Arm Pump

Arm pump is a hard, swollen feeling in the forearms that makes it difficult to hold the bar, pull the clutch or brake. It happens when the forearm muscles work hard and blood flow cannot keep up, so pressure builds inside the muscle compartment. It is very common in motocross and enduro.

Typical causes are gripping the bar too tightly, poor body position, tension and nerves, too little warm-up and poor fitness or hydration. Bar height, lever position and grip thickness also matter.

To reduce it, grip the bike with your knees and keep arms relaxed, warm up properly before the first session, ride regularly and stay hydrated. Severe, recurring arm pump that does not respond to training should be checked by a sports doctor.