The effect of 14 days Actovegin administration with or without high intensity training on exercise capacity and skeletal muscle mitochondrial respiration

PURPOSE: Evidence exists that Actovegin has enhancing effects on mitochondrial respiratory capacity (MRC) in skeletal muscle, and it is well known that high intensity training (HIT) improves MRC and exercise performance. The aim was to investigate the effects of Actovegin administration on exercise performance and mitochondrial respiratory capacity in mice skeletal muscle fibers alone or in combination with HIT. METHODS: 40 healthy male mice were randomized into 4 groups; control (C), Actovegin (A), trained control (CT) and trained Actovegin (AT). All mice were given intraperitoneal injections every other day for 14 days of either 0.1 ml Actovegin (10 mg/ml) or 0.1 ml saline. The training consisted of a HIT protocol (5x1 min at 80-90 % of maximal running speed with 2 minutes of active recovery in between) performed every other day by the trained groups. All mice completed a maximal exercise capacity test before and after the intervention. High-resolution respirometry was used to measure skeletal muscle mitochondrial respiratory capacity. Citrate synthase activity was used as a biomarker for mitochondrial content. RESULTS: The CT and AT groups improved their exercise capacity significantly after the 14-day intervention compared to C and A. The increase in performance was significantly higher in the AT group compared to the CT group. Complex I + II linked mitochondrial respiratory capacity was increased in the A, CT and AT groups compared to the C group. CONCLUSION: This is the first study showing enhancing effects of Actovegin on exercise performance and skeletal muscle mitochondrial respiratory capacity with in vivo administration in mice.