Purpose: Our goal was to quantify if small (1%–3%) changes in running economy quantitatively affect distance-running performance. Based on the linear relationship between metabolic rate and running velocity and on earlier observations that added shoe mass increases metabolic rate by ~1% per 100 g per shoe, we hypothesized that adding 100 and 300 g per shoe would slow 3000-m time-trial performance by 1% and 3%, respectively.
Methods: Eighteen male sub-20-min 5-km runners completed treadmill testing, and three 3000-m time trials wearing control shoes and identical shoes with 100 and 300 g of discreetly added mass. We measured rates of oxygen consumption and carbon dioxide production and calculated metabolic rates for the treadmill tests, and we recorded overall running time for the time trials.
Results: Adding mass to the shoes significantly increased metabolic rate at 3.5 m·s−1 by 1.11% per 100 g per shoe (95% confidence interval = 0.88%–1.35%). While wearing the control shoes, participants ran the 3000-m time trial in 626.1 ± 55.6 s. Times averaged 0.65% ± 1.36% and 2.37% ± 2.09% slower for the +100-g and +300-g shoes, respectively (P < 0.001). On the basis of a linear fit of all the data, 3000-m time increased 0.78% per added 100 g per shoe (95% confidence interval = 0.52%–1.04%).
Conclusion: Adding shoe mass predictably degrades running economy and slows 3000-m time-trial performance proportionally. Our data demonstrate that laboratory-based running economy measurements can accurately predict changes in distance-running race performance due to shoe modifications.
1Locomotion Lab, Department of Integrative Physiology, University of Colorado Boulder, CO; and 2Nike Explore Team, Sport Research Lab, NIKE Inc., Beaverton, OR
Address for correspondence: Wouter Hoogkamer, Ph.D., Department of Integrative Physiology, University of Colorado Boulder, 354 UCB, Boulder, CO 80309-0354; E-mail: firstname.lastname@example.org.
Submitted for publication February 2016.
Accepted for publication June 2016.