Effects and moderators of coping skills training on symptoms of depression and anxiety in patients with cancer: Aggregate data and individual patient data meta-analyses

PURPOSE

This study evaluated the effects of coping skills training (CST) on symptoms of depression and anxiety in cancer patients, and investigated moderators of the effects.

METHODS

Overall effects and intervention-related moderators were studied in meta-analyses of pooled aggregate data from 38 randomized controlled trials (RCTs). Patient-related moderators were examined using linear mixed-effect models with interaction tests on pooled individual patient data (n = 1953) from 15 of the RCTs.

RESULTS

CST had a statistically significant but small effect on depression (g = -0.31,95% confidence interval (CI) = -0.40;-0.22) and anxiety (g = -0.32,95%CI = -0.41;-0.24) symptoms. Effects on depression symptoms were significantly larger for interventions delivered face-to-face (p = .003), led by a psychologist (p = .02) and targeted to patients with psychological distress (p = .002). Significantly larger reductions in anxiety symptoms were found in younger patients (p_interaction < 0.025), with the largest reductions in patients <50 years (β = -0.31,95%CI = -0.44;-0.18) and no significant effects in patients ≥70 years. Effects of CST on depression (β = -0.16,95%CI = -0.25;-0.07) and anxiety (β = -0.24,95%CI = -0.33;-0.14) symptoms were significant in patients who received chemotherapy but not in patients who did not (p_interaction < 0.05).

CONCLUSIONS

CST significantly reduced symptoms of depression and anxiety in cancer patients, and particularly when delivered face-to-face, provided by a psychologist, targeted to patients with psychological distress, and given to patients who were younger and received chemotherapy.

Effects and moderators of exercise on sleep in adults with cancer: Individual patient data and aggregated meta-analyses

OBJECTIVES

To evaluate the effects of exercise interventions on sleep disturbances and sleep quality in patients with mixed cancer diagnoses, and identify demographic, clinical, and intervention-related moderators of these effects.

METHODS

Individual patient data (IPD) and aggregated meta-analyses of randomized controlled trials (RCTs). Using data from the Predicting OptimaL cAncer RehabIlitation and Supportive care project, IPD of 2173 adults (mean age = 54.8) with cancer from 17 RCTs were analyzed. A complementary systematic search was conducted (until November 2018) to study the overall effects and test the representativeness of analyzed IPD. Effect sizes of exercise effects on self-reported sleep outcomes were calculated for all included RCTs. Linear mixed-effect models were used to evaluate the effects of exercise on post-intervention outcome values, adjusting for baseline values. Moderator effects were studied by testing interactions for demographic, clinical and intervention-related characteristics.

RESULTS

For all 27 eligible RCTs from the updated search, exercise interventions significantly decreased sleep disturbances in adults with cancer (g = -0.09, 95% CI [-0.16; -0.02]). No significant effect was obtained for sleep quality. RCTs included in IPD analyses constituted a representative sample of the published literature. The intervention effects on sleep disturbances were not significantly moderated by any demographic, clinical, or intervention-related factor, nor by sleep disturbances.

CONCLUSIONS

This meta-analysis provides some evidence that, compared to control conditions, exercise interventions may improve sleep disturbances, but not sleep quality, in cancer patients, although this effect is of a small magnitude. Among the investigated variables, none was found to significantly moderate the effect of exercise interventions on sleep disturbances.

The potential therapeutic effects of creatine supplementation on body composition and muscle function in cancer

Low muscle mass in individuals with cancer has a profound impact on quality of life and independence and is associated with greater treatment toxicity and poorer prognosis. Exercise interventions are regularly being investigated as a means to ameliorate treatment-related adverse effects, and nutritional/supplementation strategies to augment adaptations to exercise are highly valuable. Creatine (Cr) is a naturally-occurring substance in the human body that plays a critical role in energy provision during muscle contraction. Given the beneficial effects of Cr supplementation on lean body mass, strength, and physical function in a variety of clinical populations, there is therapeutic potential in individuals with cancer at heightened risk for muscle loss. Here, we provide an overview of Cr physiology, summarize the evidence on the use of Cr supplementation in various aging/clinical populations, explore mechanisms of action, and provide perspectives on the potential therapeutic role of Cr in the exercise oncology setting.

Overwhelming research and clinical evidence of exercise medicine efficacy in cancer management-translation into practice is the challenge before us

The paper “Connecting people with cancer to physical activity and exercise programs: a pathway to create accessibility and engagement” is very timely. [...]

Effects and moderators of psychosocial interventions on quality of life, and emotional and social function in patients with cancer: An individual patient data meta-analysis of 22 RCTs

Objective

This individual patient data (IPD) meta‐analysis aimed to evaluate the effects of psychosocial interventions (PSI) on quality of life (QoL), emotional function (EF), and social function (SF) in patients with cancer, and to study moderator effects of demographic, clinical, personal, and intervention‐related characteristics.

