The effects of adding high-intensity of effort resistance training to routine care in persons with type II diabetes: An exploratory randomized parallel-group time-series study.

AIMS: This study considered the effects of supervised, low volume, high intensity of effort resistance training compared to continued routine care in persons with type II diabetes. METHODS: We utilized a randomized parallel-group time-series design. All participants completed baseline testing (T0) and then participated in an educational training intervention regarding the management of their diabetes and were followed up for six months, during which they received routine care before being retested (T1). Participants were then randomly allocated to either continue with routine care (CON) or receive the high intensity of effort resistance training intervention (HIT). Participants from both groups were retested again after six months (T2). All participants were followed up for a further 12 months before being finally tested (T3). Data were available from 57 participants who completed the whole duration of the study (HIT, n = 29; CON, n = 28) for measures of anthropometry (body mass, waist circumference, and BMI), body composition (body fat mass, body fat percentage, lean mass, and visceral fat mass), total body water, phase angle, HbA1c, fasted blood glucose, and subjective wellbeing (WHO-5). RESULTS: During the initial 6-months of routine care significant improvements were noted for waist circumference, body fat mass, lean mass, body fat percentage, lean mass percentage, visceral fat mass, HbA1c, fasted blood glucose, and subjective wellbeing. During the successive 6-months (intervention) and 18-months (follow-up), data suggest that many of these positive changes during the initial 6-months were negated or reversed for CON. In contrast, participants engaging in HIT continued to show positive changes for waist circumference, body fat mass, lean mass, body fat percentage, lean mass percentage, and visceral fat. For blood markers and wellbeing, HbA1c continued to decrease, fasted blood glucose decreased, and subjective wellbeing continued to increase. These positive responses were still evidenced and significantly different compared to CON after the 12-month follow-up. CONCLUSION: The results of this exploratory pragmatic trial suggest that the addition of high intensity of effort RT alongside routine care can have a positive impact on a range of outcomes in type 2 diabetics having undergone prior routine care.

Neither repetition duration nor number of muscle actions affect strength increases, body composition, muscle size, or fasted blood glucose in trained males and females.

A key variable within resistance training (RT) is that of repetition duration: the time (seconds) taken to perform the concentric and eccentric muscle actions of a repetition. Research has produced equivocal results with regard to strength and muscle mass increases; many studies have created parity in the number of repetitions, but there has been disparity in the load used and the time under load (TUL). The purpose of this study was to compare load- and TUL-matched groups performing resistance exercise using different repetition durations. Fifty-nine male and female participants were randomized into 3 groups: 2s:4s (n = 18), 10s:10s (n = 20), or a group that performed 30 s of eccentric, 30 s of concentric, and 30 s of eccentric muscle actions (e.g., 1.5 repetitions; n = 21). Participants were supervised in one-on-one RT sessions 2 days/week for 10 weeks. Outcomes were 10 repetitions maximum (RM) and predicted 1RM for chest press, leg press, and pulldown exercises, as well as body composition, upper arm and thigh muscle mass, and fasted blood glucose. Analyses revealed significant increases in strength for all exercises but no between-group differences and no statistically significant time course changes for the other variables. Repetition duration does not affect the increases in strength in trained participants when exercise is performed to momentary failure. Because time constraints and perceived difficulty are often cited as barriers to exercise, it is important to recognize that the low-volume (single-set), machine-based protocol employed herein produced worthwhile strength increases in trained participants.

A minimal dose approach to resistance training for the older adult; the prophylactic for aging.

