{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T03:05:15Z","timestamp":1791947115011,"version":"4.3.4"},"reference-count":41,"publisher":"Public Library of Science (PLoS)","issue":"8","license":[{"start":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T00:00:00Z","timestamp":1786924800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Scientific and Technological Research Council of T\u00fcrkiye","award":["1919B012408991"],"award-info":[{"award-number":["1919B012408991"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>This study compared the physiological and metabolic demands of treadmill and overground running by examining running economy (RE), oxygen cost of transport (O2-COT), and energy cost (EC) across ventilatory threshold-scaled intensities in trained endurance athletes. Twelve male runners (21.3\u200d\u00b1\u200d2.4 years; 176.2\u200d\u00b1\u200d6.8 cm; 67.8\u200d\u00b1\u200d5.9 kg) completed a ramp test to determine V\u0307O2max, followed by identical stepwise protocols (8\u201315 km\u00b7h\u200d1\u200d\u00b9; 3-min stages) performed indoors on a treadmill and outdoors on a 400 m track. Breath-by-breath gas exchange was averaged over the final 60\u201390 s of each stage to determine steady-state V\u0307O2. Within-subject comparisons were used to evaluate differences between field and treadmill running across exercise intensities. Two-way repeated-measures ANOVA revealed significant main effects of Condition and Intensity domain for all three primary outcomes (all p\u200d\u2264\u200d0.012). RE was significantly higher during overground running (51.3\u200d\u00b1\u200d2.2 vs. 49.6\u200d\u00b1\u200d3.1 mL\u00b7kg\u200d1\u200d\u00b9\u00b7min\u200d1\u200d\u00b9; p-FDR\u200d=\u200d0.01), with divergence occurring primarily at intensities between 70% and 100% of VT2. O2-COT was consistently greater during overground running across all intensity domains (204.2\u200d\u00b1\u200d11.3 vs. 197.1\u200d\u00b1\u200d12.3 mL\u00b7kg\u200d1\u200d\u00b9\u00b7km\u200d1\u200d\u00b9; p-FDR\u200d\u2264\u200d0.01), with no significant Condition\u200d\u00d7\u200dIntensity interaction, indicating a consistent between-condition difference across all intensity domains. Energy cost remained consistently higher during overground running (3.87\u200d\u00b1\u200d0.21 to 4.60\u200d\u00b1\u200d0.27 vs. 3.65\u200d\u00b1\u200d0.22 to 4.10\u200d\u00b1\u200d0.18 J\u00b7kg\u200d1\u200d\u00b9\u00b7m\u200d1\u200d\u00b9; p-FDR\u200d&lt;\u200d0.001), with a significant Condition\u200d\u00d7\u200dIntensity interaction (p\u200d=\u200d0.045). Carbohydrate oxidation was significantly higher during overground running at intensities approaching VT2 (p-FDR\u200d=\u200d0.02). These findings suggest that the commonly used 1% treadmill grade correction does not fully replicate the energetic demands of overground running, with implications for laboratory-based performance evaluation.<\/jats:p>","DOI":"10.1371\/journal.pone.0355988","type":"journal-article","created":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T17:30:26Z","timestamp":1786987826000},"page":"e0355988","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Overground running incurs a higher energetic cost than treadmill running at a 1% grade: A comparison of running economy, oxygen cost of transport, and energy cost in endurance athletes"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5379-3567","authenticated-orcid":true,"given":"Seyed 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