Effects of exercise training with weighted vests on bone turnover and isokinetic strength in postmenopausal women

Effects of resistance training on microcirculation of bone tissue and bone turnover markers in postmenopausal women with osteopenia or osteoporosis: A systematic review

After menopause, there is an imbalance between bone formation and resorption activity, which could lead to postmenopausal osteopenia or osteoporosis. Resistance training (RT) can induce mechanical stress on bone which is necessary for bone remodeling and angiogenic-osteogenic response. This systematic review aims to assess the effects of RT on bone microcirculation and bone turnover markers (BTMs) in postmenopausal women with osteopenia or osteoporosis. We conducted a comprehensive search for related studies published up to April 2023 to identify eligible articles. Out of 316 articles identified, the full texts of 69 articles were screened. There is not any study which consider the effect of resistance exercises on bone microcirculation in PMOP women, but four articles aseess the effect of RT on BTMs and were reviewed. The quality of the articles was assessed by using the Physiotherapy Evidence Database (PEDro) scale. In one study, after 6- and 12 -months RT, bone formation and bone resorption biomarkers decreased not significantly. According to another study, bone formation and resorption biomarkers increased significantly after 3-months RT. Two other studies reported increases in biomarkers of bone formation along with decreases of biomarkers in bone resorption after 6-months of RT, but these were not significant. However, these results suggest that RT had some beneficial effects on BTMs but it is not an effective tool for modifying BTMs in women with osteoporosis or osteopenia. This may be due to the site-specific skeletal stimulation that RT provides. In addition considering the effect of RT on microcirculation of bone are important . So, there is a need for further, high-quality studies in this field.

Exercise with weight vest plus chicken protein supplementation delayed muscle and bone loss in older female adults

PURPOSE

This study examined the effects of moderate-to-heavy exercise training combined with weighted vest and chicken protein supplementation in older adult females.

METHODS

Fifty-two female participants, 60-79 yearsold, were randomly divided into three groups: control (non-exercise) (CON), exercise with weighted vest (WV), and exercise with weighted vest and protein supplementation (3 g of protein daily; WVP).A ll participants performed brisk walking and strengthening exercises for 50 min/day, three times/week, for 8 weeks. Muscle mass, bone mineral content, T-score, and physical performance were measured.

RESULTS

The WVP group demonstrated a substantial increase in thoracic spine bone mineral content (8.4 ± 7.7 g, p = 0.001), and total body lean mass (0.2 ± 1.0 kg) compared with that in the other two groups. The CON and WV groups showed a decrease in thoracic spine bone mineral content (CON= -1.8 ± 1.8, WV= -3.9 ± 0.1 g) and total body lean mass (CON= -0.7 ± 0.9, WV= -0.8 ± 0.9 kg) compared with those in the WVP group. The WVP and WV groups had increased T-score (WVP= 0.01 ± 0.16, WV= 0.02 ± 0.18) when compared with that of the CON group (-0.19 ± 0.12). Both the WV and WVP groups displayed improved physical performance compared with that of the CON group.

CONCLUSION

Combined exercise with either a weighted vest or protein supplementation proved to be effective in protecting against trunk bone and muscle mass loss, and improving physical fitness in older female adults.

Effects of Using a Special Weighted Vest on Muscle Activity around the Scapula during Knee Push-Up Plus in Healthy Subjects

Muscle imbalances in the upper body can lead to ineffective movement patterns and potential injury. The purpose of this study was to investigate the muscle activity, impact, and muscle activation ratio of the serratus anterior (SA), upper trapezius (UT), lower trapezius (LT), and pectoralis major (PM) during the knee push-up plus (KPUP) exercise under various loads.

METHOD

Electromyography assessed scapular muscle activity in 32 healthy adults (15 males, 17 females) during three KPUP variations.

RESULTS

PM and UT showed no significant activity differences across loads, whereas SA and LT did. SA activity was significantly higher in the weighted KPUP (WKPUP) 3 kg than that in KPUP and WKPUP 1 kg. LT activity was also significantly higher in WKPUP 3 kg compared to KPUP and WKPUP 1 kg, with KPUP showing higher activity than WKPUP 1 kg. PM/SA ratios remained consistent across loads, while UT/LT ratios varied significantly, being notably lower at 3 kg compared to 0 kg and 1 kg. Similarly, UT/SA ratios differed significantly among loads, being notably lower at 3 kg and 1 kg compared to 0 kg.