Methods

Relevant studies were identified via literature searches in 4 databases. We pooled IPD from 22 (n = 4217) of 61 eligible randomized controlled trials. Linear mixed‐effect model analyses were used to study intervention effects on the post‐intervention values of QoL, EF, and SF (z‐scores), adjusting for baseline values, age, and cancer type. We studied moderator effects by testing interactions with the intervention for demographic, clinical, personal, and intervention‐related characteristics, and conducted subsequent stratified analyses for significant moderator variables.Results: PSI significantly improved QoL (β = 0.14,95%CI = 0.06;0.21), EF (β = 0.13,95%CI = 0.05;0.20), and SF (β = 0.10,95%CI = 0.03;0.18). Significant differences in effects of different types of PSI were found, with largest effects of psychotherapy. The effects of coping skills training were moderated by age, treatment type, and targeted interventions. Effects of psychotherapy on EF may be moderated by cancer type, but these analyses were based on 2 randomized controlled trials with small sample sizes of some cancer types.

Conclusions

PSI significantly improved QoL, EF, and SF, with small overall effects. However, the effects differed by several demographic, clinical, personal, and intervention‐related characteristics. Our study highlights the beneficial effects of coping skills training in patients treated with chemotherapy, the importance of targeted interventions, and the need of developing interventions tailored to the specific needs of elderly patients.

Effects of physical exercise on breast cancer-related secondary lymphedema: a systematic review

PURPOSE

The aim of this systematic review is to assess the effect of different types of exercise on breast cancer-related lymphedema (BCRL) in order to elucidate the role of exercise in this patient group.

METHODS

A systematic data search was performed using PubMed (December 2016). The review is focused on the rehabilitative aspect of BCRL and undertaken according to the PRISMA statement with Levels of Evidence (LoE) assessed.

RESULTS

11 randomized controlled trials (9 with LoE 1a and 2 with LoE 1b) that included 458 women with breast cancer in aftercare were included. The different types of exercise consisted of aqua lymph training, swimming, resistance exercise, yoga, aerobic, and gravity-resistive exercise. Four of the studies measured a significant reduction in BCRL status based on arm volume and seven studies reported significant subjective improvements. No study showed adverse effects of exercise on BCRL.

CONCLUSION

The evidence indicates that exercise can improve subjective and objective parameters in BCRL patients, with dynamic, moderate, and high-frequency exercise appearing to provide the most positive effects.

Abstract P6-12-06: Effect and moderators of exercise on fatigue in patients with breast cancer: Meta-analysis of individual patient data

Background - Fatigue is one of the most common and disabling complaints in patients with breast cancer and can effectively be reduced by physical exercise, with small to moderate effect sizes. To identify heterogeneity in responses to exercise and to further personalize exercise prescriptions, moderators of exercise effects on fatigue should be investigated. However, most randomized controlled trials (RCTs) are not adequately powered for such analyses. Therefore we conducted meta-analyses using the individual patient data of several exercise RCTs. The aim is to investigate the effect and moderators of physical exercise on cancer-related fatigue in patients with breast cancer.

Methods - Within the Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS) consortium, principal investigators of 34 exercise RCTs worldwide have shared their individual patient data. Twenty-two of these RCTs included patients with breast cancer with a total sample size of 3,061. Different questionnaires to assess level of fatigue were used, which was acknowledged by using z-scores in the analysis. A one-step individual patient data meta-analysis, using a linear mixed-effect model adjusted for baseline fatigue, with a random intercept on study (to account for study clustering) was undertaken to investigate effect of exercise on fatigue. The result, a between-group difference in z-scores, corresponds to a Cohen's d effect size. An interaction term was included in the model to assess potential moderators including demographic (age, marital status, education), clinical (body mass index, presence of distant metastasis), intervention-related (intervention timing, delivery mode and duration), and exercise-related (exercise type, frequency, intensity, duration) characteristics.

Results – Exercise significantly reduced fatigue reported by women with breast cancer (β= -0.15, 95% CI -0.21;-0.09). This effect did not differ significantly between patients with different demographic and clinical characteristics (p-valuesinteraction &gt;0.05). Also, neither timing (during or post-treatment) and duration of the intervention, nor exercise-related factors moderated intervention effects on fatigue. Supervised exercise had significantly larger effects on fatigue than unsupervised exercise (βdifference= -0.17, 95%CI -0.28;-0.05). Compared to the control group, supervised exercise significantly improved fatigue (β = -0.21, 95%CI = -0.28;-0.14), while unsupervised exercise did not (β = -0.04, 95%CI = -0.14;0.06).

