Age Does Not Affect Exercise Intensity Progression among Women

The effect of exercise modality on age-related changes observed during running

INTRODUCTION

With the increase in participation by older adults in endurance events, research is needed to evaluate how exercising throughout the lifespan can affect the aging process regarding gait and mobility. The purpose of this study was to determine how the type of exercise modality one participates in will affect age-related declines observed during running.

METHODS

Fifty-six individuals between the ages of 18-65 who considered running, resistance training or cycling/swimming as their primary form of activity participated in this study. Kinematics were captured using a 10-camera motion capture system while participants ran at a controlled pace of 3.5 m/s (± 5%) over a 10-m runway with force platforms collecting kinetic data. Eight successful trials were chosen for analysis. A one-way ANOVA assessed differences in mean kinematic and kinetic variables of interest between physical activity groups (α = 0.05).

RESULTS

Older resistance trainers exhibited greater maximal knee power compared to older runners. No other group differences were observed.

CONCLUSION

Despite type of exercise modality, regularly participating in exercise has positive effects. This is evident through the preservation of the function of the lower extremity with age, specifically function of the ankle, and its contribution to healthy movement patterns.

Short-term community-based exercise programs in low-income older women: Does exercise intensity and modality matters?

Our aim was to evaluate the effect of community-based exercise program (CBEP) intensity and modality on anthropometric, hemodynamic, and functional capacity parameters in low-income older women. Forty insufficiently active older women (68.2 ± 7.9 years) were randomly assigned to perform 12 weeks of twice-weekly high-intensity interval training combined with resistance training (HIIT+RT/n = 12), moderate-intensity continuous training combined with resistance training (MICT+RT/n = 13), or resistance training alone (RT/n = 15). Anthropometric (body mass index and waist circumference), hemodynamic (blood pressure and heart rate), and functional capacity variables (flexibility, upper and lower limb muscle strength, and mobility) were assessed before and after training programs. Waist circumference reduced similarly after all CBEP (~3 to ~4 cm; P < 0.05). Tendency toward reduction in diastolic blood pressure (~4 mm Hg; P = 0.073), and improvements in flexibility (14.5%, P = 0.011) and handgrip strength (15.8%; P = 0.02) were found only in HIIT+RT. Indeed, only RT was effective to improve five-time sit to stand (14.1%; P = 0.013). No significant difference between groups was found during follow-up in any variable. The results of present study suggest that low-income older women may improve anthropometric, hemodynamic and functional capacity variables by participating in twice-weekly short-term (i.e.: 12 weeks) CBEP. However, the CBEP-effects on hemodynamic and functional capacity appears to be affected by exercise intensity (only HIIT+RT tended toward improving diastolic BP) and modality (only RT improved significantly five-time sit to stand), respectively.

Resistance Training as a Tool for Preventing and Treating Musculoskeletal Disorders

The aging process is characterized by several physiological, morphological, and psychological alterations that result in a decreased functional and health status throughout the life span. Among these alterations, the loss of muscle mass and strength (sarcopenia) is receiving increased attention because of its association with innumerous age-related disorders, including (but not limited to) osteoporosis, osteoarthritis, low back pain, risk of fall, and disability. Regular participation in resistance training programs can minimize the musculoskeletal alterations that occur during aging, and may contribute to the health and well-being of the older population. Compelling evidence suggest that regular practice of resistance exercise may prevent and control the development of several musculoskeletal chronic diseases. Moreover, resistance training may also improve physical fitness, function, and independence in older people with musculoskeletal disorders, which may result in improved quality of the years lived. In summary, regular participation in resistance training programs plays an important role in aging and may be a preventive and therapeutic tool for several musculoskeletal disorders.

Voluntary resistance wheel exercise from mid-life prevents sarcopenia and increases markers of mitochondrial function and autophagy in muscles of old male and female C57BL/6J mice

Background

There is much interest in the capacity of resistance exercise to prevent the age-related loss of skeletal muscle mass and function, known as sarcopenia. This study investigates the molecular basis underlying the benefits of resistance exercise in aging C57BL/6J mice of both sexes.

