Sex-dependent associations between daily physical activity and leg exercise blood pressure responses

The authors examined interindividual and sex-specific variation in systolic (SBP) and diastolic (DBP) blood pressure responses to graded leg-extension exercise in healthy older (60-78 yr) women (n = 21) and men (n = 19). Maximal oxygen uptake (VO2max), body composition, physical activity (accelerometry), and vascular function were measured to identify predictors of exercise BP. Neither VO2max nor activity counts were associated with the rise in SBP or DBP during exercise in men. The strongest predictors of these responses in men were age (SBP: r2 = .19, p = .05) and peak exercise leg vasodilation (DBP: r2 = -.21, p < .05). In women, the modest relationship observed between VO2max and exercise BP was abolished after adjusting for central adiposity and activity counts (best predictors, cumulative r2 = .53, p < .05, for both SBP and DBP). These results suggest that determinants of variation in submaximal exercise BP responses among older adults are sex specific, with daily physical activity influencing these responses in women but not men.     

Pilot study comparing physical and psychological responses in medical qigong and walking

Identifying alternative exercise modalities in an effort to stimulate and promote participation in physical activity, especially among older adults, is a critical health consideration. The purpose of this study was to compare physiological and psychological responses to medical qigong with self-paced brisk walking. Older women (55-79 years) performed 22 min of either qigong or walking on two separate days. During exercise performance, heart rate and ratings of perceived exertion were assessed. Psychological affect, blood pressure, and pulse rate were assessed before and after the exercise bouts. Heart-rate data indicated that both forms of exercise were at a moderate level of intensity. In addition, similar values were found for the physiological and psychological variables as a function of the two forms of exercise. Therefore, it was concluded that this form of medical qigong can be considered a moderate-intensity physical activity that should have both physiological and psychological benefits for older women.     

The association between mood states and physical activity in postmenopausal, obese, sedentary women

Mood states influence evaluative judgments that can affect the decision to exercise or to continue to exercise. This study examined how mood associated with graded exercise testing (GXT) in sedentary, obese, postmenopausal women (N = 25) was associated with physical activity and predicted VO2max during and after a behavioral weight-loss program (BWLP). Measures of physical activity included planned exercise, calories from physical activity, leisure-time physical activity, and predicted VO2max. Mood before and after pre-BWLP GXT was assessed using the Profile of Mood States. Mood before and after the GXT was more strongly associated with planned exercise than other forms of physical activity, and this effect became stronger over time. Mood enhancement in response to exercise was not related to physical activity. Mood before and after exercise might yield important clinical information that can be used to promote physical activity in sedentary adults.     

Misconceptions about strength exercise among older adults

The purposes of this study were to determine current opinions of strength exercise among older adults and whether knowledge of recommended protocols differs between strength-exercise participants and nonparticipants. One hundred twenty-nine older adults (77.5 +/- 8.6 years) responded to questions about their opinions, experiences, and knowledge of strength-exercise recommendations. Some misconceptions were identified in the sample, with 48.4% of participants responding "no" to "strength training increases muscle mass," 45% responding "no" to "increasing weight is more important than number of repetitions for building strength," and 37% responding that walking is more effective than lifting weights at building muscle strength. The number of correct responses was related to the number of years in school (semipartial r(2)= .046). More education is needed about the benefits and recommendations to ensure proper use of current strength-exercise protocols among older adults.     

Physical activity and fitness among midlife and older rural women

This study investigated physical activity and fitness of midlife and older rural women. Random-digit dialing was used to recruit 225 women (57.9 +/- 5.6 years old). Self-reported activity (moderate activity, flexibility, and strength) and fitness (body composition, flexibility, strength, and estimated VO(2max)) were assessed. The women demonstrated low daily energy expenditure (30.74 +/- 10.63 kcal x kg(-1) x day(-1)) and estimated VO(2max) (20.12 +/- 7.81 ml x kg(-1) x min(-1)), with 51.5% reporting fair or poor health. Few women reported meeting Healthy People 2010 targets for moderate activity (43.1%), flexibility (28.9%), or strength )14.2%). When classified by estimated VO(2max) into three categories, differences were observed for body-mass index, percent body fat, sit and reach, and timed chair stands, with the poorest performance by those with low cardiorespiratory fitness. Adherence to Healthy People 2010 targets for moderate activity and strengthening was associated with higher cardiorespiratory fitness. These rural women are targets for physical activity interventions because of their sedentary behaviors and low cardiorespiratory fitness.     

