Barefoot running is becoming more popular, there is no doubt about it. But the exact reasons why any one person may choose to take up this style of running is highly variable. Some people gravitate to barefoot or minimalist running as a way to prevent or heal running injuries.
From the 2001 Sport Science journal:
Burkett et al. (1985) found that oxygen consumption during running increased as the amount of mass they added to the foot increased; shoes and orthotics representing 1% of body mass increased oxygen consumption by 3.1%. Flaherty (1994) found that oxygen consumption during running at 12 km/h was 4.7% higher in shoes of mass ~700 g per pair than in bare feet. An increase in oxygen consumption of ~4% is of little importance to the recreational runner, but the competitive athlete would notice a major effect on running speed.
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