Frequent, consistent physical activity, together with proper nutrition, is one of the cornerstones for staying healthy and reducing the risk of many diseases. But many wonder what the nutritional needs really are for those who practice physical activity, and whether they need to follow special diets.
In this regard, the first thing to consider is the extent, in terms of intensity, frequency and duration, of the physical activity that is performed. If the athletic lifestyle in question is very intense, demanding long and intense daily workouts, it will be necessary to follow an appropriate diet. Not surprisingly, athletes often have a dietician or nutritionist when their sport is at a competitive level. In other less intense cases, the level of physical activity is usually not high enough to warrant the need for change in one’s diet because there is no real increase in requirements. Indeed, particularly if the motivation for physical activity is (also) to lose weight, individuals must be careful not to fall into the usual “I did some exercise, therefore I can eat more” trap, because the calories burned are usually lower than what we think.
For those who practice physical activity, the most important thing is to replenish the water lost, and also to drink before, during and after the sport. In cases of profuse sweating, a reintegration of minerals, in particular potassium and magnesium, may also be necessary. However, replenishing sodium levels is not needed. It is true that we have lost some of this through sweat, but there is too much of it in our diet anyway, so these losses will not give us problems anyway!
As for macronutrients, a slight increase in protein content may be necessary if we often do intense physical activity, but without going over the top, and without increasing the presence of red meat and salami in the diet. Remember that it is not the amount of dietary protein that “builds muscles”, but training.
For carbohydrates, starches are still the recommended choice (like bread, pasta, potatoes) over sugars, just as for fats an athlete must choose unsaturated (vegetable oils) over saturated (animal fats).
Regarding vitamins, it is good to keep an eye out for foods with antioxidant properties (vitamins A, E and C), because intense physical activity brings us into a state of oxidative stress, and therefore it is good to have our defences ready with the help of these vitamins.
Finally, never do physical activity immediately after a “heavy” meal because you won’t have finished digesting, but similarly, don’t do it on an empty stomach either: in both cases your muscular system will not respond with full efficiency.
Department of Agricultural and Food Sciences,
University of Bologna