4 ms·

Energy efficiency per distance of running improves very little with training. According to the book “Burn” by Herman Pontzer we are talking about few percents,

• elil17 4y ago
  Just being skinny probably makes him more efficient than average.
• nonameiguess 4y ago
  That is presumably talking about differences in metabolic and mechanical efficiency, but assuming those are held equal, energy output still scales linearly with work performed, which is directly proportional to body mass, and energy loss from atmospheric and wind drag is going to operate similarly. Simply being smaller and having a slimmer profile will result in less energy needed per unit of distance compared to an average person. That said, Aleksandr is smaller than an average 40 year-old man, but actually pretty large for a distance runner, 20 kg heavier than the current world record holder in the marathon.
  • _0w8t 4y ago
    That book described total energy expenditure for an individual per distance traveled. It does not improves much even after years of training. It is interesting that for running the efficiency does not depend on speed as wind drag does not contribute much below 20 km/h. This is different from walking. Walking at relaxed pace is the most efficient and uses 2 times less energy per distance than running. At about 7 km/h walking becomes less efficient than running.