Muscle glycogen provides a key fuel for training and racing a marathon. Carbohydrate ‘loading’ can enhance marathon performance by allowing the competitor to run at their optimal pace for a longer period before fatiguing. For the well trained runner, this may be achieved by tapering exercise over the final days before the marathon and ensuring carbohydrate intakes of 10–12 g/kg/day over the 36–48 hours prior to the race. Sports nutrition guidelines recommend that the runner consumes sufficient carbohydrate to promote restoration of muscle glycogen between training sessions. This strategy should allow the runner to ‘train harder’ and recover optimally between workouts. A recent hypothesis suggests that runners might ‘train smarter’ by training with low glycogen stores, since this might promote greater stimulation of the training response. However, there is no evidence that a low carbohydrate diet enhances the outcomes of training or provides benefits as a depletion phase prior to carbohydrate loading. In fact, a low carbohydrate diet may even impair performance if carried out for extended periods. If there are benefits to manipulating glycogen stores for some workouts, this is likely to happen as the natural outcome of the periodisation of the high-volume programme of an elite runner.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Price excludes VAT (USA)
Tax calculation will be finalised during checkout.
Ahlborg G, Bergstrom J, Brohult J. Human muscle glycogen content and capacity for prolonged exercise after difference diets. Forsvarsmedicin 1967; 3: 85–99
Sherman WM, Costill DL, Fink WJ, et al. Effect of exercise-diet manipulation on muscle glycogen and its subsequent utilisation during performance. Int J Sports Med 1981; 2: 1148
Bussau VA, Fairchild TJ, Rao A, et al. Carbohydrate loading in human muscle: an improved 1 day protocol. Eur J Appl Physiol 2002; 87: 290–5
Burke L. Middle and long distance running. In: Practical sports nutrition. Champaign (IL): Human Kinetics, 2007: 109–139
Tarnopolsky MA, Zawada C, Richmond LB, et al. Gender differences in carbohydrate loading are related to energy intake. J Appl Physiol 2001; 91: 225–30
Karkson J, Saltin B. Diet, muscle glycogen, and endurance performance. J Appl Physiol 1971; 31: 203–6
Burke LM, Mens B. “Fat adaptation” for athlefic performance: the nail in the coffin? J Appl Physiol 2006; 100 (1): 7–8
Burke LM, Mens B, Ivy JL. Carbohydrates and fat for training and recovery. J Sports Sci 2004; 22: 15–30
Hansen AK, Fischer CP, Plomgaard P, et al. Skeletal muscle adaptation: training twice every second day vs training once daily. J Appl Physiol 2005; 98: 93–9
Achten I, Halson SH, Moseley L, et al. Higher dietary carbohydrate content during intensified running training results in better maintenance of performance and mood state. J Appl Physiol 2004; 96: 133–140
Louise M. Burke is a contracted researcher for Nestec Ltd.
About this article
Cite this article
Burke, L.M. Nutrition Strategies for the Marathon. Sports Med 37, 344–347 (2007). https://doi.org/10.2165/00007256-200737040-00018