Short-term Circuit Training on Muscle Mass and Quality of Life in Sedentary Postmenopausal Women

A randomized controlled trial design will investigate the effects of circuit training on the following dependent variables: muscle mass, strength, inflammatory markers, balance, functional capacity, and quality of life.

Body composition measurements will utilize IN-BODY technology. The Motor Control Screen Lower Body (MCS) will determine balance. For assessing strength, we will use the Dynamometer, specifically for grip strength. Ultrasound will gauge muscle mass, while the BTE (Baltimore Therapeutic Equipment) will handle quadriceps isometric muscle tests. The Peak Expiratory Flow (PEF) will evaluate respiratory strength. Participants' aerobic capacity will be gauged via the 6-minute Walk Test. Heart Rate Variability (HRV) evaluations will rely on Polar devices, and the Fitbit Inspire3. We will also employ the Fitbit Inspire3for tracking sleep quality. Psychosocial factors will be examined through: Falls Efficacy Scale-International (FES-I), SF-36 QOL Questionnaire, PHQ-ADS, and the Pittsburgh Sleep Quality Index (PSQI). Activity levels will be determined through the IPAQ-SF questionnaire. The questionnaires will be completed on Qualtrics or in hardcopy format. Blood tests will monitor inflammatory markers such as IL-6, TNF-α, and hs-CRP. The study will be conducted over 10 weeks, starting from the initial and final data collection. During the first week, participants will need to visit the research laboratory to undergo basic tests. After completing all procedures, including informed consent and blood collection, participants will be randomly assigned (computerized generated) to the experimental (exercise) group (N=18) or control (non-exercise) group (N=18).

In the first week, the exercise group will participate for two additional days to introduce the exercise, evaluate their movements, and determine their maximum exercise capacity. The experimental group will participate in circuit strength training sessions lasting approximately 45 minutes three times a week for 8 weeks. The exercise protocol will consist of a 10-minute warm-up and cool-down, two sets of 12-minute high-intensity circuit training exercises, and a 3-minute break between sets. The intensity of the exercises will be gradually increased every two weeks for 8 weeks.

Meanwhile, the control group will need to maintain their sedentary lifestyle without changing their activity levels or diet.

After completing the 8-week exercise protocol, all participants will visit the lab for a second round of data collection. Additionally, the exercise protocol will be shown to the control group during the retest day of the study.

Inclusion criteria

• Females aged between 50 and 75 years.
• Self-reported postmenopausal status (i.e., cessation of menstruation for a minimum of 12 months).
• Physically capable of participating in an exercise intervention.
• No engagement in structured resistance or aerobic training programs in the six months preceding the study.

Exclusion criteria

• Classification as moderate and highly active on the International Physical Activity Questionnaire (IPAQ) (600-3000 MET-minutes/week for "moderate" and higher than 3000 MET-minutes/week for "high" score)
• Diagnosis of any health condition that constitutes a contraindication to physical exercise (e.g., significant cardiovascular disease, orthopedic or neuromuscular restrictions impacting exercise performance or safety).
• Regular use of medication with the potential to affect study outcomes (e.g., corticosteroids, immunosuppressants).