The quiet epidemic of under-fuelling in recreational sport

The paradox of the health-conscious athlete

The most under-fuelled athletes are not elite competitors with demanding schedules — they are health-conscious recreational athletes who are simultaneously trying to perform and manage their body composition. They train hard. They eat clean. They count calories. And then wonder why they are tired, injured more often than their less disciplined peers, and not improving despite the effort.

Relative Energy Deficiency in Sport: not just for elite women

RED-S — previously known as the Female Athlete Triad before its scope was expanded — describes a state of insufficient energy availability relative to exercise energy expenditure. It was initially identified in female endurance athletes but affects all genders across all sports. The physiological consequences include hormonal disruption, reduced bone density, impaired immunity, poor recovery and suppressed performance.

How much is actually enough

Energy availability — the calories available for physiological function after exercise expenditure is subtracted — should sit at or above 45 kcal per kg of fat-free mass per day. Most under-fuelled athletes are operating at 25 to 30. The difference is not visible from the outside. They are not dramatically thin. They are simply running on a metabolic deficit that compounds silently over months and years.

Carbohydrate: the most feared and most misunderstood macronutrient in sport

Low-carbohydrate diets have genuine utility in specific contexts. They have essentially no utility for athletes performing repeated high-intensity efforts, team sports, or interval training. Glycogen depletion produces a cascade of fatigue, cortisol elevation, and impaired neuromuscular function that no amount of fat adaptation fully compensates for. The fear of carbohydrate in active populations is one of the most counterproductive nutritional trends in modern sport.

Fuelling before and during training: who actually needs it

For sessions under 45 minutes at moderate intensity, intra-workout carbohydrate offers minimal benefit for trained athletes. For sessions over 60 minutes, particularly at moderate to high intensity, carbohydrate during training measurably sustains performance and reduces post-session fatigue. An easily digestible carbohydrate source — like Keforma's Ultra Fuel — removes the guesswork and digestive risk associated with whole food options during intense efforts.

The mental performance cost of under-fuelling

Cognitive function, decision-making under pressure, and emotional regulation are all significantly impaired by glycogen depletion and caloric insufficiency. Athletes who report reduced motivation, increased irritability and difficulty concentrating are frequently under-fuelled, not under-rested. The brain runs primarily on glucose. A brain running low on fuel does not perform well, regardless of how much the athlete wants to succeed.

The first step to fixing it

The counterintuitive first intervention for under-fuelled athletes is to eat more — specifically more carbohydrate around training — before attempting to change anything else. Many athletes resist this because they fear weight gain. In practice, appropriately increasing training nutrition improves body composition in the medium term because better recovery allows more training quality, which improves the body's long-term energy partitioning. Eat for the training you do, not the training you think you should do.