A plethora of research has supported the numerous health benefits of resistance training as we age, including positive relationships between muscular strength, muscle mass and reduced all-cause mortality. As such, resistance training has been referred to as medicine. However, participation and adherence remains low, with time constraints and perceived difficulty often cited as barriers to resistance training. With this in mind, we aimed to summarise the benefits which might be obtained as a product of a minimal dose approach. In this sense, participation in resistance training might serve as a prophylactic to delay or prevent the onset of biological aging. A short review of studies reporting considerable health benefits resulting from low volume resistance training participation is presented, specifically considering the training time, frequency, intensity of effort, and exercises performed. Research supports the considerable physiological and psychological health benefits from resistance training and suggests that these can be obtained using a minimal dose approach (e.g. ≤60min, 2d-wk-1), using uncomplicated equipment/methods (e.g. weight stack machines). Our hope is that discussion of these specific recommendations, and provision of an example minimal dose workout, will promote resistance training participation by persons who might otherwise have not engaged. We also encourage medical professionals to use this information to prescribe resistance exercise like a drug whilst having an awareness of the health benefits and uncomplicated methods.

Nutrition programs enhance exercise effects on body composition and resting blood pressure.

The purpose of our study was to examine the effects of exercise alone and exercise combined with specific nutrition programs on body composition and resting blood pressure rate. Adult participants (99 women, 22 men; aged 20-86 years) completed a combined strength and endurance exercise program (Exercise Only), or in conjunction with 1 of 2 nutrition plans (Exercise/Protein; Exercise/Protein/Diet). The Exercise-Only group performed 1 set of 9 resistance machines regimens interspersed with 3 bouts of recumbent cycling (5 minutes each). The Exercise/Protein group performed the same exercise program as Exercise-Only group, plus consumed 1.5 g of protein per kg of ideal body weight on a daily basis. The Exercise/Protein/Diet group followed an identical Exercise/Protein protocol along with a restricted daily caloric intake (1200-1500 cals/day for women; 1500-1800 cals/day for men). After 10 weeks of training, the Exercise/Protein group attained greater increases (P < 0.05) in lean weight and greater decreases (P < 0.05) in diastolic blood pressure (DBP) rate than the Exercise-Only group. The Exercise/Protein/Diet group experienced greater reductions (P < 0.05) in body weight, body mass index (BMI), percent fat, fat weight, waist circumference (WC), systolic blood pressure (SBP) rate, and DBP rate than the Exercise-Only group, as well as greater reductions (P < 0.05) in body weight, BMI, percent fat, fat weight, and WC than the Exercise/Protein group. Our findings suggest that a higher protein nutrition plan may enhance the effects of exercise for increasing subject lean weight and decreasing DBP rate. The findings further indicate that a higher protein and lower calorie nutrition plan may enhance the effects of exercise for decreasing subject body weight, BMI, percent fat, fat weight, WC, SBP rate, and DBP rate, while attaining similar gains in lean body mass.

Resistance training is medicine: effects of strength training on health.

Inactive adults experience a 3% to 8% loss of muscle mass per decade, accompanied by resting metabolic rate reduction and fat accumulation. Ten weeks of resistance training may increase lean weight by 1.4 kg, increase resting metabolic rate by 7%, and reduce fat weight by 1.8 kg. Benefits of resistance training include improved physical performance, movement control, walking speed, functional independence, cognitive abilities, and self-esteem. Resistance training may assist prevention and management of type 2 diabetes by decreasing visceral fat, reducing HbA1c, increasing the density of glucose transporter type 4, and improving insulin sensitivity. Resistance training may enhance cardiovascular health, by reducing resting blood pressure, decreasing low-density lipoprotein cholesterol and triglycerides, and increasing high-density lipoprotein cholesterol. Resistance training may promote bone development, with studies showing 1% to 3% increase in bone mineral density. Resistance training may be effective for reducing low back pain and easing discomfort associated with arthritis and fibromyalgia and has been shown to reverse specific aging factors in skeletal muscle.

Effects of the Youth Fit for Life protocol on physiological, psychological, and behavioral factors at YMCA Calgary after-school care sites.

