How to Optimise Your Protein Intake with Exercise
Emily Stynes
ANutr, REGISTERED ASSOCIATED NUTRITIONIST, MSC DIETETICS STUDENT
One of the most frequently asked questions in relation to nutrition and performance is - How can I make sure that I am getting enough protein in my diet?
To ensure that you are getting the most out of your protein intake, there are other factors to consider other than simply recommending a daily protein dose.
In this blog post, I will delve into the 5 key factors to optimise your protein intake with exercise so that you can get the most out of your training!
The Importance of Consuming Protein Alongside Exercise
Consuming protein following resistance training enhances ‘muscle protein synthesis' (MPS) which is a process that enables us to build and repair muscle (1). Protein plays an important role in sports performance as it can reduce muscle soreness during recovery (2). Also, performing exercise increases the ability of your muscles to respond to protein intake, promoting muscle growth and repair (3). Therefore, resistance training and nutrition including optimal protein intake, increases muscle mass and strength through MPS which improves your overall net protein balance (4).
Obtaining adequate muscle mass and strength is not only required for physical activity and athletic performance but also for our metabolic health. This includes a reduced risk of developing chronic diseases such as obesity, cardiovascular disease, insulin resistance, diabetes and osteoporosis (6).
So, below are the 5 key factors to make sure that you get enough protein into your diet and reap the benefits for your training and long-term health.
1. Dosage
As discussed in the previous blog on ‘Should I use protein powders for my health, training and performance? - the general recommendations of protein for most people are 20-25g doses per meal (7). Higher amounts of protein in the range of 30-40g are needed for older people to trigger MPS as well as exercising individuals and those with increased muscle mass to maximise MPS (8)(9).
What is the optimal daily amount of protein required with exercise?
Recent research from a large study concluded that a daily protein intake for an active individual (working out 3-4 times per week) of 1.6 g/kg/day may be the optimal amount of protein to increase muscle mass through enhancements in MPS (10). Therefore, consuming protein at the RDA of 0.8 g/kg/day could be insufficient for those who have the goal of gaining greater strength and fat-free mass with resistance exercise training (10).
2. Timing of Protein Intake
Previous research suggested that protein should be consumed as soon as possible following exercise to enhance MPS (11)(12). This concept is defined as the “anabolic window of opportunity” which is the belief that the response or sensitivity of our muscles to protein will be impaired or disappear if protein is not consumed shortly following exercise (13).
However, the latest research has now shown that our muscles are actually sensitised to the effects of protein and amino acids (building blocks of protein) up to 24 hours after completion of a bout resistance training (14)(15).
So, unless you are training again within the space of 8 hours (for example, a dual workout for athletes), then there is no “set deadline” post-exercise for protein to be ingested to enhance MPS (16).
This means that it is not essential to consume protein immediately after a workout. What is more important is what you consume over those 24 hours. In particular this includes getting a balance between carbohydrate, proteins, fat and energy into your meals.
In terms of consuming protein before exercise, a high protein snack before bed time has been shown to result in increased muscle mass and strength for those who do strength and resistance training (17).
3. Combination of Protein Intake with Other Macronutrients
Protein and Fat
Consuming protein alongside fat may enhance the MPS response following exercise as studies have shown that both whole milk and whole eggs result in greater use of amino acids and MPS in contrast to skimmed milk and egg whites respectively (18)(19).
Protein and Carbohydrates
Previous research conducted in an animal study has suggested that the addition of carbohydrate to protein should be considered post exercise to promote greater muscle strength during prolonged resistance training (20).
However, more recently a study conducted in humans has shown that consuming a combination of protein (whey) and carbohydrate may not lead to greater gains in muscle strength (21). This means that the evidence for consuming protein with carbohydrates to enhance muscle protein synthesis and increase or maintain muscle mass is controversial and weak.
4. Protein Distribution
Spreading the intake of protein evenly throughout your meals in the day has been shown to be more effective for MPS than consuming all of your protein recommendations in one sitting (15). The latest evidence recommends consuming at least 20-25g of protein for the general population with each main meal within no more than 3-4 hours between meals to enhance MPS (22).
As a guide, make sure that you include fairly even sized amounts of protein for each meal such as breakfast, lunch and dinner and include high protein snacks into your diet.
Example of high protein snacks:
· Low-fat Greek yoghurt or plain soya yoghurt
· Hummus with vegetables
· Baked chickpeas
· Nuts and nut butters or you could even try baking your own peanut or almond butter protein balls at home!
5. Protein Quality
The quality of protein in food is determined by the 9 essential amino acids (EEA’S) profile, digestibility and bioavailability (absorption and utilisation in the body) (23). The 9 EEA’s are the building blocks of protein that cannot be made within the body and must be obtained from food.
The two main types of protein sources are animal and plant protein, which differ in quality. Animal proteins are considered ‘complete’ proteins as they contain all 9 EAA’s. You may have heard of mycoprotein which is a fungal protein that is often found in Quorn products that are used as meat substitutes. They are also considered as a ‘complete protein’ which can be suitable for vegans and vegetarians.
Most plant proteins are considered ‘incomplete’ as they lack one or more of the EAA’s and they are less easily digested, absorbed and utilised by the body (24). They also have less leucine, an EAA that is important for MPS (24).
Can I get enough protein in my diet if I am vegan or vegetarian?
Yes, absolutely! If you are on a plant-based diet you can get all the amino acids that you need by combining different plant sources of protein together known as ‘complementary protein feeding’. For example, grains tend to be low in the amino acid lysine and pulses low in the amino acid methionine. So, the classic beans on toast provides a complete amino acid profile! The combination of plant protein sources does not necessarily need to be eaten together in the one meal as they can be consumed throughout the day.
Other ways to ensure that you get enough protein on a plant-based diet includes incorporating a variety of protein sources into your meals to make sure that you are getting a full range of amino acids and by increasing your portion sizes of plant-based proteins.
For athletes who need higher amounts of protein, providing more than one protein source within a meal can be beneficial.
See below for a range of high quality animal (complete) and plant (complete and incomplete) protein sources to incorporate into your diet!
Take Home Message
Overall, optimising your protein intake alongside exercise is not simply based on how much protein you consume in your daily diet. The 5 key dietary factors including dosage, timing, distribution, combination with other macronutrients and quality of protein are all essential to increase or maintain your muscle mass and strength and get the most of your training sessions!
Written by Emily Stynes, ANutr, Registered Associated Nutritionist, MSc Dietetics Student, with contributions from Ciara McNulty, RD and PG in Sports and Exercise Nutrition
References
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