Mitochondrial‐targeted antioxidant ingestion acutely blunts VO2max in physically inactive females

Abstract

Abstract Purpose To determine the acute effects of a mitochondrial targeting antioxidant (MitoQ) on the metabolic response during exercise. Methods Nine (n = 9) physically inactive females (age 47 ± 22 years) performed two trials (Placebo and MitoQ) in a double‐blind randomized cross‐over design. In both trials, participants performed an exercise protocol consisting of 3‐min stages at submaximal workloads followed by a ramp protocol to volitional exhaustion. Participants received either Placebo or MitoQ (80 mg) 1 h prior to exercise. Indirect calorimetry and cardiovascular measurements were collected throughout the duration of the exercise bout. Results Submaximal metabolic and cardiovascular variables were not different between trials (p > 0.05). VO2max was higher (p = 0.03) during Placebo (23.5 ± 5.7 mL kg min−1) compared to MitoQ (21.0 ± 6.6 mL kg min−1). Maximal ventilation was also higher (p = 0.02) in Placebo (82.4 ± 17.7 L/min) compared to MitoQ (75.0 ± 16.8 L/min). Maximal cardiovascular variables and blood lactate were not different between trials (p > 0.05). Conclusion An acute dose of MitoQ blunted VO2max, which was primarily mediated by impairment of ventilatory function. These data suggest that the acute accumulation of exercise‐induced mitochondrial reactive oxygen species (mtROS) are necessary for maximal aerobic capacity. Further research is warranted on mtROS‐antioxidant cell signaling cascades, and how they relate to mitochondrial function during exercise.

Keywords

• cardiorespiratory fitness
• exercise
• mitochondria