Essential Recovery for Endurance Athletes

Created On: 16 May 2010

Barry Murray, a Performance Nutritionist based in Loughborough here explains the science and practical application behind recovery for endurance athletes. Barry holds a BSc in Science and an MSc in Sport and Exercise Nutrition from Loughborough University, he also lectures under the Exercise and Fitness programme at Loughborough College.

As a special offer to our readers Barry is keen to answer a few of your questions about his article and recovery for endurance athletes. So if you have a question for Barry please e-mail asktheexpert@trifinder.co.uk  and we will then publish the answers over the coming weeks.

As a Sports Nutritionist, a favorite saying of mine is that "You don't get fitter during training, you get fitter after". The most important part of your nutrition strategy is what you drink/eat during the first few hours after exercise. The reason for this is that all of the physiological changes that take place as a result of training happen mainly post training (ref 1,2). Aerobic and Anaerobic infrastructure are built after training. New muscle fibre tissue is produced after training. Prevention of immune system damage is most prominent post training. Thus, Recovery is not simply "refuelling", there are more complex biochemical processes that take place such as

-         Capillarisation: new capillaries are formed around muscle tissue to increase oxygen delivery and increase removal of waste products

-         Mitochondrial Biogenesis: mitochondria are your energy rooms for the production of ATP. More mitochondria, more energy.

-         Krebs cycle enzymes: The conversion of food to ATP is controlled by enzymes. The more of these you have, the more efficient you become at energy production

-         Protein synthesis: certain exercise type's damages muscle. New muscle fibre tissue is therefore required. Amino acids from protein are not simply only building blocks for muscle. Everything mentioned above, enzymes, mitochondria, capillaries are made from amino acids.

Ok, so it's important to replace some of the "carbs" that you burnt. But in terms of fitness improvements, it is the biological processes above that make you fitter. In order for those changes to take place, the right type and the right amount of nutrients are required after you train. 

How Does it Work?

The highest rates of nutrient uptake occur during the first 30mins after training (3). This is because all the nutrient transport and storage mechanisms become switched on thus increasing the body's absorption rates. The nutrients that are required are glucose (from Carbohydrate) and amino acids (from Proteins).

Carbohydrate functions:

-         Replenish muscle glycogen

-         Spike insulin secretion

-         Reduce cortisol

Protein functions:

-         Reduce muscle damage

-         Build fitness infrastructure

Carbohydrate Type and Amount:

As carbohydrate transport and absorption is essentially "switched on", muscles want a quick supply of carbohydrate.

This should come in the form of high glycaemic index foods (see table below). Low GI foods are not suitable at this time as the time taken to release the glucose from these foods is slow, which defeats the purpose of recovery (4). Fruits and fruit juices should be the preferred option due to a) their simple sugar content b) the antioxidant content and c) their alkalizing effect. Although fruits contain citric acid, they have an alkalizing affect on blood plasma (5). This improves the pH balance and has been shown to reduce bone damage and muscle breakdown. Therefore, while breads, muffins, donuts, chocolate etc do contain simple carbohydrates - they do not offer the same benefits.

Table 1: Carbohydrate Recovery Foods

The amount/quantity of carbohydrate required is based on 1 the duration/intensity of the training session and 2 individual weight. Carbohydrate feeding for the purpose of recovery is not limited to just immediately post exercise but should also be consumed for the remainder of the day. However, glycogen synthesis rates are elevated during the first 2hrs post exercise with the highest rates occurring during the first 45mins post exercise (6). Thus, the majority of your daily carbohydrate intake should be consumed within the first few hours post training

Table 2: Carbohydrate Recovery Quantities

Protein Type and Amount:

Protein degradation is increased post endurance training. Amino acids are required to increase rates of protein synthesis to help form new muscle tissue and to provide the building blocks needed for training adaptations (7). In a similar way to carbohydrate, a fast digesting, easy to absorb type of protein is the most desirable option.

This is determined by the proteins digestion rate and biological value. The biological value is a measure of the proportion of the amino acids contained in the protein that are absorbed and used by the body. Whey protein and chicken have similar biological values; however, the digestion rate of whey protein is faster due to the fact that it is not a solid food. Hence, water soluble powdered protein food types are the preferred source of amino acids immediately post exercise. 

