Vitamin D3 supplementation combined with sprint interval training improves aerobic and anaerobic exercise performance over sprint interval training alone in recreational combat sport athletes

Objectives. - Correcting vitamin D deficiency might improve aerobic and anaerobic exercise performance. However, it is unclear if vitamin D-3 supplementation can convey a positive ergogenic benefit to aerobic and anaerobic exercise performance when combined with sprint interval training (SIT). Methods. - Twenty-seven recreational male combat sport athletes were recruited (age: 25 +/- 5 years, stature: 178 +/- 7 cm, weight: 77 +/- 10 kg). Participants completed baseline haematocrit and haemoglobin testing, lower body and upper body VO2peak testing and two consecutive lower and upper body Wingate tests separated by five minutes rest. Participants were randomly assigned to either the vitamin D(3 )group (VITD) or placebo group (CON) and underwent 6 weeks of twice-weekly SIT and weekly supplementation (50,000 IU.week(-1)). Following the intervention, testing was repeated. Results. - Haemoglobin (P < 0.001), haematocrit (P < 0.001) and LB VO2peak (P = 0.016) increased in VITD, remaining unchanged in CON (haemoglobin P = 0.981; haematocrit P = 0.947, LB VO2peak P = 0.750). UB VO2peak was unchanged in both groups (P = 0.284). LB and UB time to exhaustion increased in both groups (P < 0.001). LB oxygen kinetics was not affected in either group (P = 0.063) with UB oxygen kinetics improved in VITD (P = 0.028). LB and UB Wingate peak power improved in both groups (P < 0.001). LB Wingate average power improved in both groups (P < 0.001) with VITD increasing average power over CON. Conclusion. - Given the results, supplementing 50,000 IU of vitamin D-3 per week for six weeks combined with six weeks of SIT may improve markers of aerobic and anaerobic performance in recreational male combat sport athletes (C) 2021 Elsevier Masson SAS. All rights reserved.