Effects of oral HPCD-angiotensin-(1-7) supplementation on recreational mountain bike athletes: a crossover study

BackgroundSupplementation with Angiotensin-(1-7) [(Ang-1-7)] has received considerable attention due to its possible ergogenic effects on physical performance. The effects of a single dose of Ang-(1-7) on the performance of mountain bike (MTB) athletes during progressive load tests performed until the onset of voluntary fatigue have previously been demonstrated. This study tested the effects of Ang-(1-7) in two different exercise protocols with different metabolic demands: aerobic (time trial) and anaerobic (repeated sprint).MethodsTwenty one male recreational athletes were given capsules containing an oral formulation of HP beta CD-Ang-(1-7) (0.8 mg) and HP beta CD-placebo (only HP beta CD) over a 7-day interval; a double-blind randomized crossover design was used. Physical performance was examined using two protocols: a 20-km cycling time trial or 4 x 30-s repeated all-out sprints on a leg cycle ergometer. Data were collected before and after physical tests to assess fatigue parameters, and included lactate levels, and muscle activation during the sprint protocol as evaluated by electromyography (EMG); cardiovascular parameters: diastolic and systolic blood pressure and heart rate; and performance parameters, time to complete (time trial), maximum power and mean power (repeated sprint).ResultsSupplementation with an oral formulation of HP beta CD-Ang-(1-7) reduced basal plasma lactate levels and promoted the maintenance of plasma glucose levels after repeated sprints. Supplementation with HP beta CD-Ang-(1-7) also increased baseline plasma nitrite levels and reduced resting diastolic blood pressure in a time trial protocol. HP beta CD-Ang-(1-7) had no effect on the time trial or repeat sprint performance, or on the EMG recordings of the vastus lateralis and vastus medialis.ConclusionsSupplementation with HP beta CD-Ang-(1-7) did not improve physical performance in time trial or in repeated sprints; however, it promoted the maintenance of plasma glucose and lactate levels after the sprint protocol and at rest, respectively. In addition, HP beta CD-Ang-(1-7) also increased resting plasma nitrite levels and reduced diastolic blood pressure in the time trial protocol.