Conclusion – Exercise significantly reduces fatigue in patients with breast cancer across subgroups formed on the basis of age, marital status, education level, body mass index, and presence of distant metastasis. The effect of exercise is significantly larger when performed under supervision. Hence, exercise, and preferably supervised exercise, represents a viable intervention for the prevention and treatment of fatigue among patients with breast cancer.

Citation Format: van Vulpen JK, Sweegers MG, Kalter J, Peeters PH, Courneya KS, Newton RU, Aaronson NK, Jacobsen PB, Steindorf K, Stuiver MM, Hayes S, Mesters I, Knoop H, Goedendorp M, Mutrie N, Thorsen L, Schmidt M, Sonke GS, Bohus M, James EL, Oldenburg HS, Velthuis MJ, Nollet F, Wenzel J, Wiskemann J, Galvão DA, Chinapaw MJ, Irwin ML, Griffith KA, van Weert E, Daley AJ, McConnachie A, Schulz K-H, Short CE, Plotnikoff RC, Potthoff K, van Beurden M, van Harten WH, Schmitz KH, Winters-Stone KM, Taaffe DR, van Mechelen W, Kersten M-J, Verdonck-de Leeuw IM, Brug J, Buffart LM, May AM. Effect and moderators of exercise on fatigue in patients with breast cancer: Meta-analysis of individual patient data [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-06.

The feasibility of a pragmatic distance-based intervention to increase physical activity in lung cancer survivors

The purpose of this study was to investigate the feasibility and preliminary efficacy of a pragmatic distance-based intervention designed to increase physical activity (PA) participation in lung cancer survivors. Fourteen lung cancer survivors were recruited via invitation from the State Cancer Registry to join a 12-week PA intervention of print materials paired with brief telephone follow-up. Outcome measures of feasibility, PA participation and quality of life (QoL) were assessed at baseline, post-intervention and follow-up via telephone interview. Eligibility, recruitment and attrition rates were 16%, 58% and 29% respectively. No adverse events were reported; however, pain scores worsened following the intervention (median change -3.6, IQR -8.0, 0.0). Average intervention adherence was 91% with low median ratings of participation burden (i.e., all items 1/7) and high trial evaluation (i.e., all items 7/7). Post-intervention, median change in self-reported moderate and vigorous PA was 84 min (IQR -22, 188), and several domains of QoL improved. However, for both of these outcomes, improvements were not maintained at follow-up. Our findings suggest that this pragmatic distance-based intervention was safe, had good adherence rates, and indicate potential for improving short-term PA and QoL in lung cancer survivors. Additional strategies are needed to improve other indicators of feasibility, particularly recruitment, retention and long-term maintenance of improvements. Australian New Zealand Clinical Trials Registration: ACTRN12612000085875.

Associations between aerobic exercise levels and physical and mental health outcomes in men with bone metastatic prostate cancer: a cross-sectional investigation

Cancer patients with bone metastases have previously been excluded from participation in physical activity programmes due to concerns of skeletal fractures. Our aim was to provide initial information on the association between physical activity levels and physical and mental health outcomes in prostate cancer patients with bone metastases. Between 2012 and 2015, 55 prostate cancer patients (mean age 69.7 ± 8.3; BMI 28.6 ± 4.0) with bone metastases (58.2% >2 regions affected) undertook assessments for self-reported physical activity, physical and mental health outcomes (SF-36), objective physical performance measures and body composition by DXA. Sixteen men (29%) met the current aerobic exercise guidelines for cancer survivors, while 39 (71%) reported lower aerobic exercise levels. Men not meeting aerobic exercise guidelines had lower physical functioning (p = .004), role functioning (physical and emotional) (p < .05), general health scores (p = .014) as well all lower measures of physical performance (p < .05). Lower levels of aerobic exercise are associated with reduced physical and mental health outcomes in prostate cancer patients with bone metastases. While previous research has focused primarily in those with non-metastatic disease, our initial results suggest that higher levels of aerobic exercise may preserve physical and mental health outcomes in prostate cancer patients with bone metastases. Clinical Trial Registry: Trial Registration: ACTRN12611001158954.

EFFECTS OF COMPRESSION ON LYMPHEDEMA DURING RESISTANCE EXERCISE IN WOMEN WITH BREAST CANCER-RELATED LYMPHEDEMA: A RANDOMIZED, CROSS-OVER TRIAL

