Influence of Pre-Exercise Muscle Temperature on Responses to Eccentric Exercise

Abstract

OBJECTIVE: We tested the hypothesis that altering the pre-exercise muscle temperature would influence the magnitude of muscle damage induced by eccentric exercise. SUBJECTS: Female students who had no experience in resistance training were placed into either a microwave treatment group (n = 10) or an icing treatment group (n = 10). DESIGN AND SETTING: Subjects in each group performed 12 maximal eccentric actions of the forearm flexors of each arm on 2 separate occasions separated by 4 weeks. Before testing, the exercise arm was subjected to either passive warming (microwave) or control for the microwave treatment group or cooling (icing) or control for the icing treatment group. The control arm performed the same exercise protocol without treatment. Limbs were randomized for treatment or control and order of testing. Deep muscle temperature increased by approximately 3 degrees C after the microwave treatment and decreased approximately 5 degrees C after the icing treatment. MEASUREMENTS: We evaluated changes in maximal isometric force and indirect markers of muscle damage, including range of motion, upper arm circumference, muscle soreness, and plasma creatine kinase activity, in the microwave and control and icing and control groups using a 2-way, repeated-measures analysis of variance. RESULTS: All measures changed significantly (P <.01) after exercise, but neither of the treatments demonstrated significant effects on most of the variables compared with the control. CONCLUSIONS: These results suggest that pre-exercise cooling does not affect the magnitude of muscle damage in response to eccentric exercise. Similarly, pre-exercise passive muscle warming did not prove beneficial in attenuating indicators of muscle damage. Thus, any beneficial effects of warm-up exercise cannot be attributed to the effects of increased muscle temperature.

Figure 1

Changes in maximal isometric force before (pre-exercise), immediately after (postexercise), and 1 to 5 days after eccentric exercise in the treatment (microwave, icing) and control conditions. No significant differences among conditions were noted.

Figure 2

Changes in range of motion of the elbow joint before (pre-exercise), immediately after (postexercise), and 1 to 5 days after eccentric exercise in the treatment (microwave, icing) and control conditions. Significant (P < .01) differences were seen between the control and microwave and microwave and icing groups but not between the control and icing groups.

Figure 3

Changes in upper arm circumference before (pre-exercise), immediately after (postexercise), and 1 to 5 days after eccentric exercise in the treatment (microwave, icing) and control conditions. No significant differences were demonstrated among conditions.

Figure 4

Changes in muscle soreness with palpation (A) and extension (B) before (pre-exercise) and 1 to 5 days after eccentric exercise in the treatment (microwave, icing) and control conditions. No significant differences were noted among conditions.

Figure 5

Changes in plasma creatine kinase (CK) activity before (pre-exercise) and 1 to 5 days after eccentric exercise in the treatment (microwave, icing) and control conditions. No significant differences were seen among conditions.