Nutrient Timing In Sports Nutrition
Advanced nutrition strategies for speeding recovery and aiding muscle growth
- Nutrient timing refers to the concept that the timing and content of feeding in-and-around training sessions has a dramatic effect on improvements in muscle mass, body composition and performance
- A new vista in sports nutrition - not just what is eaten, but when it is eaten
- Overwhelming evidence now supports the specific and the strategic use of liquid formulations to provide carbohydrate and protein in precise amounts to support recovery and training adaptations.
Many of the metabolic responses to exercise and training reflect a balance between breakdown (catabolism) and growth/synthesis (anabolism). For instance, the fuel stores in muscle for exercise (mostly in the form of carbohydrate molecules known as glycogen) are, at any given point in time, determined by the breakdown/use during exercise and the recovery/synthesis as a result of a high carbohydrate (CHO) diet or carefully-planned recovery meals. Similarly, the growth of muscle in response to training is now accepted as being determined by an individual’s ability to optimise training and nutrition strategies so that the processes affecting the growth of muscle (known as muscle protein synthesis) exceed the processes causing breakdown of muscle (known as muscle protein degradation) over a prolonged period of time. In recent years, it has become increasingly apparent that carefully choosing when and what is eaten in-and-around training sessions and competition can have a dramatic effect on the metabolic response to that session, recovery from that session and, perhaps most importantly, determine the nature of adaptation to training in terms of body composition.
These observations have led to the concept of “Nutrient Timing” in sports nutrition1. In short, nutrient timing adds another layer of complexity to sports nutrition advice as it is concerned not just with WHAT is eaten, but WHEN it is eaten. The concept is that specifically and strategically manipulating nutrient intakes pre-, during, and post-exercise can optimise the processes of muscle growth, fat burning/body composition and recovery of fuel stores.
The post-exercise ‘window of opportunity’
One of the key factors that explains why nutrient timing can be more effective for bringing about these adaptive changes (compared to nutrition strategies that only rely on addressing overall daily intakes) is a phenomenon known as the post-exercise ‘window of opportunity’. This is a short period of time (0-4 hours) after exercise where anabolic (growth) processes in the body are maximised. This means that the muscles that have worked hard during your training or competition are primed to take-up nutrients and (i) store them for future exercise (i.e. muscle glycogen), or (ii) create new muscle proteins that repair damaged muscle and help to grow muscle. For instance, the rate at which muscle can recover its fuel stores by converting carbohydrate-containing foods into muscle glycogen, or can increase muscle growth processes is markedly reduced if the consumption of a recovery meal is delayed by 2-3 hours2, 3, 4, 5.
The implication here, and the key point about nutrient timing, is that by providing the body with nutrients as soon as possible after exercise, recovery and activation of a variety of processes are optimised (Fig. 1). In fact, beginning that recovery process by drinking a shake either immediately before and/or during your session may provide an added benefit for muscle growth processes3, 6.
Composition of recovery meal and formulations in nutrient timing
Many studies have looked at the composition of the post-exercise recovery meal and its effects on recovery from exercise. To review all these is beyond the scope of this article. In short, in almost all cases, the optimal recovery nutrition strategy is one that combines both a source of carbohydrate and a source of protein, while limiting fat intake. Current studies focus on optimising the ratio between these macronutrients, and the consensus at present based on the most recent International Society of Sports Nutrition and the American College of Sports Medicine position stands7, 8 is that a ratio of CHO-to-protein of 3:1 and 4 or 5:1 are optimal for recovery of CHO stores and muscle protein synthesis, respectively.
The reason such combinations are so effective is that the CHO provides a source of glucose (sugar) in the blood for the recovery of fuel stores, whereas the protein provides a source of amino acids (building blocks of proteins) for the same. The synergistic effect comes from the fact that glucose and amino acids together can stimulate the production of insulin, which in turn acts as a very powerful anabolic hormone to stimulate muscle recovery and growth. The combination of sources of high glycemic index CHO or sugar and fast-digesting protein or amino acids is seen as critical to the ‘perfect’ recovery drink9.