The use of compression garments during exercise is recommended for women with breast cancer-related lymphedema, but the evidence behind this clinical recommendation is unclear. The aim of this randomized, cross-over trial was to compare the acute effects of wearing versus not wearing compression during a single bout of moderate-load resistance exercise on lymphedema status and its associated symptoms in women with breast cancer-related lymphedema (BCRL). Twenty-five women with clinically diagnosed, stable unilateral breast cancer-related lymphedema completed two resistance exercise sessions, one with compression and one without, in a randomized order separated by a minimum 6 day wash-out period. The resistance exercise session consisted of six upper-body exercises, with each exercise performed for three sets at a moderate-load (10-12 repetition maximum). Primary outcome was lymphedema, assessed using bioimpedance spectroscopy (L-Dex score). Secondary outcomes were lymphedema as assessed by arm circumferences (percent inter-limb difference and sum-of-circumferences), and symptom severity for pain, heaviness and tightness, measured using visual analogue scales. Measurements were taken pre-, immediately post- and 24 hours post-exercise. There was no difference in lymphedema status (i.e., L-Dex scores) pre- and post-exercise sessions or between the compression and non-compression condition [Mean (SD) for compression pre-, immediately post- and 24 hours post-exercise: 17.7 (21.5), 12.7 (16.2) and 14.1 (16.7), respectively; no compression: 15.3 (18.3), 15.3 (17.8), and 13.4 (16.1), respectively]. Circumference values and symptom severity were stable across time and treatment condition. An acute bout of moderate-load, upper-body resistance exercise performed in the absence of compression does not exacerbate lymphedema in women with BCRL.

The relationship between BPAQ-derived physical activity and bone density of middle-aged and older men

The bone-specific physical activity questionnaire (BPAQ) accounts for activities that affect bone but has not been used in studies with older adults. Relationships exist between the BPAQ-derived physical activity and bone density in healthy middle-aged and older men but not men with prostate cancer. Disease-related treatments detrimental to bone should be considered when administering the BPAQ.

INTRODUCTION

The bone-specific physical activity questionnaire (BPAQ) was developed to account for bone-specific loading. In this retrospective study, we examined the relationship between BPAQ-derived physical activity and bone mineral density (BMD) in middle-aged and older men with and without prostate cancer.

METHODS

Two groups, 36 healthy men and 69 men with prostate cancer receiving androgen suppression therapy (AST), completed the BPAQ and had whole body, total hip, femoral (FN) and lumbar spine BMD assessed by dual-energy X-ray absorptiometry.

RESULTS

Past (pBPAQ), current (cBPAQ) and total BPAQ (tBPAQ) scores for the healthy men were related to FN BMD (pBPAQ r = 0.36, p = 0.030; cBPAQ r s = 0.35, p = 0.034; tBPAQ r = 0.41, p = 0.014), and pBPAQ and tBPAQ were related to total hip (r s = 0.35, p = 0.035 and r s = 0.36, p = 0.029, respectively) and whole body BMD (r s = 0.44, p = 0.007 and r s = 0.45, p = 0.006, respectively). In men with prostate cancer, the BPAQ was not significantly associated with BMD. In stepwise regression analyses, body mass and tBPAQ predicted 30 % of the variance in total hip BMD (p = 0.003), cBPAQ predicted 14 % of the variance in FN BMD (p = 0.002), and body mass, age and tBPAQ predicted 47% of the variance in whole body BMD (p < 0.001) in healthy men. In men with prostate cancer, the BPAQ was not an independent predictor of BMD.

CONCLUSIONS

Although BPAQ-derived estimates of physical activity are related to bone status in healthy middle-aged and older men, the adverse effect of AST on bone appears to obscure this relationship in men with prostate cancer.

Evidence-based physical activity guidelines for cancer survivors: current guidelines, knowledge gaps and future research directions

Physical activity during and after cancer treatment has beneficial effects on a number of physical and psychosocial outcomes. This paper aims to discuss the existing physical activity guidelines for cancer survivors and to describe future research directions to optimize prescriptions. Studies on physical activity during and after cancer treatment were searched in PubMed, Clinicaltrials.gov, Australian New Zealand Clinical Trials Registry, and Dutch Trial registry. Physical activity guidelines for cancer survivors suggest that physical activity should be an integral and continuous part of care for all cancer survivors. However, the development of these guidelines has been limited by the research conducted. To be able to develop more specific guidelines, future studies should focus on identifying clinical, personal, physical, psychosocial, and intervention moderators explaining 'for whom' or 'under what circumstances' interventions work. Further, more insight into the working mechanisms of exercise interventions on health outcomes in cancer survivors is needed to improve the efficacy and efficiency of interventions. Finally, existing programs should embrace interests and preferences of patients to facilitate optimal uptake of interventions. In conclusion, current physical activity guidelines for cancer survivors are generic, and research is needed to develop more personalized physical activity guidelines.

The effects of multidisciplinary rehabilitation in patients with early-to-middle-stage Huntington's disease: a pilot study

BACKGROUND AND PURPOSE

Despite advances in the understanding of Huntington's disease (HD), treatment remains symptomatic. Multidisciplinary rehabilitation, however, appears to impact disease progression. Here we show the feasibility, safety and efficacy of a 9-month multidisciplinary rehabilitation programme in a small cohort of patients with early-to-middle-stage HD.

