Author(s): SPUDIC, D., STERMECKI PUKL, M., SMAJLA, D., Institution: UNIVERSITY OF LJUBLJANA, Country: SLOVENIA, Abstract-ID: 1261

INTRODUCTION:
Flywheel (FW) resistance devices represent a promising and relatively underexplored approach for assessing and improving power performance in older adults during both concentric and eccentric contractions (1), potentially mitigating age-related declines in power (“powerpenia”) (2). This study aimed to examine the intra- and inter-session reliability and validity of an FW squat power test in older adults and to investigate the effects of a 6-week FW squat power training protocol on knee strength, squat power, force–velocity (F-v) characteristics, and functional performance.
METHODS:
Thirty older adults (mean age 69.5 years) completed two pre-intervention assessments and one post-intervention assessment following a 6-week training program. Assessments included functional tests (30-second sit-to-stand and timed up-and-go), isokinetic knee flexion and extension at 30°/s and 180°/s, and squats using both FW and hex-bar devices across three loading conditions. Absolute and relative reliability coefficients were calculated for FW squat force, velocity, and power outcomes within and between sets during concentric and eccentric phases. Pearson correlation coefficients were calculated between FW squat and functional test results. After the second session, participants were assigned to two power training groups. Training was performed twice weekly at peak-power load condition using FW or hex-bar devices. Between-group differences in outcome changes over time were analysed using ANCOVA.
RESULTS:
Velocity was the most reliable within-, between-set and inter-session outcome (ICC > 0.84). Reliability of all outcomes improved across sessions (ICC = 0.72–0.89; CV = 14–2%). Correlations between FW squat outputs and functional tests ranged from |r| = 0.43 to 0.80, with strongest associations observed for power, during the third session in the eccentric phase at the highest FW load (0.075 kg·m^2). Power training led to significant improvements in isokinetic knee strength, squat power and functional tests (8–20%; p < 0.05). Both training groups improved the F–v profile velocity components of the isokinetic test, the eccentric phase of the FW squat, and the concentric phase of the hex-bar squat. In contrast, they improved the force component in the concentric phase of the FW squat. ANCOVA revealed no significant differences in adaptations between the training groups (p > 0.05).
CONCLUSION:
Reliability of FW squat power testing improves with repeated exposure in older adults. Higher FW loads and velocity measures yielded the most reliable results. Eccentric phase power at higher FW loads showed the strongest associations with functional performance. FW squat training is a practical and effective modality for power assessment and strength, power, and consequently functionality enhancement in older adults. Nevertheless, it was not found to be superior to hex-bar squat power training.
1) Spudić & Nosaka, Sport. Med. - Open 2026; 2) Freitas et al., BJSM, 2025