It’s logical to think heavier footwear can decrease movement economy and running time. The results of a 2016 study get more specific.
The 3-week study, produced by researchers from the University of Colorado Boulder, involved 18 experienced male runners. Each week, they completed a treadmill test to measure running economy, as well as a 3,000-meter time trial. During the first week, the runners wore identical sets of shoes that were true to their original weight. During the second and third weeks, without the runners’ knowledge, the shoes’ tongues were loaded with 100 and 300 grams of pellets, respectively.
Results confirmed the researchers’ hypotheses that extra weight would require more energy and result in slower times. Runners’ average metabolic rate increased by about 1% per 100 g of added weight. There was an inverse association with running time—for every 100 g increase, the runners ran 1% slower.
“Adding shoe mass predictably degrades running economy and slows 3,000-m time-trial performance proportionally,” the authors said. “Our data demonstrate that laboratory-based running economy measurements can accurately predict changes in distance-running race performance due to shoe modifications.”
They added that this information could be useful to someone whose primary goal is to become a faster and more efficient runner. For example, elite marathon runners wearing shoes 100 g lighter than they are used to could potentially run about 57 seconds faster. However, the researchers warned that lighter isn’t always better, as previous studies have shown that cushioning can be important for running economy.
The report appeared in Medicine & Science in Sports & Exercise (2016; 48 , 2175–80).