METHODS

Twenty patients with HD were assigned to two groups, equally matched for cognitive and motor scores. One group received the intervention, whilst the other served as control. The Unified-Huntington's-Disease-Rating-Scale-Total-Motor-Score was the primary outcome measure. Neurocognitive/psychological tests, body composition, postural stability, strength and quality of life assessments were secondary outcome measures.

RESULTS

The intervention reduced motor and postural stability deterioration, with minor improvements in depression, cognition and quality of life. Significant gains were observed for fat-free mass and strength.

CONCLUSION

This pilot study suggests that a prolonged multidisciplinary rehabilitation programme in early-to-middle-stage HD is feasible, well-tolerated and associated with therapeutic benefit. Further explorative, larger studies are warranted.

Exercise and Parkinson's: benefits for cognition and quality of life

OBJECTIVES

The benefits of physical exercise for psychological aspects of quality of life (QoL) are well established in normally ageing adults, yet potential benefits for people with Parkinson's disease (PD) have received limited attention. This study evaluated the benefits of exercise for cognitive functioning, mood and disease-specific QoL for people with PD.

METHODS

Twenty-eight individuals with PD were allocated to an exercise intervention program (EIP, n = 15) or control group (n = 13). The EIP group undertook a programme of progressive anabolic and aerobic exercise twice weekly for 12 weeks. The control group maintained their usual lifestyle.

RESULTS

Exercise was shown to have selective benefits for cognitive functioning by improving frontal lobe based executive function. No significant effects were demonstrated for mood or disease-specific QoL.

CONCLUSIONS

These results are consistent with previous research demonstrating selective benefits of exercise for executive function among normal ageing adults and PD.

Endocrine and immune responses to resistance training in prostate cancer patients

This study examined the effect of 20 weeks resistance training on a range of serum hormones and inflammatory markers at rest, and following acute bouts of exercise in prostate cancer patients undergoing androgen deprivation. Ten patients exercised twice weekly at high intensity for several upper and lower-body muscle groups. Neither testosterone nor prostate-specific antigen changed at rest or following an acute bout of exercise. However, serum growth hormone (GH), dehydroepiandrosterone (DHEA), interleukin-6, tumor necrosis factor-alpha and differential blood leukocyte counts increased (P < 0.05) following acute exercise. Resistance exercise does not appear to compromise testosterone suppression, and acute elevations in serum GH and DHEA may partly underlie improvements observed in physical function.

Salivary Cortisol, Testosterone, and T/C Ratio Responses during a 36-hole Golf Competition

The purpose of this investigation was to study the effects of 36 continuous holes of competitive golf on salivary testosterone, cortisol, and testosterone-to-cortisol ratio and their relation to performance in eight elite male collegiate golfers (age 20.3 [+/- 1.5] years). Thirty-six holes of a 54-hole NCAA golf tournament were played on the first day of the competition. A saliva sample was taken 45 minutes prior to the round and immediately following each hole for a total of 37 samples per subject. Time matched baseline samples were collected on a different day to account for circadian variation. Six-hole areas under the curve (AUC) values were calculated for endocrine measures. Significant (p < 0.05) increases were noted for cortisol during competition, however, testosterone did not change during competition compared to baseline. Testosterone-to-cortisol (T/C) ratio was significantly lower throughout the competition compared to baseline measures. Thirty-six-hole AUC testosterone-to-cortisol ratio response was correlated (r = 0.82) to 36-hole score. There was a high correlation between pre-round testosterone (r = 0.71), T/C ratio response (r = 0.82), and 36-hole score. CSAI-2 somatic anxiety was correlated to pre-round cortisol (r = 0.81) and testosterone (r = - 0.80) response. These results indicate a significant hormonal response during 10 hours of competitive golf. Good golf performance (low golf scores) in this competition was related to low T/C ratio (r = .82). Additionally, results from this investigation validated CSAI-2 somatic anxiety with physiological measures of anxiety.

Exercise can prevent and even reverse adverse effects of androgen suppression treatment in men with prostate cancer

Side effects accompanying androgen deprivation therapy (ADT), including sarcopenia, loss of bone mass and reduction in muscle strength, can compromise physical function, particularly in older patients. Exercise, specifically resistance training, may be an effective and cost-efficient strategy to limit or even reverse some of these adverse effects during and following therapy. In this review, we discuss common morphological and physiological ADT-related side effects or 'Androgen Deprivation and Sarcopenia-Related Disorders' and the existing clinical trials incorporating physical exercise in prostate cancer patients receiving active therapy. Further, training concepts and guidelines are provided for prescribing resistance exercise programs for this population.