Several studies support the notion that the composition of the recovery meal is critical for adaptation. In a study of almost 400 male US Marine recruits supplemented immediately after exercise each day during the 54 day basic training phase, those receiving a CHO-protein supplement had less muscle soreness and joint problems, fewer infections and medical visits, and less instances of heat exhaustion compared to groups who consumed either a placebo or CHO only supplement10. In men performing 14 weeks of resistance training combined with either 25 g of protein or CHO before and immediately after each training bout, only the protein group showed improvement sin muscle size (15-25%) and performance (vertical jump) in response to training11. These results were replicated in another 10 week training study of almost identical design, and although in this study the CHO group did increase muscle mass and strength, the changes were greater in the protein group12. Finally, another resistance training study (12 weeks) compared the effect of consuming either placebo, 38 g of CHO, 6 g of essential amino acids (EAAs), or a combined CHO (38 g) and EAA (6 g) supplement as a drink during exercise. Although all groups reduced their fat mass by a similar amounts, the CHO+EAA group increased lean body mass (i.e. muscle) to a greater extent than any of the other three groups, whereas either CHO or EAA alone was better than placebo in that context13. This effect was explained by the greater ability of the CHO+EAA supplement to prevent muscle protein breakdown during recovery.
Another key finding in terms of nutrient composition is that a specific subset of amino acids known as the branched chain amino acids (BCAAs), and specifically the BCAA leucine are largely responsible for the effects of protein on stimulating muscle growth processes during recovery14, 15. These amino acids are covered in more detail in our amino acid article, but it is worth noting that even as little as 6 g of BCAAs can be a potent stimulus to muscle growth during recovery14.
Role of nutrient timing in adaptation and recovery - evidence from literature
For recovery of muscle fuel stores, a seminal paper described the effect of delaying the post-exercise recovery meal by 2 hours as resulting in a rate of glycogen synthesis during the two hours after each meal that was 45% lower than consuming the meal immediately after exercise4. In addition, when muscle glycogen was measured 4 hours into recovery, the overall levels were 35% greater in the immediate recovery meal compared to the delayed recovery meal. However, a similar paper that extended these findings to measurements at 8 and 24 hours of recovery found no difference in recovery of fuel stores when feeding was delayed by 2 hours16. In short, for athletes performing intense two-a-day work-outs or in competition where several events take place in one day, timing of the recovery meal so as to avoid delays is extremely important.
The adverse effect of delaying post-exercise feeding has also been shown for muscle growth processes. For instance, having a recovery meal immediately after exercise resulted in three times greater muscle protein synthesis during recovery compared to delaying feeding by 3 hours2. As stated above, drinking a CHO-amino acid combination immediately before and during exercise may add even more benefits in terms of kick-starting muscle growth processes3.
However, these two studies focussed on the recovery processes from exercise in a very short time-period, and only in response to one exercise session – the question must be asked whether these observations on processes of recovery ultimately result in genuine increases in muscle mass or improvements in training adaptation. The short answer is that they do…
An early rodent study where rats were either fed a meal either right after or 4 hours after each resistance exercise session reported that muscle mass was higher (6%) and fat mass was lower (24%) in those fed immediately after 10 weeks of training17. A couple of years later, this principle was first shown in humans, where elderly men undertaking a 12 week resistance training programme consumed a 10 g protein, 7 g CHO, 3 g fat supplement either immediately after or 2 h after each training session. The quad muscle size increased only in the immediately fed group, and gains in leg strength were about 25% greater than the delayed feeding group18. Finally, a 10 week resistance training intervention was performed on two groups of young men whose diets were matched and who consumed an identical CHO-protein-creatine supplement. The difference between the two groups was the timing of consumption: one group took the supplement immediately pre- and post-training, whereas the other group took the supplement at times in the morning and evening away from training. After 10 weeks of training, although both groups improved their strength and increased muscle mass, increases in strength and muscle mass as well as decreases in body fat were greater in the pre/post-timed supplement group6.