CONCLUSION

WKPUP with 3 kg demonstrated significantly higher SA and LT activity compared to KPUP and WKPUP 1 kg. The lowest UT/LT ratio was observed during the WKPUP 3 kg, suggesting its effectiveness for optimizing muscle activation balance during KPUP exercises. These findings may inform the development of exercise protocols aimed at improving scapular stabilization.

Effects of weight-bearing dance aerobics on lower limb muscle morphology, strength and functional fitness in older women

Objective

To investigate the effects of 12-week weight-bearing dance aerobics (WBDA) on muscle morphology, strength and functional fitness in older women.

Methods

This controlled study recruited 37 female participants (66.31y ± 3.83) and divided them into intervention and control groups according to willingness. The intervention group received 90-min WBDA thrice a week for 12 weeks, while the control group maintained normal activities. The groups were then compared by measuring muscle thickness, fiber length and pennation angle by ultrasound, muscle strength using an isokinetic multi-joint module and functional fitness, such as 2-min step test, 30-s chair stand, chair sit-and-reach, TUG and single-legged closed-eyed standing test. The morphology, strength, and functional fitness were compared using ANCOVA or Mann-Whitney U test to study the effects of 12 weeks WBDA.

Results

Among all recruited participants, 33 completed all tests. After 12 weeks, the thickness of the vastus intermedius (F = 17.85, P < 0.01) and quadriceps (F = 15.62, P < 0.01) was significantly increased in the intervention group compared to the control group, along with a significant increase in the torque/weight of the knee flexor muscles (F = 4.47, P = 0.04). Similarly, the intervention group revealed a significant improvement in the single-legged closed-eyed standing test (z = -2.16, P = 0.03) compared to the control group.

Conclusion

The study concluded that compared to the non-exercising control group, 12-week WBDA was shown to thicken vastus intermedius, increase muscle strength, and improve physical function in older women. In addition, this study provides a reference exercise program for older women.

Effects of whole body vibration exercise combined with weighted vest in older adults: a randomized controlled trial

BACKGROUND

To evaluate the training effects of whole body vibration (WBV) combined with weighted vest (WV) in older adults.

METHODS

This randomized controlled trial study was conducted in healthy older adults living in the community. Fifty-one participants were randomly allocated into 3 groups: group 1 (n = 17), WBV alone, training on WBV at a frequency 30 Hz, amplitude 2 mm, 10 sets of 1 min squats, with 60 s rest, group 2 (n = 15), WV alone, squat exercise, 10 sets of 1 min, with 60 s rest, while WV loaded with 10% body weight and group 3 (n = 19), WBV + WV, combining WBV exercise with the addition of a WV. All groups completed training 3 times per week for 8 weeks. The outcomes were total muscle mass, muscle thickness, maximal isometric strength, single-leg-stance and timed-up-and-go evaluated at baseline and after training.

RESULTS

As a result of training all groups improved their isometric muscle strength with little difference between groups. The single-leg-stance significantly improved only in WBV + WV group 25.1 ± 10.8 s (mean ± 95% CI, p < 0.01). The timed-up-and-go improved in all groups, but the improvement was significantly greater in the WBV + WV group (17.5 ± 6.9%) compared to the WV (8.5 ± 3.2%) and WBV groups (9.2 ± 5.4%, p = 0.043, 0.023 respectively). Rectus femoris muscle thickness and total muscle mass were significantly increased in all groups equally with little difference between groups.

CONCLUSION

The combined WBV + WV had a greater effect on the single-leg-stance and the timed-up-and-go compared to WV or WBV alone.

TRIAL REGISTRATION

TCTR20190306001. Thai Clinical Trials Registry ( www.thaiclinicaltrials.org ). Date of registration: 6 March 2019.