Youth inactivity and inappropriately high weight is a problem in the United States, Canada, and much of the industrialized world. Physiological and behavioral changes associated with the Youth Fit For Life protocol, a physical activity and nutrition education treatment based on self-efficacy theory, were assessed in 7- to 12-yr.-olds (N - 43) from Calgary, Alberta, Canada. Body Mass Index, strength, and cardiorespiratory endurance significantly improved over a 12-wk. period when contrasted with changes based on normative data. Significant within-group improvements in measures of self-efficacy, vegetable intake, and voluntary moderate-to-vigorous physical activity were also found over 12 wk. Multiple regression analysis indicated that score changes in measures of self-regulatory and task self-efficacy, and general self, accounted for changes in voluntary physical activity. Implications for use of behaviorally based methods for large-scale obesity prevention treatments in preadolescents were discussed.

Prescribing physical activity: applying the ACSM protocols for exercise type, intensity, and duration across 3 training frequencies.

When physicians advise patients to attain more physical activity, they usually recommend a walking program. However, in a similar way to no exercise, those embarking on a walking program will typically lose 4 to 6 lb of lean weight and reduce their resting metabolic rate 2% to 3% every decade. These effects may be mitigated by the inclusion of resistance exercise. The American College of Sports Medicine (ACSM) minimum exercise guidelines recommend 20 minutes of aerobic activity 3 days per week, and 1 set (8-12 repetitions) of 8 to 10 resistance exercises to train the major muscle groups 2 days per week. However, large-scale testing of these recommendations in a field setting has been minimal. Men and women between 21 and 80 years (N = 1725) [corrected] participated in a 10-week combined strength and aerobic activity program based on the ACSM protocols for exercise intensity and duration across 3 training frequencies (1, 2, or 3 sessions/week). Across all training frequencies, mean changes included a reduction in body fat of 1.97%, a decrease in fat weight of 1.7 kg, an increase in lean weight of 1.35 kg, a reduction in systolic blood pressure of 3.83 mm Hg, and a reduction in diastolic blood pressure of 1.73 mm Hg. More frequent weekly training sessions were associated with greater improvements in body fat percent, fat weight, and lean weight. Participants responded favorably to the ACSM exercise program with a 91% completion rate and a 95% satisfaction rating. This article presents recommendations for prescribing safe, effective, and time-efficient exercise programs.

Correlates of upper and lower body muscular strength in children.

Despite the widespread use of and acceptance of muscular fitness field tests in national youth fitness test batteries, little is known about how these field tests compare to 1 repetition maximum (1RM) strength in children. Therefore, the aim of this study was to characterize and identify correlates of muscular strength in children 7 to 12 years of age. Ninety children (39 girls and 51 boys) between the ages of 6.7 and 12.3 years volunteered to participate in this study. Children were tested on 1RM chest press (CP) strength, 1RM leg press (LP) strength, handgrip strength, vertical jump, long jump, sit and reach flexibility, and height and weight (used to determine body mass index [BMI]). For the combined sample, LP 1RM ranged from 75% to 363% of body weight and CP 1RM ranged from 25% to 103% of body weight. Multiple regression analyses predicting LP 1RM showed that BMI and long jump were significant (R = 44.4% with age and gender not significant) and BMI and vertical jump were significant (R = 40.8% with age and gender not significant). Multiple regression analyses predicting CP 1RM showed that BMI and handgrip strength were significant (R = 58.6% with age and gender not significant). Age and gender alone accounted for 4.6% (not significant) of the variation in LP 1RM and 15.4% (significant) in CP 1RM. In summary, these data indicate that BMI, handgrip strength, long jump, and vertical jump relate to 1RM strength in children and therefore may be useful for assessing muscular fitness in youths.

The H-Wave((R)) Device Induces NODependent Augmented Microcirculation and Angiogenesis, Providing Both Analgesia and Tissue Healing in Sports Injuries.

