Acute effects of low and high-volume resistance training on hemodynamic, metabolic and neuromuscular parameters in older adults

Objective: To analyze the acute effects of low or high-volume resistance training (RT) on hemodynamic, metabolic and neuromuscular parameters in institutionalized older adults. Methods: Thirty-one subjects (78.9 +/- 7.2 years old) performed two RT protocols (low versus high-volume), separated by one-week rest. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and blood lactate concentration ([La-]) were evaluated before and immediately after both RT protocols. The seated medicine ball throw (SMBT) was evaluated before and 5 min after both sessions, the countermovement jump (CMJ) height was evaluated before and 6 min after both RT protocols and the absolute handgrip strength (HGS) was evaluated before and 7 min after both RT protocols. Results: At baseline, no significant differences between RT protocols were found in all variables. After training session, both RT protocols induced significant increases in SBP (low versus high-volume: 5.3% vs 10.7%), DBP (5.9% vs 6.8%), HR (6.8% vs 17.9%) and [La-] (86.1% vs 200.0%). Moreover, the high-volume protocol induced significant decreases in SMBT (- 2.5%) and CMJ (- 8.3%), whilst the low-volume protocol significantly increased the HGS (3.4%). Conclusions: Both RT protocols induced significant acute responses on cardiovascular and metabolic parameters, as well as on neuromuscular function in institutionalized older adults. However, a greater acute response after the high-volume RT protocol was found, thus reflecting greater hemodynamic, metabolic and neuromuscular stress than low-volume RT. Moreover, low-volume RT showed an acute increase in general strength.