Improvements in glucose metabolism after high-, but not low-, volume strength exercise in individuals with obesity are associated with baseline insulin resistance: a secondary analysis from a randomized clinical trial.

This study is a secondary analysis from a clinical trial and aimed to evaluate the effects of strength exercise volume on glucose metabolism indices in individuals with obesity who are sensitive or resistant to insulin. Fifteen (14 women) individuals with obesity (fat percentage and visceral fat content > 90th percentile for age and sex) were divided into insulin-sensitive (n = 7) or resistant (n = 8, 1 man) (HOMA-IR cutoff of 2.71) and subjected to three randomized sessions separated by at least 4 washout days: (1) high-volume (HIGH) strength exercise (8-RM, 21 sets to failure); (2) low-volume (LOW) strength exercise (7 sets to failure); and (3) control. An OGTT was performed the following morning. Improvements in oral glucose insulin sensitivity, and the area under the curve for glucose, insulin, and C-peptide were observed only after HIGH in the resistant group. For these indices, there was a higher percentage of responders after HIGH in the resistant group (25–37.5%), followed by resistant after LOW (0–25%), sensitive after HIGH (0–14.3%), and sensitive after LOW (0%). There were no improvements for any group in hepatic insulin resistance, hepatic insulin extraction, and C-peptidogenic index. These results suggest that improvements in indices of glucose metabolism after strength exercise are dependent on exercise volume and associated with insulin resistance in individuals with obesity. The protocol of this study was prospectively registered ( https://ensaiosclinicos.gov.br/rg/RBR-3vj5dc5 ) and was funded by the National Council for Scientific and Technological Development (CNPq Grant#407975/2018-7 and # 402091/2021-3) and by the Minas Gerais State Agency for Research and Development (Grant# APQ-00008-22).