Flywheel Resistance Training and Traditional Resistance Training in Older Women With Sedentary Behaviors

There are easily accessible and safe strategies, such as resistance training, that can contribute to reducing depressive symptoms and preserving physical and executive function in older women. Resistance training is defined as exercises performed either in water or on land, involving the use of a constant load or uniform weight, regardless of the training program. Various types of resistance training equipment are available, including free weights, pneumatic resistance machines, elastic bands, or even body weight. Specifically, eccentric muscle action occurs when the force applied to the muscle exceeds the momentary force produced by the muscle itself, resulting in the forced elongation of the muscle-tendon system during contraction.

To date, evidence from randomized clinical trials has compared the effectiveness of aerobic, resistance, and Pilates exercises in reducing depressive symptoms and improving physical and executive function in older women.

While experimental studies have demonstrated the efficacy of physical exercise, the effect of long-term eccentrically reinforced resistance training on depressive symptoms, physical function, and executive function in sedentary older women remains unclear.

Therefore, this study aims to evaluate the safety and effect of eccentrically reinforced resistance exercise versus traditional resistance training on depressive symptoms, physical and executive function, quality of life, different manifestations of muscle strength, body composition, vital signs, abdominal circumference, fall risk, and fatigue symptoms in sedentary older women over a 10-month period.

Seventy Four older women will be randomly assigned to two groups: Flywheel resistance training and traditional resistance training. The interventions will be conducted at the Physical Education Department of the Federal University of Viçosa, with all sessions supervised by Physical Education professionals. Follow-up will be carried out through WhatsApp messages and phone calls. Both groups will train twice a week for 10 months. Participants in the experimental group will perform Flywheel resistance training on a multi-leg isoinertial machine targeting upper and lower body muscles, while the control group will use traditional machines and free weights. Each session will include 6 to 7 exercises, performed in 4 sets of 8 to 12 repetitions, with a 2-minute rest between sets and exercises. Training progression will be adjusted based on the participant's ability to exceed the maximum suggested repetitions with the same mobilized weight. Exercises will target various muscle groups, including leg extension, leg curl, bicep curl, tricep extension, seated row, shoulder flexion, and shoulder elevation.

Participants will be assessed at three time points during the training program: pre-intervention, 5 months, and 10 months after the intervention starts. Lower limb muscle strength will be evaluated using one-repetition maximum (1RM) tests on a knee extension machine and through maximal voluntary isometric contraction (MVIC), assessed with a load cell. Depressive symptoms will be measured using the Geriatric Depression Scale (GDS), validated for use in Brazil. Physical function will be assessed through the Timed Up and Go (TUG) test and the Senior Fitness Test (SFT). Executive function will be evaluated using the Victoria Stroop test, Digit Span (forward and backward), and the Trail Making Test (parts A and B). Quality of life will be assessed using the Brazilian version of the WHOQOL-Bref, while body composition will be analyzed through dual-energy X-ray absorptiometry (DXA). Blood pressure (systolic, diastolic, and mean arterial pressure) will be measured using an aneroid sphygmomanometer, and resting heart rate will be manually recorded after 3 minutes in a seated position. Abdominal circumference will be measured with a metal tape at the midpoint between the lower costal margin and the iliac crest, at the end of a normal expiration. Fall risk will be assessed using the Falls Efficacy Scale-International (FES-I) and the Berg Balance Scale. Fatigue symptoms will be evaluated using the Fatigue Symptom Inventory (FSI).

Eligibility Criteria:
Inclusion Criteria:

* 60 years or older.
* Self-reported proficiency in speaking, writing, and understanding Portuguese.
* Willingness and availability to participate in all trial procedures.
* Good vision in at least one eye.
* Absence of any medical contraindications for engaging in physical exercise.
* Engage in less than 150 minutes of physical activity per week.
* Not clinical diagnosis of major depressive disorder at the time of the interventions.

Exclusion Criteria:

* Have uncontrolled chronic or psychiatric illnesses.
* Surgical procedures scheduled during the intervention period.
* Diagnosis of joint diseases such as osteoarthritis and arthrosis.
* Participating in aerobic or resistance exercise programs twice a week for the past three months.