The effect of exercise training on osteocalcin, adipocytokines, and insulin resistance: a systematic review and meta-analysis of randomized controlled trials

Recently, it has been reported that osteocalcin (OC), in particular its undercarboxylated (ucOC) form, is not only a bone remodeling marker but also an active hormone that intercedes glucose metabolism in humans. This study aimed to determine the impact of an exercise intervention on ucOC, adiponectin, leptin, and insulin resistance (measured by HOMA-IR). PubMed, CINAHL, Medline, Google Scholar, and Scopus databases and reference lists of included studies were searched. Twenty-two randomized controlled trials (RCTs) of exercise training impact in adults were included in the analysis. Results showed an overall significant increase in serum ucOC (MD: 0.15 ng/ml; 95% CI: 0.05 to 0.25) and adiponectin (MD: 2.83 mg/ml; 95% CI: 1.67 to 3.98), a significant decline in leptin (MD: - 4.89 pg/ml; 95% CI: - 6.94 to - 2.84), fasting glucose (MD: - 2.29 mg/dl; 95% CI: - 4.04 to - 0.54), fasting insulin (MD, - 8.90 μIU/ml; 95% CI: - 13.81 to - 3.98), and HOMA-IR (MD: - 1.96; 95% CI: - 3.11 to - 0.80). However, after removal of studies that had prescribed a balanced diet along with exercise intervention, total OC (TOC) levels also increased in the exercise group compared with the control group (MD: 0.36 ng/ml; 95% CI: 0.07 to 0.65). Our findings demonstrate that exercise-induced increases in ucOC are the probable cause of increased adiponectin. Additionally, increases in ucOC itself are probably due to changes in leptin levels and other factors, rather than its direct impact on bone and its osteoblastic activity. Further studies are required to clarify the mechanisms underlying the impact of exercise training on ucOC, adipocytokines, and insulin resistance.

Feasibility of Weighted Vest Use during a Dietary Weight Loss Intervention and Effects on Body Composition and Physical Function in Older Adults

BACKGROUND

While intentional weight loss in older adults with obesity yields clinically important health benefits there is a need to minimize the negative effects of weight loss on concomitant loss of muscle mass and strength. Data show wearing weighted vests during exercise improves lean mass and lower extremity strength, however the efficacy of wearing a weighted vest during a period of weight loss to mitigate muscle and strength loss is not known.

OBJECTIVES

This study examined the feasibility of daily weighted vest use during a dietary weight loss intervention, and examined effects of vest use on body composition and physical function in well-functioning older adults with obesity.

DESIGN

Randomized, controlled pilot study.

SETTING

Wake Forest Baptist Medical Center in Winston-Salem, NC.

PARTICIPANTS

37 older (age=65-79 yrs), obese (BMI=30-40 kg/ m2) sedentary men and women.

INTERVENTIONS

22-week behavioral diet intervention (targeting 10% weight loss, 1100-1300 kcals/day) with (Diet+Vest; n=20) or without (Diet; n=17) weighted vest use (goal of 10 hours/ day with weight added weekly according to individual loss of body mass).

MEASUREMENTS

Body composition by dual-energy x-ray absorptiometry and measures of physical function, mobility, and muscle strength/power.

RESULTS

Average weighted vest use was 6.7±2.2 hours/day and the vest-wear goal of 10 hrs/day was achieved for 67±22% of total intervention days. Five participants reported adverse events from wearing the vest (all back pain or soreness). Both groups lost a similar amount of weight (Diet= -11.2±4.4 kg; Diet+Vest = -11.0±6.3 kg; p<0.001), with no differences between groups (p=0.25). Fat mass, lean mass, and % body fat decreased significantly (p<0.0001), with no differences between groups. Compared to Diet+Vest, the Diet intervention resulted in greater decreases in leg power (p<0.02), with no other between group differences in physical function.

CONCLUSION

This pilot study showed that vest use during dietary weight loss is feasible and safe in well-functioning older adults with obesity. Larger studies are needed to definitively determine whether external replacement of lost weight during caloric restriction may preserve lower extremity muscle strength and power.

