As discussed in a previous blog, recovery is a broad term that refers to restoration of performance capacity. After a workout you are fatigued and performance capacity is down. In the hours and days after the workout you “recover” and performance capacity returns to normal (and can even become better). The time course of this process depends on many factors including - of course - how hard the workout was. This blog will give a very brief overview of what is important for rapid recovery from a nutrition point of view. Rapid recovery here is defined as the 1-6 hours after exercise.
Acute recovery (first 6 hours)
When we only have a few hours to recover before our next performance and we want to be as prepared as possible there are a number of methods we can use to optimize recovery in the available time frame. Nutrition plays an important role but there are also other methods such as cold water immersion (ice bath), contrast water therapy (intermittent cold water and hot water, usually 1 min each for about 15 min), massage, stretching and wearing compression garments. There is also a large psychological component that needs to be addressed in an appropriate way to make sure another good performance can be delivered a few hours later. Some methods have more evidence than others but it is beyond the scope of this blog post to discuss those methods. Here we will focus on nutrition.
During the exercise bout the athlete may have become dehydrated, may have become glycogen depleted, and may have become sore. Nutritional strategies may tackle any of these issues. We will discuss these issues briefly here and then we will discuss the role of protein in more detail in the next blog.
It is recommended to start exercise in a state of euhydration (sufficient fluids, not too much, not too little). The best measure of this is probably body weight. If you have regular body weight measurements over a longer period of time you will know what a normal hydrated weight is. In order to achieve hydration after exercise, it is often recommended to ingest 150% of the fluids you lost in the 5 hours following exercise. In other words you would need to drink 600ml/h (20 floz) (for 5 hours) for every 2 kg (4.4lbs) (you lost). This recommendation is based on the fact that if you drink fluids rapidly this will stimulate urine production and not all of the fluid is retained. Adding sodium can also help retention. This sodium can come from a drink or the foods that you would eat in the hours after exercise. Such an aggressive hydration strategy is only needed when large amounts of fluids are lost and there is another workout lined up a few hours later. In weight category sports with a weigh-in such strategies can be crucial.
During most activities both muscle and liver glycogen are used. Glycogen stores are important because below a critical level, they are related to impaired performance, especially at higher intensities. In a 2h window very little muscle glycogen is resynthesized. This is because ingested carbohydrate is preferentially stored in the liver. When glucose is absorbed, it will enter the liver first and can be stored or passed on to other tissues. Initially it will be mostly stored and as liver glycogen stores fill up more glucose is passed on for other tissues (the muscle).
The process of complete muscle glycogen synthesis will take 24 hours and sometimes longer, especially when there is muscle damage or carbohydrate intake is modest. Within a 4-6 hour window carbohydrate ingestion can results in significant elevations in muscle glycogen and in a number of studies (not all) this has resulted in better endurance performance in the second exercise bout. To achieve muscle glycogen synthesis carbohydrate intake is critical. The advice is usually 1.2 g/kg/h for 3-4 hours post exercise to maximize glycogen synthesis.
There are a number of proposed strategies to reduce muscle soreness. There are suggestions that antioxidants can help, tart cherry juice has been proposed as a strategy and protein has been suggested as well. There is some evidence for all of these. However, as discussed in a previous blog, ingesting large amounts of these may actually interfere with training adaptation. So this is a strategy that should be used only when there is a focus on rapid recovery and this is far more important than long term adaptation. A tournament with multiple rounds, or a race with more than 1 stage in a day are examples.
What about protein?
So far the number 1 recovery ingredient hasn’t really featured, yet we have discussed the most important strategies for recovery. Is there a role for protein? Find out in the next blog where experts Dr James Betts from the University of Bath and Professor Stuart Phillips from McMaster University will share their views as well.