Endurance sports success relies on factors like consistent training, correct intensity distribution, technique, and resilience. One thing that can get overlooked is meeting energy requirements. As an endurance athlete, fueling your body adequately is essential for peak performance and overall health. It's not just a recommendation; it's a necessity.

Endurance sport athletes train more than the normal person. To effectively endure this, it is essential to consume enough calories and nutrient-rich food to meet the energy demands of training and competition.

Here are a few important reasons why this is crucial.

  1. Ensuring that you meet your energy requirements is important for optimal performance. If you don't consume enough calories, you may experience early fatigue and compromised form, which can negatively impact your performance.

  2. Proper nutrition is essential for recovery. Insufficient energy intake can delay the recovery process and raise the likelihood of injury.

  3. Insufficient energy intake can lead to a suppressed immune system, making athletes more vulnerable to illnesses that can disrupt training schedules and reduce consistency.

  4. Long-term energy deficiency can negatively impact bone health and increase the likelihood of stress fractures.

  5. Hormonal imbalances can disrupt hormonal regulation, potentially leading to irregular menstrual cycles in female athletes and negatively impacting overall health.

  6. Inadequate nutrition can lead to a loss of lean muscle mass, which can result in a decrease in power and strength over time.

The most accurate method to determine if you are meeting your energy needs is by calculating your energy availability, here’s the calculation:

The formula for Energy Availability (EA) is calculated by subtracting Exercise Energy Expenditure (EEE) from Energy Intake (EI) and then dividing the result by Fat-Free Mass (FFM).

  1. Energy Intake (EI) is the total caloric consumption an athlete obtains from both food and beverages.

  2. Exercise Energy Expenditure (EEE) is a measure of the calories burned by an athlete during exercise. It can be determined using different methods, including power meters, heart rate monitors, fitness trackers, or estimations based on exercise duration and intensity.

  3. Fat-Free Mass (FFM), also known as LBM (Lean Body Mass), refers to the total body mass of an athlete excluding the fat mass. This measurement can be obtained through techniques such as dual x-ray absorptiometry (DEXA) or estimated using skin fold callipers.

Practical Example:

Let's consider the example of a female endurance athlete.

  1. Her energy intake is 2,500 calories per day.

  2. She burns 700 calories per hour during her daily 2-hour training sessions, resulting in a total of 1,400 calories.

Her fat-free mass is 55 kilograms.

Using the formula:

The equation to calculate EA is (2,500 EI - 1,400 EE) / 55 LBM, with EA equal to 20.

The athlete's energy availability is 20 calories per kilogram of lean body mass, indicating a significant energy deficit that may negatively impact her performance and health.

Energy Availability Guidance:

A score of 45 or higher is considered to be optimal in terms of EA.

The range of 30-45 is classified as subclinical low EA.

A value below 30 is considered clinically low EA.

Endurance athletes must meet their energy requirements for optimal performance, recovery, and overall health. It's not only about calories but also about the quality and timing of those calories, along with a balanced intake of macronutrients. Each athlete is different, so personalised nutrition plans are necessary to address individual energy needs. In endurance sports, fueling the body is not optional; it is the basis for success.