Carbohydrate in bodybuilding, as well as lipids, are the main sources of energy during exercise and the contribution of each one depends on the intensity and duration of exercise, with carbohydrate being the largest contributor to moderate and high intensity. Carbohydrate is stored in the liver and skeletal muscle in the form of glycogen, mainly used in high intensity exercises, such as bodybuilding aimed at increasing strength, explosion and hypertrophy.
Although recommendation of carbohydrate intake in endurance exercises, both before, during and after exercise, are well established. In resistance training it is less evident, because of Controversial evidence in a considerably smaller amount of studies in relation to endurance. Because of this, carbohydrate intake recommendations should be based on the particularities of resistance training.
Benefits of carbohydrate intake
Usually during resistance exercise there may be depletion of 24-40% of muscle glycogen, this depletion can cause problems in muscle contraction and play a role in fatigue. Glycogenolysis (breakdown of muscle glycogen) in addition to occurring during training, can occur in fasting periods, such as night fasting. However, there is an insignificant depletion of muscle glycogen during the night time (fasting), but the intake of meals with medium and high amount of carbohydrate before bed time increases muscle glycogen stocks by 12-42%.
In addition, carbohydrate intake can increase plasma glucose as a readily available fuel source and transmit signals to regions of the brain related to motivation, reward and motor production.
Relationship between carbohydrate in bodybuilding
The scientific literature investigating the effects of carbohydrate on resistance training shows that their intake does not seem to optimize peak power and maximum strength. However, carbohydrate intake has the potential to improve variables such as the number of total repetitions and the total training volume.
In a meta-analysis of 21 studies entitled
“The Ergogenic Effects of Acute Carbohydrate Feeding on Resistance Resistance Performance: A Systematic Review and Meta-analysis
” showed that carbohydrate intake allows a greater volume of resistance training to be done, being effective for training lasting more than 45 minutes and at least 8 to 10 repetitions. Furthermore, carbohydrate intake was shown to be effective in fasting periods of at least 8 hours or more. Therefore, the ergogenic effect of carbohydrate depends on the duration of training and fasting before exercise. The dose used for recovery of muscle glycogen after fasting would be 1.0 – 1.5 g/kg from 30 minutes to two hours before the activity, and when dosed after exercise or during did not result in performance improvements.
Clinical practice
The ideal is to provide a good carbohydrate intake in the meal, of 1.0 – 1.5g after a period of more than eight hours of fasting, so that much of the muscle glycogen is recovered. And if there is an increase in training sessions, the importance of carbohydrate intake increases, and the dose does not seem to influence the ergogenic effect, but it is important that a sufficient amount is offered to supply signs of hunger.
References:
Study suggestion: Should I restrict carbohydrates to lose weight?
Article: KING, Andrew et al. The ergogenic effects of acute carbohydrate feeding on resistance exercise performance: a systematic review and meta-analysis. Sports Medicine, v. 52, n. 11, p. 2691-2712, 2022. Doi: https://doi.org/10.1007/s40279-022-01716-w
