What exercise recommendations are suitable for individuals with Avoidant/Restrictive Food Intake Disorder (ARFID)?

Exercise Recommendations for Individuals with ARFID

Direct Recommendation

Individuals with ARFID should engage in moderate-intensity aerobic exercise for at least 150 minutes per week combined with strengthening exercises twice weekly, while carefully monitoring for signs of energy depletion and adjusting intensity based on nutritional status and tolerance. This approach prioritizes safety given the inherent risk of inadequate energy intake in ARFID patients while maintaining the well-established benefits of regular physical activity on quality of life and overall health.

Exercise Protocol Framework

Aerobic Exercise Guidelines

• Target at least 150 minutes per week of moderate-intensity aerobic activity (60-80% peak heart rate), spread across at least 3 days with no more than 2 consecutive days without exercise 1
• Moderate-intensity activities include brisk walking, slow cycling, recreational swimming, dancing, and gardening 1
• Exercise can be performed alone or in groups, with slight benefit favoring group settings for adherence and psychosocial support 1

Resistance Training Parameters

• Perform strengthening exercises at least twice weekly, targeting major muscle groups with 8-10 different exercises per session 1
• Begin with 1 set of 10-15 repetitions at low resistance (40% of one-repetition maximum) 2
• Execute movements in a rhythmical manner at moderate to slow controlled speed through full range of motion 2
• Allow at least 48 hours rest between sessions for any single muscle group 2

Critical Safety Considerations for ARFID Population

Nutritional Monitoring Requirements

The ARFID population requires heightened vigilance compared to general exercise recommendations due to baseline nutritional deficiencies and energy insufficiency 3, 4, 5. Key monitoring includes:

• Screen for nutritional deficits and negative nitrogen balance as contributing factors to post-exertional exhaustion, as chronic malnutrition is common in ARFID patients 2
• Monitor for signs of inadequate energy availability including excessive fatigue, delayed recovery, or weight loss 6
• Patients closer to target weight may progress more slowly through exercise programs, requiring individualized intensity adjustments 6

Exercise Intensity Modifications

• Start with shorter periods of low-intensity exercise and slowly increase intensity and duration, particularly in patients with significant nutritional compromise 1
• Adjust intensity based on individual tolerance and disease severity 2
• Avoid physical inactivity entirely—even light activity is preferable to sedentary behavior 1, 2

When to Avoid or Modify Exercise

• If significant weight loss or failure to achieve expected weight gain is present, exercise intensity must be reduced or temporarily suspended until nutritional rehabilitation progresses 3, 5
• Patients dependent on enteral feeding or dietary supplements require medical clearance before initiating exercise programs 3
• Exercise should complement, not replace, medical and nutritional treatment for ARFID 1, 2

Practical Implementation Strategy

Phased Approach Based on Nutritional Status

1. Initial Phase (Significant Malnutrition): Focus on nutritional rehabilitation with minimal physical activity beyond activities of daily living 3, 4
2. Intermediate Phase (Improving Nutrition): Introduce low-to-moderate intensity aerobic exercise 2-3 times weekly for 20-30 minutes 1
3. Maintenance Phase (Adequate Nutrition): Progress to full exercise recommendations of 150 minutes weekly aerobic plus twice-weekly resistance training 1

Multidisciplinary Coordination

• Regular discussions between patients and healthcare professionals regarding exercise tolerance are essential given the complexity of ARFID and potential interactions between nutritional status and physical activity 1
• Consultation with healthcare professionals experienced in eating disorders is essential before starting any exercise program 2, 4
• The dietitian should monitor weight, height, and nutritional status to determine appropriate exercise progression 3

Key Clinical Pitfalls to Avoid

Common Errors in ARFID Exercise Management

• Do not apply standard exercise recommendations without considering baseline nutritional status—ARFID patients may lack adequate energy reserves for typical exercise prescriptions 3, 4, 6
• Avoid using exercise as a weight loss intervention in ARFID, as weight concerns are not part of the disorder and patients may already be underweight 5, 7
• Do not postpone all physical activity until full nutritional rehabilitation—it is never too late to start exercising at an appropriate intensity 1

Monitoring for Adverse Outcomes

• Watch for slower weight gain or failure to reach target weight in patients engaging in exercise, which may indicate inadequate energy balance 6
• Monitor for signs of overtraining or excessive energy expenditure relative to intake 4, 6
• Reassess exercise prescription if psychosocial functioning deteriorates or eating behaviors worsen 3, 5

Benefits Supporting Exercise in ARFID

Exercise provides benefits beyond weight management that are particularly relevant to ARFID patients, including improvements in pain, function, fatigue, and health-related quality of life 1. These benefits support overall health and well-being even when direct effects on eating behaviors may be limited 1. Exercise is safe when appropriately prescribed and monitored, with studies reporting few adverse events when intensity is matched to patient capabilities 1.