Abstract
This study examined the influence of physical activity (PA) on the retention of rate of torque development (RTD) effects achieved following a 16-week high-speed resistance training (HSRT) over a 12-month follow-up period. Secondly, the fear of falling was also assessed. After the follow-up, 36 participants were categorized into two groups according to the PA: light activity group (LAG, N = 20, age 70.00 ± 3.66 years) and moderate-to-vigorous activity group (MVAG, N = 16, age 68.50 ± 2.09 years). At the four time points, RTD(PEAK) and its time intervals for knee extension and flexion were measured using an isokinetic dynamometer at 60º/s, and the fear of falling was assessed using the Falls Efficacy Scale-International questionnaire. Both groups showed significant RTD(PEAK) improvements from pre-intervention to the 12-month follow-up (moderate-to-large effect sizes). However, PA levels suggested to influence the retention effects: LAG showed declines in dominant RTD(PEAK) (2% in extension and flexion) and in non-dominant side (6% extension and 5% flexion). In contrast, the MVAG maintained or slightly improved RTD(PEAK) performance in dominant (1% extension and 2% flexion) and in non-dominant side (3% extension and 1% flexion). Fear of falling scores remained significantly reduced in both groups compared to pre-intervention, regardless of PA level. In summary, maintaining moderate-to-vigorous PA during follow-up appears to enhance the long-term retention of HSRT-induced neuromuscular adaptations, whereas HSRT effects on fear of falling were sustained regardless of PA level, highlighting its clinical potential for fall prevention.