Kristin Briem

Effects of whey proteins and carbohydrates on the efficacy of resistance training in elderly people: double blind, randomised controlled trial.

Background/objectives:A few previous studies indicate that protein supplementation increases gains in muscle mass and strength during a resistance exercise program. The purpose of this study was to investigate whether whey protein supplementation results in greater increases in lean body mass, muscle strength and physical function in elderly individuals during 12 weeks of resistance exercise when compared to isocaloric carbohydrate supplementation.Subjects/Methods:A total of 161 men and women, 65–91 years old, participated in a randomized, controlled, double-blind intervention study, involving dietary supplementation and a 12-week resistance exercise program, designed to increase muscle mass and strength of all major muscle groups. Participants exercised three times a week and received either 20 g of whey protein (n=83) or isocaloric carbohydrate (n=78) in liquid form immediately after each workout. Data were obtained at baseline and end point.Results:The primary outcomes, lean body mass, strength and physical function increased significantly during the course of the study. Type of dietary supplementation did not influence gains in lean body mass (P=0.365), quadriceps strength (P=0.776) or performance during a 6-min walk (P=0.726) or a timed up-and-go test (P=0.151). Twenty participants discontinued the intervention.Conclusions:Ingestion of 20 g of whey protein immediately after resistance exercise three times per week, does not lead to greater gains in lean body mass, strength and physical function in elderly people with sufficient energy and protein intakes when compared to isocaloric carbohydrate.

Effect of 12-Week Resistance Exercise Program on Body Composition, Muscle Strength, Physical Function, and Glucose Metabolism in Healthy, Insulin-Resistant, and Diabetic Elderly Icelanders

BACKGROUND Insulin is a stimulator of skeletal muscle protein anabolism and insulin resistance might therefore negatively affect muscle protein metabolism. We investigated muscle mass and physical function before and after a resistance exercise program in participants with prediabetes or type 2 diabetes mellitus (T2DM) in comparison to healthy controls. METHODS This was a secondary analysis of a randomized controlled intervention designed to investigate resistance training among older adults. Glucose metabolism status was not a selection criteria for the trial, and group designation was done retrospectively. Participants (N = 237, 73.7 ± 5.7 y, 58.2% women) participated in a 12-week resistance exercise program (3 times/week; three sets, six to eight repetitions at 75%-80% of the one-repetition maximum), designed to increase strength and muscle mass of major muscle groups. Body composition, muscular strength, timed up and go test, 6-minute walk for distance, and blood chemical variables were measured at baseline and endpoint. RESULTS Participants completing the study (n = 213) experienced significant changes in muscle strength or muscle function, which did not differ significantly between healthy (n = 198), prediabetic (n = 20), and T2DM participants (n = 17). Changes in serum glucose during the intervention differed by group: only glucose improved significantly in the prediabetic group, glucose and triacylglycerol improved significantly in the healthy group, whereas no serum parameter improved significantly in the T2DM group. CONCLUSIONS A 12-week resistance exercise program improves muscle strength and muscle function to a similar extent in healthy, prediabetic, and T2DM elderly people. However, according to our data, T2DM participants do not experience favorable changes in fasting glucose or HbA(1C).

Physical function predicts improvement in quality of life in elderly icelanders after 12 weeks of resistance exercise

BackgroundLittle is known about the effects of resistance training on health related quality of life (HRQL) in the elderly.AimThe main purpose of the study was to investigate the effects of resistance training on strength, body composition, functional capacity and HRQL in independent living elderly people. We hypothesised that resistance training would improve lean mass, muscle strength, physical function and HRQL.MethodsSubjects (N = 237, 73.7±5.7yrs, 58.2% female) participated in a 12-week resistance exercise program (3 times/week; 3 sets, 6–8 repetitions at 75–80% of the 1-repetition maximum) designed to increase strength and muscle mass of major muscle groups. Body composition, quadriceps- and grip strength, timed up and go test (TUG), six minute walk for distance (6MW) and HRQL were measured at baseline and endpoint.ResultsTwo hundred-and-four participants completed the study. Although the increase in lean mass was small (+0.8 kg, P<0.01), quadriceps strength (+53.5N), grip strength (+3.0lb), TUG (-0.6sec), 6MW (+33.6m) and HRQL (+1.2 t-score) improved significantly (all P<0.01). Changes in 6MW predicted improvement in HRQL after 12 weeks.ConclusionsOur study shows that a 12-week resistance exercise program significantly improves lean mass, muscle strength, physical function and HRQL in elderly individuals, and that improvements in physical function predict improvements in HRQL. Our study indicates that resistance training should be promoted for the elderly as it has the potential to improve physical performance, thereby prolonging healthy, independent aging.

Muscular strength and physical function in elderly adults 6–18 months after a 12-week resistance exercise program

Aims: Benefits of resistance exercise in elderly people are well documented; however, sustaining these benefits can be difficult and adherence is often poor. Muscular strength and physical function usually decline after a supervised resistance exercise program (REP). We investigated these changes in older adults during an observational follow-up and whether leisure time physical activity (LTPA) or unsupervised resistance exercise (RE) limit these changes. Methods: Subjects (N=236, 73.7±5.7 years, 58.2% female) had participated in a supervised 12-week REP. Quadriceps strength and timed-up-and-go performance (TUG) at follow-up were compared to values before and after REP. Multivariate statistics were used to predict changes in strength or function. Results: Two hundred and eleven (90.3%) participants completed REP and 149 (63.1%) completed follow-up (11.4±2.9 months). Quadriceps strength at follow-up decreased significantly compared to after REP (–27N), but was higher than before REP (+30N). TUG did not decrease during follow-up and was better than before REP (–0.9 seconds). LTPA (+38.0N, p<0.001) and RE (+31.6N, p=0.006) predicted strength at follow-up, although they did not completely prevent loss of strength during follow-up. Conclusions: Quadriceps strength declines after a 12-week resistance exercise program in older adults. Neither LTPA nor RE completely prevents loss of quadriceps strength during follow-up, although they limited the loss. TUG did not change during follow-up and was better at follow-up than before the start of the resistance exercise program.

