|Title of the paper:||High-velocity resistance training improves the force-velocity profile of middle-aged and older adults with and without mobility limitation|
|Authors:||SCHAUN, G.Z., CSAPO, R., ANDRADE, L.S., DAVID, G.B., HÄFELE, M.S., MENDES, G.F., ALBERTON, C.L.|
|Institution:||University of Vienna|
|Department:||Centre for Sport Science and University Sports|
The ability to produce muscle power is reflected by the force-velocity (F-V) relationship. Aging is associated with neuromuscular remodeling processes that result in reduced maximum shortening velocity and impaired muscle force. Regular physical exercise can mitigate these effects, but the impact of high-velocity resistance training (HVRT) on the F-V relationship of older individuals remains poorly understood (1). The goal of the present investigation was to assess whether HVRT can improve the F-V profile of different samples of older adults and evaluate the influence of different baseline F-V profiles on training responses and functional capacity.
Middle-aged (n=14, 48±5 yrs) and older adults with (n=15, 69±7 yrs) and without (n=7, 76±8 yrs) mobility limitations were included in this study. The participants F-V profiles were determined both before and after a 12-wk HVRT program (3x/wk, 40-60% 1RM) in the leg press exercise using incremental loads ranging between 30-90% 1RM and a linear position transducer. The resultant F-V data points were fitted using linear regressions to estimate the maximal isometric force (F0), maximal unloaded velocity (V0), maximum power (Pmax), as well as the force (Fopt) and velocity (Vopt) at Pmax. Functional capacity was measured using the maximal gait speed (MGS) test. Timepoint x group repeated measures ANOVAs, t-tests, and linear regression models were used for statistical analyses.
All three groups improved Pmax, F0, and Fopt (p<0.05), whereas V0 and Vopt remained unchanged. Notwithstanding this, an inspection of the individual F-V curves revealed two major patterns in response to training: an increase in both V0 and F0 or an increase in F0 without changes in V0. A moderate negative correlation (r=-0.63, p<0.001) was observed between V0 at pre-training and change in V0, suggesting that the slower participants at baseline achieved greater gains as compared to the faster individuals. This was also supported by comparisons between groups created based on V0 tertiles, which confirmed greater gains in V0 (11±9% vs. -1±10%; p=0.001) in the lowest V0 tertile. In this group, greater gains in V0 also correlated with changes in MGS (r=0.69, p=0.01).
Our results show that HVRT improves maximal force and power output in middle-aged and older adults. On average, the power gains were achieved through an increase in force without a concomitant increase in velocity. However, follow-up analyses of individual F-V profiles showed that the training-induced changes in V0 were contingent upon baseline V0 levels, with originally velocity-deficient subjects showing the largest gains (2). Hence, it can be concluded that HVRT improved power output through improvements in F0 in all subjects and gains in V0 in originally velocity-deficient subjects only. In the latter, improving V0 also seemed to influence the transfer of these improvements to functional capacity.
1. Raj et al, Exp Gerontol 2010
2. Alcazar et al, Exp Gerontol 2018
|Topic:||Training and Testing|