Proper nutrition is key to fueling training sessions and facilitating adequate recovery. Athletes should see nutrition, which includes both fuel and food, as a training tool to enhance athletic performance and prevent injury. If our tank is empty, not only will we fall short of our goals but we run the risk of injuring ourselves, too.
The link between Low Energy Availability (LEA) and injury
LEA is when the body has insufficient energy to support all of the physiological functions required for optimal health. Essentially, the energy going into the body isn’t enough to support both our secondary activities (i.e., sport, work, day-to-day activities) and our normal physiological processes (breathing, sleeping, digesting, etc.).
Given athletes’ high levels of activity, they have greater susceptibility to LEA compared to the general population. This can be unintentional, due to increased energy expenditure from a high training load, or intentional, due to energy intake restrictions, e.g., body dissatisfaction.
The consequences of LEA include poor performance, poor adaptation to training stressors, reduced endurance capacity, increased fatigue, greater susceptibility to injury, suppression of the immune system, poor hormone function (menstrual irregularities) and reduced bone density.
Essentially, if the energy intake of the athlete does not fulfil the energy demands of training, daily life and physiological processes, their health will be affected. They will experience negative impacts on performance and their ability to sustain training blocks through increased injury, illness and poor response to training load. Additionally, high correlations exist between LEA and risk of bone injuries such as stress fractures.
How to avoid LEA and related injuries:
- Eat regular meals and snacks; eat often.
- Pay attention to quantity and balance of macronutrients: protein, fats and particularly carbohydrates.
- Focus on pre and post training nutrition; avoid training fasted and pack a snack with you for after training. Small changes can make a big difference.
- Fasted training increases the breakdown of muscle protein, reduces strength and increases soft tissue injuries.
- Reduce energy expenditure (e.g., reduce intensity/mileage).
- Pay attention to day-to-day activities (e.g., take the bus instead of walking to work).
- If you are struggling to consume sufficient nutrition due to lack of hunger or feelings of fullness, opt for high energy density foods with a lower volume (e.g., nut butters, seeds and oils).
Nutrients needed to fuel our active bodies
Prior to and during exercise, high carbohydrate availability is crucial. Low glycogen levels are a limiting factor to high intensity exercise performance and inadequate energy intake is a risk factor to LEA and related injury.
Before training, place the focus on easily digestible carbohydrate-based meals/snacks. Following training, consume energy dense meals/snacks with plenty of carbohydrates and protein to restore muscle glycogen levels and facilitate muscle protein synthesis.
Calcium and vitamin D are extremely important micronutrients that support injury prevention, especially in the context of bone related injuries resulting from poor bone health. Athletes with poor bone health may run the risk of incurring stress fractures. Calcium also supports nervous system function and muscle contraction.
If sufficient calcium intake cannot be achieved through diet, calcium supplementation can increase bone mineral density, thus decreasing stress fracture risk.
Vitamin D supports calcium regulation, bone health, immune response, muscle strength and protein synthesis. It also enhances intestinal calcium absorption, an essential micronutrient for bone density and re-modeling.
Avoid calcium and iron together. Both micronutrients compete for the same receptors and may inhibit absorption. Instead, take vitamin D with calcium to aid in calcium absorption. A glass of milk followed by a walk in the sunlight will do the trick too!
The recommended calcium intake for adults is 700mg/day. For athletes, these numbers go up: approximately 1000mg/day for male endurance athletes and approximately 1300mg/day for female endurance athletes. Female endurance athletes with poor menstrual function require additional calcium (consult a doctor for blood examination first) and may be recommended to increase calcium intake to 2000mg/day.
The recommended daily intake for the general population of Vitamin D is 600 IU. Endurance athletes should aim to take significantly more vitamin D, between 2000-5000 IU per day.
. . .
Becky Briggs (Coach at NRG Coaching) is a British record holder and elite marathon runner who has competed for Great Britain over both cross country and road. With over 12 years of experience in distance running, competing internationally on the track, cross country and road, Becky has first-hand experienced the rise from grass roots athletics to the elite level and shares this passion with helping others achieve their goals in the sport.