Optimal nutritional strategies to promote recovery has always been a hotly discussed topic amongst sports scientists.
Some more traditional approaches to eating and recovery often focus on the requirement to replenish muscle glycogen stores and promote rehydration with both aims typically achieved by consuming high-carbohydrate meals and recovery drinks, as well as electrolyte drinks.
Why you should consider fuelling with protein
Although this approach (eating and drinking high-carb food and drinks) is relevant for replenishing energy stores, it's often the failure to consume dietary protein in close proximity to the training session that impairs training adaptation. A lack of protein intake upon the cessation of ‘evening’ and ‘night-time’ training sessions may be particularly problematic given that our muscles are naturally deprived of nutrient intake during the fasting period associated with sleeping.
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This issue is especially relevant for runners given that it is common practice for many club runners to perform intense track and interval sessions in the late evening period. For this reason, ensuring a sufficient intake of protein prior to sleeping may enhance overnight recovery, reduce muscle soreness and enhance training adaptation thereby allowing us to feel refreshed and more ready to train on the subsequent day.
Although protein is often considered essential for athletes involved in weight training in order to promote muscle growth, it is my experience in working with endurance athletes that the function of dietary protein is not well understood. Indeed, proteins have a variety of functions that far extend beyond the mere requirement to build muscle. In the context of the endurance athlete, proteins not only give our muscles the basic structure they need to perform but also provide the building blocks to make the many thousands of enzymes that are required in order to provide energy from the breakdown of carbohydrates and fat.
The stress of every training session causes our muscle protein stores to actually break down (referred to as protein degradation) which, of course, can be detrimental to training adaptation. Thankfully, in the presence of adequate protein feeding, the combined effects of exercise and protein ingestion result in the formation of new proteins being made (referred to as protein synthesis) such that we can better withstand the physical demands associated with the next training session. It is these repeated changes in protein synthesis in response to every training session that forms the basis of how our muscles adapt and recondition to the demands of heavy training. In order for such optimal training adaptation to occur, it is therefore essential that protein is ingested in close proximity to the exercise stimulus given that protein-rich foods and supplements contain the key amino acids that are used as the building blocks to make new proteins in our muscles.
What happens if you don't eat protein after a run?
As alluded to earlier, the failure to consume protein after a late-night training session as well as prior to sleeping can be especially detrimental to inducing protein synthesis during overnight recovery. Indeed, research from Prof Luc Van Loon has demonstrated that consuming carbohydrates (60 g) and protein (20 g) immediately after a late night training session (9 pm) as well as protein (40 g) prior to sleep (11:30 pm) is sufficient to increase overnight rates of muscle protein synthesis compared to when no protein is consumed prior to sleep, thus having beneficial implications for recovery.
In the context of overnight recovery, it may also be more beneficial to consume a casein-based protein (as opposed to whey) given its slower rate of absorption which can therefore provide a ‘sustained’ supply of amino acids to the muscle overnight. Long-term training studies are now required to investigate the effects of chronic protein feeding prior to sleeping on training adaptation and subsequent performance.
Why you shouldn't neglect your sleep
In addition to overnight protein synthesis, optimal overnight recovery should also focus on the requirement to ensure sufficient sleep itself. The late Prof Tom Reilly from Liverpool John Moores University repeatedly studied the negative effects of sleep deprivation on both physical and cognitive performance. As such, an emerging area of research is the ability of nutritional interventions to improve sleep quality. In this regard, accumulating data suggest a daily diet higher in protein and lower in fat as well as post-exercise carbohydrate ingestion and ingestion of tryptophan prior to sleep are collectively showing promise.
Optimal post-race nutrition:
When taken together, it is therefore suggested that for athletes with no body composition issues, an evening training session is supported with an immediate post-exercise intake of carbohydrates, protein and fluid so as to promote muscle glycogen re-synthesis, protein synthesis and rehydration in the early recovery period. Additionally, ingestion of 30-40 g of casein-based protein with additional tryptophan (approx 1 g) can also enhance overnight muscle protein synthesis and improve sleep quality.
