Cardiorespiratory Responses to Downhill Versus Uphill Running in Endurance Athletes

• Published in: Research quarterly for exercise and sport Vol. 89; no. 4; pp. 511 - 517
• Main Authors: Lemire, Marcel, Lonsdorfer-Wolf, Evelyne, Isner-Horobeti, Marie-Eve, Kouassi, Blah Y. L., Geny, Bernard, Favret, Fabrice, Dufour, Stéphane P.
• Format: Journal Article
• Language: English
• Published: United States Routledge 02-10-2018
• Subjects: Athletes; Athletics; Exercise Physiology; Heart rate; Human Body; inclined treadmill; Metabolism; oxygen uptake; Physical Activities; pulmonary ventilation; Heart rate; oxygen uptake; pulmonary ventilation; inclined treadmill
• ISSN: 0270-1367; 2168-3824
• DOI: 10.1080/02701367.2018.1510172

Purpose: Mountain running races are becoming increasingly popular, although our understanding of the particular physiology associated with downhill running (DR) in trained athletes remains scarce. This study explored the cardiorespiratory responses to high-slope constant velocity uphill running (UR) and DR. Method: Eight endurance athletes performed a maximal incremental test and 2 15-min running bouts (UR, +15%, or DR, −15%) at the same running velocity (8.5 ± 0.4 km·h
−1
). Oxygen uptake (
O
2
), heart rate (HR), and ventilation rates (
E
) were continuously recorded, and blood lactate (bLa) was measured before and after each trial. Results: Downhill running induced a more superficial
E
pattern featuring reduced tidal volume (p < .05, ES = 6.05) but similar respiratory frequency (p > .05, ES = 0.68) despite lower
E
(p < .05, ES = 5.46),
O
2
(p < .05, ES = 12.68), HR (p < .05, ES = 6.42), and bLa (p < .05, ES = 1.70). A negative slow component was observed during DR for
O
2
(p < .05, ES = 1.72) and HR (p < .05, ES = 0.80). Conclusions: These results emphasize the cardiorespiratory responses to DR and highlight the need for cautious interpretation of
O
2
, HR, and
E
patterns as markers of exercise intensity for training load prescription and management.