What are the protein intake demands for recreational athletes and their goals?

11 Apr

We all know that eating protein can help you lose body fat and increase your fat-free-mass. But research has also shown that a high-protein diet can reduce food cravings, help you eat less, improve your recovery, balance your hormones, reduce inflammation, regulate your metabolism, and reduce impulsivity.

We have made the mistake of thinking we only need 50-60grams of protein per day for far too long. When scientists first started focusing on protein intake, they looked at the amount of protein we human need to prevent malnutrition. The recommended dietary allowances (RDA’s) were formed on the minimum amount of protein we need to survive, but not what we need to recover, build and maintain fat-free mass, increase strength and power, lose body fat thrive.

Thankfully, protein discussions among health and fitness circles began to centre around health, performance, recovery, hormones, and body composition. Instead of focusing on the minimum amount of protein we needed to not be malnourished, we started asking, “How much protein is required to stay strong, healthy and active while also looking good naked?”

Before we get into the research on the protein intake demands for recreational athletes and their goals, it's important to understand:

Protein intake alone is not going to keep you healthy, strong and active without the support of physical exercises. You can certainly improve your health and energy levels by changing your diet, but your diet is only one aspect of The 5-Pillars of Sustainable Health.
Your digestive health is critical to both your physical and mental performance. Recreational athletes with poor digestive health must focus on improving their digestion as the number one priority. One of my teachers, Charles Poliquin, would always say, "fix the gut first."

Thanks to the effort of countless scientists (and gym rats), we landed on three important findings:

Consume 30 grams of quality protein every four hours. To maximise protein syntheses, recreational athletes need to eat roughly 30g of high-quality protein every four hours. This is an approximation of the amount of protein needed to meet the leucine threshold. Plant sources of protein are lower in leucine, which means you will require a larger amount of total protein to get the same effect.
Increase total protein intake by supplementing with BCAA's. Essential free form amino acids (such as BCAA's) can be consumed two hours after meals to further enhance muscle protein synthesis signalling. If you're going to supplement with BCAA's, you must also supplement with vitamin-B6 as the body uses BCAA's and B6 to make energy. This isn't a bad thing, but it can deplete your B6 levels, which can affect the nervous system and sleep quality.
Eat protein post-workout. You can strengthen the body's muscle-building signalling after your workout and speed up recovery by consuming protein shortly after your workout.

These recommendations are an excellent starting place for most recreational athletes, no matter their sport. These basic can often create the health and performance benefits that most recreational athletes are looking for. However, if the results from these basic steps do not deliver the results you are looking for, you may need to experiment further.

My regular readers will know that many different variables have a key role to play when it comes to calculating an individuals macronutrient requirements. Your age, gender, height, weight, body type, physical activity levels, energy system demands of training/sport, stress levels, health status, and goals are important variables that can impact your nutritional needs. Using a cookie-cutter formula that calculates macronutrients based on age, height, weight and physical activity level is not always going to be enough.

In this post, I want to discuss the recommended protein requirements for the different energy system demands of training and sport. In an earlier post, I wrote about recreational athletes body types and energy system demands. "The energy demands of running a marathon, sprinting 200m, playing a team sport, or Olympic lifting are all very different. The body type of the athletes and the energy system demands of their sport is different, and so are nutritional demands. "

Protein intake needs will depend on the type of physical activity and the goals of the recreational athlete.

Endurance Athletes Protein Requirements

The protein requirements for endurance athletes will vary depending upon training volume, frequency, and intensity. [1] Multiple studies have reported protein intakes of 0.94g per Kg, 0.86g per Kg, and 1.0g per Kg as being inadequate. [3,4,5] No surprise, as these numbers are below the adjusted RDA of 1.2g per Kg. These protein intakes resulted in a negative protein balance following endurance exercise. This means the body will have a hard time recovering from training, and there is a high chance of fat-free-mass breakdown.

A small number of additional studies has examined the protein needs of an elite endurance athlete. One such study found that 1.6g per Kg was needed in six elite endurance athletes [7]. Another study found a protein intake range of 1.5-1.8g per Kg was optimal within a Tour de France simulation [8].

If you are a recreational endurance athlete, you should experiment with a daily protein intake somewhere between 1.5-1.8g per Kg of body weight.

Higher protein intake for endurance athletes may help reduce physiological stress and declines in performance commonly seen during blocks of high-intensity training [9]. As the training intensity increases, the level of stress placed on the body increases, and we know that higher levels of stress require a higher protein intake.

Strength and Power Athletes

As with endurance athletes, multiple factors impact protein balance and protein requirements for strength/power athletes; however, training history and training status significantly impact the efficiency with which the body processes protein. [11, 15]

Resistance training increases both the rate of muscle protein synthesis and fat-free-mass breakdown. [10,11] Regular resistance exercise and adequate protein ingestion result in a positive protein balance that can increase lean body mass and decrease body fat. [7]

Regular resistance exercise is also a source of stress and trauma that requires greater protein availability to recover. [12] This suggests that recreational strength/power athletes have an increased requirement of dietary protein when compared to the needs of sedentary individuals. [7,13,12] No real surprise there.

A meta-analysis involving 680 participants across 22 published studies has also demonstrated a positive impact of protein intake on improvements in fat-free-mass and leg strength compared to a placebo in young and old populations. [14]

Antonio et al. conducted several studies with protein levels as high as 4.4g per Kg of bodyweight. In 2014, an 8-week study was conducted with well-trained subjects. [17] Subjects were divided into two groups: 1.8g per Kg vs. 4.4g per Kg protein. The study resulted in no change in training volume, body weight, fat mass, fat-free mass, or percent body fat between groups (there was a change in these scores, but no significant difference between them). Interestingly, the 4.4g per Kg group consumed on average an extra 800 calories per day for the 8 weeks, yet they maintained the same body composition as the group with lower calories. This really makes you wonder, do calories really matter?

