Causes of Exercise Addiction

Neural Causes of Exercise Addiction

  1. Reward pathway in response to beta-endorphins
    • Exercise releases endorphins, naturally-occurring opiates that contribute to feelings of euphoria and may cause dependence
    • Ventral tegmental area, nucleus accumbens, and prefrontal cortex are possibly implicated
    • Evidence that the influence of beta-endorphins leads to exercise addiction in humans is still inconclusive (can only be done via autopsy)
    • Evidence in rats: the number of opioid receptor-binding sites increased after chronic exercise
  2. ΔFosB
    • Transcription factor found in high levels in the nucleus accumbens in the brains of drug and alcohol users
    • Also found in high levels in the nucleus accumbens of those who “chronically consume natural rewards”, including exercise
  3. Lower basal heart rate
    • Regular exercise lowers one’s resting heart rate, which leads to lower sympathetic activity at rest and lower levels of arousal
    • May be interpreted by the exerciser as lethargy, which could initiate him or her to increase arousal through exercise
  4. Thermogenic hypothesis
    • Physical activity increases body temperature, which may cause the body to enter a more relaxed state that reduces anxiety
    • Acts as positive reinforcement to exercise
  5. Catecholamine hypothesis
    • Exercise increases the circulating catecholamines  in the body
    • Catecholamines play an important role in the brain’s reward system
  6. Greater relative left frontal activity has been correlated with higher exercise addiction scores


Psychological Causes of Exercise Addiction

  • Cognitive Appraisal Hypothesis: by using exercise to cope with stress, the individual learns to depend on and need exercise during times of stress
    • Exercise=healthy coping mechanism, but gradually becomes more intense and frequent
    • Withdrawal symptoms= irritability, guilt, anxiety, and lethargy
    • Lack of a coping mechanism when exercise is stopped prompts the individual to exercise again to instantly reduce anxiety

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  • Affect Regulation Hypothesis: exercise has a dual effect on mood
    1. Positive affect (general mood state) is increased by exercise
    2. Negative affect (withdrawal symptoms and anxiety) is decreased by exercise
      • Negative affect becomes more severe after longer periods without exercise