうした値を推定できる機能がデバイスについて、普段のトレーニングから値を推定してくれるのはより手軽に指標を得られる事になるのでとても便利な機能だと思います。この機能のためだけでも、デバイスをアップグレードするメリットはあると思います。

Trekking Pole

Trekking Pole and Pole for skiing

   It is September now.  I have been busy this summer for many unexpected things.  New school year started for our kids in mid August and it is back to normal now and finally I have some spare time to write an article.

   Today's topic is "Trekking Poles" that many hikers are using nowadays at least in the US.   I did not use them when I was young.  But I started using them a few years ago since I am getting old and I'd probably better to get some support using them.   I was using one for skiing, but it was broken and I bought a pair of trekking poles last year.

Trekking Poles

What I bought was one from Black Diamond, you can find it in Amazon.  There are many different types, this is a folding type  Another type is an adjustable type, which is easy to adjust the length.  Most of folding type is fixed length, but one I bought was there is a part to adjust the length on the top part.

Adjustable part

   This is a model for women, I think the main difference is strength and weight.  I think it is good enough for my weight.  I am relatively smaller than typical men.
　
   A difference between trekking poles and ski poles are the tip portion.
　

Tip portion for a skiing pole

   Tip portion for skiing is designed easy to stick surface of snow with metal tip.  It is also having larger ring not sinking into the snow.

Tip for a trekking pole

   On the other hand, trekking pole is using rubber material to get more friction on rocks.  The ling is smaller or nothing.  This model can replace the tip to a metal part to use on the snow.

Metal tip for replacement

   Some models, it is also possible to replace the ring to use for skiing.  However, I have different poles for each purpose.  The model i have, it is ok to use on a snow course in summer time.  But for skiing the ling is too small and sinking into the snow when I use them for skiing.  Also, the length on the tip portion is too short to use for skiing as well.
　The tip has many different shapes.  Some of them are bigger tip to get more friction and stable on rocks.

   As I mentioned, I was using poles for skiing in my previous hiking.  However, the stress to the big ring is big on summer trail.  Also, the friction might be smaller and not very stable.   However, the friction is not a big deal, just need to have some experience to adjust how we use it.

Advantage to use trekking poles

   Talking about advantage using trekking poles, the major advantage is helping to keep the balance.  Using poles, the chance to loose the balance is probably getting less, it is also easy to recover when people loose their balance with the poles.  In general, many people select boots to protect their ankles.  However if people using poles they may choose lighter pair and the selection is more flexible.  Especially having heavy backpack, people tend to pick really heavy boots for a better protection.   With the poles, they may pick liter boots.  Also, if they do not have heavy backpack, they may pick shoes instead of boots.  It is really depending on strength of legs, experience and skill to pick shoes / boots.  I would say with combination with trekking poles, the selection will be more flexible and easier for many people.

   In my case, my leg strength is getting weaker than when I was young.  It is really helpful to distribute weight with pole to reduce weight to legs.   That is the primary reason I started using poles.
   I think many people using a pair of pole on the both hand.  I guess it might be better to keep balance during hiking.   However, I personally do not like to occupy the both hands, therefore, I just using a single pole to help the balance.

Low cost models?

   By the way, when I am looking into listing on Amazon, there are many low cost models.   Most of time, I usually go to outdoor stores to see one I want to buy.  Therefore, I do not see many low cost model in the stores.  However, some of friends mentioned that there are many low cost models and I realize there are so many low cost models.
   For example, this model  is USD $36.99.  I have never used them and I cannot tell what they look.  Just based on the specification, its pair of weight is 1.1(lb).  One the other hand one I bought is 1.6(lb).  It is about a 0.25(lb) difference.   It is probably some difference for the material and strength.  I do not have any experience to use them, so this is just my speculation.   I guess it is not a big problem in most of cases.  Probably, it might be easy to broken or deform when they get unexpected force during hiking.  So this is really up to how people think and use them.

  Personally trekking poles are probably one of good equipment for middle age to older age hikers to minimize injury during the hiking.