da Silva et al. 2022, metabolic cost of aerodynamic drag in marathon running

Controlled study in the Journal of Applied Physiology that emulated aerodynamic drag with horizontal impeding forces applied at the waist, across three running speeds, to measure its metabolic cost. Gross metabolic power rose about 6.1% per 1% of body weight of horizontal impeding force (individual range roughly 4.2–8.1%). For a solo runner of about 52 kg at two-hour marathon pace, overcoming aerodynamic drag amounts to about 7.8% of gross metabolic power, closely matching Pugh’s older figure with modern methods. Perfect drafting was estimated to save roughly 3 min 42 s to 5 min 29 s over a marathon, a useful upper-bound illustration of the value of shelter; real-world savings are smaller because drafting is never perfect for a whole race. The drag cost is measured directly, but the marathon time savings are modelled rather than observed.