Improvements in functional capacity from Nordic walking: a randomized-controlled trial among elderly people

This study examined the effects of an instructed structured Nordic walking (NW) exercise program on the functional capacity of older sedentary people. Volunteers were randomly assigned to an NW group (68.2 ± 3.8 yr old) or control group (69.9 ± 3.0 yr old). Before and at the end of the 9-wk intervention, functional tests and 2-dimensional ground-reaction-force (GRF) patterns of normal (1.40 m/s) and fast (1.94 m/s) walking speeds were measured. The intervention included a 60-min supervised NW session on an inside track twice a week for 9 wk. The mean changes in functional tests differed between groups significantly. Gait analyses showed no significant differences between the groups on any GRF parameters for walking speed either before or after the intervention. The study showed that NW has favorable effects on functional capacity in older people and is a suitable form of exercise for them.     

Affective and self-efficacy responses to acute aerobic exercise in sedentary older and younger adults

This study examined the psychological responses to an acute bout of aerobic exercise in sedentary older and younger adults. Eighteen young (mean age 24 years) and 15 older adults (mean age 64 years) completed a 20-min bout of stationary cycling at 65% of VO2peak. Affective responses were assessed before, during, and immediately after exercise. Participants'exercise self-efficacy beliefs were assessed before and immediately after exercise. Both groups reported reduced pleasant feeling states and self-efficacy and increased physical exhaustion in response to acute exercise. Older adults also demonstrated a significant decrease in revitalization during and after cycling. Correlation analyses revealed that self-efficacy was related to feelings of fatigue during exercise and postexercise feelings of energy and fatigue. Both groups reported negative shifts in affect and self-efficacy during and 5 min after cycling.Acute affective and self-efficacy responses might influence one's motivation to adopt and maintain regular physical activity. The relationship between these acute responses and physical activity behavior across the life span warrants future inquiry.     

The effects of respiratory-muscle training on exercise in older women

This research examined the effects of respiratory-muscle (RM) training on RM function and exercise performance in older women. Twenty-six women (60-69 yr of age) were assessed for spirometry, RM strength (maximal inspiratory and expiratory pressure), inspiratory-muscle endurance, and walking performance to a perceived exertion rating of "hard." They were randomly allocated to a threshold RM training group (RMT) or a nonexercising control group (CON) for 8 wk.After training, the 22% (inspiratory) and 30% (expiratory) improvements in RM strength in the RMT group were significantly higher than in the CON group (p < .05). The RMT group also displayed several significant performance improvements, including improved within-group treadmill performance time (12%) and reductions in submaximal heart rate (5%), percentage of maximum voluntary ventilation (16%), and perceived exertion for breathing (8%). RM training appears to improve RM function in older women. Furthermore, these improvements appear to be related to improved submaximal exercise performance.     

Oxygen consumption, heart rate, rating of perceived exertion, and systolic blood pressure with water treadmill walking

The purpose of this study was to examine the cardiovascular responses to water treadmill walking at 2.0 mph (3.2 km/hr), 2.5 mph (4.0 km/hr), and 3.0 mph (4.8 km/hr) in older adults. Responses to water treadmill walking in 92 degrees F (33 degrees C) water were compared with responses to land treadmill walking at 70 degrees F (21 degrees C) ambient temperature. After an accommodation period, participants performed 5-min bouts of walking at each speed on 2 occasions. Oxygen consumption (VO2), heart rate (HR), systolic blood pressure (SBP), and rating of perceived exertion (RPE) were significantly higher during therapeutic water treadmill walking than during land treadmill walking. Furthermore, VO2, HR, and RPE measures significantly increased with each speed increase during both land and water treadmill walking. SBP significantly increased with each speed during water treadmill walking but not land treadmill walking. Thus, it is imperative to monitor HR and blood pressure for safety during this mode of activity for older adults.     

Why older Australians participate in exercise and sport

Research on variables that encourage older adults to exercise is limited. This study was carried out to identify the participation motives of older Australians involved in regular exercise and sport. The 815 participants (399 men, 416 women) ranged in age from 55 to 93 years (M = 63.6, SD = 7.8) and were participating in their activities of choice at least once per week. All participants completed the Participation Motivation Questionnaire for Older Adults. The most common exercise/sport activities that participants were involved in were walking, golf, lawn bowls, tennis, and swimming. The most highly reported motives for participation were to keep healthy, liking the activity, to improve fitness, and to maintain joint mobility. Principal-components analysis of the questionnaire revealed 6 factors: social, fitness, recognition, challenge/benefits, medical, and involvement. Analyses of variance showed significant differences in reasons for participation in exercise and sport based on gender, age, education level, and occupation.     

Effects of 10-week walking and walking with home-based resistance training on muscle quality,muscle size,and physical functional tests in healthy older individuals

Background

Older individuals have been shown to present muscle atrophy in conjunction with increased fat fraction in some muscles. The proportion of fat and connective tissue within the skeletal muscle can be estimated from axial B-mode ultrasound images using echo intensity (EI). EI was used to calculate the index of muscle quality. Walking, home-based weight-bearing resistance training, and its combinations are considered simple, easy, and practical exercise interventions for older adults. The purpose of this study was to quantify the effects of walking and walking with home-based resistance training on muscle quality of older individuals.

