Purpose:To compare the effect of inter-set cooling and no cooling during resistance exercise (RE) on the total repetitions and select muscle damage biomarker responses.Methods:Sixteen healthy men volunteered to participate in this study and were randomly assigned to Cooling (n = 8) or Control (n = 8) groups. They performed a RE protocol consisting of four sets of biceps curl at 80% of 1RM. The cooling group received the application of wet bags of ice during each inter-set rest interval (Cooling), while the Control realized the same protocol without ice application. Exercise was performed to voluntary fatigue and the numbers of repetitions per set were recorded. Subjects provided blood samples before and at 24, 48, and 72 h following RE to evaluate serum CK activity and myoglobin concentration.Results:The Cooling group produced a greater number of repetitions (approx. 21%) than did the Control, but there were no differences in serum CK activity and myoglobin responses between the groups.Conclusion:Incorporating inter-set external cooling augments the number of repetitions per set during RE without inducing an additional muscle damage biomarker response.

Purpose: To determine how the rest interval (RI) lengths of 30 and 90 s between sets of biceps curl exercise affect the total volume of work performed and serum CK activity, and to verify the relationship between inter-individual variability of CK activity and total volume performed when the resistance exercise bout is conducted with 30 or 90 s Methods: Twenty-seven healthy sedentary men (18À20 years old) volunteered to participate in this study and were divided into two groups: 30RI (n ¼ 16) or 90RI (n ¼ 11), based on the RI length of 30 or 90 s between the sets of a resistance exercise protocol. The one repetition maximum (1RM) assessment of the elbow flexion was carried out and then a resistance exercise protocol which constituted five sets of biceps curl at 85% of 1RM with 30-s Correspondence to: . Downloaded from www.worldscientific.com by MONASH UNIVERSITY on 08/25/15. For personal use only.(30RI group) or 90-s (90RI group) RI length between sets was performed. Each bout was performed to voluntary fatigue and the number of repetitions and workout volume completed were calculated. Subjects provided blood samples prior to resistance exercise, and at 48 and 96 h following exercise to evaluate serum CK activity. The inter-individual serum CK activity along the 96 h after exercise was analyzed. Results: The results demonstrated that the longer RIs provided greater workout volume as expected, but there were no differences in serum CK activity between the groups. Additionally, it was possible to identify two high responder subjects, one from each RI group, who showed a great interindividual serum CK activity variability. Conclusion: Exercising with short RIs does not appear to present any additional muscle microtrauma to untrained subjects. Further studies are necessary to evaluate if the inter-individual variability of the serum CK activity is influenced by the inter-set RI length.