Maximal intended velocity enhances strength training-induced neuromuscular stimulation in older adults

Sit-to-Stand Power Is a Stronger Predictor of Gait Speed than Knee Extension Strength

With a growing aging population, the routine assessment of physical function may become a critical component of clinical practice. The purpose of this cross-sectional study is to compare two common assessments of muscular function: (1) isometric knee extension strength (KES) and (2) sit-to-stand (STS) muscle power tests, in predicting objective physical function (i.e., gait speed) in aging adults. 84 adults (56% female, mean (SD) age = 66.6 (9.4) years) had their relative KES, STS power, usual gait speed (UGS), and fast gait speed (FGS) assessed. Multiple linear regression examined the associations between KES, STS power, and gait outcomes. When entered in separate models, KES and STS power were both independently associated with UGS and FGS (Std. β = 0.35-0.44 and 0.42-0.55 for KES and STS power, respectively). When entered in the same model, STS power was associated with UGS and FGS (Std. β = 0.37 [95%CI: 0.15, 0.58] and 0.51 [95%CI: 0.31, 0.70], respectively), while KES was only associated with FGS (Std. β = 0.25 [95%CI: 0.02, 0.48]). STS power seems to be a valid indicator of function in aging adults. Its feasibility as a screening tool for "low" function in the primary care setting should be explored.

Effects of Eccentric Phase Velocity on Bench Press Concentric Bar Velocity in the Young and Elderly

This study aimed to investigate the impact of bar velocity during the eccentric phase on subsequent concentric performance in the young and elderly. Twelve elderly women (65.2+4.2 years) and 16 young women (23.1+2.1 years) were randomly assigned to four experimental conditions that combined high-velocity eccentric actions (HVECC; maximum velocity) and moderate-velocity eccentric actions (MVECC; 2.0 s), using 30% and 60% of their 1-repetition maximum (1RM) on the Smith machine bench press. Measurements of mean propulsive velocity (MPV), peak velocity (PV), and mean power (MP) were recorded. Two-way ANOVA with repeated measures was applied for each variable, when needed, the Bonferroni post hoc was used. Statistical significance was set at p<0.05, and effect size (ES) was established by Cohen's d z. The results demonstrated that elderly women showed improved performance in MPV (+10.0%; ES=- 0.58; p=0.009) and MP (+11.7%; ES=- 0.14; p=0.045) when utilizing HVECC at 30% 1RM only. Moreover, young women exhibited superior performance for both 30% and 60% 1RM when using HVECC for all variables analyzed (p<0.05). The HVECC appears to have an impact on the subsequent performance of the concentric phase, particularly when lighter loads (30% 1RM) are utilized, regardless of the age group.

Changes in strength-related outcomes following velocity-monitored resistance training with 10 % and 20 % velocity loss in older adults

We compared the effects of velocity-monitored resistance training with an intra-set velocity loss (i.e., the decrement in repetition velocity over the set) of 10 % vs. 20 % on strength-related outcomes in older adults. We randomly assigned eighteen older adults to a velocity loss group of 10 % (n = 10; 78 ± 12 years) or 20 % (n = 8; 73 ± 10 years) to perform a 10-week training program. The primary outcomes were the one-repetition maximum (1RM) and the average mean velocity against absolute loads associated with loads <60 % 1RM (MVlow) and ≥ 60 % 1RM (MVhigh) in the leg and chest press exercises, assessed at pre-, mid- (week 5), and post-test. Secondary outcomes included handgrip strength, 1-kg medicine ball throw distance, 10-m walking time, and five-repetition sit-to-stand time. No differences between groups were found in any outcome at any time (p > 0.05). Both groups improved the 1RM leg press from pre- to mid- and post-test and the MVlow and MVhigh from pre- to mid-test (p < 0.05). No group improved the 1RM chest press (p > 0.05), but both increased the MVlow from pre- to mid-test (p < 0.05). Furthermore, both groups improved the sit-to-stand time, while only the 20 % velocity loss group significantly improved handgrip strength and 10-m walking time (p < 0.05). The results showed that both velocity losses improved leg press strength and velocity, chest press velocity, and sit-to-stand time in older adults, although a 10 % velocity loss was more efficient as it required less volume (i.e., total repetitions) than 20 %. Nevertheless, the latter seems required to optimize handgrip strength and 10-m walking time in older people.

