Exercise Reduces Morphine-Induced Hyperalgesia and Antinociceptive Tolerance

Figure 7

Exercise preconditioning did not prevent the development of morphine antinociceptive tolerance in the (a) hot-plate test and (b) tail-flick test. Rats first received 30-minute exercise training for 2 weeks, then morphine 30 mg/kg was injected daily, and behavior tests were performed 30 minutes after morphine subcutaneous injection.

(a)

(b)