Key pointsr Recent studies have indicated that antioxidant supplementation may blunt adaptations to exercise, such as mitochondrial biogenesis induced by endurance training. However, studies in humans are sparse and results are conflicting.r Isolated vitamin C and E supplements are widely used, and unravelling the interference of these vitamins in cellular and physiological adaptations to exercise is of interest to those who exercise for health purposes and to athletes.r Our results show that vitamin C and E supplements blunted the endurance training-induced increase of mitochondrial proteins (COX4), which is important for improving muscular endurance.r Training-induced increases inV O 2 max and running performance were not detectably affected by the supplementation.r The present study contributes to understanding of how antioxidants may interfere with adaptations to exercise in humans, and the results indicate that high dosages of vitamins C and E should be used with caution.Abstract In this double-blind, randomised, controlled trial, we investigated the effects of vitamin C and E supplementation on endurance training adaptations in humans. Fifty-four young men and women were randomly allocated to receive either 1000 mg of vitamin C and 235 mg of vitamin E or a placebo daily for 11 weeks. During supplementation, the participants completed an endurance training programme consisting of three to four sessions per week (primarily of running), divided into high-intensity interval sessions [4-6 × 4-6 min; >90% of maximal heart rate (HR max )] and steady state continuous sessions (30-60 min; 70-90% of HR max ). Maximal oxygen uptake (V O 2 max ), submaximal running and a 20 m shuttle run test were assessed and blood samples and muscle biopsies were collected, before and after the intervention. Participants in the vitamin C and E group increased theirV O 2 max (mean ± S.D.: 8 ± 5%) and performance in the 20 m shuttle test (10 ± 11%) to the same degree as those in the placebo group (mean ± S.D.: 8 ± 5% and 14 ± 17%, respectively). However, the mitochondrial marker cytochrome c oxidase subunit IV (COX4) and cytosolic peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC-1α) increased in the m. vastus lateralis in the placebo group by 59 ± 97% and 19 ± 51%, respectively, but not in the vitamin C and E group (COX4: −13 ± 54%; PGC-1α: −13 ± 29%; P ࣘ 0.03, between groups). Furthermore, mRNA levels of CDC42 and mitogen-activated protein kinase 1 (MAPK1) in the trained muscle were lower in the vitamin C and E group than in the placebo group (P ࣘ 0.05). Daily vitamin C and E supplementation attenuated increases in markers of mitochondrial biogenesis following endurance training. However, no clear interactions were detected for improvements inV O 2 max and running performance. Consequently, vitamin C and E supplementation hampered cellular adaptations in the exercised muscles, and although this did not translate to the performance tests applied in this study, we advocate caution when considering antioxidant supplemen...

Objective: We have measured the effect of combined strength and high intensity endurance training on physical capacity and lipid profile in patients with heart and coronary diseases. We wanted to see whether cardiac patients were able to increase training intensity to improve strength without losing endurance capacity.Methods: Thirty heart-operated subjects participated in an intervention period of 10 weeks. The age of the participants was between 52-72 years. The Resistance-Interval group (RE-INT) practiced four times a week with two intensive endurance (spinning) sessions and two strength training sessions. The endurance training consisted of intervals where the heart rate reached>90% of maximum heart rate. Strength training was performed in three series with a load of 8-12 repetition maximum (RM). The subjects in the control group (CON) performed two to three sessions per week according to a national program specialized for coronary patients (called "Ullevaal model"). We had a randomized controlled trial. Results:Maximal leg strength increased in both groups during the intervention, but the increase was higher in the RE-INT group (from 107.9 ± 8.1 kg to 162.0 ± 8.4 kg) compared to the CON group (from 110.8 ± 8.9 to 125.4 ± 9.5 ) (p<0.001). Strength in chest press, the maximal oxygen uptake and the concentration of high densitylipoprotein (HDL) protein increased in both groups during the test period. However, no differences were observed between the RE-INT and CON group. Low density-lipoprotein (LDL), blood pressure and body weight did not change during the intervention period in any of the groups. Conclusion:Cardiac patients were able to increase training intensity, strength and maximal oxygen uptake during a period of 10 weeks. We found that combined training has an effective impact on the increase in leg strength. The increase in muscle strength can be vital for the everyday quality of life in cardiac patients.