Methods

Thirty-one participants performed walking training only (W-group; 72?±?5?years) and 33 participants performed walking and home-based resistance training (WR-group; 73?±?6?years). This study was a non-randomized controlled trial with no control group. All participants were instructed to walk 2 or 3 sets per week for 10?weeks (one set: 30-min continuous walking). In addition, the WR-group performed home-based weight-bearing resistance training. EI was measured as a muscle quality index using axial B-mode ultrasound images of the rectus femoris and vastus lateralis of the mid-thigh. We further averaged these parameters to obtain the EI of the quadriceps femoris (QF). Participants further performed five functional tests: sit-ups, supine up, sit-to-stand, 5-m maximal walk, and 6-min walk.

Results

QF EI was significantly decreased in both groups after training (W-group 69.9?±?7.4?a.u. to 61.7?±?7.0?a.u., WR-group 64.0?±?9.5?a.u. to 51.1?±?10.0?a.u.; P?<?0.05), suggesting improved muscle quality. QF EI was further decreased in the WR-group compared with the W-group. The sit-up test in both groups and the sit-to-stand and 5-m maximal walk tests in the W-group were significantly improved after training.

Conclusion

These results suggest that training-induced stimulation is associated with a decrease in EI in some thigh regions. Furthermore, the addition of home-based resistance training to walking would be effective for a greater reduction of EI.

     

Relationship between balance and gait stability in healthy older adults

Age-related adaptations during walking create a more stable walking pattern, which is less effective for forward progression and might be related to balance deficiencies. This study determined the relationship between walking stability and measures of balance in older adults. Seventeen older and 20 young adults performed the Berg Balance Test (BBT) and walked 10 m. Walking velocity (WV) and cadence were measured, and a gait-stability ratio (GSR) was calculated. Higher GSR indicated that a greater portion of the gait cycle was spent in double-limb support. Age-group comparisons established declines in BBT scores and WV and increases in GSR with age. Significant relationships were identified for BBT Item 12 (alternate stepping on a stool) with WV (r =.58, r(2) =.34) and GSR (r = -.74, r(2) =.54). The correlation of BBT Item 12 with GSR was stronger than with WV (p <.05). Results indicated a strong relationship between increased gait stability and decreased balance for a dynamic weight-shifting task. Therefore, GSR is a better indicator of balance deficits during walking than is WV alone.     

Exercise behavior in older adults: a test of the transtheoretical model

The transtheoretical model (TTM) was developed as a guide for understanding behavior change. Little attention has been given, however, to the appropriateness of the TTM for explaining the adoption of exercise behavior in older adults. The purposes of this study were to determine the reliability of the TTM instruments and validate TTM predictions in 86 community-dwelling older adults (mean age 75.1 +/- 7.0 years, 87% women) who were participants in a 16-week walking program. TTM construct scales--self-efficacy, decisional balance (pros and cons), and processes of change (behavioral and cognitive)--were generally reliable (all>.78). Behavioral processes of change increased from baseline to follow-up, but pros, cons, and cognitive processes did not change among participants who became regular exercisers. Stage of change did not predict exercise adoption, but baseline self-efficacy predicted walking behavior. These results lend partial support to the TTM in predicting exercise behavior.     

Aging, physical activity, and hormones in women--a review

Women experience significant changes in endocrine function during aging. Decreasing levels of anabolic hormones may be associated with musculoskeletal atrophy and decrease in function that is observed in older women and, as a result, there has been an increase in the use of pharmacological hormone therapies. It is difficult to distinguish, however, between physiological changes that are truly age related and those that are associated with lifestyle factors such as physical activity participation. Some research has shown that circulating levels of anabolic hormones such as DHEA(S) and IGF-I in older women are related to physical activity, muscle function, and aerobic power. Exercise-intervention studies have generally shown that increasing age blunts the acute hormonal response to exercise, although this might be explained by a lower exercise intensity in older women. There have been relatively few studies that examine hormonal adaptations to exercise training. Physical activity might have an effect on hormone action as a result of changes in protein carriers and receptors, and future research needs to clarify the effect of age and exercise on these other components of the endocrine system. The value and safety of hormone supplements must be examined, especially when used in combination with an exercise program.     