Table 3: Recovery Proteins

The amount/quantity required again depends on 1 intensity/duration of exercise and 2 body weight. Most studies which have looked into protein requirements for athletes have measured only the rates of muscle protein synthesis (8). However, while muscle tissue repair is important following endurance exercise, net muscle growth is not the objective. So, the studies done have not measured the affect of protein ingestion on rates of enzyme production, cappillarization and mitochondrial biogenesis post exercise. Studies have shown that ingestion of protein with carbohydrate improves rates of glycogen synthesis (9). Studies have also shown that markers of muscle damage are reduced when protein drinks are consumed immediately post exercise (10). Therefore, improvements to recovery following endurance exercise have been observed with protein feedings. In addition, there are strong indications that the physiological training adaptations that occur post exercise require amino acids.

Table 4: Protein Recovery Quantities

Reduce Muscle Damage/Immune System Damage

Endurance exercise creates a highly catabolic state (a process where large structural molecules like muscle tissue are broken down into smaller units) (11). This process is driven by a hormonal response to prolonged exercise whose function is to counteract the hypoglycaemic state caused. Carbohydrate, Proteins and Lipids are broken down and converted to energy. The hormone responsible for this - Cortisol, also weakens the immune system and causes inflammation. This leads to two common ailments experienced by endurance athletes - delayed onset of muscle soreness (DOMS) and illness. Although inflammation and cortisol production are part of the adaptation mechanism, it is necessary to control these responses to prevent over-training symptoms such as injury and chronic illness.

To counteract cortisol action and muscle damage, insulin release is required. This prevents breakdown and increases synthesis. As discussed earlier, Insulin is released by the presence of high blood glucose levels provided by High GI carbohydrates. Thus, consuming simple carbohydrates immediately after exercise will help to reduce muscle damage, reduce inflammation and prevent illness.

Another damaging action of endurance exercise is the production of free radicals and reactive oxygen species (ROS). These are produced as a result of oxidative stress caused by the enzymatic reactions that control the production of ATP (12). Free radicals cause cellular damage resulting in inflammation, muscle soreness and injury. The molecules known to disarm these free radicals are called antioxidants. There are literally 100's of different types of antioxidants such as Vitamin C, Vitamin E, polyphenols, bioflavonoids and anthocyanins. Many of these nutrients can be found in fruits such as oranges, apple, banana, grapes and pineapple, to name but a few. Hence, these foods are an essential part of your recovery.

Timing and Putting it all Together

The most critical part of recovery is the first 5-10mins after exercise. The longer you wait to consume carbohydrate and protein, the longer it will take you to recover and benefit from the training adaptations. However, there are different phases of recovery, depending on the exercise. There are specific considerations when choosing post training meals and solid foods. Meals after training should ideally contain the following:

Med - High GI Carbs: to replenish glycogen and help muscle repair e.g. rice, pasta, potato, couscous, noodles

Lean Complete Proteins: to re-build muscle and help training adaptations e.g.  Chicken/Turkey Fillet, fish, Eggs,

Essential Fats: to help muscle repair and bring down inflammation e.g.  Oily Fish, Flaxseed, Walnut, Omega 3 Eggs

Vegetables particularly greens: help repair cell damage and helps to alkalize and balance pH e.g.  Spinach, broccoli, kale, green beans, lettuce, rocket, watercress

Your approach to recovery nutrition should be based on the duration and intensity of the exercise.

Moderate exercise 1-2hrs: immediate recovery (first 5-10mins) and next solid meal (1-2hrs later)

Long exercise >3hrs: immediate recovery, next solid meal, and 2-3 additional feedings throughout the day

Heavy Endurance >5hrs: immediate recovery, then nutrition for the following 24-48hrs needs to be tailored in terms of carbohydrate and protein intake.

