Weighty matters: heavy trainers make for heavy work
WE ALL know that clumpy, heavy shoes make running feel more like hard work. But does wearing cumbersome footwear translate into slower times?
Researchers at University of Colorado’s Department of Integrative Physiology set to find out in an innovative study measuring running economy when wearing shoes that looked similar but had subtle and significant differences.
Each of the 18 runners who took part in the trial – all sub 20-minute 5km performers – were asked to perform treadmill tests wearing three pairs of nearly identical shoes, two pairs of which had small lead pellets hidden inside the tongues to make them weigh more. Compared with the normal weight trainer, each of the other shoes was made either 100g heavier or loaded with 300g of lead pellets per shoe.
First, the athletes completed treadmill tests which showed energy costs rose by about 1% with each extra 100g of shoe weight. Over the following weeks, they then completed 3000m time trials on an indoor track in each of the three shoe pairs once a week for three weeks. Unaware of the differences in shoe weight (the researchers insisted on putting on and taking off the shoes for the test subjects), results showed that the runners replicated the laboratory findings and ran roughly 1% slower for each 100g of lead added to the shoes in each race.