When faced with questions around meal timings with workouts, it’s important to reiterate that when you eat is far less impactful on your nutrition and health status than what you eat. For that reason, these types of queries make for a good opportunity to discuss getting the fundamentals right, before sweating the small stuff. But, if your client is particularly performance focused, then it’s great to be armed with the research in the area.
“When and what should I eat before my workout?”
When we start working out our muscles will begin to burn the stored energy (typically glucose or fat) in our bloodstream, muscles, liver and fat cells. More or less in that order. So before you workout, the goal is to make sure you’ve actually got enough of these fuels available.
A good rule of thumb for performance is that for higher intensity workouts (whether that’s in terms of effort or duration) we need to ensure we’re topped up with carbohydrates, whereas for lower and slower workouts, fats could help too. The reason being that stored and circulating glucose from carbohydrates can be easily broken down to create energy – but we only store a finite amount. Whereas fatty acids require quite a bit of energy and oxygen to be broken down, but, our fat stores are unlikely to run out (1,2).
So how can we make sure that your clients blood stream, muscles and liver have enough circulating or stored glucose before the workout begins? For amateur athletes, this could be easily achieved through a few days of eating and rest, but for those working out at a high intensity most days or multiple times a day, a pre workout higher carb meal or snack may help performance (2). This could be along the lines of toast with honey, or ½ a cup of muesli – both around 45g of carbohydrate. Whilst protein before a workout is unlikely to help performance, it marks yet another good opportunity to get in a little extra protein in your day – so no harm in it!
“When and what should I eat after my workout?”
During a workout we damage and work our muscles, therefore after a workout, for most the goal is to replace and rebuild. Put simply, carbohydrates help to replenish and top up the stored glucose our muscles have burnt, and then protein then helps to repair and rebuild the muscle. Notably, if we just eat protein post workout (which I see many doing with plain protein shake and not much else!) – a portion of this protein seems to be used to just replace the energy we’ve burnt in the workout (2,5) not what we’re trying to achieve if the goal is muscle building.
Let’s start with timing, does that matter? The evidence suggests that the answer depends on the intensity of exercise but there are still a few tidbits to keep in mind. You can think about post workout nutrition in two phases, the replace phase, and then the rebuild phase.
During the replace phase, thanks to metabolic effects of exercise, 1-2 hours after a workout our muscles are particularly well equipped to take on carbohydrates (3,4). Therefore, consider aiming to replace carbohydrates within an hour or two of exercising to make the most of your freshly sensitive muscles. There is a difference of opinion on whether or not eating protein with your carbohydrates here will help to replenish the muscle, some saying it might (5,6) others saying it won’t (9,10).
What is certain is that protein does play a significant role in the rebuild phase of recovery but whether or not there is an ideal “window” of time to eat protein remains unsolved (2). For amateur athletes the main priority should be to get enough protein over the next 24 hours – rather than only focusing on straight after the workout. With all the above in mind, window or not I still recommend a mostly carbohydrate rich but also protein containing snack or meal post workout as it’s just another fantastic opportunity to add protein to your day. To ensure you’re fuelling up post workout some find it helpful to time your workout to end with breakfast, lunch, or dinner.
So how much carbohydrate and protein do you need after your workout? Experts suggest about 1-2g of carbohydrate per kilogram of body weight per hour of exercise (4,7,8) and about 20-35g of protein (5). In truth, the exact ratio of carbs to protein to aim for after a workout is up for debate, but the general advice is at least more carbs than protein, possibly in a ratio of 3g carbs to 1g protein (3,5). Of course, the overall amount of food will mostly depend on the intensity of the session, the goal, and the calorie and protein needs of the athlete.
- Burke, L. M. (2015). Re-examining high-fat diets for sports performance: did we call the ‘nail in the coffin’too soon?. Sports medicine, 45(1), 33-49.
- Arent SM, Cintineo HP, McFadden BA, Chandler AJ, Arent MA. Nutrient Timing: A Garage Door of Opportunity? Nutrients. 2020; 12(7):1948. https://doi.org/10.3390/nu12071948
- Ivy, J. L., & Ferguson-Stegall, L. M. (2014). Nutrient timing: the means to improved exercise performance, recovery, and training adaptation. American journal of lifestyle medicine, 8(4), 246-259.
- Beelen, M., Burke, L. M., Gibala, M. J., & Van Loon, L. J. (2010). Nutritional strategies to promote postexercise recovery. International journal of sport nutrition and exercise metabolism, 20(6), 515-532.
- Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement: nutrition and athletic performance. Med Sci Sports Exerc. 2016;48(3):543–68.
- Schoenfeld, B. J., Aragon, A. A., & Krieger, J. W. (2013). The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. Journal of the International Society of Sports Nutrition, 10(1), 53.
- Burke, L. M. (2010). Fueling strategies to optimize performance: training high or training low?. Scandinavian journal of medicine & science in sports, 20, 48-58.
- Alghannam, A. F., Gonzalez, J. T., & Betts, J. A. (2018). Restoration of muscle glycogen and functional capacity: role of post-exercise carbohydrate and protein co-ingestion. Nutrients, 10(2), 253.
- Moore, D. R. (2019). Maximizing post-exercise anabolism: the case for relative protein intakes. Frontiers in nutrition, 147.
- Hawley, J. A., Tipton, K. D., & Millard-Stafford, M. L. (2006). Promoting training adaptations through nutritional interventions. Journal of sports sciences, 24(07), 709-721.
