Abstract
We compared the effects of eccentrically biased (EB) and conventional (CONV) resistance training on muscle architecture, one-repetition maximum (1RM), isometric strength, isokinetic force-velocity characteristics, functional capacity, and pulse wave velocity in older men and women. Twenty-eight older adults participated in the study (mean ± SD: age = 68 ± 5 yr). Of these, 13 were allocated to a waitlist control, 10 of whom progressed to training (CONV, n = 12; EB, n = 13). Training was twice a week for 16 wk. EB involved three sets of 10 concentric lifts at 50% of 1RM with the eccentric portion of repetitions performed unilaterally, alternating between limbs with each repetition. CONV involved two sets of 10 repetitions at 75% of 1RM. EB and CONV were matched for total work. Isokinetic knee extensor strength was assessed across a range of velocities (0-360°·s(-1)). Functional capacity was assessed via a 6-m fast walk test, a timed up and go test, stair climb and descent power test, and vertical jump test. Vastus lateralis and gastrocnemius medialis architecture were assessed using ultrasonography. Both EB and CONV improved 1RM (Δ 23%-35%, P < 0.01). Compared to the control group, both training regimens improved 6-m fast walk (Δ 5%-7%, P < 0.01) and concentric torque at 60 and 120°·s(-1) (Δ 6%-8%, P < 0.05). Significant improvements were evident in EB for isometric and concentric torque at 240 and 360°·s(-1) (Δ 6%-11%, P < 0.05), vastus lateralis thickness (Δ 5%, P < 0.05), and stair climb (Δ 5%, P < 0.01). Timed up and go (Δ 5%, P < 0.01), stair descent (Δ 4%, P < 0.05), and vertical jump (Δ 7%, P < 0.01) improved in CONV. Pulse wave velocity, pennation angle, and fascicle length remained unchanged in both training groups. EB seems superior to CONV at increasing torque at high contraction velocities, whereas CONV seems more effective at improving some functional performance measures and vertical jump. This has important implications for preserving functional capacity.
Highlights
The benefits of conventional (CONV) and eccentrically-biased (EB)resistance training for older adults are well-established,[1,2,3] resistance training is advocated as an important component of exercise programs for older adults to maintain their health and physical function.[4]
The finding of a difference in platelet count between the control condition and the two exercise conditions (EB and CONV) post exercise (Post 0) appears to agree with the results of previous studies that demonstrated an increase in platelet count following resistance exercise.[5, 6, 23]
It could be interpreted that the higher platelet count in the exercise conditions as compared to the control condition post exercise was largely due to the significant decrease during the control condition rather than an increase in platelet count during the exercise conditions per se
Summary
The benefits of conventional (CONV) and eccentrically-biased (EB)resistance training for older adults are well-established,[1,2,3] resistance training is advocated as an important component of exercise programs for older adults to maintain their health and physical function.[4]. Whilst resistance training has been proven to convey considerable benefits to older people; immediately post-exercise there may be elevated transient risks for cardiac events and falls. Objectives and Measurements: We assessed the acute effects of eccentricallybiased (EB) and conventional (CONV) resistance exercise on: platelet number, activation and granule exocytsosis; and mean velocity of centre of pressure displacement (Vm). Eccentrically-biased and conventional resistance exercise training regimens do not appear to present an elevated acute risk in the context of changes to platelet function contributing to a cardiac event or postural stability increasing falls risk for apparently healthy older adults
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