Results

This study is the first to demonstrate that long-term (34 weeks) voluntary resistance wheel exercise (RWE) initiated at middle age, from 15 months, prevents sarcopenia in selected hindlimb muscles and causes hypertrophy in soleus, by 23 months of age in both male and female C57BL/6J mice. Compared with 23-month-old sedentary (SED) controls, RWE (0–6 g of resistance) increased intramuscular mitochondrial density and oxidative capacity (measured by citrate synthase and NADH-TR) and increased LC3II/I ratios (a marker of autophagy) in exercised mice of both sexes. RWE also reduced mRNA expression of Gadd45α (males only) and Runx1 (females only) but had no effect on other markers of denervation including Chrng, Chrnd, Musk, and Myog. RWE increased heart mass in all mice, with a more pronounced increase in females. Significant sex differences were also noted among SED mice, with Murf1 mRNA levels increasing in male, but decreasing in old female mice between 15 and 23 months.

Conclusions

Overall, long-term RWE initiated from 15 month of age significantly improved some markers of the mitochondrial and autophagosomal pathways and prevented age-related muscle wasting.

Electronic supplementary material

The online version of this article (doi:10.1186/s13395-016-0117-3) contains supplementary material, which is available to authorized users.

Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association

Mounting evidence has firmly established that low levels of cardiorespiratory fitness (CRF) are associated with a high risk of cardiovascular disease, all-cause mortality, and mortality rates attributable to various cancers. A growing body of epidemiological and clinical evidence demonstrates not only that CRF is a potentially stronger predictor of mortality than established risk factors such as smoking, hypertension, high cholesterol, and type 2 diabetes mellitus, but that the addition of CRF to traditional risk factors significantly improves the reclassification of risk for adverse outcomes. The purpose of this statement is to review current knowledge related to the association between CRF and health outcomes, increase awareness of the added value of CRF to improve risk prediction, and suggest future directions in research. Although the statement is not intended to be a comprehensive review, critical references that address important advances in the field are highlighted. The underlying premise of this statement is that the addition of CRF for risk classification presents health professionals with unique opportunities to improve patient management and to encourage lifestyle-based strategies designed to reduce cardiovascular risk. These opportunities must be realized to optimize the prevention and treatment of cardiovascular disease and hence meet the American Heart Association's 2020 goals.

Strength training-induced responses in older adults: attenuation of descending neural drive with age

Although reductions in resting H-reflex responses and maximal firing frequency suggest that reduced efferent drive may limit muscle strength in elderly, there are currently no reports of V-wave measurements in elderly, reflecting the magnitude of efferent output to the muscle during maximal contraction. Furthermore, it is uncertain whether potential age-related neural deficiencies can be restored by resistance training. We assessed evoked reflex recordings in the triceps surae muscles during rest and maximal voluntary contraction (MVC), rate of force development (RFD), and muscle mass in seven elderly (74 ± 6 years) males before and after 8 weeks of heavy resistance training, contrasted by seven young (24 ± 4 years) male controls. At baseline, m. soleus (SOL) V/M ratio (0.124 ± 0.082 vs. 0.465 ± 0.197, p < 0.05) and H/M ratio (0.379 ± 0.044 vs. 0.486 ± 0.101 p = 0.07) were attenuated in elderly compared to young. Also, SOL H-reflex latency (33.29 ± 2.41 vs. 30.29 ± 0.67 ms, p < 0.05) was longer in elderly. The reduced neural drive was, despite similar leg muscle mass (10.7 ± 1.2 vs. 11.5 ± 1.4 kg), mirrored by lower MVC (158 ± 48 vs. 240 ± 54 Nm, p < 0.05) and RFD (294 ± 126 vs. 533 ± 123 Nm s(-1), p < 0.05) in elderly. In response to training SOL V/M ratio (0.184 ± 0.092, p < 0.05) increased in the elderly, yet only to a level ~40 % of the young. This was accompanied by increased MVC (190 ± 70 Nm, p < 0.05) and RFD (401 ± 147 Nm[Symbol: see text]s(-1), p < 0.05) to levels of ~80 % and ~75 % of the young. H/M ratio remained unchanged. These findings suggest that changes in supraspinal activation play a significant role in the age-related changes in muscle strength. Furthermore, this motor system impairment can to some extent be improved by heavy resistance training.