An evaluation of a new test of reactive agility and its relationship to sprint speed and change of direction speed

The purpose of this study was to evaluate the reliability and validity of a new test of agility, the reactive agility test (RAT), which included anticipation and decision-making components in response to the movements of a tester. Thirty-eight Australian football players took part in the study, categorized into either a higher performance group (HPG) (n=24) or lower performance group (LPG) (n=14) based on playing level from the previous season. All participants undertook testing of a 10m straight sprint (10mSS), a 8-9m change of direction speed test (CODST), and the RAT. Test-retest and inter-tester reliability testing measures were conducted with the LPG. The intra-class correlation (ICC) of the RAT was 0.870, with no significant (p<0.05) difference between the test results obtained on the first and second test sessions using a t-test. A dependent samples t-test revealed no significant (p<0.05) difference between the test results of two different testers with the same population. The HPG were significantly (p=0.001) superior to those of the LPG on the RAT, with no differences observed on any other variable. The RAT is an acceptably reliable test when considering both test-retest reliability, as well as inter-rater reliability. In addition, the test was valid in distinguishing between players of differing performance level in Australian football, while the 10mSS and CODST were not. This result suggests that traditional closed skill sprint and sprint with direction change tests may not adequately distinguish between players of different levels of competition in Australian football.

Physiological and anthropometric characteristics of starters and non-starters and playing positions in elite Australian Rules Football: a case study

A purpose of this study was to determine if pre-season anthropometric and physiological measures were significantly different for the players from one Australian Football League (AFL) club selected to play in the first game of the season compared to the players not selected. Another purpose was to compare fitness test results for defenders, forwards and mid-fielders in the same AFL club. Thirty-four players were tested for isolated quadriceps and hamstrings strength, leg extensor muscle strength and power, upper body strength, sprinting speed, vertical jump (VJ), endurance, skinfolds and hamstring flexibility. The starters who were selected to play the first game were a significantly older and more experienced playing group, and were significantly better (p < 0.05) in measures of leg power, sprinting speed and the distance covered in the Yo Yo intermittent recovery test compared to the non-starters. Although there were trends for the superiority of the starters, the differences in lower and upper body strength, VJ and predicted VO2max were non-significant. The forwards generally produced the worst fitness scores of the playing positions with the midfielders having significantly lower skinfolds and the defenders possessing better hamstring strength and VJ compared to the forwards. It was concluded that some fitness qualities can differentiate between starters and non-starters, at least in one AFL club. Comparisons of playing positions and the development of fitness norms for AFL players require further research.

Muscle fiber characteristics in patients with peripheral arterial disease

PURPOSE

There have been conflicting reports of muscle fiber type changes in patients with peripheral arterial disease (PAD). The purpose of this study was to examine the myosin heavy chain (MHC) expression as well as histochemical changes in the gastrocnemius muscle in patients with symptomatic PAD.

METHODS

Needle biopsy specimens were obtained from the medial gastrocnemius of 14 subjects with PAD (mean age (+/- SD), 69.7 +/- 4.8 yr) and eight activity-matched control subjects (mean age, 65.1 +/- 6.6 yr). Ankle-brachial index was assessed using Doppler ultrasound to determine the hemodynamic status of the patients, and maximal walking performance was determined during a graded treadmill test. Expression of MHC isoforms was determined by SDS-PAGE.

RESULTS

The proportion of MHC I was significantly smaller in PAD than in the controls (45.6 +/- 9.1% vs 58.8 +/- 15.0%). The proportion of MHC IIx was also larger in the subjects with PAD compared with the controls (22.9 +/- 9.1% vs 16.0 +/- 11.3%). In addition, there was a significant decrease in the cross-sectional area of the type I and type IIA fibers in the subjects with PAD as well as enhanced capillary density.

CONCLUSIONS

This study showed a significant modification in the expression of MHC isoforms and muscle fiber type in the gastrocnemius in patients with symptomatic PAD. These results suggest that muscle ischemia resulting from PAD is an important factor in causing the adaptations in the contractile apparatus of the muscle.

Testosterone responses after resistance exercise in women: influence of regional fat distribution

Regional fat distribution (RFD) has been associated with metabolic derangements in populations with obesity. For example, upper body fat patterning is associated with higher levels of free testosterone (FT) and lower levels of sex-hormone binding globulin (SHBG). We sought to determine the extent to which this relationship was true in a healthy (i.e., non-obese) female population and whether RFD influenced androgen responses to resistance exercise. This study examined the effects of RFD on total testosterone (TT), FT, and SHBG responses to an acute resistance exercise test (ARET) among 47 women (22+/-3 years; 165+/-6 cm; 62+/-8 kg; 25+/-5%BF; 23+/-3 BMI). RFD was characterized by 3 separate indices: waist-to-hip ratio (WHR), ratio of upper arm fat to mid-thigh fat assessed with magnetic resonance imaging (MRI ratio), and ratio of subscapular to triceps ratio (SB/TRi ratio). Skinfolds were measured for the triceps, chest, subscapular, mid-axillary, suprailaic, abdomen, and thigh regions. The ARET consisted of 6 sets of 10 RM squats separated by 2-min rest periods. Blood was obtained pre- and post- ARET. TT, FT, and SHBG concentrations were determined by radioimmunoassay. Subjects were divided into tertiles from the indices of RFD, and statistical analyses were performed by an ANOVA with repeated measures (RFD and exercise as main effects). Significant (p < or = .05) increases following the AHRET were observed for TT (approximately 25%), FT (approximately 25%), and SHBG (4%). With multiple regression analysis, anthropometric measures significantly predicted pre- concentrations of FT, post-concentrations of TT, and pre-concentrations of SHBG. The SB/TRi and MRI ratios but not the WHR, were discriminant for hormonal concentrations among the tertiles. In young, healthy women, resistance exercise can induce transient increases in testosterone, and anthropometric markers of adiposity correlate with testosterone concentrations.

