Author(s): GARCIA-ALBIN, D., GARCIA-AGUIRRE, M., GUTIERREZ-REGUERO, H., BALTASAR-FERNANDEZ, I., ARA, I., GARCIA-GARCIA, F.J., ALEGRE, L.M., ALCAZAR, J., Institution: UNIVERSIDAD DE CASTILLA- LA MANCHA, Country: SPAIN, Abstract-ID: 2043

INTRODUCTION:
Muscle power influences physical performance and health and declines with age. However, it is unclear whether this loss is uniform across the force-velocity relationship (FVR) and whether highly active aging ameliorates it. This study examined neuromuscular power differences in young, middle-aged, older adults, and master athletes.
METHODS:
A total of 110 participants were categorized into four groups: 27 young adults (YA; 14 men, 13 women; 25±3 years), 30 middle-aged adults (MA;15 men,15 women; 55±1 years), 31 robust older adults (OA;13 men,18 women; 70±4 years), and 23 master athletes (MAT; 10 men,13 women; 69±4 years). The FVR was assessed in the leg press exercise, and a hybrid (linear + hyperbolic) model was applied to obtain F-V and power outcomes (Alcazar et al., 2022). The FVR was segmented into three bands relative to estimated maximal isometric force (F0) normalized to body mass, and areas under the curve (AUC) denoting overall power production (W/kg) were calculated: 0–33% of F0 (AUC_low), 33–66% of F0 (AUC_med), and 66–100% of F0 (AUC_high). Group differences were examined using ANOVA with group and sex as fixed factors, and Cohen’s d was calculated to determine effect sizes (ES).
RESULTS:
A significant group effect was found for AUC_low (F =47.64; p < 0.001), with higher values in YA (6.76±2.00 W/kg) compared to the other groups, and greater values in MA (4.01±1.19 W/kg) compared to OA (3.08±0.89 W/kg) and MAT (3.90±0.92 W/kg) (all p<0.05). Similar group effects were found for AUC_med (F = 47.02; p <0.001). YA showed higher values (3.17±0.85 W/kg) than the other groups, and MA exhibited higher levels (2.03±0.73 W/kg) than OA (1.51±0.41 W/kg) and MAT (1.96±0.37 W/kg) (all p<0.05). A significant group effect was also reported for AUC_high (F = 46.27; p<0.001). YA showed higher values (1.07±0.29 W/kg) than the other groups, and MA produced higher values (0.69±0.25 W/kg) than OA (0.52±0.11 W/kg) and MAT (0.67±0.13 W/kg) (all p<0.05). No significant differences were found between OA and MAT in any AUC (all p>0.05). ES analyses showed that differences between YA and the rest of the groups were very large (all ES ≥ 1.31). In contrast, differences between MA and OA were moderate (ES = 0.50 to 0.62), whereas those between MA and MAT were classified as trivial (all ES < 0.08).
CONCLUSION:
These findings indicate that aging is associated with a uniform reduction in muscle power across the F–V spectrum, although highly active aging partially attenuates this decline.

Funding: CB16/10/00456; CB16/10/00477; 2025-GRIN-38408; TEC 2022-007; SBPLY/19/180501/000312; PI031558, PI07/90637, PI07/90306, RD06/0013, PI18/00972; SBPLY/23/180225/000155
REFERENCES

Alcazar J, et al. Eur J Appl Physiol. 2022;122:2305–2313