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Winning or Losing in Sports is Tied to Energy Availability

According to the U.S. Energy Information Administration (ELA), energy is defined, “as the ability to do work” – ranging from heat, light, motion, electrical, chemical, nuclear, and gravitational. There are, according to the ELA, two types – stored (potential) and working (kinetic) energy.

A lower body plyometric exercise, such as a depth jump and react – stepping off a 22-inch box, quickly absorbing the landing, before you jump forward – is a classic example of storing the potential energy during the amortization phase – the short deceleration – before jumping forward (kinetic energy).

From a dietary standpoint, the food you consume metabolizes to chemical energy, which is stored, until such time that it’s needed as kinetic energy for daily living, recreation, or coping with illness.

Research – Pitfalls of Conducting and Interpreting Estimates of Energy Availability in Free-Living Athletes – appearing in the July issue of the International Journal of Sports Nutrition and Exercise Metabolism (IJSN&EM) – defines energy availability (EA) as, “energy that can be devoted to individual body systems.”

From a sports perspective, EA is the net energy available for use by the athlete, once you subtract the energy expended during training or competition from the athlete’s energy (food and liquid) intake.

The EA status can have a significant impact, not only on an athlete’s performance, but also their health. When the EA is sub-optimal for a protracted period of time – such as the case with the Female Triad – “defined as a medical condition observed in athletic girls and women compromising three components: low energy availability, menstrual dysfunction, and low bone mineral density” – the athlete’s in trouble.

Prior research concluded that low energy availability (LEA) is a cornerstone of impaired menstrual function and suboptimal bone health in female athletes.

Energy balance is a point of equilibrium between intake and expenditure. As you would expect, a positive energy balance might result in the athlete gaining scale weight (muscle, fluid, or fat), while a negative balance might reflect the opposite.

You might have an athlete – such as a boxer, wrestler, jockey, or overweight NFL lineman – who purposely creates a negative energy balance to “make or cut weight” before a competition – only to find that they run out of gas (EA) during the event.

The IJSN&EM researchers give the examples of low carbohydrate intake and low carbohydrate availability in relation to training sessions, or inadequate protein intake and poor spread of protein over the day in relation to training, as nutritional characteristics often associated with EA in diets of free-living subjects.

Related research – Relative Energy Deficiency in Sport (RED-S) in Male Athletes: A Commentary on Its Presentation Among Selected Groups of Male Athletes – notes a, “heightened risk of LEA (low energy availability) in some populations of male athletes: road cyclists, rowers (lightweight and open weight), athletes in combat sports, distance runners, and jockeys.”

RED-S results from an energy deficit between intake and expenditure necessary to support metabolic balance, health, daily activities, and sports participation. It’s necessary to understand the demands – stresses – on the athlete’s life, culture, and chosen sport, which might contribute to LEA.

Research points to several known facts about LEA and RED-S in specific populations of male athletes, such as, “reduced sex hormone testosterone seen in subset of male athletes, particularly in endurance, lean sports or during periods of LEA; impaired skeletal health in male athletes with LEA, including running or sports with reduced weight bearing, such as jockeys and cyclists.” Low body weight may also be associated with low bone mineral density, particularly in adolescent male athletes.

The take-away message for the athlete is to: develop, with sports dietitian’s input, a well-balanced eating plan to support energy expenditure needs; establish proper timing of meals; discourage weight cycling; and match periodized food intake to the demands of the sport.

Train like you fight and fight like you train – on a full fuel tank.