Effects of resistance training in older women with knee osteoarthritis and total knee arthroplasty

OBJECTIVES

This study sought to analyze the effects of resistance training on functional performance, lower-limb loading distribution and balance in older women with total knee arthroplasty (TKA) and osteoarthritis (OA) in the contralateral knee. In addition, this older knee OA and TKA group (OKG) was compared to older (OG) and young women (YG) without musculoskeletal diseases who underwent the same resistance training program.

METHODS

Twenty-three women divided into OKG (N = 7), OG (N = 8) and YG (N = 8) had their functional performance, lower-limb loading distribution and balance compared before and after 13 weeks of a twice-weekly progressive resistance training program.

RESULTS

At baseline, the OKG showed lower functional performance and unilateral balance, and impaired lower-limb loading distribution compared to the OG and the YG (p<0.05). After resistance training, the OKG showed improvements in functional performance (∼13% in sit-to-stand and rising from the floor, ∼16% in stair-climbing and ∼23% in 6-minute walking (6 MW)), unilateral balance (∼72% and ∼78% in TKA and OA leg, respectively) and lower-limb loading distribution, which were greater than those observed in the OG and the YG. The OKG showed post-training 6 MW performance similar to that of the OG at baseline. Sit-to-stand performance and unilateral stand balance were further restored to post-training levels of the OG and to baseline levels of the YG.

CONCLUSIONS

Resistance training partially restored functional, balance and lower-limb loading deficits in older women with TKA and OA in the contralateral knee. These results suggest that resistance training may be an important tool to counteract mobility impairments commonly found in this population.

The relationship between health-related fitness and quality of life in postmenopausal women from Southern Taiwan

Background

Health-related fitness has been reported to be associated with improved quality of life (QoL) in the elderly. Health-related fitness is comprised of several dimensions that could be enhanced by specific training regimens. It has remained unclear how various dimensions of health-related fitness interact with QoL in postmenopausal women.

Objective

The purpose of the current study was to investigate the relationship between the dimensions of health-related fitness and QoL in elderly women.

Methods

A cohort of 408 postmenopausal women in a rural area of Taiwan was prospectively collected. Dimensions of health-related fitness, consisting of muscular strength, balance, cardiorespiratory endurance, flexibility, muscle endurance, and agility, were assessed. QoL was determined using the Short Form Health Survey (SF-36). Differences between age groups (stratified by decades) were calculated using a one-way analysis of variance (ANOVA) and multiple comparisons using a Scheffé test. A Spearman’s correlation analysis was performed to examine differences between QoL and each dimension of fitness. Multiple linear regression with forced-entry procedure was performed to evaluate the effects of health-related fitness. A P-value of <0.05 was considered statistically significant.

Results

Age-related decreases in health-related fitness were shown for sit-ups, back strength, grip strength, side steps, trunk extension, and agility (P<0.05). An age-related decrease in QoL, specifically in physical functioning, role limitation due to physical problems, and physical component score, was also demonstrated (P<0.05). Multiple linear regression analyses demonstrated that back strength significantly contributed to the physical component of QoL (adjusted beta of 0.268 [P<0.05]).

Conclusion

Back strength was positively correlated with the physical component of QoL among the examined dimensions of health-related fitness. Health-related fitness, as well as the physical component of QoL, declined with increasing age.

Correlation of postural balance and knee muscle strength in the sit-to-stand test among women with and without postmenopausal osteoporosis

The task of standing up from a chair forms a part of daily life for all independent individuals. However, this task becomes more difficult with advancing age. Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up.

