Visit a gym regularly and you’re bound to hear a conversation like, “I just started my new whey protein shake. He says one scoop after practice in the tub, but I take two just to be sure.
Until now, sports nutritionists would have said you were wasting your money. All research has indicated that you only need one scoop (20g-25g) of high quality protein whey or egg white to maximize the growth effects of resistance training. Taking more seemed to offer little or no additional benefit. This is why the recommended dose on the tub is usually one scoop per workout.
But recent work from our laboratory reveals the opposite. This raises the need for a major shift in sports nutrition recommendations. For many people, it seems like the logic of the gym isn’t so wrong after all.
The links between protein and resistance exercise are complicated. It is becoming increasingly clear, however, that an amino acid found in higher levels in higher quality proteins called leucine is intimately linked to bodybuilding – or even the key amino acid in the process. The superiority of whey over soy as a muscle-building protein has been assigned to its leucine content, for example.
On the question of the right dose of protein, we already knew that age is relevant. The results to date all relate to healthy young adults. No such maximum protein response has been noted in the elderly. Some research suggests the optimal dose for older people might be 40g or maybe even more – double the amount needed for younger people, in other words. Certainly, in the rested state, we know that older adults need at least double the protein dose that young adults need to maximize muscle building through food.
Unique size?
We looked at two other factors whose effect on the optimal dose of protein after a workout has never been clear: the amount of muscle the individual has and the amount of muscle exercised. In other words, does a 90 kg rugby player need the same post-workout protein intake as a 60 kg boxer? And will the rugby player need more protein if he works his whole body rather than just his legs?
Believe it or not, these questions had never been tested empirically. Post-workout protein recommendations come primarily of of them studies resistance-trained young men with a similar body mass (80 kg to 85 kg) working only one part of the body (legs).
Instead of research findings, recommending 20-25g for all healthy young adults has been a simple try to take into account possible variations from person to person – without even acknowledging that many athletes perform full body workouts in the real world. Rightly, this unique approach has been interrogates by many in the business.
For our study, we recruited two groups of male lifters, one with 65 kg or less of muscle mass and one with 70 kg or more. We assessed the muscle-building response after a full-body weightlifting routine.
What we found goes against a commonly accepted paradigm in sports nutrition. We showed that 40g of protein consumed post-workout was more effective than 20g of protein in stimulating the muscle growth response.
It had nothing to do with the height of our participants, which made no difference to their protein needs. It seems that the amount of muscle you work in a single session is more important for the optimal post-workout protein dose than the absolute amount of muscle you have – although it’s important to point out that we didn’t not explicitly tested this question.
Although our data will require further validation, the results suggest that the recommended protein intake will depend in the future on the nature of previous training – according to the lines in the graph below:
It should also be pointed out that the American College of Sports Medicinethe largest exercise science organization in the world, specifically recommended older people perform full-body resistance exercises.
If our findings hold true for older adults, it may mean they need to take even higher doses of protein to reach optimal levels. Still, this might not be feasible for practical reasons – for example, you would need to consume about two chicken breasts or about a liter of a thick shake to get 60g of protein. So, instead of leading to changes in nutrition, follow-up research may lead to recommending that older adults switch from a full-body routine to a split routine to maximize their muscle potential.
