Do dexamphetamines (amphetamine-like stimulants) enhance muscle growth and strength exercise?

Dexamphetamines' Effect on Muscle Growth and Strength Exercise

Dexamphetamines are not recommended for enhancing muscle growth or strength exercise performance due to potential cardiovascular risks and limited evidence of benefit for these outcomes. 1

Effects on Physical Performance

• Amphetamines may increase certain physical performance parameters through masking fatigue rather than directly enhancing muscle growth 2, 3
• Research shows amphetamines can increase knee extension strength, acceleration, anaerobic capacity, and time to exhaustion during exercise testing 3
• However, amphetamines have no demonstrated effect on improving aerobic power 3
• The primary mechanism appears to be higher lactic acid tolerance and altered fatigue perception rather than direct enhancement of muscle tissue 3

Cardiovascular Risks

• Dexamphetamines significantly increase systolic blood pressure (average 1.93 mmHg), diastolic blood pressure (average 1.84 mmHg), and heart rate (average 3.71 beats per minute) 4
• These cardiovascular effects persist with long-term use and place users at increased risk for adverse cardiovascular events 4
• The risk of withdrawal due to adverse effects is 2.69 times higher with amphetamines compared to placebo 4
• Higher doses of amphetamine increase cardiovascular risks without necessarily providing additional performance benefits 5, 6

Medical Guidelines and Recommendations

• The American Heart Association/American Stroke Association explicitly states that "the use of dextroamphetamine or methylphenidate to facilitate motor recovery is not recommended" 1
• Clinical practice guidelines limit the upper range of amphetamine dosing to 40 mg daily, with recommendations against exceeding this dose 5, 6
• Amphetamines are recognized as substances that may be misused as performance enhancers, but their use for this purpose is discouraged 1
• The potential for adverse effects, including cardiovascular complications, represents a serious risk to otherwise healthy individuals 7

Ethical and Practical Considerations

• Amphetamines are controlled substances with potential for tolerance and dependence 5
• Their use for performance enhancement in sports is prohibited by most athletic organizations 2, 8
• The perceived benefits may be more psychological than physiological, creating an illusion of better performance when actual performance may be unchanged or impaired 2, 7

Alternative Approaches

• For those seeking to enhance muscle growth and strength, evidence-based approaches include:
  • Strength training programs that incorporate progressive resistance 1
  • Proper nutrition with adequate protein intake 1
  • Sufficient recovery between training sessions 1
  • Natural ergogenic aids with established safety profiles 7

Common Pitfalls to Avoid

• Assuming that stimulant effects on alertness and energy translate to muscle growth benefits 2
• Overlooking the serious cardiovascular risks that outweigh potential performance benefits 4
• Ignoring the potential for tolerance, requiring escalating doses for the same effect 5
• Failing to recognize that masking fatigue can lead to overtraining and increased injury risk 3