ENERGY SYSTEMS
- ATP is the energy source for all muscle contractions.
- Had a great chart explaining how the three major systems work (plumbing analogy) -- nice and simple way to explain what is going on. I'll just note some highlights.
- Three main ways to produce ATP --
(1) Creatine Phosphate (CP),
(2) Glycolosis
(3) Aerobic.
- In swimming, glycolosis relies almost exclusively on muscle glycogen -- this is due to the nature of event duration. He noted that every race in swimming is done at a pace in excess of 90% of VO2 Max.
- All three systems are always working at all times.
- Even at moderate efforts (used example of 150-watt cycling test), CP levels drop significantly, stay low for duration of effort and take 4-6 minutes to recover.
- Noted the importance of long recoveries when training the high-end energy systems -- otherwise we exhaust them.
- TIP -- In his mind the single biggest error in swim training is not having enough recovery built into the high intensity sets -- Don't count yards, instead focus on main sets that are targeted at specific energy systems as well as technique gains. My coach this summer never cared about yards, only the main set, work and rest intervals. This reminded me of the benefit of the walk-back when doing strides in run training.
- He favors active recovery for LaTol (lactate tolerance sets) -- lactate clears fastest at 40-50% of VO2 Max, important for SS run sessions. Note this is a different sort of training from CP resynthesis.
- Some coaches like to train lactate clearance separately from lactate production -- in his opinion both systems are being trained with LaTol work.
- Lactate is not the problem! The true limiter is the change in muscle pH levels. Contractions stop at around 6.3/6.4 pH -- at rest muscles are neutral (7 pH). The amount of lactate required to reach a level of 6.3 varies from person to person and this is what he seeks to train.
- Interestingly, lactic acid inhibits the body's ability to produce lactate -- a built in safety device so we don't "melt" ourselves.
- Phosphate loading works but he is cautious as some athletes will experience explosive diarrhea. Reported a swimming double blind study were 200 times dropped from 2:03 to 2:00.
- Aerobic training improves the body's ability to remove blood lactate. This is an important element of performance for sprinters and is why even sprinters need to do aerobic endurance training (to train this ability).
- Note -- if you see an athlete with outstanding endurance, but no top-end speed, then perhaps they are glycogen depleted or over-reached. They have an impaired explosive ability. The taper works magic for this athlete -- not because of a peak, but because they are able to move from a "depleted" to a "normal" state. Very common in swimmers. His view is that chronic glycogen depletion is the most common source of overtraining in swimmers.
Five Training Adaptations
- Aerobic Endurance -- AE, ability to sustain a sub-maximal pace for an extended period
- Aerobic Power -- AP, VO2 max, maximum ability to consume oxygen
- Lactate Tolerance -- LaTol, the ability to prevent large drops in pH when lactic acid accumulates, physiological (buffer capacity) and psychological (pain tolerance) factors
- Anaerobic Power -- Sprints, ability to reach and maintain maximum velocity
- Economy -- oxygen cost of exercising at any given intensity
- These are the five adaptations that we should seek to develop in our training.
- We don't want to rely on accidental success. We should have targeted success with targeted workouts.
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