The Effect of Tibial Rotation on the Contribution of Medial and Lateral Hamstrings During Isometric Knee Flexion.

Background: Selective atrophy of hamstring components may result from muscle strain or graft harvesting for anterior cruciate ligament reconstruction. Assessment and rehabilitation that specifically targets medial (MH) or lateral (LH) hamstring components may improve patient outcomes. The purpose of this study was to evaluate effects of volitional tibial rotation medially (MR) versus laterally (LR) on activation levels of MH versus LH and strength measures during isometric testing of knee flexors. Hypothesis: Muscle activation of MH and LH during knee flexor strength testing will be augmented when coupled with MR and LR of the tibia, respectively, without affecting knee flexor strength measures. Study Design: Cross-sectional laboratory study. Level of Evidence: Level 3. Methods: Surface electrodes were used to record neuromuscular activity from MH and LH of the right lower limb in 40 healthy young men and women during isometric knee flexor strength testing at 40° of knee flexion, where participants maintained concurrent volitional MR or LR of the tibia. Statistical analyses of variance included general linear models for repeated measures. Results: A significant interaction was found for tibial rotation and hamstring component variables (P < 0.01). When isometric knee flexion was coupled with LR, normalized activation levels were similar for MH and LH. When performed with MR, a significant drop in LH activation led to dissimilar activation levels of the 2 components. Significantly greater strength measures were found when isometric knee flexion was performed with concurrent LR of the tibia (P < 0.01). Both sexes demonstrated the same rotation-dependent differences. Conclusion: Coupling tibial rotation with knee flexor activities primarily affects the LH component. Clinical Relevance: Strategies involving volitional tibial rotation may be considered for specific assessment/rehabilitation of the MH or LH component.

Frontal plane pelvis and hip kinematics of transfemoral amputee gait. Effect of a prosthetic foot with active ankle dorsiflexion and individualized training – a case study

Abstract Following a transfemoral amputation (TFA), numerous changes in movement patterns during gait can occur. Frontal plane hip and pelvis compensatory strategies are recognized among individuals with a TFA, some thought to aid in safe foot clearance during the swing phase of gait. The aim of this case study was to evaluate the effect of an active ankle dorsiflexion provided by a microprocessor-controlled prosthetic foot, as well as the effect of individualized training on these parameters. In this case study, a 42-year-old male underwent 3 D gait analysis. Data were captured for two conditions; with a microprocessor-controlled prosthetic foot with active/inactive ankle dorsiflexion, during two sessions; before and after 6 weeks of individualized training. The main outcomes analyzed were frontal plane pelvis and hip kinematics. Prior to training, pelvic lift decreased slightly, coupled with an increase in hip abduction, during gait with the active ankle dorsiflexion of a prosthetic foot, compared to inactive dorsiflexion. After the training period, the pelvic lift was further decreased and an increase in hip adduction was concurrently seen. The results of this case study indicate a positive effect of the active dorsiflexion of the prosthetic foot but highlight the need for specific training after prescription of a microprocessor prosthetic foot. Implications for rehabilitation Decreased compensatory changes seen in this case study indicate a positive effect of the active dorsiflexion of the prosthetic foot, especially after a 6-week training period. Individualized training should be aimed at helping the user utilizing the benefits of the active dorsiflexion of the microprocessor prosthetic foot, implementing exercises that improve gait quality, technical training for this specific foot, strength training and balance exercises.

Gender, Success, and Drop-Out during a Resistance Exercise Program in Community Dwelling Old Adults

Background Resistance exercise training can be effective against sarcopenia. We identified predictors of drop-out and compared physical outcomes between men and women after such training. Methods Subjects (N = 236, 73.7 ± 5.7 years) participated in a 12-week resistance exercise program. Outcome variables were measured at baseline and endpoint. Results Drop-out was 11.9% and not significantly different between genders. Drop-outs were significantly older and had poorer strength and physical function in comparison to completers. Anthropometrics, QoL, and cognitive function were not related to drop-out. According to multivariate analysis, gait speed and physical activity were the strongest predictors of drop-out. After the training, gains in lean mass or appendicular muscle were significantly higher in men than women; however relative gains in appendicular muscle as well as absolute improvements in strength and function were similar in men and women, respectively. Conclusions Participants who drop out are older, have poorer physical function, and are less physically active. Old women do not drop out more frequently than men and show meaningful improvements in relevant outcomes similar to men after such a training program. The trial is registered at the US National Library of Medicine (NCT01074879).

Response to 'Increasing physical activity requires increasing energy intake in elderly'.

We are grateful for the review of our article1 by Dr Safer et al.2 The question is whether or not the benefits of protein intake would have been more pronounced if energy intake had been adequate in the study population.