Purpose: The purpose of this study was two-fold: (1) determine if muscle activation was greater in a BFR exercise condition compared to non-BFR exercise condition using MRI T2 mapping, and (2) determine if the muscle activation for both BFR and non-BFR exercise conditions differs between postbariatric surgery individuals and individuals in 2 control groups. Methods: Three groups participated: (1) a normal-BMI group, (2) a postbariatric surgery group, and (3) a matched group for the surgery individuals. Ultrasound imaging was used to find the optimal BFR pressure for each participant. All participants participated in both BFR and non-BFR exercises. Using a 3-Telsa MRI, a T2 map was imaged prior to and immediately following exercise. Analyses included within-group-across-condition comparisons and within-condition-across-group comparisons. The outcome variable of interest was the change in muscle activation determined via T2 mapping. Results: There was no statistical difference in the increase in muscle activation between BFR and non-BFR exercise conditions (p-value range 0.1091 to 0.9166). When comparing groups across conditions, we found that the surgery group elicited a significantly greater increase in activation compared to the normal-BMI group in every condition (p-value range 0.0014 to 0.0217) and in several muscles when compared to the matched group (p-value range 0.0060 to 0.0311). Other muscles compared to the matched group were not significantly different (p-value range 0.0683 to 0.129). No difference was found between the control groups (p-value range 0.2041 to 0.9557) in muscle activation for either condition. Conclusion: These results did not suggest a difference between BFR exercise and non-BFR exercise for the calf-raise protocol. Postbariatric surgery patients elicited an equal muscle activation response in some conditions and a greater muscle activation response in others when compared to both control groups. Further research is needed to determine whether a greater intensity or duration of exercise is needed to elicit an acute response to BFR and what factors are contributing to the increased muscle activation seen in the postbariatric surgery group.



College and Department

Exercise Sciences



Date Submitted


Document Type





muscle activation, T2 mapping, KAATSU



Included in

Life Sciences Commons