Stimulants and the Athlete's Body: Four Changes to Watch For

More than a focus medication

ADHD medications help athletes focus, but they also change how the body responds to exercise. Heart rate, core temperature, and hormones can all shift. Many athletes taking these medications don't know that.

An estimated 7 to 8% of elite athletes have ADHD, and many of them train and compete on medication. Here are the four changes the research points to, and what to do about each one.

The study

A 2022 systematic review in Sports Medicine – Open pulled together every randomized trial it could find on ADHD medications and physical performance. Berezanskaya and colleagues screened more than 13,000 abstracts and kept 9 studies, with 157 participants in total.

The medications studied were:

• Amphetamine (the active ingredient in Adderall, Dexedrine, and Vyvanse)
• Methylphenidate (Ritalin, Concerta, Focalin)
• Bupropion (Wellbutrin), a non-stimulant sometimes used off-label for ADHD
• Inhaled L-methamphetamine, in one study

The review's main question was performance, and most of the medications did show some performance effect. But the researchers also tracked what happened to the body along the way. Those secondary effects are what every athlete on these medications should know.

1. Core temperature

Core body temperature rose during exercise in every study that measured it. Three studies tracked it, and all three found a significant increase on medication.

• Methylphenidate: in trained cyclists exercising in the heat (30°C, about 86°F), core temperature ran higher on methylphenidate and stayed higher into recovery. In cooler conditions (18°C, about 64°F), there was no difference.
• Bupropion: two studies, also in the heat, found higher core temperature with bupropion, with moderate to large effect sizes.

The heat finding matters most. These medications seemed to have the biggest effect on temperature exactly when the body is already working hardest to cool down. Animal research also suggests amphetamine may let the body push to higher temperatures before fatigue sets in.

What to do:

1. Hydrate on a schedule, not based on thirst.
2. Be extra cautious training or competing in the heat.
3. Watch for warning signs like dizziness or confusion. Don't rely on "feeling hot" as your signal.

2. Heart rate and blood pressure

Heart rate was higher on medication than on placebo under the same exercise conditions. Four studies found a significant increase:

• Amphetamine: maximum heart rate rose significantly in college students who were former high school athletes.
• Methylphenidate: heart rate was higher at every point of a timed cycling trial in the heat.
• Bupropion: heart rate was higher in the final minutes of all-out effort.
• Children with ADHD on their usual stimulant: heart rate was higher than on placebo during cycling.

Increased blood pressure is a known side effect of stimulant medications. Only one study in the review measured it during exercise (inhaled L-methamphetamine), and it found no significant change. So these trials tell us less about blood pressure than about heart rate.

What to do:

1. Avoid stacking other stimulants, like caffeine or pre-workout, on top of your medication.
2. Report chest pain or unusual palpitations right away. Don't push through it.

3. Hormonal changes

Bupropion raised stress-related hormones during exercise. Four studies measured hormones, and three found significant increases, all with bupropion:

• Cortisol and ACTH were higher during and at the end of prolonged cycling.
• Growth hormone was higher in trained cyclists exercising in the heat.
• Prolactin was higher at the end of exercise.

The one methylphenidate study that checked hormones found no difference from placebo. The amphetamine studies didn't measure them. So this finding applies most clearly to athletes taking Wellbutrin.

What to do:

1. Prioritize recovery on purpose: sleep, nutrition, and rest days.
2. Tell your prescribing physician about anything unusual, like persistent fatigue or disrupted sleep.

4. Perceived exertion

Athletes' sense of how hard they were working didn't change, even though their bodies were working harder. Five studies asked athletes to rate their effort or how hot they felt, and none found a significant difference between medication and placebo.

That is the most important finding for safety. Heart rate and core temperature went up, but athletes didn't feel it. The authors suggest these medications may dull the sense of fatigue, though they say more research is needed to confirm it.

What to do:

1. Don't rely on how you feel in the moment.
2. Use a heart rate monitor.
3. Build scheduled breaks into training.
4. Have a coach or parent watch for physical signs, not just ask if you're okay.

Know your body's full picture

This isn't about avoiding necessary treatment. ADHD medication is an important treatment for many athletes, and no study in this review reported an adverse event. It's about knowing your body's full picture, not just the parts you can feel.

The evidence has limits worth knowing. The studies were small, most participants were male, and most took a single dose before testing rather than daily long-term use. Only two studies included children with ADHD already on treatment. The authors call for more research on dosing, long-term use, and safety.

If you're an athlete on ADHD medication, or the parent of one, talk with your prescribing physician about training in the heat, caffeine use, and your sport's rules. Many sports organizations allow stimulants with a documented diagnosis and the right paperwork, so check your governing body's requirements.

References

This post is for educational purposes only and is not medical advice.

1. Berezanskaya J, Cade W, Best TM, Paultre K, Kienstra C. ADHD prescription medications and their effect on athletic performance: a systematic review and meta-analysis. Sports Med Open. 2022;8:5. doi:10.1186/s40798-021-00374-y