INTRODUCTION

This study aims to evaluate postural balance during the transition from sitting to standing and its relationship with knee extensor and flexor strength among women with and without postmenopausal osteoporosis.

METHODS

Assessments were made on 126 women (aged 55-65 years), divided into osteoporosis and control groups according to lumbar bone density. Their balance during the task of standing up from a chair was evaluated using the Balance Master® device. Knee muscle strength was evaluated using an isokinetic dynamometer (Biodex®), in concentric/concentric mode, at a velocity of 60°/s. Spearman's correlation between the variables of muscle strength and postural balance was evaluated. Subsequently, to evaluate the association of each balance variable with the group and with muscle strength, multiple linear regression models were fitted. The significance level was set at 0.05.

RESULTS

There was a difference in knee muscle strength between the groups (P < 0.05). However, independent of the muscle strength values, there were no differences in relation to weight transfer times (P = 0.556) or center of gravity sway velocity (P = 0.952). Transfer time diminished with increasing extensor strength (P = 0.025). The center of gravity sway velocity tended to increase with increasing extensor strength (P = 0.013) and was the same in the two groups (P = 0.264).

CONCLUSION

Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up.

Evaluation of the association between osteoporosis and postural balance in postmenopausal women

The incidence of osteoporosis has been increasing, as have fractures resulting from falls. Postural balance was evaluated in postmenopausal women with and without lumbar osteoporosis. One hundred and twenty-six postmenopausal women aged 55-65 years were evaluated and separated into two groups according to the bone mineral density values of their lumbar spine: the osteoporosis group and the control group, paired by age (P = 0.219) and physical activity (P = 0.611). There was no difference between the groups (P = 0.139) regarding falls reported in the previous 12 months. Functional mobility was evaluated through the Timed Up and Go Test. Postural balance was evaluated using a portable force platform in standard standing position, with eyes open and closed, for 60s. Muscle strength was evaluated through an isokinetic dynamometer. This study shows that there is no difference in knee muscle strength and functional mobility (P = 0.121), postural balance with eyes open [mediolateral displacement (P = 0.286) and mean velocity of the center of pressure (COP) (P = 0.173)] and with eyes closed [mediolateral displacement (P = 0.163), and the mean velocity of displacement of the COP (P = 0.09)] in both groups. Subjects reporting falls had greater mediolateral displacement (P = 0.028) in both groups. Postmenopausal women aged between 55 and 65 years do not present changes in postural balance irrespective of lumbar osteoporosis. Greater COP mediolateral displacement is related to the occurrence of falls in postmenopausal women in the previous year.

Exercise training as a preventive tool for age-related disorders: a brief review

Aging populations are a worldwide phenomenon affecting both developed and developing countries. This issue raises serious concerns for both governments and the general population. Regular participation in physical activity and/or exercise training programs can minimize the physiological alterations that occur during aging and may contribute to improvements in health and well-being. The present review will discuss the role of regular exercise training in preventing age-related physiological decline and, consequently, associated chronic diseases. Compelling evidence that regular exercise and/or physical activity can improve quality of life, prevent or control the development of chronic disease and increase life expectancy is shown. In summary, regular exercise training and/or physical activity has an important influence on aging and may help to prevent age-related disorders.

The intensity and effects of strength training in the elderly

BACKGROUND

The elderly need strength training more and more as they grow older to stay mobile for their everyday activities. The goal of training is to reduce the loss of muscle mass and the resulting loss of motor function. The dose-response relationship of training intensity to training effect has not yet been fully elucidated.

METHODS

PubMed was selectively searched for articles that appeared in the past 5 years about the effects and dose-response relationship of strength training in the elderly.

