Nutrition and physical activity in people with cerebral palsy: Opposite sides of the same coin

For people with cerebral palsy (CP), the last decade has seen an increasing number of interventions focussed on bolstering participation rates of physical activity and muscle strengthening exercise.^{1, 2} Given the high prevalence of sedentary lifestyles and risk for chronic conditions in adults with CP,³ these interventions are absolutely vital for health preservation through the lifespan. However, it is important to emphasize that the acute stimulus of repeated exercise bouts is only one of a multitude of factors contributing to the chronic adaptive-response and long-term effectiveness of training. Many other factors play an important role, including adherence to training guidelines, motivation, and injury prevention. Perhaps the single best example of this is the often disregarded health and fitness benefits that are associated with proper nutrition. Indeed, it is the position of the American Dietetic Association (ADA) and the American College of Sports Medicine (ACSM) that balanced nutrition is essential for all individuals that are physically active, and can enhance the long term effectiveness of exercise training.⁴

Diet can affect performance, and the foods chosen during periods of training will directly influence training as well as the risk of illness or injury. The responses to training cannot be maximized unless the body is given sufficient nutrients to ensure adequate recovery, repair, and adaptation. Meeting energy needs is a nutrition priority for athletes, and optimum performance is only realized when healthy nutrition and adequate energy intake are in conjunction with exercise. This is of paramount importance for people with CP, as the prevalence of malnutrition (both under- and over-nutrition) are elevated in this population.⁵

The ACSM⁴ recommendation contains two important nutrients that we will discuss; carbohydrates and protein. Prior to exercise, the recommendation is to consume a meal or snack that is rich in complex carbohydrates to optimize maintenance of blood glucose, and to also include a moderate amount in protein. A carbohydrate is considered to be the most basic unit of energy. All carbohydrates are eventually broken down into glucose (simple sugar)-molecules that are used to supply muscle and tissues with energy to perform daily tasks and exercise. It is therefore important to consume and store carbohydrate as a source of fuel for the muscle and brain during exercise. Carbohydrate intake prior to exercise allows for blood glucose homeostasis during exercise and replaces muscle glycogen during recovery. For many types of moderate to intense physical activities, low serum glucose is a factor contributing to fatigue and reduced performance. After each bout of exercise, the primary dietary goals are to provide adequate fluids for rehydration, and carbohydrates to replace muscle glycogen and ensure rapid recovery. Moreover, protein consumed after exercise will provide amino acids for the repair of muscle tissue.⁴ Proteins are considered to be the building blocks of one’s body, and the amino acids that comprise different proteins act to repair muscle after exercise. Given that exercise causes actual muscle micro-damage, it is important to replace and rebuild this tissue in order to allow for hypertrophy and strength increases. For people with CP, it is crucial that a regular dietary intake of high-quality proteins is achieved in order to allow for muscle preservation and growth to occur. Recently, Pasiakos et al.⁶ concluded that as the duration, frequency, and volume of resistance training increase, protein supplementation may promote muscle hypertrophy and enhance gains in strength for both untrained and trained individuals. Evidence also suggests that protein supplementation following training for several weeks will enhance gains in maximal oxygen consumption in previously untrained individuals.⁶

In summary, a successful physical activity or training regime requires more than just regular participation in exercise. It is important to reiterate the need to compliment all exercise training programs with good nutrition, as both are equally important for individuals with CP. To date, no research has been conducted on the effects of combining an exercise program with a targeted nutrition intervention in people with CP. Based on the available evidence, we strongly suggest that this combined intervention of proper diet and exercise needs to be examined in this population.