Abstract
Background
Daily nutrition plays an important role in supporting training adaptions and endurance performance. The objective of this 10-week study was to investigate the consequences of varying carbohydrate consumption and the glycaemic index (GI) together with an endurance training regimen on substrate oxidation, muscle energy storage and endurance performance under free-living conditions. Sixty-five moderately trained healthy men (29 ± 4 years; VO2 peak 55 ± 8 mL min−1 kg−1) were randomized to one of three different nutritional regimes (LOW-GI: 50–60% CHO with ≥ 65% of these CHO with GI 70 per day, n = 20; LCHF: ≤ 50 g CHO daily, n = 21). Metabolic alterations and performance were assessed at baseline (T0) and after 10 weeks (T10) during a graded exercise treadmill test. Additionally, a 5 km time trial on a 400-m outdoor track was performed and muscle glycogen was measured by magnet resonance spectroscopy.
Results
Total fat oxidation expressed as area under the curve (AUC) during the graded exercise test increased in LCHF (1.3 ± 2.4 g min−1 × km h−1, p 0.05) and decreased in HIGH-GI (− 1.7 ± 1.5 g min−1 × km h−1, p
Description
This study examines the effects of different carbohydrate diets on endurance performance.