This study examined the use of heat and cold therapy in conjunction with either static stretching or a technique of proprioceptive neuromuscular facilitation stretching to determine which combination of these treatment techniques would elicit the greatest amount of relaxation in muscle which exhibits delayed, postexertional pain as indicated by changes in levels of EMG activity. Results indicated 1) a strenuous exercise task can produce an increase in electrical activity and is considered to be effective in inducing experimental muscle pain; 2) the use of cold followed by static stretching appeared to be superior to other treatments in reducing delayed muscle pain; 3) treatments involving the use of cold followed by some type of stretching are more effective than treatments involving heat and stretching for inducing muscle relaxation; 4) treatments involving static or proprioceptive neuromuscular facilitation stretching appear equally effective in reducing muscle pain; and 5) subcutaneous fat may serve as a type of insulation against the penetrative effects of heat or cold therapy.