Effects of Resistance Training on Muscle Quality Index, Muscle Strength, Functional Capacity, and Serum Immunoglobulin Levels between Obese and Non-obese Older Women

International Journal of Exercise Science 14(7): 707-726, 2021. Considering the negative impact of obesity on neuromuscular and immune systems, we sought to compare the effects of a 10-week resistance training (RT) program on muscle quality index (MQI), muscle strength, functional capacity, and immunoglobulins in older women with and without obesity. Thirty-nine older women participated in the present study (age: 69.02 ± 6.16, fat (%): 38.80% ± 6.28) and underwent a linear RT program performed on two non-consecutive days of the week. Body composition, functional tests, immunoglobulins, muscle quality of upper and lower limbs and absolute muscular strength of the upper and lower limbs were measured. Both groups displayed an increased statistically significant difference in MQI between pre-post training, however obese participants showed a lower field and laboratory MQI when compared to non-obese participants at the same time-points. Obese participants displayed an increased statistically significant 30-second chair stand test, with no differences for non-obese participants. Obese participants showed a higher statistically significant difference for immunoglobulin M when compared to the non-obese group at post-training. Finally, both groups displayed an increased statistically significant difference in muscle strength between pre-post-training. However, obese participants showed a statistically significant lower 10-RM low row score when compared to non-obese participants at post-training. Obese older women showed a lower field and laboratory MQI when compared to non-obese post-training, besides a lower 10-RM low row score which reinforces that obesity blunts the beneficial effects of RT on muscle quality and strength