Differential effects of exhaustive cycle ergometry on concentric and eccentric torque production

The purpose of this study was to investigate the potential differences in peak isokinetic concentric end eccentric torque following low- and high-intensity cycle exercise fatigue protocols. Ten healthy, recreationally-active men were tested in a balanced, randomized testing sequence for peak eccentric and concentric isokinetic torque (60 degrees/sec) immediately before and after three experimental conditions each separated by 48 hours: 1) a bout of high intensity cycling consisting of a maximal 90-second sprint; 2) a bout of low-intensity cycling at 60 rpm equated for total work with the high-intensity protocol: and 3) no exercise (control bout). Blood was drawn from an antecubital vein and plasma lactate concentrations were determined immediately before and after each experimental bout. Post-exercise plasma lactate concentrations were 15.1 +/- 2.5 and 4.7 +/- 1.9 mmol l(-1), respectively, following the high- and low-intensity protocols. The high intensity exercise bout resulted in the only post-exercise decrease in concentric and eccentric isokinetic peak torque. The percent decline in maximal force production was significantly (P< 0.05) greater for concentric muscle actions compared to eccentric (29 vs 15%, respectively). In conclusion, a 90-second maximal cycling sprint results in a significant decline in maximal torque of both concentric and eccentric muscle actions with the greatest magnitude observed during concentric muscle actions.

Physiological and performance responses to tournament wrestling

PURPOSE

The purpose of this study was to investigate the physiological and performance responses to a simulated freestyle wrestling tournament after typical weight loss techniques used by amateur wrestlers.

METHODS

Twelve Division I collegiate wrestlers (mean +/- SD;19.33 +/- 1.16 yr) lost 6% of total body weight during the week before a simulated, 2-d freestyle wrestling tournament. A battery of tests was performed at baseline and before and immediately after each individual match of the tournament. The test battery included assessment for body composition, reaction/movement time, lower and upper body power and isokinetic strength, and a venous blood sample.

RESULTS

Lower body power and upper body isometric strength were significantly reduced as the tournament progressed (P < or = 0.05). Significant elevations in testosterone, cortisol, and lactate were observed after each match (P < or = 0.05). However, there was a significant reduction (P < or = 0.05) in resting testosterone values in the later matches. Norepinephrine increased significantly (P < or = 0.05) after each match, whereas epinephrine increased significantly (P < or = 0.05) after each match except the last match of each day. Plasma osmolality was consistently higher than normal values at all times including baseline, with significant increases observed after each match (P < or = 0.05).

CONCLUSIONS

Tournament wrestling augments the physiological and performance decrements of weight loss and its impact is progressive over 2 d of competition. The combined effects of these stresses may ultimately be reflected in a wrestler's ability to maintain physical performance throughout a tournament.

Changes in electromyographic activity, muscle fibre and force production characteristics during heavy resistance/power strength training in middle-aged and older men and women

