In my previous article, I spoke about the effects of exercise on aging, the second part of this series on aging deals with nutrition, focusing on protein intake. A brief protein review tells us it is one of three macronutrients essential to our diets, it provides 4 kcal/g of energy, and protein is composed of amino acid chains. There are over 300 in nature but, only 20 of them are essential building blocks of bodily proteins.

Exercise potentiates the anabolic window effect of protein intake, heightening the magnitude and duration of the response[1]. In other words, activity, in combination with protein intake, increases muscle growth. A slight delay in muscle protein synthesis happens before a dramatic increase between 45 – 150 minutes post workout1. Ingesting complete protein sources provides maximum benefit.

Animal-based proteins are complete, meaning they have all 20 essential amino acids (EAA). Vegetable-based proteins are incomplete, meaning you will have to combine different vegetables to create a complete amino acid profile.

The one essential amino acid you should pay particular attention to is leucine. Leucine is a branched-chain amino acid (BCAA) that a lot of research has shown to regulate muscle mass. Research has shown that a 2 g oral dose of leucine is necessary to attain the threshold in young, healthy people1. Leucine requirements are more significant in older populations. As we age, muscles become desensitized to EAA. Older adults require approximately double the amount of leucine compared to their younger counterparts to initiate muscle protein synthesis1.

The key to mitigating muscle loss as we age is a combination of resistance training and nutrient intake, emphasizing increased protein intake.

Connect with one of our Exercise Specialists to set up a strength program to help you with strength training or try our Older Adult classes.

Read the previous article in this series Don’t Sit as You Age, Lift

by Kyle Dunlop

Kyle Dunlop holds a Bachelor of Kinesiology and is certified with the Canadian Society for Exercise Physiology and National Strength and Conditioning Association as a Certified Exercise Physiologist and Strength and Conditioning Specialist. He specializes in strength, power training, and teaching fundamental movements to individuals and athletes to reduce injury.

[1] Brad Schoenfeld. “Science and development of muscle hypertrophy”, p. 141-144. 2016.