Effects of short-term step aerobics exercise on bone metabolism and functional fitness in postmenopausal women with low bone mass

Measurement of bone turnover markers is an alternative way to determine the effects of exercise on bone health. A 10-week group-based step aerobics exercise significantly improved functional fitness in postmenopausal women with low bone mass, and showed a positive trend in reducing resorption activity via bone turnover markers.

INTRODUCTION

The major goal of this study was to determine the effects of short-term group-based step aerobics (GBSA) exercise on the bone metabolism, bone mineral density (BMD), and functional fitness of postmenopausal women (PMW) with low bone mass.

METHODS

Forty-eight PMW (aged 58.2 ± 3.5 years) with low bone mass (lumbar spine BMD T-score of -2.00 ± 0.67) were recruited and randomly assigned to an exercise group (EG) or to a control group (CG). Participants from the EG attended a progressive 10-week GBSA exercise at an intensity of 75-85 % of heart rate reserve, 90 min per session, and three sessions per week. Serum bone metabolic markers (C-terminal telopeptide of type 1 collagen [CTX] and osteocalcin), BMD, and functional fitness components were measured before and after the training program. Mixed-models repeated measures method was used to compare differences between the groups (α = 0.05).

RESULTS

After the 10-week intervention period, there was no significant exercise program by time interaction for CTX; however, the percent change for CTX was significantly different between the groups (EG = -13.1 ± 24.4 % vs. CG = 11.0 ± 51.5 %, P < 0.05). While there was no significant change of osteocalcin in both groups. As expected, there was no significant change of BMD in both groups. In addition, the functional fitness components in the EG were significantly improved, as demonstrated by substantial enhancement in both lower- and upper-limb muscular strength and cardiovascular endurance (P < 0.05).

CONCLUSION

The current short-term GBSA exercise benefited to bone metabolism and general health by significantly reduced bone resorption activity and improved functional fitness in PMW with low bone mass. This suggested GBSA could be adopted as a form of group-based exercise for senior community.

The impact of obesity on skeletal muscle strength and structure through adolescence to old age

Obesity is associated with functional limitations in muscle performance and increased likelihood of developing a functional disability such as mobility, strength, postural and dynamic balance limitations. The consensus is that obese individuals, regardless of age, have a greater absolute maximum muscle strength compared to non-obese persons, suggesting that increased adiposity acts as a chronic overload stimulus on the antigravity muscles (e.g., quadriceps and calf), thus increasing muscle size and strength. However, when maximum muscular strength is normalised to body mass, obese individuals appear weaker. This relative weakness may be caused by reduced mobility, neural adaptations and changes in muscle morphology. Discrepancies in the literature remain for maximal strength normalised to muscle mass (muscle quality) and can potentially be explained through accounting for the measurement protocol contributing to muscle strength capacity that need to be explored in more depth such as antagonist muscle co-activation, muscle architecture, a criterion valid measurement of muscle size and an accurate measurement of physical activity levels. Current evidence demonstrating the effect of obesity on muscle quality is limited. These factors not being recorded in some of the existing literature suggest a potential underestimation of muscle force either in terms of absolute force production or relative to muscle mass; thus the true effect of obesity upon skeletal muscle size, structure and function, including any interactions with ageing effects, remains to be elucidated.

The impact of obesity on skeletal muscle architecture in untrained young vs. old women

