(English follows)
Running economy is a bit like fuel economy in a car, it's the energy cost to cover a given distance.
1. Endurance training (running)
Training experience is believed to be one of the most important factors in improving running economy, although longitudinal studies on this subject are few and far between. One author even suggests that the most important factor in improving running economy is the number of kilometers accumulated in training over time.
According to the author of the study, training volume would certainly have a role to play, but no study seems to focus on this subject.
Interval training seemed to be very effective in improving running economy. In particular, training performed at a speed close to maximum aerobic speed and training performed at lactate threshold appeared to be the most effective.
2. Bodybuilding
Strength training would be a great way to improve running economy. In general, protocols that use heavier weights (6 reps or less) would be more effective than protocols that work strength-endurance (12 reps or more
3. The altitude
Training and living at altitude, by different mechanisms, would significantly improve racing economy.
4. Flexibility
In general, studies suggest that more musculotendinous stiffness improves running economy. However, they do mention that stretching should not be avoided, in order to prevent injury and maximize stride length.
5. Food
It seems that nitrate supplementation with beet juice could improve running economy, but more research on this subject will be needed.
