TY - JOUR
T1 - Extreme Events Reveal an Alimentary Limit on Sustained Maximal Human Energy Expenditure
AU - Thurber, Caitlin
AU - Dugas, Lara R.
AU - Ocobock, Cara
AU - Carlson, Bryce
AU - Speakman, John R
AU - Pontzer, Herman
N1 - Acknowledgments: We thank the RASUA runners for their participation and the 100 Mile Club ® for developing and supporting RAUSA. Jenny Paltan assisted with isotope analyses. Funding: Hunter College, Loyola Medical School, Grand Valley State University, and Purdue University. J.R.S. was supported by the strategic priority research program of the Chinese Academy of Sciences (grant XDB13030100), the 1000 Talents organization, and a Wolfson merit award from the UK Royal society. Author contributions: All authors contributed to study design and writing the manuscript. H.P. designed DLW analyses for the RAUSA subjects. C.T. collected DLW and other RAUSA data in the field. L.D. collected RMR measures for RAUSA subjects. B.C. organized RAUSA data collection. H.P. and J.R.S. analyzed data on expenditure and weight change, and developed the alimentary constraint model. Competing interests: Authors declare no competing interests. Data and materials availability: All data is available in the main text or the supplementary materials.
PY - 2019/6/5
Y1 - 2019/6/5
N2 - The limits on maximal sustained energy expenditure in humans and other animals are unclear, but are of extreme interest in multiple fields because they constrain maximal reproductive output, thermoregulation, and physical activity. Here, we show that sustained expenditure in humans, measured as maximum sustained metabolic scope (SusMS), is a function of event duration. We compiled published measurements of total energy expenditure (TEE) and basal metabolic rate (BMR) from human endurance events, and extended the range of these observations with new data from adults running ~250km/week for 20 weeks in a transcontinental race. For events lasting 0.5 to 250+ days, SusMS decreases curvilinearly with event duration, plateauing below 3×BMR. This relationship differs from that of shorter events (e.g., marathons). Incorporating data from overfeeding studies, we find evidence for an alimentary energy supply limit in humans of ~2.5×BMR; greater expenditure requires drawing down the body’s energy stores. Transcontinental race data suggests humans can partially reduce TEE during long events to extend endurance.
AB - The limits on maximal sustained energy expenditure in humans and other animals are unclear, but are of extreme interest in multiple fields because they constrain maximal reproductive output, thermoregulation, and physical activity. Here, we show that sustained expenditure in humans, measured as maximum sustained metabolic scope (SusMS), is a function of event duration. We compiled published measurements of total energy expenditure (TEE) and basal metabolic rate (BMR) from human endurance events, and extended the range of these observations with new data from adults running ~250km/week for 20 weeks in a transcontinental race. For events lasting 0.5 to 250+ days, SusMS decreases curvilinearly with event duration, plateauing below 3×BMR. This relationship differs from that of shorter events (e.g., marathons). Incorporating data from overfeeding studies, we find evidence for an alimentary energy supply limit in humans of ~2.5×BMR; greater expenditure requires drawing down the body’s energy stores. Transcontinental race data suggests humans can partially reduce TEE during long events to extend endurance.
UR - http://www.scopus.com/inward/record.url?scp=85067252975&partnerID=8YFLogxK
UR - http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aaw0341
UR - http://www.mendeley.com/research/extreme-events-reveal-alimentary-limit-sustained-maximal-human-energy-expenditure
U2 - 10.1126/sciadv.aaw0341
DO - 10.1126/sciadv.aaw0341
M3 - Article
C2 - 31183404
VL - 5
JO - Science Advances
JF - Science Advances
SN - 2375-2548
IS - 6
M1 - eaaw0341
ER -