Training Aerobic Capacity – Session 1 Follow Up Questions

Alice:

Great questions.

1. In the image of the three athlete metabolic profiles, how are % fats vs % carbs measured in each athlete?  Calories of each. Sometimes this is done in grams of each but since fat has roughly twice as many calories/gram as carbs that makes that sort of comparison an apples to oranges thing. So, I prefer cal to cal.

2. What advice do you have for finding the right balance between higher intensity lactate threshold workouts vs low intensity aerobic workouts? If you are aerobically deficient (which we’ll dig into next time) that should be the focus. Fix that isse first and then think about supplementing with HIT. This holds true unless you are within a couple of months of some important event.  Then you need to add intensity regardless of your aerobic base.  If you are not aerobically deficient, what Kilian and I came up with in the book Training for the Uphill Athete is to add intensity volume at the rate and to the extent that you are still recovering well and not having to reduce overall aerobic base volume by more than 10%.  This is a general rule of course and would need to be adjusted if you are tapering for an event., The idea is to not let the aerobic base slide much since it is the support for that high intensity work. I’ve read/heard about the 10/90% guidance, but what I’m more curious about is what athletes should be paying attention to most or measure/track when trying to find this balance?  Recovery is the thing to pay attention to.  The 90/10 balance is when viewed on an annual basis and will certainly shift to 80/20 or so in during blocks where HIT is a priority.  Kilian and I covered this in our podcast last week.  

3. When you talk about fat metabolism, what kind of nutrition and fueling should athletes consider? If you are training over about 6-8 hours of aerobic base work a week you are probably getting well fat adapted because you are getting glycogen depleted frequently. This is true especially if you are doing one session over 2 hours.  Recall the little joke I made with Kilian about his diet when we first met. He was breakfasting on lots of sugary donuts and rolls. When you are training 20+ hours a week like him you can eat anything you want and still be fat adapted. It might not be the heathiest diet but you will get fat adapted. I don’t think any special diet is needed for most endurance athletes. We see very high level ultra runners with diets ranging from full carnivore to vegan.  The most important thing is to get enough calories. Calorie restriction for endurnace athletes is a very dangerous thing to do. Nothing will push you into an overtraining situation faster if you are a serious endurance athlete than a calorie restricted diet. Etlespecially for leaner, smaller athletes who don’t have a lot of body fat reserves. Where is the fat in the “fat metabolism” you mentioned coming from in the body? The fat used for this fat metabolism during exercise is coming from the fat stores in the muscles. The next time you are at the butcher shop look at the grass fed beef. Notice that it has a lot of little fat lines running through the red meat.  That’s because grass fed beef spend their days walking around in an aerobic state using fat for fuel.  Your muscles develop similar fat stores within them. That makes the fat easily accessible to the muscle cells for energy.  The adipose fat, the kind you can grab a hold of is not as easily used for fuel.  That is why it is so hard to lose adipose fat.   Feed lot fed beef that stand around a lot and eat a very high calorie diet develop a lot of adipose fat. This is the layer of fat you see around the edges of the steak in the butcher case.  This is why I mentioned that even the leanest marathon runner will have huge fat stores. You can’t see that fat on their body. It is in the muscles themselves as opposed to between the muscle and the skin.  The more fat adapted the athlete the greater the amount of fat stored this way.

4. What are the positive signs that one’s aerobic base training is working?  Increased heart rate, decreased pace while maintaining aerobic work? If one is aerobically deficient the HR at aerobic threshold will move up as the aerobic capacity improves. At the same time the pace at AeT will also increase. You will be be moving faster because your aerobic system is now producing more energy (ATP) so it can support a higher power output.  Depending on the volume of training and your genetics you should begin to notce that you are moving faster at the same HR after about 4-6 weeks., When you see some improvement in your daily runs, like:  “wow I am 3 minutes faster on my normal morning running route than I was a month ago”.  When you see that, you know your aerobic metabolism is becoming more productive. Aerobic capacity is increasing and it time to re-evaluate your AeT because there is good chance your AeT HR has gone up as well.  Eventually (like after 61-12 months of consistent aerobic base training) the AeT HR will cease to increase.  BUT…the AeT pace can and will continue to increase.  I have seen AeT pace increase in an elite athlete for 10 consecutive years.  This is how Eliud Kipchoge and other can manage to get their AeT pace down to 4:30/mile.  In their case it took decades and very good genetics but the rest of can still make masive gains in this area.