Antonio's next study in 2015 compared a high protein intake group (2.3g per Kg) to a very height protein intake group (3.4g per Kg) in 48 well-trained subjects. [18] The subjects in both groups were put on a periodised split routine for the 8-week period. The very high protein intake group lost an average of 1.6kg of body fat mass (2.4% body fat), while the high protein group lost 0.3kg of body fat mass (0.6% body fat). The very high protein group consumed more calories than the high protein group (2614 vs. 2119 calories). The fat-free-mass gain was the same between groups. Let's repeat that the group who ate more food lost more body fat. Isn't this the total opposite of the mainstream health and fitness advice to "eat less and move more?"

This study showed that a diet high in protein and high in calories led to the same fat-free-mass gains and greater body fat reduction.

A 2018 study did a systematic review, meta-analysis, and meta-regression on protein supplementation effects on resistance training adaptations. [16] Data from the review, including 49 previous studies and 1863 participants, showed that protein intake significantly improved fat-free-mass gains and maximal strength. The authors also noted that a protein intake higher than 1.62g per Kg showed no further improvements in fat-free mass gain.

Although 1.6-2.0g per Kg protein amount will maximise muscle protein synthesis, there is evidence that going even higher to 3.4g per Kg or even 4.4g per Kg could allow high-calorie intake and lead to a decrease in fat mass. We don’t have research to explain the mechanisms behind the fat reduction, but Antonio et al. hypothesised that protein foods' higher thermic effect could be the cause. Protein takes more energy (calories) to digest.

If you are a recreational athlete in a strength and power sport, you need to take your body composition, health status and goals into consideration:

If you have body fat to lose, you could experiment with a protein intake between 3.4-4.4g per kg of body weight per day.
If you are looking to gain and maintain your fat-free-mass, you could experiment with a protein intake between 1.6-2.0g per Kg of body weight per day.

These recommendations are only guidelines as they are based on recreational athletes' training goals, and they do not consider other lifestyle factors. Two recreational athletes with the same body types, body composition and training goals may not see the same outcomes if their daily stress levels are different or if one works a physically active job and the other one sits at a desk all day. As mentioned at the beginning of this article, gut health also has a critical role to play.

Should Recreational Athletes Be Restricting Calories to lose fat?

Increased protein intake is often seen as beneficial when wanting to gain fat-free-mass when a recreational athlete wants to decrease body fat, and increased protein intake is even more critical.

20 healthy male athletes were split into two groups that followed a 2-week diet with a 40% reduction in caloric intake, ingesting either 1.0g per Kg or 2.3g per Kg of protein per day. [19] They found that the higher protein dieters lost significantly less fat-free-mass, and both groups lost similar amounts of body fat and performed similarly in all physical tasks assessed. However, if the study had gone for longer, it would have been interesting to see the fat loss difference. I expect the high protein group would have lost more fat because they maintain a bigger furnace.

A separate study also compared two diets differing in protein intakes alongside a steady-state endurance exercise programme. [20] The participants were split into diet groups ingesting either 0.8g per Kg, 1.6g per Kg, or 2.4g per Kg of protein per day. Following the 21-week intervention, the two groups that consumed the higher amounts of protein (1.6g per Kg and 2.4g per Kg) lost the largest body fat and the least amount of fat-free-mass.

A more recent study conducted in 2016 had participants ingest either 1.2g per Kg or 2.4g per Kg alongside an intense 6 days per week exercise programme. [21] Following 8 weeks, those in the higher protein group were able to gain more fat-free-mass and decrease fat mass simultaneously.

Lastly, a 2015 study took 48 healthy resistance-trained men and women and split them into a normal protein group (2.3g per Kg) and a high protein group(3.4g per Kg). [29] The study lasted 8-weeks, and all participants followed a heavy split routine resistance program five days per week. The high protein group was also on a surplus of total calories.

The high protein group lost more fat mass and improved their body composition. Both groups gained strength, improved the vertical jump and the total number of pull-ups. The study concluded, "consuming a high protein diet (3.4 g per Kg) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition." [29]

If you are a recreational athlete looking to lose body fat and improve your body composition, you should experiment with a daily protein intake somewhere between 3.4-4.4g per Kg of body weight.

Isn't a high protein diet bad for your kidneys?

There is a misconception that a high protein diet is bad for our kidneys and bones. In 2018, Antonio et al. conducted a case study over 2 years on 5 well trained male bodybuilders and monitored liver and kidney function. [29]

Protein intakes on average were 3.2g per Kg in the first year and 3.5g per Kg in the second year of the study. They found no abnormal liver or kidney function.

Antonio et al. investigated bone health in women and followed two groups of women for 6 months. [30] There was no change in bone mineral density or bone mass between the group that consumed 1.5g per Kg vs. the group consumed 2.8g per Kg per day. Protein amounts around the 3g per Kg mark are safe on kidneys and bones in healthy subjects.

Protein is an incredible part of our diet that has far-reaching effects on our ability to build lean muscle and hormones that regulate our metabolism and body composition. In my experience, 99% of people are not eating enough quality protein to reach their health and fitness goals. There are many misconceptions around animal protein, and it's a very controversial topic for a lot of people. But, when it comes to staying healthy, strong and active, I believe a high-protein diet is essential.

Most recreational athletes' easiest place to start is by eating 30 grams of high-quality protein at each meal, especially breakfast. This will create a solid physiological foundation for a healthy, strong and active high-performance body.

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