UNLABELLED: The hypothesis that the H-Wave(R) device (Electronic Waveform Lab, Inc., Huntington Beach, CA), a small-diameter fiber stimulator, is a paradigm shift of electrotherapeutic treatment of pain associated with human neuropathies and sports injuries is based on a number of its properties. The primary effect of H-Wave(R) device stimulation (HWDS) is the stimulation of "red-slow-twitch" skeletal muscle fibers. The authors propose, based on the unique waveform, that the H-Wave(R) device specifically and directly stimulates the small smooth muscle fibers within the lymphatic vessels ultimately leading to fluid shifts and reduced edema. In unpublished rat studies, it has been observed that HWDS induces protein clearance. The H-Wave(R) device was designed to stimulate an ultra low frequency (1-2 Hz), low tension, nontetanizing, and nonfatiguing contraction, which closely mimics voluntary or natural muscle contractions. The H-Wave(R) device can stimulate small fibers due in part to its exponentially decaying waveform and constant current generator activity. The main advantage of these technologies over currently applied electrical stimulators (eg, transcutaneous electrical nerve stimulator [TENS], interferential [IF], neuromuscular electrical stimulation [NMES], high-volt galvanic, etc.) is that H-Wave\'s(R) small fiber contraction does not trigger an activation of the motor nerves of the large white muscle fibers or the sensory delta and C pain nerve fibers, thus eliminating the negative and painful effects of tetanizing fatigue, which reduces transcapillary fluid shifts. Another function of the H-Wave(R) device is an anesthetic effect on pain conditions, unlike a TENS unit which in the short term activates a hypersensory overload effect (gate theory) to stop pain signals from reaching the thalamic region of the brain. When the H-Wave(R) device is used at high frequency (60 Hz), it acts intrinsically on the nerve to deactivate the sodium pump within the nerve fiber, leading to a long-lasting anesthetic/analgesic effect due to an accumulative postsynaptic depression. Moreover, HWDS produces a nitric oxide (NO)-dependent enhancement of microcirculation and angiogenesis in rats. Thus, the authors hypothesize that because of these innate properties of the H-Wave(R) device, it may provide a paradigm shift for the treatment of both short- and long-term inflammatory conditions associated with pain due to sports injuries. A recent meta-analysis found a moderate-to-strong effect of the H-Wave(R) device in providing pain relief, reducing the requirement for pain medication, and increasing functionality. The most robust effect was observed for improved functionality, suggesting that the H-Wave(R) device may facilitate a quicker return to the field. KEYWORDS: H-Wave(R) device; sportsmedicine, nitric oxide-dependent blood flow; analgesia; angiogenesis.

Relations of self-appraisal and mood changes with voluntary physical activity changes in african american preadolescents in an after-school care intervention.

There is an increasing prevalence of overweight in preadolescents that predicts physical problems over the lifespan. Physical inactivity has been implicated as an associated factor, with African American youth being at an increased risk. Based on social cognitive theory, and proposed correlates of physical activity in youth, changes over 12 weeks in measures of self-appraisal (general self, physical appearance, physical self-concept, exercise barriers self-efficacy) and mood (tension, vigor), and their relations with voluntary physical activity changes, were assessed within an after-school care physical activity intervention. Participants were volunteers recruited from children already registered for a 12-week segment of YMCA after-school care. The treatment group consisted of 146 African American preadolescents with the control group comprised of 123 African American preadolescents who were scheduled to receive the program during the next sequence that it was offered. Results indicated the intervention group reported significantly more positive self-appraisals, reduced tension, and enhanced vigor. Bivariate and multiple regression analyses indicated that when each of the 4 self-appraisal and 2 mood factors were simultaneously entered into a regression equation, 36% of the variance in voluntary physical activity was explained. Findings support the treatment's association with theoretically based correlates of physical activity in the present sample, and suggest directions for physical activity interventions for youth. Key pointsSocial cognitive theory offers a framework for understanding correlates of physical activity in youth.This study suggests that it is possible for a convenient physical activity intervention, led by after-school care counselors with minimal training, to improve participants' self-perceptions, mood, and voluntary physical activity.Improvements in self-perceptions and mood appeared to be significantly associated with increased free-time physical activity in African American 8- to 12-year-olds.This study's findings may lead to a better understanding of physical activity promotion in youth, and foster improvements in physical activity curricula.

Comparison of two exercise protocols on fitness score improvement in poorly conditioned Air Force personnel.