It is unknown whether loading of the lower limbs through additional storage of fat mass as evident in obesity would promote muscular adaptations similar to those seen with resistance exercise. It is also unclear whether ageing modulates any such adjustments. This study aimed to examine the relationships between adiposity, ageing and skeletal muscle size and architecture. A total of 100 untrained healthy women were categorised by age into young (Y) (mean ± SD: 26.7 ± 9.4 years) vs. old (O) (65.1 ± 7.2 years) and body mass index (BMI) classification (underweight, normal weight, overweight and obese). Participants were assessed for body fat using dual energy x-ray absorptiometry, and for gastrocnemius medialis (GM) muscle architecture (skeletal muscle fascicle pennation angle and length) and size [GM muscle volume and physiological cross-sectional area (PCSA)] using B-mode ultrasonography. GM fascicle pennation angle (FPA) in the obese Y females was 25% greater than underweight (P = 0.001) and 25% greater than normal weight (P = 0.001) individuals, while O females had 32 and 22% greater FPA than their underweight (P = 0.008) and normal weight (P = 0.003) counterparts. Furthermore, FPA correlated with body mass in both Y and O females (Y r = 0.303; P < 0.001; O r = 0.223; P = 0.001), yet no age-related differences in the slope or r-values were observed (P > 0.05). Both GM muscle volume (P = 0.003) and PCSA (P = 0.004) exhibited significant age × BMI interactions. In addition, muscle volume and PCSA correlated with BMI, body mass and fat mass. Interestingly, ageing reduced both the degree of association in these correlations (P < 0.05) and the slope of the regressions (P < 0.05). Our findings partly support our hypotheses in that obesity-associated changes in GM PCSA and volume differed between the young and old. The younger GM muscle adapted to the loading induced by high levels of body mass, adiposity and BMI by increasing its volume and increasing its pennation angle, ultimately enabling it to produce higher maximum torque. Such an adaptation to increased loading did not occur in the older GM muscle. Nonetheless, the older GM muscle FPA increased to a similar extent to that seen in young GM muscle, an effect which partly explains the relatively enhanced absolute maximum torque observed in obese older females.

The benefits of a high-intensity aquatic exercise program (HydrOS) for bone metabolism and bone mass of postmenopausal women

This study aimed to evaluate the 24-week effects of a high-intensity aquatic exercise program on bone remodeling markers and bone mass of postmenopausal women. In this randomized, controlled trial we studied 108 women (58.8 ± 6.4 years), randomized into Aquatic Exercise Group (AEG), n = 64, performing 24 weeks of aquatic exercises, and Control Group (CG), n = 44, sedentary. They had their fasting morning blood sample collected for the measures of intact parathyroid hormone (iPTH), procollagen type 1 amino-terminal propeptide (P1NP) and carboxy-terminal cross-linking telopeptide of type I collagen (CTx). Bone mass was measured by dual-energy X-ray absorptiometry before and after the intervention. Participants of both groups received a daily supplementation of 500 mg of elementary calcium and 1,000 IU of vitamin D (cholecalciferol). Results showed an augment in bone formation marker (P1NP) only in the AEG (15.8 %; p = 0.001), and although both groups experienced significant enhancements in bone resorption marker (CTx), this increase was less considerable in the AEG (15 % in the AEG and 29 % in the CG). IPTH was increased by 19 % in the CG (p = 0.003) at the end. The femoral trochanter BMD presented a 1.2 % reduction in the CG (p = 0.009), whereas in the AEG no change was observed (p = 0.069). The proposed aquatic exercise program was efficient in attenuating bone resorption raise and enhancing bone formation, which prevented the participants in the AEG from reducing the femoral trochanter BMD, as happened in the CG.

Obesity decreases both whole muscle and fascicle strength in young females but only exacerbates the aging-related whole muscle level asthenia

Obesity has previously been associated with greater muscle strength. Aging, on the other hand, reduces muscle specific force (the force per unit physiological cross‐sectional area [PCSA] of muscle). However, neither the effect of obesity on skeletal muscle specific force nor the combined effects of aging and obesity on this parameter are known. This study aimed to describe the interplay between body mass index (BMI)/adiposity, aging, and skeletal muscle specific force. Ninety‐four untrained healthy women categorized by age into young (Y; mean ± SD: 25.5 ± 9.0 years) versus old (O; 64.8 ± 7.2 years) were assessed for body composition, gastrocnemius medialis (GM) muscle volume (V), net maximum voluntary contraction (nMVC), and specific force (SF). The young obese, while demonstrating 71% and 29% (P < 0.001) higher V and nMVC compared to normal BMI individuals, were in fact 26% (P = 0.007) weaker than these, where V was used to scale nMVC (i.e., nMVC/V). The weakness associated with obesity was further exemplified in the 34% (P < 0.001) lower SF relative to normal BMI individuals. Similarly, ≥40% body fat was associated with 60% and 27% (P < 0.001) higher V and nMVC, but 11% and 25% (P < 0.01) lower nMVC/V and SF than <40% body fat. The aging‐related rates of decline in V (−2 cm³/year P < 0.05) and nMVC (−1.2 cm³/year P < 0.05) were highest in obesity defined by BMI. This effect was also seen when segregating by >40% adiposity. Interestingly, however, obesity appeared advantageous to the aging‐related changes in nMVC/V (P < 0.001) and SF (P < 0.001). Unlike previous reports of greater strength in the obese compared with leaner age‐matched counterparts, we in fact demonstrate that the young sedentary obese, are substantially weaker, where the volume of skeletal muscle is used to scale the maximal torque output, or forces are quantified at the fascicular level. The seemingly positive impact of obesity on rate of aging, however, is complex and warrants further investigations.

