Vitamin C and E treatment blunts sprint interval training–induced changes in inflammatory mediator-, calcium-, and mitochondria-related signaling in recreationally active elderly humans

Sprint interval training (SIT) has emerged as a time-efficient training regimen for young individuals. Here, we studied whether SIT is effective also in elderly individuals and whether the training response was affected by treatment with the antioxidants vitamin C and E. Recreationally active elderly (mean age 65) men received either vitamin C (1 g/day) and vitamin E (235 mg/day) or placebo. Training consisted of nine SIT sessions (three sessions/week for three weeks of 4–6 repetitions of 30-s all-out cycling sprints) interposed by 4 min rest. Vastus lateralis muscle biopsies were taken before, 1 h after, and 24 h after the first and last SIT sessions. At the end of the three weeks of training, SIT-induced changes in relative mRNA expression of reactive oxygen/nitrogen species (ROS)and mitochondria-related proteins, inflammatory mediators, and the sarcoplasmic reticulum Ca2+ channel, the ryanodine receptor 1 (RyR1), were blunted in the vitamin treated group. Western blots frequently showed a major (>50%) decrease in the full-length expression of RyR1 24 h after SIT sessions; in the trained state, vitamin treatment seemed to provide protection against this severe RyR1 modification. Power at exhaustion during an incremental cycling test was increased by ~5% at the end of the training period, whereas maximal oxygen uptake remained unchanged; vitamin treatment did not affect these measures. In conclusion, treatment with the antioxidants vitamin C and E blunts SIT-induced cellular signaling in skeletal muscle of elderly individuals, while the present training regimen was too short or too intense for the changes in signaling to be translated into a clear-cut change in physical performance

The physiological impact of high?intensity interval training in octogenarians with comorbidities

BackgroundDeclines in cardiorespiratory fitness (CRF) and fat-free mass (FFM) with age are linked to mortality, morbidity and poor quality of life. High-intensity interval training (HIIT) has been shown to improve CRF and FFM in many groups, but its efficacy in the very old, in whom comorbidities are present is undefined. We aimed to assess the efficacy of and physiological/metabolic responses to HIIT, in a cohort of octogenarians with comorbidities (e.g. hypertension and osteoarthritis).MethodsTwenty-eight volunteers (18 men, 10 women, 81.2 ± 0.6 years, 27.1 ± 0.6 kg·m−2) with American Society of Anaesthesiology (ASA) Grade 2–3 status each completed 4 weeks (12 sessions) HIIT after a control period of equal duration. Before and after each 4 week period, subjects underwent body composition assessments and cardiopulmonary exercise testing. Quadriceps muscle biopsies (m. vastus lateralis) were taken to quantify anabolic signalling, mitochondrial oxidative phosphorylation, and cumulative muscle protein synthesis (MPS) over 4-weeks.ResultsIn comorbid octogenarians, HIIT elicited improvements in CRF (anaerobic threshold: +1.2 ± 0.4 ml·kg−1·min−1, P = 0.001). HIIT also augmented total FFM (47.2 ± 1.4 to 47.6 ± 1.3 kg, P = 0.04), while decreasing total fat mass (24.8 ± 1.3 to 24 ± 1.2 kg, P = 0.0002) and body fat percentage (33.1 ± 1.5 to 32.1 ± 1.4%, P = 0.0008). Mechanistically, mitochondrial oxidative phosphorylation capacity increased after HIIT (i.e. citrate synthase activity: 52.4 ± 4 to 67.9 ± 5.1 nmol·min−1·mg−1, P = 0.005; membrane protein complexes (C): C-II, 1.4-fold increase, P = 0.002; C-III, 1.2-fold increase, P = 0.03), as did rates of MPS (1.3 ± 0.1 to 1.5 ± 0.1%·day−1, P = 0.03). The increase in MPS was supported by up-regulated phosphorylation of anabolic signalling proteins (e.g. AKT, p70S6K, and 4E-BP1; all P < 0.05). There were no changes in any of these parameters during the control period. No adverse events were reported throughout the study.ConclusionsThe HIIT enhances skeletal muscle mass and CRF in octogenarians with disease, with up-regulation of MPS and mitochondrial capacity likely underlying these improvements. HIIT can be safely delivered to octogenarians with disease and is an effective, time-efficient intervention to improve muscle mass and physical function in a short time frame