Spirulina supplementation improves oxygen uptake in arm cycling exercise

PURPOSE: Spirulina has previously been reported to improve high-intensity exercise performance and hemoglobin. However, spirulina’s effect on arm cycling exercise has yet to be investigated. The purpose of this study was to investigate the responses of spirulina supplementation on hemoglobin and on oxygen uptake, RER and HR during seated arm cycling exercise. METHODS: In a double-blinded randomized crossover design, eleven males untrained in arm cycling ingested 6 g/day of spirulina or placebo for seven days. Seated on the Arm Crank Ergometer, each participant performed a baseline V̇O(2max) test, and then after supplementation, 2 × 30-min submaximal exercise bouts corresponding to 55% of their V̇O(2max), followed by an incremental test to fatigue. A seven-day wash-out period was required between conditions. Oxygen uptake, RER and HR were measured continuously during exercise and hemoglobin measured prior to exercise after both conditions. RESULTS: Spirulina significantly (p < 0.05) increased Hb in comparison to Placebo (144.1 g/l ± 10.5 Vs 154.5 g/l ± 6.9). After spirulina supplementation, during the 30-min exercise bouts, oxygen uptake and HR were significantly lower (2170 ml/min ± 173 Vs 2311 ml/min ± 189 and 154 bpm ± 14 Vs 149 bpm ± 17), RER was not significantly different. In comparison to placebo, Spirulina significantly increased oxygen uptake at time of fatigue (34.10 ml/min/kg ± 6.03 Vs 37.37 ml/min/kg ± 5.98). Time taken to fatigue was not different. CONCLUSION: Spirulina supplementation significantly reduces oxygen uptake and HR during arm cycling submaximal exercise, allowing for an increased oxygen uptake during an incremental test to fatigue.