If you’re a runner, drinking a protein shake after an exhaustive workout can help protect your bones, reduce your risk of a stress fracture, and help you train multiple times a day. Long, grueling bouts of exercise can be pretty tough on your skeleton.
The reality for the majority of athletes is that endurance and strength capacities decline with age. In general, you’re more likely to have decreased cardiac output, increased resting heart rate, and a diminished heart function.
Athletes seeking to increase strength or muscle tone need to prime their bodies with cellular energy and increase nutrient delivery prior to training. They need to trigger muscle protein synthesis after training, and, an hour or two before training they should consume a moderate meal of carbohydrate, protein, and fat depending on digestion and comfort.