A 12-wk. study was conducted to contrast the effects of a longer and more frequent aerobic exercise protocol with a shorter and less frequent circuit strength-training protocol for improving U.S. Air Force physical fitness test scores of subjects who previously failed to achieve a passing point total. 83 men and women of the U.S. Air Force (M age = 32.7 yr.) participated in either the unsupervised standard conditioning program, which recommended approximately 60 min. of aerobic activity 4 to 5 days per week (n=26), or the supervised circuit strength-training program, which required approximately 25 min. of alternating strength and endurance exercises 3 days per week (n=57). Subjects were assessed on a 2400-m (1.5-mile) run, abdominal circumference, push-ups completed in 1 min., and abdominal crunches completed in 1 min. Dependent t tests with Bonferroni adjustment indicated that significant improvements were attained by the circuit strength-training group only on each of the aforementioned measures. Significantly more participants in the circuit strength-training group (26%) achieved a passing point total than in the standard conditioning group (19%) at Wk. 12 (chi1(2) =3.96, p = .05). Implications for enhancing physical fitness in poorly conditioned adults were discussed.

Relations of physical self-concept and muscular strength with resistance Exercise-induced Feeling State scores in older women.

Formerly sedentary older women (M age = 62 yr.) were recruited for either a wait-list control group (n=40) or a 10-.wk., 3 days/wk. weight-training treatment group (n=48). Only the treatment group demonstrated significant before- to after-exercise improvements on the Exercise-induced Feeling Inventory scales of Positive Engagement, Revitalization, Tranquility, and Physical Exhaustion (ds = /.43/ to /.96/). For the treatment group, scores on Physical Self-concept of the Tennessee Self-concept Scale: 2 were significantly correlated (r = -.28) with after-exercise changes in Physical Exhaustion. Muscular strength was significantly correlated with after-exercise changes in scores on three Exercise-induced Feeling Inventory scales (rs= /.28/ to /.31/). Simultaneous entry of Physical Self-concept scores and muscular strength into multiple regression equations increased the explained variance in Exercise-induced Feeling Inventory score changes for each of its four scales. Statistical significance was only reached, however, on changes in the Physical Exhaustion scale (R2 = .16, p = .02). Limitations and implications for theoretical development and applied use were discussed.

Age as a moderator of relations of physical self-concept and mood changes associated with 10 weeks of programmed exercise in women.

Significant correlations were found between reported changes in scores on the Physical Self-concept scale of the Tennessee Self-concept Scale, with those on the Depression (r=-.34) and Total Mood Disturbance (r=-.38) scales of the Profile of Mood States, for 35 women who initiated a structured exercise program. Accounting for age in simultaneous multiple regression equations added to the explained variance in changes in both Depression (R2=.29) and Total Mood Disturbance (R2=.18) scores. Findings supported propositions of social cognitive theory and self-efficacy theory. Limitations and the need for replication and extension were discussed.

Effects of a 12-week physical activity protocol delivered by YMCA after-school counselors (Youth Fit for Life) on fitness and self-efficacy changes in 5-12-year-old boys and girls.

To address reduced physical education (PE) in elementary schools, a 12-week physical activity protocol was tested on 5-12-year-old, primarily African American, girls (n = 226) and boys (n = 344) at 14 YMCA after-school care sites. The 3 times/week, 45-min session curriculum included cardiovascular, resistance, and flexibility training, in which all children could participate simultaneously, and a behavioral skills education component. After-school counselors, formerly untrained in PE methods, administered the sessions, with periodic supervision by YMCA wellness staff members. Analyses of the eight Age x Sex subsamples indicated significant improvements on body composition, strength, and endurance, both within-groups and when predicted changes due to maturation were accounted for. Exercise barriers self-efficacy significantly increased in subsamples of 9-10- and 11-12-year-old girls only. The need for replication across ethnic groups was suggested. Limitations and the need for extension of research on supplementation of elementary school PE were discussed.

Relationship of feeling states after exercise and Total Mood Disturbance over 10 weeks in formerly sedentary women.

