Abstract
Introduction: We hypothesised that eccentrically biased resistance training (ECC) would lead to greater strength, muscle architectural and functional gains than conventional training (CONV) in older adults.
Methods: Twelve participants were randomly assigned to CONV (seven males and five females; mean age 67.8 years, range 60–74), 13 to ECC (eight males and five females; mean age 68.2 years, range 60–75) and 13 to wait-list control (7 males and 6 females; mean age 66.5 years, range 60–74). Training was performed twice a week for 16 weeks. Exercises were leg press, toe press, bench press and latissimus pulldown. Participants in ECC performed three sets of 10 bilateral concentric lifts at 50% of one repetition maximum (1RM). Following each concentric lift, the eccentric phase was performed unilaterally, alternating between each leg or arm with each repetition, thus performing five unilateral eccentric contractions in each set. Participants in CONV performed two sets of 10 bilateral eccentric and concentric lifts at 75% of 1RM. Rating of perceived exertion (RPE) was recorded after each set. Isometric and concentric knee extensor strength was assessed on an isokinetic dynamometer from 0°/s to 360°/s. Vastus lateralis (VL) and gastrocnemius medialis (GM) muscle architecture (fascicle length, pennation angle and thickness) was assessed using ultrasonography. The six-metre fast walk test (6MFWT), timed up and go test (TUG), stair climb and descent power, and vertical jump were used to assess functional capacity.
Results: Training increased strength at 60°/s (p < 0.05) and 120°/s (p < 0.01) in both training groups (6–8%). Isometric strength and strength at fast contraction speeds (240°/s and 360°/s) only increased (p < 0.05) in ECC (7, 5 and 11% respectively). Training improved performance in the 6MFWT in both training groups (p < 0.01) by 5–7%. TUG and vertical jump performance improved in CONV (p < 0.01) by 5% and 7% respectively. Stair climb performance improved in ECC (p < 0.01) by 5%. VL thickness increased (p < 0.05) by 5% in ECC. RPE was lower in ECC than CONV for bench press (p < 0.05) and latissimus pulldown (p < 0.01).
Conclusions: The improvement in strength at fast contraction speeds in ECC means that this modality may be more effective than CONV when seeking to improve performance at tasks requiring fast contractions such as recovering from a trip. It is inconclusive as to which modality is more effective at improving function. ECC may be more effective at increasing muscle mass than CONV. The lower RPE in ECC may make it preferable to CONV for older adults.