In Part 1 I established that there’s a benefit in eating more protein than the recommended daily allowance of 0.8 – 0.9 gram per day for general health maintenance. An athlete in regular endurance training should aim for a daily intake of between 1.2 grams and 1.8 grams daily – less when training volume and intensity are low, more when they are high.
If you missed Part 1, you can access it here.
Timing, amount and quality of protein intake are all very important for promoting recovery – and good recovery is essential for being able to maintain high quality training over days and weeks.
The research is sparse when it comes to long term studies on protein intake and endurance athletes. Many studies are carried out over a short time period, often less than a week, in laboratory settings and with elite male athletes. Sometimes it’s just one test done to exhaustion. This is not the same as the months of training required for an ultra-event and carried out by average real world athletes like you and I.
Taking all of that into consideration, I’ve put together these guidelines for you based on the research I’ve looked at:
- Its better to eat some protein with each meal and snack, rather than a large portion at one or two meals. The optimal amount needed in a meal to support the protein synthesis needed for muscle repair is 0.25gm – 0.3gm per kilogram bodyweight, which is approximately 20 – 40 grams. I suggest you aim for 5 – 10 grams in a snack, and up to 30 grams in a meal.
- Protein pacing throughout the day will optimise the way in which your body absorbs and uses protein. It’s thought that the ideal ‘pacing’ is to eat protein every 3 hours – this appears to be the best duration for maximum absorption and synthesis. Eating a smaller amount more often doesn’t improve uptake or recovery. Likewise, eating a larger amount less often is not as effective for muscle repair and recovery.
- Make sure that you have a post training recovery meal if your exercise session was longer than an hour, and especially if it included strength/power or intensity/speed work. Ideally consume this within 30-60 minutes, and no longer than 2 hours after exercise. Your muscles are very efficient and can begin the repair process with carbohydrates only, so you can just have carbohydrates immediately after training. However in that case you should ensure that you have a nutritious meal with both protein and carbohydrates in the next 2 – 3 hours.
- Branch chain amino acids (or BCAAs) are 3 essential amino acids that we must consume from food. They are important for muscle activity, and muscle and bone growth. One of these, leucine, is rapidly used up during endurance exercise. BCAAs are found in all animal proteins. Eggs are a high-quality source. For vegans, the best sources of leucine are legumes – especially soybeans, tofu and tempeh, kidney beans and peanuts.
- While protein powders and bars are convenient, it’s not recommended to rely on them for daily protein intake. Stick to real food as much as possible, as it provides a slower release of proteins during the day, which will improve overall muscle repair and recovery. When it forms part of a meal, protein absorption is slower, and this assists with pacing.
- Over consumption of protein can adversely affect your performance. Your body can only utilise a limited amount – and you don’t want eating more protein to be at the expense of carbohydrate deficiency. This is a cause of diminished performance for some triathletes. Your body can make glucose from fat and protein, but your endurance performance may suffer. A recent study of runners taking an extra 50 grams of protein daily, while training for 10 weeks with progressive load increase, resulted in their time trial performance being worse than the runners who ate normally while following the same training protocol.
- Very few studies have been done on protein intake pre- and during exercise for endurance athletes. However, it may improve performance, and it doesn’t appear to have a negative effect. Ultra-distance events can lead to muscle catabolism, especially when energy levels are low – this is evidenced by an increase in creatine kinase (a muscle damage marker). The International Society of Sports Nutrition recommends taking 0.25gm protein per kilogram bodyweight per hour, with carbohydrate, during exhaustive endurance activity to minimise muscle damage. Another approach would be to take a pre-exercise dose of 0.3gm/kg protein. Be aware that individual gut tolerance can be an issue when adding protein – so this should be well tested in endurance training before using in a key event.
Protein Foods and Amounts
There are plenty of resources where you can check food sources and portion sizes for protein. To help you out here’s a list of some common foods to give you a basic idea.
Protein in animal foods (approximate values):
1 cup yogurt = 12 grams
1 egg = 6 grams
100gm chicken = 22 gram
100gm beef mince = 22 gm
100gm beef sirloin = 28 gm
100gm snapper = 24 gm
Optimal plant protein foods:
Soy bean (including tofu and tempeh), amaranth and quinoa are complete protein sources as they contain the key essential amino acids.
Each of the food items listed below contain approximately 5-6gm protein and have the highest protein per gram in each of the key food groups. For snacks choose 1-2 items, and for main meals choose at least 3 items. Vegans and vegetarians should aim to eat from all these food groups over the course of the day.
1 cup of any of these – asparagus, broccoli, brussel sprouts, corn, mushrooms, silver beet
½ cup cooked any legumes eg. black beans, chickpeas, edamame beans, kidney beans, lentils
¾ cup green peas
|Nuts & Seeds: |
25gm of any of these: almond, cashew, chia, pumpkin, sunflower, sesame
|Grains & Cereals:|
¾ cup cooked of any of these: amaranth, barley, buckwheat, bulgur wheat, oats, quinoa, spelt, wild rice
Note: durum wheat has the highest protein content (14gm per 100gm dry weight) – white rice and pasta only contain 3gm protein per 100gm cooked portion
I used many research sources, including clinical trials. If you’re keen to know more, these key references are a good starting point.
Nutrient timing for peak performance, Heidi Skolnik & Andrea Chernus, Human Kinetics, 2010
Dietary protein requirements and adaptive advantages in athletes, British Journal of Nutrition, Volume 108, Issue S2 August 2012, pp. S158-S167
Restoration of Muscle Glycogen and Functional Capacity: Role of Post-Exercise Carbohydrate and Protein Co-Ingestion, Nutrients. 2018 Feb; 10(2): 253.
Protein Supplementation Throughout 10 Weeks of Progressive Run Training Is Not Beneficial for Time Trial Improvement, Front Nutr. 2018; 5: 97.
International Society of Sports Nutrition Position Stand: protein and exercise, Jnl of the Intl Soc of Sports Nut. Vol 14:20 (2017)
Nutrition and Supplement Update for the Endurance Athlete: Review and Recommendations, Nutrients. 2019 Jun: 11(6): 1289