The Comparative Effect of Different Times Under Tension in Eccentric Phase of Isotonic Resistance Exercise on Markers of Delayed-Onset of Muscle Soreness

The aim of this study was to compare the effects of different times under tension in eccentric phase of resistance exercise on delayed onset of muscle soreness markers. 32 non-athletes men (with mean age of 21.71± 2.88y, height of 175.21± 5.42 cm, weight of 71.87± 8.4 kg, BMI of 23.60± 3.28 kg/m2 and body fat percent of 19.18± 4.79) voluntarily participated in the study. Subjects were randomly divided into four groups, with ratios from concentric to eccentric were divided as a ratio of 1: 1, 1: 2, 1: 3 and 1: 4 respectively. Parameters measured included serum creatine kinase, lactate dehydrogenase and muscular pain perception. Indices were measured in the before, 24 and 48 hours after resistance exercise. Repeated measures analysis of variance and ANOVA test were used to assess differences between the groups. The levels of creatine kinase and pain perception in all groups at 24 and 48 hours after resistance exercise had a significant increase (P≥0.05). A significant difference between groups 1: 1 and 1: 2 with 1: 4 group was observed (P≥0.05). In all groups Lactate dehydrogenase only had a significant increase at 24 hours after resistance exercise (P≥0.05), but no significantly difference between groups was observed. This study showed that increase in the time under tension as ratio 1 to 4 (slow tempo) can increase muscle damage and DOMS.