No effect of dietary nitrate supplementation on endurance training in hypoxia |
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| Authors: | J. Puype M. Ramaekers R. Van Thienen L. Deldicque P. Hespel |
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| Affiliation: | Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Belgium |
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| Abstract: | We investigated whether dietary nitrate (NO3?) supplementation enhances the effect of training in hypoxia on endurance performance at sea level. Twenty‐two healthy male volunteers performed high‐intensity endurance training on a cycle ergometer (6 weeks, 5×30 min/week at 4–6 mmol/L blood lactate) in normobaric hypoxia (12.5% FiO2), while ingesting either beetroot juice [0.07 mmol NO3?/kg body weight (bw)/day; BR, n = 11] or a control drink (CON, n = 11). During the pretest and the posttest, the subjects performed a 30‐min simulated time trial (TT) and an incremental VO2max test. Furthermore, a biopsy was taken from m. vastus lateralis before and after the TT. Power output during the training sessions in both groups increased by ～6% from week 1 to week 6 (P < 0.05). Compared with the pretest, VO2max in the posttest was increased (P < 0.05) in CON (5%) and BR (9%). Power output corresponding with the 4 mmol/L blood lactate threshold, as well as mean power output during TT increased by ～16% in both groups (P < 0.05). Muscle phospho‐AMP‐activated protein kinase, hypoxia inducible factor‐1α mRNA content, and glycogen breakdown during the TT were similar between the groups in both the pretest and the posttest. In conclusion, low‐dose dietary NO3? supplementation does not enhance the effects of intermittent hypoxic training on endurance exercise performance at sea level. |
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| Keywords: | Nitric oxide altitude high‐intensity endurance training aerobic capacity |
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