In:
International Journal of Sport Nutrition and Exercise Metabolism, Human Kinetics, Vol. 33, No. 2 ( 2023-03-1), p. 73-83
Abstract:
Endurance training in fasted conditions (FAST) induces favorable skeletal muscle metabolic adaptations compared with carbohydrate feeding (CHO), manifesting in improved exercise performance over time. Sprint interval training (SIT) is a potent metabolic stimulus, however nutritional strategies to optimize adaptations to SIT are poorly characterized. Here we investigated the efficacy of FAST versus CHO SIT (4–6 × 30-s Wingate sprints interspersed with 4-min rest) on muscle metabolic, serum metabolome and exercise performance adaptations in a double-blind parallel group design in recreationally active males. Following acute SIT, we observed exercise-induced increases in pan-acetylation and several genes associated with mitochondrial biogenesis, fatty acid oxidation, and NAD + -biosynthesis, along with favorable regulation of PDK4 ( p = .004), NAMPT ( p = .0013), and NNMT ( p = .001) in FAST. Following 3 weeks of SIT, NRF2 ( p = .029) was favorably regulated in FAST, with augmented pan-acetylation in CHO but not FAST ( p = .033). SIT induced increases in maximal citrate synthase activity were evident with no effect of nutrition, while 3-hydroxyacyl-CoA dehydrogenase activity did not change. Despite no difference in the overall serum metabolome, training-induced changes in C3:1 ( p = .013) and C4:1 ( p = .010) which increased in FAST, and C16:1 ( p = .046) and glutamine ( p = .021) which increased in CHO, were different between groups. Training-induced increases in anaerobic ( p = .898) and aerobic power ( p = .249) were not influenced by nutrition. These findings suggest some beneficial muscle metabolic adaptations are evident in FAST versus CHO SIT following acute exercise and 3 weeks of SIT. However, this stimulus did not manifest in differential exercise performance adaptations.
Type of Medium:
Online Resource
ISSN:
1526-484X
,
1543-2742
DOI:
10.1123/ijsnem.2022-0142
Language:
Unknown
Publisher:
Human Kinetics
Publication Date:
2023
SSG:
31
Permalink