Filho J, et al. - In the present study authors' aim was to examine the chronic impacts of different rest intervals (RIs) between sets on dynamic and isometric muscle strength and muscle activity. Data reported that different RIs between sets did not affect dynamic and isometric muscle strength and muscle activity in resistance-trained older women.

Methods

• A repeated-measures design (pretraining and posttraining) was used with independent groups (different RI).
• 21 resistance-trained older women (66.4 ± 4.4 years) were randomly assigned to either a 1-minute RI group (G-1 min; n = 10) or 3-minute RI group (G-3 min; n = 11).
• Both groups completed three supervised sessions per week during two months.
• In each session, members performed 3 sets of 15 repetitions of leg press exercise, with a load that elicited muscle failure in the third set.
• 15 maximum repetitions, maximal voluntary contraction, peak rate of force development, and integrated electromyography activity of the vastus lateralis and vastus medialis muscles were evaluated pretraining and posttraining.

Results

• The analysis in this study showed that there was a significant increase in load of 15 maximum repetitions posttraining for G-3 min only (3.6%; P< 0.05).
• Posttraining results demonstrated no significant differences between G-1 min and G-3 min groups for all dependent variables (P > 0.05).