The majority of endurance athletes training sessions (particularly triathletes) take approximately 1-3hrs to complete. The recovery plan below (Table 5) is based on a long run (1.5-2hrs) or bike (2.5-3hrs) for a 70Kg athlete:

Table 5: Recovery Plan for 70Kg athlete

Summary:

• Fitness adaptations take place after training
• Rates of absorption and transport of carbohydrates and proteins to muscle cells is increased during the first 0-2hrs post training
• Rates of glycogen synthesis and protein synthesis are increased post training
• Consume High GI carbohydrates and fast digesting proteins immediately after exercise
• Quantify food quantities based on body weight and exercise intensity/duration i.e. 0.5-1.5g CHO/Kg BW and 0.3-0.4g PRO/Kg BW.
• Fruit and/or fruit juices play several key roles and should be an essential part of your recovery
• Recovery after training sessions involves consuming food/drink immediately and 1hr later post exercise
• Nutrition recovery considerations following prolonged endurance exercise are required over a longer timeframe

About the Author:

Barry Murray is a Performance Nutritionist based in Loughborough and runs his own practice - OptimumNutrition4Sport. Barry holds a BSc in Science and an MSc in Sport and Exercise Nutrition from Loughborough University. He also lectures to undergraduates in the Sports, Exercise and Fitness programme at Loughborough College.

Barry works with elite athletes and any individual wanting to improve their general health, well-being and performance. He specialises in nutrition for endurance sports and designs comprehensive nutrition programmes tailored to the individual. He has worked with every level of athlete from beginner to those competing at an international and Olympic standard. He provides one to one consultations and presents seminars to teams, clubs and corporate clients.  See www.optimumnutrition4sport.com/ for further info.

Don't forget if you have a question about this article and how you can apply this knowledge to your training e-mail asktheexpert@trifinder.co.uk

References:

1. John A. Hawley ; Kevin D. Tipton ;Mindy L. Millard-Stafford (2006)Promoting training adaptations through nutritional interventions  Journal of Sports Sciences, Volume24, Issue7,  , pages 709 - 721
2. Coffey, V. G., & Hawley, J. A. (2007). The molecular basis of training adaptation. Sports Medicine, 37, 737 - 763.
3. Berardi, J. M., Price, T. B., Noreen, E. E., & Lemon, P. W.(2006). Post exercise muscle glycogen recovery enhanced with carbohydrate - protein supplement. Medicine and Science in Sports and Exercise, 38, 1106 - 1113.
4. Burke, L. M., Collier, G. R., & Hargreaves, M. (1993). Muscle glycogen storage after prolonged exercise: Effect of the glycaemia index of carbohydrate feedings. Journal of Applied Physiology, 75, 1019 - 1023.
5. Ailsa A. Welch, Angela Mulligan, Sheila A. Bingham and Kay-tee Khaw (2008) Urine pH is an indicator of dietary acid-base load, fruit and vegetables and meat intakes: results from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk population study,British Journal of Nutrition ,99:1335-1343 Cambridge University Press
6. Decombaz, J. (2003). Nutrition and recovery of muscle energy stores after exercise. Sportmedizin und Sporttraumatologie, 51, 31 - 38.
7. Tipton, K. D., &Wolfe, R. R. (2004). Protein and amino acids for athletes. Journal of Sports Sciences, 22, 65 - 79.
8. Borsheim, E., Tipton, K.D., Wolf, S.E. and Wolfe, R.R.(2002). Essential amino acids and muscle protein recovery from resistance exercise. American Journal of Physiology,283, E648-E657.
9. Ivy, J. L., Goforth, H. W., Jr., Damon, B. M., McCauley, T. R., Parsons, E. C., & Price, T. B. (2002). Early post exercise muscle glycogen recovery is enhanced with a carbohydrate -protein supplement. Journal of Applied Physiology, 93, 1337 -1344.
10. Rennie, M.J. and Tipton, K.D. (2000). Protein and amino acid metabolism during and after exercise and the effects of nutrition. Annual Reviews in Nutrition, 20, 457-483.

11. Rodriguez, Nancy R; Vislocky, Lisa M; Gaine, P Courtney. (2007)Dietary protein, endurance exercise, and human skeletal-muscle protein turnover, Current Opinion in Clinical Nutrition and Metabolic Care: Volume 10 - Issue 1 - p 40-45

12. St-Pierre J, Drori S, Uldry M, et al. (2006) Suppression of reactive oxygen species and neurodegeneration by the PGC-1 transcriptional coactivators. Cell 127, 397-408.

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