RESULTS

Strength training in the elderly (>60 years) increases muscle strength by increasing muscle mass, and by improving the recruitment of motor units, and increasing their firing rate. Muscle mass can be increased through training at an intensity corresponding to 60% to 85% of the individual maximum voluntary strength. Improving the rate of force development requires training at a higher intensity (above 85%), in the elderly just as in younger persons. It is now recommended that healthy old people should train 3 or 4 times weekly for the best results; persons with poor performance at the outset can achieve improvement even with less frequent training. Side effects are rare.

CONCLUSION

Progressive strength training in the elderly is efficient, even with higher intensities, to reduce sarcopenia, and to retain motor function.

Exercise-induced improvements in cardiorespiratory fitness and heart rate response to exercise are impaired in overweight/obese postmenopausal women

OBJECTIVE

The purpose of this study was to compare the heart rate response to exercise and the exercise-induced improvements in muscle strength, cardiorespiratory fitness and heart rate response between normal-weight and overweight/obese postmenopausal women.

METHODS

Sedentary women (n = 155) were divided into normal-weight (n = 79; BMI <25 kg/m(2); 58.3 ± 8.6 years) and overweight/obese (n = 76; BMI >25 kg/m(2); 58.3 ± 8.6 years) groups, and have their 1-repetition maximum strength (adjusted for body mass), cardiorespiratory fitness and heart rate response to a graded exercise test compared before and after 12 months of a three times-per-week exercise-training program.

RESULTS

Overweight/obese women displayed decreased upper and lower extremity muscle strengths, decreased cardiorespiratory fitness, and lower peak and reserve heart rates compared to normal-weight women. After follow-up, both groups improved their upper (32.9% and 41.5% in normal-weight and overweight/obese women, respectively) and lower extremity(49.5% and 47.8% in normal-weight and overweight/obese women, respectively) muscle strength. However, only normal-weight women improved their cardiorespiratory fitness (6.6%) and recovery heart rate (5 bpm). Resting, reserve and peak heart rates did not change in either group.

CONCLUSIONS

Overweight/obese women displayed impaired heart rate response to exercise. Both groups improved muscle strength, but only normal-weight women improved cardiorespiratory fitness and heart rate response to exercise. These results suggest that exercise-induced improvements in cardiorespiratory fitness and heart rate response to exercise may be impaired in overweight/obese postmenopausal women.

Muscle strength and exercise intensity adaptation to resistance training in older women with knee osteoarthritis and total knee arthroplasty

OBJECTIVES

To analyze muscle strength and exercise intensity adaptation to resistance training in older women with knee osteoarthritis and total knee arthroplasty.

METHODS

Twenty-three community-dwelling women were divided into the following groups: older, with knee osteoarthritis and total knee arthroplasty in the contralateral limb (OKG; N= 7); older, without symptomatic osteoarthritis (OG; N= 8); and young and healthy (YG; N= 8). Muscle strength (1-repetition maximum strength test) and exercise intensity progression (workload increases of 5%-10% were made whenever adaptation occurred) were compared before and after 13 weeks of a twice-weekly progressive resistance-training program.

RESULTS

At baseline, OKG subjects displayed lower muscle strength than those in both the OG and YG. Among OKG subjects, baseline muscle strength was lower in the osteoarthritic leg than in the total arthroplasty leg. Muscle strength improved significantly during follow-up in all groups; however, greater increases were observed in the osteoarthritic leg than in the total knee arthroplasty leg in OKG subjects. Greater increases were also seen in the osteoarthritic leg of OKG than in OG and YG. The greater muscle strength increase in the osteoarthritic leg reduced the interleg difference in muscle strength in OKG subjects, and resulted in similar posttraining muscle strength between OKG and OG in two of the three exercises analyzed. Greater exercise intensity progression was also observed in OKG subjects than in both OG and YG subjects.

CONCLUSIONS

OKG subjects displayed greater relative muscle strength increases (osteoarthritic leg) than subjects in the YG, and greater relative exercise intensity progression than subjects in both OG and YG. These results suggest that resistance training is an effective method to counteract the lower-extremity strength deficits reported in older women with knee osteoarthritis and total knee arthroplasty.