Post Number: 361
|Posted on Tuesday, April 15, 2008 - 12:39 pm: |
Some may remember the "statement" , that a change in intensity may change the substrate requirement on the body , as it may be more a question on ATP production and depletion.
Meaning : if you make a sudden increase or change in intensity ( from slow to faster or more intense ) the muscle needs immediately the ATP as energy source , and because of teh "lag " of ATP production over the oxygen dependent system , the oxygen independent ATP production has to kick in first , and if the "new" intensity ( ATP needs) can be covered over oxygen dependent suppliers the body will somewhat later switch over to this system, otherwise it has to shut down.
As you know from high intensity workouts, this is the case ( we shut down ) But as well you can feel a different sensation in your body , anytime you change to a new level in a step test, and as closer you come to LBP as more you feel at the beginning of a step , that you may not be able to go through it but after 1 - 1/2 min you feel better. ???
Okay , I had some e mails asking , how come , that I think if we change this intensity and the heart rate is always very lo ( in "fat " burning intensity ) that we still with the change in intensity will burn glucose and not Fat.
1. We possibly always burn from all the ATP supplier energy . ( even in all out intensities we will burn fat and glucose and oxygen independent.
Again the question is , who , or what system can supply optimal needed ATP at a given intensity.
Here my small Case study done on 2 people.
Subject 1. 53 year old
Subject 2 16 year old.
What did we tried.
Okay we used a Fit Mate , lactate pro a polar watch and a gluco-meter.
a) we measured with the fit mate caloric output by different intensities.
We made a FaCT IRIS and here the results n a summary.
1. We check for the so called STF zone
FTF a zone
STF zones for us was considered oxygen dependent with mainly "
Fat " as the optimal ATP delivery system.
FTF a below LBP 5 beats was for us an intensity , where mainly oxygen dependent glucose was used.
We assumed, that the liver would store app. 100 - 130 gr of glycogen
The muscles about 200 - 300 gr of glycogen.
We tested the caloric need in one hour and over three hours. by the HR in the STF zone and the FTF /LBP area.
Example of one of the subjects.
STF zone 142.
Total calories in glycogen storage
app 400 gr +- equals 1600 kcal .
So subject 1 would burn in 3 hours by 135 - 1 40 just over 1600 kcal.
In FTF HR just above 2200 kcal.
Same calculations where done on Subject 2.
Now we did a stable heart rate workout on the bike for 3 hours in the STF zone and checked blood sugar and lactate every 15 min.
Result no change in whats ever.
We followed with a workout in the FTF "zone" and we had a drop of blood sugar by about 1 h 45 but no incline in lactate.
We kept going and had to quit with subject 1 because the blood sugar dropped below 3 mmol and there was the risk of an acute hypoglycemic situation
Subject 2 just got tired and had to slow down and the blood sugar stayed above 4. no lactate.
Now we did a 3 hour "stop and start " workout golfing where the average heart rate was far below 135 so absolutely clear in the FTF zone. Result.
Subject 1 had to quit the golfing after 1 h 50 min due to a blood sugar level of 2.7 mmol and sever shaking and start of dizziness due to sever hypoglycemic situation.
Subject 2 was just somewhat tired but blood sugar above 4 and no lactate as well.
When we repeated the bike on LBP and the golf and we where substituting every 15 min with a 23 gr glucose intake the blood sugar stayed stable no lactate and no problem.
The beauty of this small case study is the fact, that subject 1 as a volunteer was diabetic I ( juvenile diab. ) and we had therefor the advantage , to see how glycogen would be used , as the healthy body will interfere with information as it will not allow to drop so far ( as seen in this small hobby research.
The interesting part is, that in diabetic research papers, the recognize this particular situation , but always write , that there is no explanation to it .
Hmmm I am not that sure anymore as you may be able to guess from the above small input.
Have fun to think about that. Juerg
PS this spec. situation triggered for us a whole set of very different ideas on some specific elements in training and we started to do some testing into that. So we will possible come with some new ideas towards this part in 1 or 2 year . So stay tuned .
Hmm that's the long term PR how we keep people coming back ( smile )