Objectives: It is well known that neuromuscular function is temperature sensitive. Changing of muscle temperature can effect voluntary muscle contraction. The aim of this study was to investigate the effects of cooling and heating on maximal isometric force generated by the elbow flexor musculature in male subjects.

Methods: Forty five healthy males encompassing 3 groups participated in the current study. The maximal isometric forces of elbow flexion were measured before and after placing ice and hot packs over the arm for 15 minutes. Paired t tests were used to compare differences between pre and post maximal forces between groups.

Results: The results showed no significant difference between pre and post maximal isometric force scores in control and heat groups (P>0.05) and significant difference between pre and post cooling maximal isometric force scores (P=0.02).

Discussion: The results suggest that the use of 15 minutes cold pack over the arm can significantly increase muscle force, however, the use of hot pack had no change in force output.