Activity-monitor accuracy in measuring step number and cadence in community-dwelling older adults

The primary purpose of this study was to investigate the accuracy of the activPAL physical activity monitor in measuring step number and cadence in older adults. Two pedometers (New-Lifestyles Digi-Walker SW-200 and New-Lifestyles NL2000) used in clinical practice to count steps were simultaneously evaluated. Observation was the criterion measure. Twenty-one participants (65-87 yr old) recruited from community-based exercise classes walked on a treadmill at 5 speeds (0.67, 0.90, 1.12, 1.33, and 1.56 m/s) and outdoors at 3 self-selected speeds (slow, normal, and fast). The absolute percentage error of the activPAL was <1% for all treadmill and outdoor conditions for measuring steps and cadence. With the exception of the slowest treadmill speed, the NL-2000 error was <2%. The SW-200 was the least accurate device, particularly at slower walking speeds. The activPAL monitor accurately recorded step number and cadence. Combined with its ability to identify primary postures, the activPAL might be a useful and versatile device for measuring activity in older adults.     

Energy expenditure during physically interactive video game playing in male college students with different playing experience

OBJECTIVE: Researchers have yet to explore the effect of physically interactive video game playing on energy expenditure, despite its potential for meeting current minimal daily activity and energy expenditure recommendations. PARTICIPANTS AND METHODS: Nineteen male college students -- 12 experienced Dance Dance Revolution (DDR) players and 7 inexperienced players -- completed maximal oxygen uptake assessments and a 30-minute DDR gaming session. The authors recorded heart rate (HR), rating of perceived exertion (RPE), respiratory exchange rate (RER), oxygen consumption (VO2), and total steps (TS30). RESULTS: Experienced participants showed higher exercise HR, RPE, RER, VO2, total and relative energy expenditure, exercise intensity, TS30, and average steps per minute, and less time and steps to expend 150 kilocalories (p < .05). CONCLUSIONS: Participants with greater playing experience can work at higher intensities, promoting greater energy expenditure.     

Perceptions of the Neighborhood Environment Associated With Walking at Recommended Intensity and Volume Levels in Recreational Senior Walkers

This study examined the relationship of perceived neighborhood environment factors with recommended volume and intensity of walking in recreational senior walkers. A sample of 85 seniors used an accelerometer and completed the ALPHA questionnaire. Binomial logistic regressions were conducted to detect associations. Perceptions about traffic safety (odds ratio [OR] = 4.395; 95% confidence interval [CI] = 1.024; 18.866) and pleasant environment (OR = 8.718; 95% CI = 1.803; 42.149) were positively related with the achievement of 10,000 steps per day, in older women. The perception of nearby parks was positively associated with the compliance with peak 30-minutes cadence above 100, in older men (OR = 14.353; CI 95% = 1.321; 15.591). No more significant associations were found between perceptions of the neighborhood environment and walking at recommended intensity and volume levels. These results indicated that community initiatives that encourage traffic safety, pleasant environment, and parks may be a promising direction to promote walking at recommended volume and intensity in senior walkers.     

Resistance training induced increase in VO2max in young and older subjects

It is an undeniable fact that resistance training (RT) is a potent stimulus for muscle hypertrophy and strength gain, but it is less understood whether RT can increase maximal aerobic capacity (VO₂max). The purpose of this brief review is to discuss whether or not RT enhances VO₂max in young (20–40 years) and older subjects (>60 years). Only 3 of 17 studies involving young subjects have indicated significant increases in VO₂max following RT, while six of nine studies in older subjects have reported significant improvements in VO₂max following RT. There was a significant negative correlation between the initial VO₂max and RT-induced change in VO₂max. This result suggests that RT-induced increase in VO₂max is dependent upon the subject’s initial VO₂max. The RT-induced increase in VO₂max may be elicited when their initial relative VO₂max is lower than 25 ml/kg/min for older subjects and lower than 40 ml/kg/min for young subjects. Thus, RT can be expected to improve concurrently both muscular and cardiovascular fitnesses within a single mode of RT when young and old persons have initially low fitness levels.     

Rate of perceived exertion as a tool to monitor cycling exercise intensity in older adults

The purpose of this study was to determine the efficacy of rate of perceived exertion (RPE) to monitor exercise intensity in older adults. Middle-aged (46.9 +/- 7.0 years, n = 24) and older women (75.5 +/- 3.8 years, n = 29) performed a graded maximal exercise test on a cycle ergometer while RPE, oxygen uptake, heart rate, and blood lactate levels were measured. The Pearson's product moment correlation coefficient between RPE and oxygen uptake for each stage of the graded exercise test was calculated for each participant. The mean coefficient for the older group (r =.954) was similar to that of middle-aged group (r =.963). The autocorrelation coefficient was much lower (r =.411) in the older group than in the middle-aged group (r =.871). Variability in RPE through the graded exercise test was similar between the two groups. In conclusion, RPE was strongly associated with oxygen uptake in the older group. These results indicate that RPE is effective in monitoring exercise intensity in older adults.