In summary, studies on nutrient timing suggest that maximising adaptation to training may lie in the ability to maximise the anabolic (growth and recovery) environment in the post-exercise period. This can be achieved by the appropriate content (a mix of CHO and protein) and timing (immediately before, during and after training). It is possible that gains in strength and some change in muscle mass can still be achieved, but these changes are likely to be smaller in magnitude than those achievable with appropriate nutrient timing strategies1.
Nutrient timing in practice with ROS Nutrition products
While undoubtedly it is possible to obtain CHO-protein combinations using whole foods and meals, given the specificity for meal content and timing for pre, during and post-workout fueling and recovery in the context of nutrient timing, it is advisable to achieve these goals by utilising liquid meal formulations. These offer the advantages of being palatable, have fast digestion and absorption profiles (much faster than whole foods thereby taking advantage of the ‘window of opportunity’), and can incorporate other active ingredients such as leucine, caffeine and creatine among others. At ROS Nutrition, we have applied the latest nutrition guidelines and scientific studies combined with a goal-orientated formulation development process, and our expertise in taste and texture optimisation to offer market-leading nutrient timing and recovery products. Our flagship recovery products are RECOVERACE STRENGTH® and RECOVERACE ENDURANCE® - both of which can be used for consumption immediately before and during training as well as into recovery, consistent with the nutrient timing principles discussed above.
1. RECOVERACE STRENGTH®
RECOVERACE STRENGTH® is a CHO-protein recovery drink designed to be more attuned to the recovery from resistance training and gaining lean muscle mass as opposed to endurance training and recovery of muscle CHO stores of its sister product RECOVERACE ENDURANCE®. RECOVERACE STRENGTH® features an optimal blend of CHO, protein and amino acids to maximise rates of muscle protein synthesis (essential for muscle growth) in order to enhance recovery and promote gains from training. With isomaltulose as the major source of CHO, we provide a recovery product that provides a source of CHO for recovery, but of a low GI that in turn allows for greater rates of fat burning during recovery than other recovery products. This is of particular interest to those individuals looking to maintain low percentage body fat, or in weight category sports where optimizing body composition is a major goal.
1. RECOVERACE ENDURANCE®
RECOVERACE ENDURANCE® is a CHO-protein recovery drink as an optimal blend designed to promote rapid rates of glycogen and protein synthesis to enhance recovery and promote gains from training and competition. Using Vitargo® as the major source of CHO, the 5:1 CHO-to-protein blend is optimal for rapid recovery of fuel stores after exertion.
Apart from our off-the-shelf recovery formulations, athletes may wish to consider making their own bespoke liquid supplement. To this end, we offer a range of protein, amino acid and CHO powder options.
If your goal involves high intakes of BCAAs, a variety of ROS formulations based on these protein powders provide BCAAs in ample amounts such as AlphaMass®, Metamuscle®, Whey TRU®, Casein TRU®, PRO-GSH Whey®, FEMME MEAL®, FEMME SHAPE® RecoverAce Strength® and RecoverAce Endurance®. Plant-protein powders such as hemp, rice and pea protein contain slightly lower concentrations of BCAAs, but have the disadvantage of not providing all EAAs required by the body.
In addition, ISO EAA® and ISO BCAA® are blends of essential and branched-chain amino acids respectively available in 1 g tablet form, with ISO BCAA® also available in a flavoured, powder form.
Finally, CHO CHARGE® and FUEL LOAD® contain designer CHO sources and additional B vitamins that can be used to provide energy in the form of high and low glycemic index respectively depending on your recovery or body composition goal.
For more information on all products, please see the individual product pages for each product.
