Stephen Phinney and Jeff Volek
have done a tremendous work on nutrition for athletes. Their seminal work published in 2016, Metabolic Characteristic of Keto-Adapted Ultra-Endurance
Runners. Metabolism, needed a
subject to proof that great athletes can follow this adaptation to perform at
the highest level. This athlete was
study by Edward Coyle few years earlier.
Maximal
blood lactate concentration was remarkably low in the trained state. It appears
that an 8% improvement in muscular efficiency and thus power production when
cycling at a given oxygen uptake (V̇o2) is the characteristic that improved most as this
athlete matured from ages 21 to 28 yr.
This case describes the physiological
maturation from ages 21 to 28 yr of the bicyclist who has now become the
six-time consecutive Grand Champion of the Tour de France, at ages 27–32 yr.
Maximal oxygen uptake (V̇o2 max) in the trained state remained at ∼6 l/min, lean body weight remained at ∼70 kg, and maximal heart rate declined from 207
to 200 beats/min. Blood lactate threshold was typical of competitive cyclists
in that it occurred at 76–85% V̇o2 max, yet maximal
blood lactate concentration was remarkably low in the trained state. It appears
that an 8% improvement in muscular efficiency and thus power production when
cycling at a given oxygen uptake (V̇o2) is the characteristic that improved most as this athlete
matured from ages 21 to 28 yr. It is noteworthy that at age 25 yr, this
champion developed advanced cancer, requiring surgeries and chemotherapy.
During the months leading up to each of his Tour de France victories, he
reduced body weight and body fat by 4–7 kg (i.e., ∼7%). Therefore, over the 7-yr period, an
improvement in muscular efficiency and reduced body fat contributed equally to
a remarkable 18% improvement in his steady-state power per kilogram body weight
when cycling at a given V̇o2 (e.g., 5 l/min). It is hypothesized that the improved muscular efficiency
probably reflects changes in muscle myosin type stimulated from years of
training intensely for 3–6 h on most days.
https://journals.physiology.org/doi/full/10.1152/japplphysiol.00216.2005
This subject studied by
Coyle developed keto-adaptation even when his nutrition was out of whack. How do I know this? I checked his hemoglobin and hematocrit in
his biological passport and it appeared he was anemic at one point. This being anemic can give us a clue
regarding caloric intake and fasting states.
When caloric intake is low, anemia could be a side effect but it promotes
keto adaptation as well as fasting in this case. This is an advantage taken by anorexic
athletes until the body breaks down due to malnutrition. Michael Phelps used to have lactates around
20 right after one of his competition; this cyclist can hardly reach 7:
Furthermore, at this time of reduced training,
maximal blood lactate concentration measured 4 min after exhaustion was 9.2 mM
compared with previously recorded values in the range of 6.3–7.5 mM. Maximal
heart rate declined from 207 to 200 beats/min from 1992 through 1999. The V̇o2 corresponding to the blood lactate threshold was
4.5–4.7 l/min when measured in 1992–1993 and, as expected, it was reduced to
4.02 l/min during the period of reduced training in August 1997.
Phinney tested athletes where the peak of fat oxidation was closed to their Vo2 max (see graph below), but what can we learn following the athlete tested by Coyle?:
1) Keto-adaptation
is a state that last a long time even when we do not pay attention to our
nutrition as long as we continue training at the same level with same
conditions. It involves activation of
genes and it is difficult to deactivate them.
2) Keto-adaptation
is obtained with five hours rides, fasting and low caloric intake for a long
time. Simulating an anorexic. No wonder Eufemiano Fuentes said that he was
helping cyclists to overcome illness when doping them; he used to give
transfusions.
3) The
lactate curves should be interpreted differently depending on the diet the
athlete is eating. The lactate curves
are designed for athletes eating a high carbohydrate diet without the training of
the champion described by Coyle and/or without the anorexic twist.
4) Training
is directly related to the development of keto-adaptation. The better we adapt the better engine we have;
leaving technique as the other physical aspect of performing at high level.
5) The
used of glucose or fatty acid depending on the diet it is shown by Volek in the
two graph below when testing two different groups, high carbohydrate diet vs
low carb diet.
6) Muscle
glycogen was the same after exercise for the two groups. This helps to understand that the keto-adapted
athletes were burning fat instead of glycogen.
See the graph taken from Phinney and Volek.