Our study demonstrates for the first time that at both whole muscle and fascicular levels, high body mass index (BMI) or adiposity categories of obesity are associated with significantly lower skeletal muscle contractile capacity in young adults. Interestingly, the aging effect on obese individuals classified by both BMI and adiposity was foremost observed through the loss of muscle tissue content as well as total muscle strength.

Combined effects of body composition and ageing on joint torque, muscle activation and co-contraction in sedentary women

This study aimed to establish the interplay between body mass, adiposity, ageing and determinants of skeletal muscle strength. One hundred and two untrained healthy women categorised by age into young (Y) (mean ± SD, 26.7 ± 9.4 years) vs. old (O) (65.1 ± 7.2 years) were assessed for body fat, lean mass, plantar flexion and dorsiflexion maximum voluntary isometric contraction (MVC) torque, muscle activation capacity and antagonist muscle co-contraction. MVC torque normalised to body mass in the obese group was 35 and 29 % lower (p < 0.05) in Y and 34 and 31 % lower (p < 0.05) in O, compared with underweight and normal weight individuals, respectively. Y with ≥40 % body fat had significantly lower activation than Y with <40 % body fat (88.3 vs. 94.4 %, p < 0.05), but O did not exhibit this effect. Co-contraction was affected by ageing (16.1 % in O vs. 13.8 % in Y, p < 0.05) but not body composition. There were significant associations between markers of body composition, age, strength and activation capacity, with the strongest correlation between muscle strength and total body mass (r (2) = 0.508 in Y, p < 0.001, vs. r (2) = 0.204 in O, p < 0.01). Furthermore, the age-related loss in plantar flexion (PF) MVC torque was exacerbated in obese compared to underweight, normal weight and overweight individuals (-0.96 vs. -0.54, -0.57 and -0.57 % per year, p < 0.05). The negative impact of adiposity on muscle performance is associated with not only muscular but also neural factors. Overall, the effects of ageing and obesity on this system are somewhat cumulative.

The effects of a 6-month resistance training and dried plum consumption intervention on strength, body composition, blood markers of bone turnover, and inflammation in breast cancer survivors

The purpose of this study was to examine the effects of resistance training (RT) and dried plum (DP) consumption on strength, body composition, blood markers of bone, and inflammation in breast cancer survivors (BCS). Twenty-three BCS (RT, n = 12; RT+DP, n = 11), aged 64 ± 7 years, were evaluated at baseline and after 6 months of intervention on the following: muscular strength (chest press and leg extension) via 1-repetition maximums (1RMs); body composition, specifically bone mineral density (BMD) by dual energy X-ray absorptiometry; biochemical markers of bone turnover (bone-specific alkaline phosphatase (BAP), tartrate resistant acid phosphatase (TRAP-5b)); and inflammation (C-reactive protein (CRP)). Target RT prescription was 2 days/week of 10 exercises, including 2 sets of 8–12 repetitions at ∼60%–80% of 1RM. RT+DP also consumed 90 g of DP daily. There were no baseline differences between groups or any group-by-time interactions for any of the variables. BCS increased upper (p < 0.05) (RT: 64 ± 14 to 80 ± 17 kg; RT+DP: 72 ± 23 to 91 ± 20 kg) and lower (p < 0.05) (RT: 69 ± 20 to 87 ± 28 kg; RT+DP: 78 ± 19 to 100 ± 21 kg) body strength. Body composition and BMD improvements were not observed. TRAP-5b decreased in the RT group (p < 0.05) (4.55 ± 1.57 to 4.04 ± 1.63 U/L) and the RT+DP group (p = 0.07) (5.10 ± 2.75 to 4.27 ± 2.03 U/L). Changes in BAP and CRP were not observed. RT was effective for improving biochemical markers of bone turnover and muscular strength in BCS. A longer and higher intensity intervention may be needed to reveal the true effects of RT and DP on body composition and biochemical markers of inflammation.

