Hvorfor utilstrekkelig energiinntak kan forsterke smerte og redusere rehabiliteringseffekt

Nutrition is often discussed in relation to body weight, performance, and metabolic health. Less attention is given to how insufficient energy intake can influence pain perception, tissue tolerance, and the effectiveness of rehabilitation. Research suggests that low energy availability may be an underrecognized barrier to progress in both active individuals and patients undergoing recovery.

Energy availability and physiological regulation

Energy availability refers to the amount of dietary energy remaining for basic physiological processes after the energy cost of physical activity is subtracted. When energy availability is chronically low, the body prioritizes survival over repair and adaptation.

This can affect:

• Hormonal regulation

• Immune function

• Pain modulation

• Muscle and tendon adaptation

The link between low energy availability and pain

Studies indicate that low energy availability may lead to:

• Elevated cortisol responses

• Reduced production of sex hormones

• Altered central pain regulation

• Lower pain thresholds

These mechanisms can contribute to pain being perceived as more intense and persistent, even at relatively low mechanical loads.

Rehabilitation without sufficient fuel

Effective rehabilitation depends on biological capacity for adaptation. Without adequate energy intake, individuals may experience:

• Limited strength and tissue adaptation

• Increased fatigue and reduced exercise tolerance

• Prolonged recovery times

• Higher risk of overuse-related symptoms

This applies not only to athletes, but also to patients recovering from injury or pain episodes.

RED-S – beyond competitive sport

Relative Energy Deficiency in Sport (RED-S) is well documented in sports medicine, but the underlying mechanisms are also relevant outside elite athletics.

Individuals at risk may include:

• Recreationally active individuals with high training volumes and low energy intake

• Those engaged in prolonged caloric restriction

• Patients experiencing pain-related appetite suppression

• Individuals with unintentional energy deficits

Practical implications in clinical settings

When rehabilitation progress is limited, energy intake should be considered as part of a comprehensive assessment:

• Is dietary intake aligned with activity level?

• Are there signs of low energy availability?

• Does the individual report disproportionate fatigue or pain?

This does not require detailed nutrition planning, but rather ensuring sufficient biological resources for recovery and adaptation.

Summary

Insufficient energy intake can amplify pain, reduce tissue tolerance, and impair rehabilitation outcomes. Adequate energy availability is a prerequisite for effective pain modulation and physical adaptation, and should be considered an integral component of holistic rehabilitation.

Sources

• Mountjoy, M., et al. (2018). IOC consensus statement on relative energy deficiency in sport (RED-S). British Journal of Sports Medicine, 52(11), 687–697. https://doi.org/10.1136/bjsports-2018-099193

• Loucks, A. B. (2014). Energy balance and energy availability. Applied Physiology, Nutrition, and Metabolism, 39(4), 395–400. https://doi.org/10.1139/apnm-2013-0408

• Slater, G. J., & Smith, A. (2021). Nutrition for injury rehabilitation and return to play. European Journal of Sport Science, 21(1), 1–12. https://doi.org/10.1080/17461391.2020.1757672