When we take part in strenuous bouts of exercise, the glycogen stores of the exercising muscles become depleted. For this reason, individuals engaged in intense training need to ingest a number of nutrients in order to optimise recovery.
Glycogen restoration is one of the most important goals of post-exercise recovery, as by refueling properly, athletes are able to maximise exercise-induced muscular adaptations. For example, research around fatigue during exercise found that up to 80% of ATP production during resistance training derived from glycolysis. To make the most of these adaptations, and to continue to perform at a high level, knowing how and why we should look to nutritionally refuel is imperative.
The effect of Carbohydrates
The rate of glycogen synthesis is largely dependent on carbohydrate intake. Sufficient consumption of carbohydrates post exercise is, therefore, essential for the restoration of glycogen stores. This amount can differ according to our individual needs; with required amounts fluctuating according to factors such muscle mass composition. For example, it has been suggested that athletes should consume around 1gram of carbohydrates per kilogram of body weight i.e. 80g for an 80kg athlete, to maximise muscle fuel for the next bout of exercise. Here, we should look to tailor our intake to our individual needs and by doing so will be able to get the best out of our post-workout nutrition and recover sufficiently.
Recovery and Timing
Carbohydrates are an important source for skeletal muscle energy provision. Fuel requirements to meet the demands of an athlete’s everyday training schedule are likely to challenge or exceed normal body carbohydrate stores. For this reason, carbohydrate feeding immediately after exercise can be considered as an important strategy to achieve refueling goals. This is because; the consumption of carbohydrates following exercise can provide an immediate source of substrate to the muscle cell to start effective recovery.
The consumption of carbohydrates shortly following exercise is particularly effective when there are short intervals in between training sessions and when athletes are training or competing twice in the same day. Following this strategy, and having a carbohydrate intake of 1.0–1.2 g/kg/h during the early recovery phase (four to six hours) will optimise the resynthesis of muscle glycogen stores.
Form of Carbohydrates
When deciding on the type of carb that you look to consume following the above strategy, high-glycemic carbohydrates are essential. The intake of high-glycemic carbohydrates are rapidly digested and absorbed by the body, which in turn can help to combat tiredness and fatigue as a result of an intense workout. High-glycemic carbohydrates can also create an insulin spike, which helps to move nutrients into your muscle tissue quicker. For example, research shows that as well as glucose, other essential nutrients such as creatine and glutamine are highly dependent on insulin to gain entry into muscle cells and provide benefits. Creatine supplementation is widely recognised by athletes and is often used to increase both power output and lean mass. As we commonly do in nutrition, it is important to not only think of the effect of a nutrient in isolation but how this also fits in with our wider supplementation, to have a combination that will allow us to fuel our bodies to meet the demands of exercise sessions, sporting competitions and everyday tasks that we are involved in.
Consuming liquid forms of nutrients pre, during and post workout in the form of a protein shake is becoming increasingly popular. This is because it can be more practical than a whole-food meal for an on-the-go lifestyle, and in this instance is particularly beneficial as it can provide nutrients that are readily available and allow the processes of recovery to begin immediately following exercise.
Taking all of the above into account, dextrose appears to offer a carb source that is tailored for optimising nutritional recovery. Dextrose rates very high on the glycemic index meaning that it enters our system straightway; resulting in a rapid and comprehensive replenishment of muscle glycogen stores. Along with this, stimulating a high insulin response very quickly. The combination of the above adaptations will allow for the athlete to refuel adequately for the next bout of exercise and continue performing at a high-level.
Carbohydrate & Protein Co-ingestion
Here we have discussed the benefits of consuming carbohydrates, particularly in the period immediately following exercise. Alongside this approach, we should also consider incorporating sources of protein into our post-workout nutrition. Like carbohydrates, protein supports glycogen resynthesis and therefore the combination of protein and carbohydrates can further accelerate muscle glycogen synthesis during post-exercise recovery.
In terms of practicality, blending two macronutrients may provide athletes with a more realistic approach to optimising post-exercise glycogen repletion as opposed to sole large carbohydrate consumption. The mixture of the two macronutrients can also result in elevated insulin levels, the importance of which has been mentioned previously. It also allows the athlete to switch from a net catabolic state into an anabolic one. This will bode well not only for initial recovery but in aiding us to push on and continue to smash PB’s, 1RM’s and sprint times.
Carbohydrates and the “Three R’s”
Resistance and cardiovascular-based training workloads can yield detrimental effects to athletic performance if the athlete is unable to recuperate completely in between training sessions. Therefore, the post-exercise period should be viewed as a time when the “three R’s”, rehydration, refueling and repair of damaged tissues should occur. The intake of a high-glycemic carb source such as dextrose will allow the athlete to meet the glycogen resynthesis threshold by providing an immediate source of substrate to the muscle cell. This, alongside a source of fast absorbing protein i.e. whey isolate ingested shortly following exercise will maximise the anabolic response to training. It is beneficiaries such as this which will allow athletes to maximise exercise-induced muscular adaptations, however, to do so, we need to refuel correctly. Carbohydrates from the outset can be perceived as a nutrient to avoid, but clearly they have their part to play in the recovery process and by matching body carbohydrate stores with the fuel demands of the session, optimal recovery and in turn performance.
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Article by John Keary BA (Hons)- Sport, Exercise & Physical Activity