Changes in feeling states after exercise and changes in overall mood after a period of 10 weeks were correlated after participation in a supervised, moderate intensity resistance training program. 52 previously sedentary, asymptomatic women (M=56 yr.) participated. Point biserial correlations were calculated between the 10-wk. change on the Profile of Mood States using the Total Mood Disturbance score as the continuous variable, and positive or negative change in feeling states after exercise, assessed via the Exercise-induced Feeling Inventory, being the dichotomous variable. Correlations were significant for both the total sample (rpb=-.49) and participants with high initial Total Mood Disturbance based on a median split (rpb=-.55). Participants with positive changes in their feeling states after exercise also showed a significantly greater decrease in Total Mood Disturbance than those with negative changes. Changes in Total Mood Disturbance were not significantly correlated with changes in resting heart rate over the 10 weeks. Discussion included limitations and, after replication, possible application of the findings.

Perceived exertion during resistance exercise by children.

This pilot study examined the validity of a new scale of perceived exertion during acute bouts of resistance exercise in young children. The researchers developed an 11-point numerical scale with five pictures representing youths at various levels of exertion while lifting weights. 26 children (M age 10.1 +/- 1.2 yr.) performed one set of 10 repetitions at 35%, 55%, and 75% of their one-repetition maximum on the chest press and leg press exercises using child-size weight training machines. Scaling procedures for the perceptual anchors on the perceived exertion scale were based on one repetition maximum testing. Children could use this scale to translate into numbers their perceptions of physical exertion during upper and lower body resistance exercise. Perceived exertion distributed as a positive linear function of the percent of one repetition maximum on the chest press and leg press exercises (rs = .70 to .77), and perceived exertion increased significantly across all three exercise intensities on both exercises. These preliminary findings provide partial evidence for validation when this scale was used during resistance exercise with children. Additional validation regarding perceived exertion during resistance exercise with children is warranted.

Maximal strength testing in healthy children.

Strength training has become an accepted method of conditioning in children. However, there is concern among some observers that maximal strength testing may be inappropriate or potentially injurious to children. The purpose of this study was to evaluate the safety and efficacy of 1 repetition maximum (1RM) strength testing in healthy children. Thirty-two girls and 64 boys between 6.2 and 12.3 years of age (mean age 9.3 +/- 1.6 years) volunteered to participate in this study. All subjects were screened for medical conditions that could worsen during maximal strength testing. Under close supervision by qualified professionals, each subject performed a 1RM test on 1 upper-body (standing chest press or seated chest press) and 1 lower-body (leg press or leg extension) exercise using child-size weight training machines. No injuries occurred during the study period, and the testing protocol was well tolerated by the subjects. No gender differences were found for any upper- or lower-body strength test. These findings demonstrate that healthy children can safely perform 1RM strength tests, provided that appropriate procedures are followed.

Comparison of 1 and 2 days per week of strength training in children.

The purpose of this study was to compare the effects of 1 and 2 days per week of strength training on upper body strength, lower body strength, and motor performance ability in children. Twenty-one girls and 34 boys between the ages of 7.1 and 12.3 years volunteered to participate in this study. Participants strength trained either once per week (n = 22) or twice per week (n = 20) for 8 weeks at a community-based youth fitness center. Each training session consisted of a single set of 10-15 repetitions on 12 exercises using child-size weight machines. Thirteen children who did not strength train served as age-matched controls. One repetition maximum (1RM) strength on the chest press and leg press, handgrip strength, long jump, vertical jump, and flexibility were assessed at baseline and posttraining. Only participants who strength trained twice per week made significantly greater gains in 1RM chest press strength, compared to the control group (11.5 and 4.4% respectively, p < .05). Participants who trained once and twice per week made gains in 1RM leg press strength (14.2 and 24.7%, respectively) that were significantly greater than control group gains (2.4%). On average, participants who strength trained once per week achieved 67% of the 1RM strength gains. No significant differences between groups were observed on other outcome measures. These findings support the concept that muscular strength can be improved during the childhood years and favor a training frequency of twice per week for children participating in an introductory strength training program.