This is an excerpt from High-Performance Nutrition for Masters Athletes by Lauren Antonucci.
Another important area of interest is decreased mood accompanying a low carbohydrate diet or a state of low carbohydrate availability. Achten and colleagues (2004) studied runners on both high carbohydrate (8.5 g/kg/day) and low-carbohydrate (5.4 g/kg/day) diets and found clear evidence of both better physical performance and improved mood state on the higher carbohydrate diet despite matched total energy intakes on both (i.e., higher fat, higher protein intake to make up for lower carb intake). In addition to improved global mood with adequate total carbohydrate intake, these studies found decreased incidence and reports of fatigue (lower RPE) in athletes, both during exercise and at rest on higher carb diets. They noted that others have studied this and found similar results in swimmers, rowers, cyclists, and runners. Such studies support the idea that training in a low carbohydrate state may play an important role in the development of overreaching in athletes. Knowing this, it is paramount that athletes and those working with them ensure adequate total carbohydrate intake daily in order to reduce risk of overreaching as well as to maintain adequate mood state and performance during training sessions.
In my professional experience, athletes are often surprised when I calculate their individual needs and inform them of their total carbohydrate goals. Because of false notions involving carbohydrate and weight and because of other current societal messaging on carbohydrate, many athletes follow plans that result in molecular level changes but not overall performance advantages, and they are chronically running on less-than-ideal fueling. Especially for Masters athletes, this becomes a long-term health, mood, and performance issue. Thankfully, it is one you can reverse with greater understanding of your needs and a quick bit of math in order to calculate them.
After reviewing all available science and noting practical evidence in working with professional, elite, and recreational athletes for more than 15 years, the question I ask is, “Will any particular nutrition intervention enhance your overall health as well as your performance or recovery?” If the answer leans toward yes, it might be worth a try to see how your body responds. But if the answer leans toward no, immediately look elsewhere to see where changes in your training, consistency, and nutritional intake can lead to performance improvements that truly can be earned.