The Influence of a Total Body Resistance Training Program on Autonomic Modulation and Strength Variables in Young...

The purpose of this study was to examine autonomic modulation using multiple quantitative measures before and after a resistance training (RT) intervention. Seventeen young adults (age 18-35 years) were tested for body composition, muscular strength, and autonomic activity. The RT protocol targeted total-body large muscle groups, which were performed three days a week for eight-weeks. Autonomic assessments included respiratory sinus arrhythmia (RSA), static handgrip exercise, Valsalva maneuver, heart rate variability (HRV), and tilt-table testing. The main finding was that tilt-table duration increased by 68 seconds (p = 0.05) after RT. Upper body strength increased by 11.2 kg (p = 0.001) and lower body strength increased by 68.3 kg (p < 0.001) following completion of the RT intervention. The average total lean mass increased by 1.5 kg (p < 0.01), while total fat mass was unchanged (Δ = 0.5 kg, p = 0.23). RSA (Δ = 0.4, p = 0.89), Valsalva ratio (Δ = -0.09, p = 0.48), static handgrip (Δ = 8 mm Hg, p = 0.07), and HRV (Δ = -0.4, p = 0.53) were not affected by RT. The results from this study suggest that RT improves tilt-table tolerance in a young healthy population as evidence by improved tilt-table duration. However, RT seemed to have no effect on cardio-vagal or adrenergic function.