jon r wrote:
Can anybody expand on how Renato say's recruiting fibers during high lactate's protects oxidation?
I am not sure I entirely understand your question,
"I always use short sprints uphill (from 60 to 100m, with a gradient of 10-15%, depending on the characteristics of the place), also during full track season (or during every period of preparation regarding marathon runners). Running long distances many times, not always fast but often moderate, athletes become unable to use completely their fibres, expecially FT. Runners of long distance become unable to have quick nervous reactions, and step by step lose capacity of MENTAL INTENSITY in efforts. So, the goal is to recruit their capacity in requiring max intensity to their brain, that means rapidity in transmitting stimula to muscles, and means also the possibility of using the most percentage possible of fibres. So, the first goal of short sprints uphill is not to improve speed, but to reach the capacity of working with the higher number of fibres in each muscle (of course interested in specific activity).
The second goal is to increase the elasticity of heart. Being a muscle, heart needs to work using a large range of possibilities. Under this point of view, if you reduce too much your max heart rate, you reduce your capacity of working. An example :
Athlete A : Basic HR 50/min - Max HR 200
Athlete B : Basic HR 40/min - Max HR 180
Athlete C : Basic HR 36/min - Max HR 180
A) is the athlete after 2-3 years of training. He's yet young, didn't work very much on long run, is able to reach a high level of HR (200) having a good elasticity in his myocardium. His coefficient of contraction is 4, as he's able to work 4 times his basic value (200 : 50).
B) the same athlete, after working 2 years in dicrection of long run, improving very much his aerobic capacity. As his heart becomes bigger, he's able to reduce his basic HR of 20% (from 50 to 40). Of course, he's no more able to have the same peak (from 200 to 180), but loses only 10%. So, now his coefficient of contraction is 4,5 (180 : 40), so the capacity of working of his heart is higher than before.
C) after thie type of work, the athlete can yet reduce a little his basic HR, using long run FAST and long intervals (2000/3000m) at speed of 10000m, with short recovery. In this way, his heart can yet become a little bit bigger, but myocardium preserves his elasticity, because heart walls are not too thick, but able to contract and to relax very fast. The improvement of basic HR is 10% (from 40 to 36), but max HR is the same. So, the capacity of working of his heart is now of 5 times (180 : 36).
The only way to keep a high level of max HR is to push your heart to its max level, only for very short time, then to relax completly. In this way, myocardium can work at its max intensity, but the effort doesn't last long time, and the muscle cannot become hypertrophic, that is damageous for health and diminutive for performances."