Optimizing mechanical performance in the bench press: The combined influence of inter-set rest periods and proximity to failure

This study examined the influence of inter-set rest periods of 1 (R1), 3 (R3) and 5 (R5) minutes on the number of repetitions completed before exceeding the minimum velocity thresholds of 0.45 m⋅s-1 (MVT0.45) and 0.35 m⋅s-1 (MVT0.35) during the bench press exercise. Twenty-three physically active individuals, 15 men and eight women, randomly completed six testing sessions consisting of four sets of the bench press exercise performed with maximal intent against 75% of the one-repetition maximum. Testing sessions differed in the length of inter-set rest periods (R1, R3, and R5) and MVT applied (MVT0.45 and MVT0.35). The number of repetitions was lower using shorter inter-set rest periods (R1 < R3 < R5), but R3 was more similar to R1 and R5 using MVT0.45 and MVT0.35, respectively. The fastest velocity of the set was reduced with the increment in the number of sets for the three protocols using MVT0.35 (greater reduction for shorter rest periods), but it was only reduced for R1 when using MVT0.45. The results suggest that, to maintain bench press mechanical performance, 5-min inter-set rest periods are necessary when sets are terminated close to failure (MVT0.35), while 3 min may suffice when sets are terminated farther from failure (MVT0.45).

Exercise effects on functional capacity and quality of life in older patients with colorectal cancer: study protocol for the ECOOL randomized controlled trial

BACKGROUND

Surgery and treatment for colorectal cancer (CRC) in the elderly patient increase the risk of developing post-operative complications, losing functional independence, and worsening health-related quality of life (HRQoL). There is a lack of high-quality randomized controlled trials evaluating the potential benefit of exercise as a countermeasure. The primary aim of this study is to evaluate the effectiveness of a home-based multicomponent exercise program for improving HRQoL and functional capacity in older adults undergoing CRC surgery and treatment.

METHODS

This randomized, controlled, observer-blinded, single-center trial aims to randomize 250 patients (>74 years) to either an intervention or a control group (i.e., usual care). The intervention group will perform an individualized home-based multicomponent exercise program with weekly telephone supervision from diagnosis until three months post-surgery. The primary outcomes will be HRQoL (EORTC QLQ-C30; CR29; and ELD14) and functional capacity (Barthel Index and Short Physical Performance Battery), which will be assessed at diagnosis, at discharge, and one, three, and six months after surgery. Secondary outcomes will be frailty, physical fitness, physical activity, inspiratory muscle function, sarcopenia and cachexia, anxiety and depression, ambulation ability, surgical complications, and hospital length of stay, readmission and mortality.

DISCUSSION

This study will examine the effects of an exercise program in older patients with CRC across a range of health-related outcomes. Expected findings are improvement in HRQoL and physical functioning. If proven effective, this simple exercise program may be applied in clinical practice to improve CRC care in older patients.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT05448846.

Effects of home-based bodyweight squat training on neuromuscular properties in community-dwelling older adults

BACKGROUND

It is important to investigate neural as well as muscle morphological adaptations to evaluate the effects of exercise training on older adults.

AIMS

This study was aimed to investigate the effects of home-based bodyweight squat training on neuromuscular adaptation in older adults.

METHODS

Twenty-five community-dwelling older adults (77.7 ± 5.0 years) were assigned to squat (SQU) or control (CON) groups. Those in the SQU group performed 100 bodyweight squats every day and the others in the CON group only performed daily activities for 4 months. Maximum knee extension torque and high-density surface electromyography during submaximal contraction were assessed. Individual motor units (MUs) were identified and divided into relatively low or high-recruitment threshold MU groups. Firing rates of each MU group were calculated. The muscle thickness and echo intensity of the lateral thigh were assessed using ultrasound. As physical tests, usual gait speed, timed up and go test, grip strength, and five-time chair stand test were performed.

RESULTS

While no improvements in muscle strength, muscle thickness, echo intensity, or physical tests were noted in either group, the firing rate of relatively low recruitment threshold MUs significantly decreased in the SQU group after intervention.

CONCLUSIONS

These results suggest that low-intensity home-based squat training could not improve markedly muscle strength or physical functions even if high-repetition and high frequency exercise, but could modulate slightly neural activation in community-dwelling older adults.