Physical activity improves strength, balance and endurance in adults aged 40-65 years: a systematic review

QUESTION

Can physical activity in adults aged 40-65 years enhance strength and balance and prevent falls?

DESIGN

Systematic review with meta-analysis of randomised clinical trials.

PARTICIPANTS

Healthy adults aged 40-65 years.

INTERVENTION

Programs that involved the performance of any physical activity in community settings and workplaces.

OUTCOME MEASURES

Strength, balance, endurance, and falls rate.

RESULTS

Twenty-three eligible trials were identified and 17 of these were pooled in the meta-analyses. The meta-analysis of strength outcomes found a moderate effect of physical activity on strength (SMD=0.54, 95% CI 0.38 to 0.70). Larger effects were observed from programs that specifically targeted strength (SMD=0.68, 95% CI 0.49 to 0.87), when compared to those that did not (SMD=0.32, 95% CI 0.09 to 0.55). This difference was statistically significant (effect of strength in meta-regression p=0.045). Physical activity also had a moderate effect on both balance (SMD=0.52, 95% CI 0.24 to 0.79) and endurance (SMD=0.73, 95% CI 0.50 to 0.96). No trials reported effects of physical activity on falls soon after receiving the intervention. A statistically non-significant effect on falls 15 years after receiving a physical activity intervention was found in one trial (RR=0.82, 95% CI 0.53 to 1.26).

CONCLUSIONS

This review found that muscle strength, balance, and endurance can be improved by physical activity in people aged 40-65 years. There were bigger effects on muscle strength from programs that used resistance exercises, indicating the need to include a resistance training component if strength enhancement is the goal.

The effect of weight training on bone mineral density and bone turnover in postmenopausal breast cancer survivors with bone loss: a 24-month randomized controlled trial

SUMMARY

This study examined whether 24 months of weight training exercises enhanced the effectiveness of risedronate, calcium, and vitamin D in maintaining or improving bone mineral density (BMD) in 223 postmenopausal breast cancer survivors. Subjects who were > or =50% adherent to exercise had no improvement in BMD but were less likely to lose BMD.

INTRODUCTION

This study examined whether (1) postmenopausal breast cancer survivors (BCS) with bone loss taking 24 months of risedronate, calcium, and vitamin D had increased bone mineral density (BMD) at the total hip, femoral neck, L1-L4 spine, total radius and 33% radius, and decreased bone turnover; (2) subjects who also participated in strength/weight training (ST) exercises had greater increases in BMD and greater decreases in bone turnover; and (3) subjects who also exercised were more likely to preserve (at least maintain) BMD.

METHODS

Postmenopausal BCS (223) were randomly assigned to exercise plus medication or medication only groups. Both groups received 24 months of 1,200 mg of calcium and 400 IU of vitamin D daily and 35 mg of risedronate weekly, and the exercise group additionally had ST exercises twice weekly.

RESULTS

After 24 months, women who took medications without exercising had significant improvements in BMD at the total hip (+1.81%) and spine (+2.85%) and significant decreases in Alkphase B (-8.7%) and serum NTx (-16.7%). Women who also exercised had additional increases in BMD at the femoral neck (+0.29%), total hip (+0.34%), spine (+0.23%), total radius (+0.30%), and additional decreases in Alkphase B (-2.4%) and Serum NTx (-6.5%). Additional changes in BMD and bone turnover with exercise were not significant. Subjects who were > or =50% adherent to exercise were less likely to lose BMD at the total hip (chi-square [1] = 4.66, p = 0.03) and femoral neck (chi-square [1] = 4.63, p = 0.03).

CONCLUSION

Strength/weight training exercises may prevent loss of BMD in postmenopausal BCS at risk for bone loss.