Effects of photobiomodulation therapy associated with resistance training in elderly men: a randomized double-blinded placebo-controlled trial.

PURPOSE: The purpose of this study was to investigate the effects of photobiomodulation therapy (PBMT) combined with resistance training on knee extensors muscle mass, strength and functional capacity in elderly men. METHODS: In this randomized double-blinded placebo-controlled trial, healthy elderly men (age 60-80 years) completed 12 weeks of resistance training (2×/week) with application of placebo (n = 13) or active PBMT (n = 11) on quadriceps muscles (850 nm, 240 J per limb) before each training session. Leg press and knee extension one-repetition maximum (1RM) tests, isometric and concentric peak torques, rectus femoris (RF) and vastus lateralis (VL) muscle thickness, timed up-and-go (TUG) and chair rise-to-standing (CRS) tests were performed before and after the intervention period. RESULTS: There were significant improvements in all outcomes for both groups (p < 0.05), except for RF muscle thickness for the placebo group (p = 0.09). Large effect sizes (ES > 0.8) were observed for leg press and leg extension 1RM and CRS tests for both groups, as well as for TUG test for PBMT group. Isokinetic peak torque for both groups and TUG for placebo group had moderate increases (ES > 0.5). Muscle thicknesses and isometric peak torque had small increases (ES > 0.2) in both groups. Both null hypothesis analysis and magnitude-based inference support similar effects of PBMT and placebo treatments. CONCLUSION: Different than previously evidenced in young subjects, PBMT with the parameters used in this study did not provide any additional benefits in comparison to placebo application on muscle mass, strength and functional capacity of healthy elderly men engaged in a resistance training program.

Effects of long-term concurrent training to failure or not in muscle power output, muscle quality and cardiometabolic risk factors in older men: A secondary analysis of a randomized clinical trial.

This study investigated the effects of concurrent training performed either with repetitions to failure or not to failure in muscle power, muscle quality (MQ), peak oxygen uptake (VO2peak), and visceral fat in older men. This is an ancillary analysis of a randomized controlled trial. 36 older men (mean age ± SD; 67.1 ± 5.1 years) were randomized into three groups: one performing repetitions to failure (RFG, n = 13), another performing repetitions not to failure and 50% of the repetitions of the RFG (NFG, n = 12), and third performing repetitions not to failure with equal training volume of the RFG (ENFG, n = 11). The training was performed twice a week for 20 weeks at intensities ranging from 65 to 80% of maximal strength. In each session, the individuals started with strengthening exercises and then performed aerobic exercise (i.e., walking) on a treadmill. The primary endpoint was change from baseline to post-20 wk of absolute and relative muscle power output during squat and countermovement jump, ultrasound measurements for MQ using quadriceps echo intensity, and visceral fat thickness, as well as their VO2peak through a maximal incremental test on a treadmill. All training groups improved similarly and significantly jump height (ranging from 9 to 16%) and all their muscle power outcomes (mean change ranging from 2 to 7%) (P < .001). In addition, all groups significantly decreased visceral fat thickness (ranging from -11 to -21%) (P < .001), and significantly increased VO2peak (ranging from 4 to 8%) (P < .01), with no differences between groups. No changes were observed in the MQ outcomes. Concurrent training performed using repetitions to failure or not to failure promoted similar gains in the muscle power output, aerobic capacity, and visceral fat in healthy older men.