- 1. Ivy, J. L., Portman, R., Nutrient Timing: The Future of Sports Nutrition; Basic Health Publications, Inc, Laguna Beach, CA 2004.
- 2. Levenhagen DK, Gresham JD, Carlson MG, Maron DJ, Borel MJ, Flakoll PJ (2001) Postexercise nutrient intake timing in humans is critical to recovery of leg glucose and protein homeostasis. Am J Physiol Endocrinol Metab. 280 (6), E982-E993.
- 3. Tipton KD, Rasmussen BB, Miller SL, Wolf SE, Owens-Stovall SK, Petrini BE, Wolfe RR (2001) Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise. Am J Physiol Endocrinol Metab. 281 (2), E197-E206.
- 4. Ivy JL, Katz AL, Cutler CL, Sherman WM, Coyle EF (1988) Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion. J Appl Physiol. 64 (4), 1480-1485.
- 5. Rasmussen BB, Tipton KD, Miller SL, Wolf SE, Wolfe RR (2000) An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J Appl Physiol. 88 (2), 386-392.
- 6. Cribb PJ, Hayes A (2006) Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. Med Sci Sports Exerc. 38 (11), 1918-1925.
- 7. Rodriguez NR, Di Marco NM, Langley S (2009) American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 41 (3), 709-731.
- 8. Kerksick C, Harvey T, Stout J, Campbell B, Wilborn C, Kreider R, Kalman D, Ziegenfuss T, Lopez H, Landis J, Ivy JL, Antonio J (2008) International Society of Sports Nutrition position stand: nutrient timing. J Int Soc Sports Nutr. 5, 17.
- 9. Manninen AH (2006) Hyperinsulinaemia, hyperaminoacidaemia and post-exercise muscle anabolism: the search for the optimal recovery drink. Br J Sports Med. 40 (11), 900-905.
- 10. Flakoll PJ, Judy T, Flinn K, Carr C, Flinn S (2004) Postexercise protein supplementation improves health and muscle soreness during basic military training in Marine recruits. J Appl Physiol. 96 (3), 951-956.
- 11. Andersen LL, Tufekovic G, Zebis MK, Crameri RM, Verlaan G, Kjaer M, Suetta C, Magnusson P, Aagaard P (2005) The effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength. Metabolism. 54 (2), 151-156.
- 12. Willoughby DS, Stout JR, Wilborn CD (2007) Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength. Amino Acids. 32 (4), 467-477.
- 13. Bird SP, Tarpenning KM, Marino FE (2006) Independent and combined effects of liquid carbohydrate/essential amino acid ingestion on hormonal and muscular adaptations following resistance training in untrained men. Eur J Appl Physiol. 97 (2), 225-238.
- 14. Tipton KD, Wolfe RR (2004) Protein and amino acids for athletes. J Sports Sci. 22 (1), 65-79.
- 15. Pasiakos SM, McClung JP (2011) Supplemental dietary leucine and the skeletal muscle anabolic response to essential amino acids. Nutr Rev. 69 (9), 550-557.
- 16. Parkin JA, Carey MF, Martin IK, Stojanovska L, Febbraio MA (1997) Muscle glycogen storage following prolonged exercise: effect of timing of ingestion of high glycemic index food. Med Sci Sports Exerc. 29 (2), 220-224.
- 17. Suzuki M, Doi T, Lee SJ, Okamura K, Shimizu S, Okano G, Sato Y, Shimomura Y, Fushiki T (1999) Effect of meal timing after resistance exercise on hindlimb muscle mass and fat accumulation in trained rats. J Nutr Sci Vitaminol (Tokyo). 45 (4), 401-409.
- 18. Esmarck B, Andersen JL, Olsen S, Richter EA, Mizuno M, Kjaer M (2001) Timing of postexercise protein intake is important for muscle hypertrophy with resistance training in elderly humans. J Physiol. 535 (Pt 1), 301-311.