The effects of a 6-month resistance training (2 day/week) designed to develop both strength and power on neural activation by electromyographic activity (EMG) of the agonist and antagonist knee extensors, muscle fibre proportion and areas of type I, IIa, and IIb of the vastus lateralis (VL) as well as maximal concentric one repetition maximum (1 RM) strength and maximal and explosive isometric strength of the knee extensors were examined. A total of 10 middle-aged men (M40; 42 +/- 2), 11 middle-aged women (W40; 39 +/- 3), 11 elderly men (M70; 72 +/- 3) and 10 elderly women (W70; 67 +/- 3) served as subjects. Maximal and explosive strength values remained unaltered during a 1-month control period. After the 6-month training maximal isometric and 1RM strength values increased in M40 by 28 +/- 14 and 27 +/- 7% (P < 0.001), in M70 by 27 +/- 17 and 21 +/- 9% (P < 0.001), in W40 by 27 +/- 19 and 35 +/- 14% (P < 0.001) and in W70 by 26 +/- 14 and 31 +/- 14% (P < 0.001), respectively. Explosive strength improved in M40 by 21 +/- 41% (P < 0.05), in M70 by 21 +/- 24% (P < 0.05), in W40 by 32 +/- 45% (NS) and in W70 by 22 +/- 28% (P < 0.05). The iEMGs of the VL and vastus medialis (VM) muscles increased during the training in M40 (P < 0.001 and 0.05), in M70 (P < 0.001 and 0.05), in W40 (P < 0.001 and 0.05) and in W70 (P < 0.001 and 0.05). The antagonist biceps femoris (BF) activity during the isometric knee extension remained unaltered in M40, in W40, and in M70 but decreased in W70 (from 42 +/- 34 to 32 +/- 26%; P < 0.05) during the first 2 months of training. Significant increases occurred during the training in the mean fibre areas of type I in W70 (P < 0.05) and of overall type II along with a specific increase in IIa in both W40 (P < 0.05) and in W70 (P < 0.05), while the changes in the male groups were not statistically significant. The individual percentage values for type II fibres at pretraining correlated with the individual values for 1 RM strength in both W70 (r=0.80; P < 0.05) and M70 (r=0.61; P < 0.05) and also at post-training for maximal isometric torque in W70 (r=0.77, P < 0.05). The findings support the concept of the important role of neural adaptations in strength and power development in middle-aged and older men and women. The muscle fibre distribution (percentage type II fibres) seems to be an important contributor on muscle strength in older people, especially older women. Women of both age groups appear to be hypertrophically responsive to the total body strength training protocol performed two times a week including heavier and lower (for fast movements) loads designed for both maximal strength and power development, while such a programme has limited effects on muscle hypertrophy in men.

Resistance training in patients with peripheral arterial disease: effects on myosin isoforms, fiber type distribution, and capillary supply to skeletal muscle

The purpose of this study was to investigate the effects of a progressive resistance training program on myosin heavy chain isoform expression, fiber type, and capillarization in patients with symptomatic peripheral arterial disease. Patients were randomized to either a training group (n = 11, mean +/- SD, 70 +/- 6 years, 4 men, 7 women) or a control group (n = 9, 66 +/- 6 years, 5 men, 4 women). The training sessions were completed 3 times/week, using 2 sets of various exercises, each performed for 8-15 repetitions. Muscle biopsies were obtained before and after 24 weeks from the medial gastrocnemius. Following the 24-week training program, the training group had significantly decreased the percentage of myosin heavy chain type IIB. The proportion of type IIB/AB fibers as measured by using myosin adenosine triphosphatase histochemistry decreased significantly in the training group. There were significant increases in type I and type II fiber areas, and capillary density also increased significantly in the training group. There were significant increases in 10 repetition maximum leg press and calf press strengths in the trained subjects. There were no significant changes in any of the measurements in the control group. It is concluded that progressive resistance training results in significant increases in muscle strength and alters skeletal muscle composition of subjects with peripheral arterial disease.

Differences in the neuromuscular capacity and lean muscle tissue in old and older community-dwelling adults

BACKGROUND

This study investigated whether there was a worsening of the neuromuscular capacity of older adults after the seventh decade of life.

METHODS

Fifteen healthy community-dwelling old (< 70 years of age) and 15 older adults (> or = 70 years of age) were assessed for maximal isometric strength (MVC) and force production characteristics, a one-repetition maximum (1-RM) performance, electromyographic (EMG) activity, and bone-free lean tissue (BFLT) mass of the lower extremity.

RESULTS

The isometric MVC, 1-RM, and BFLT mass values in the old group were significantly greater than in the older group. In addition, the individual BFLT mass values correlated significantly with the isometric MVC values (r = .85) and the 1-RM scores of the thigh muscle groups (r = .54-.80). The old group generated significantly greater isometric maximal rate of torque development than the older group and performed significantly better at all intervals of the absolute and relative force-time curves. The voluntary muscle activation of the knee extensors of the old group produced significantly higher integrated EMG (iEMG) activity at each epoch in the early iEMG-time curve compared with the old group.

CONCLUSIONS

The results suggest that the age-related deterioration in maximal strength measures and rapid force production characteristics in older adults could be related to a reduction in the mass and neural activation of the thigh muscles. The deterioration of the neuromuscular system of community-dwelling older adults may contribute to an increased difficulty in performing daily activities and may increase their risks of tripping and falling.

Effect of resistance training on women's strength/power and occupational performances

PURPOSE

The effects of resistance training programs on strength, power, and military occupational task performances in women were examined.

METHODS

Untrained women aged (mean +/- SD) 23 +/- 4 yr were matched and randomly placed in total- (TP, N = 17 and TH, N = 18) or upper-body resistance training (UP, N = 18 and UH, N = 15), field (FLD, N = 14), or aerobic training groups (AER, N = 11). Two periodized resistance training programs (with supplemental aerobic training) emphasized explosive exercise movements using 3- to 8-RM training loads (TP, UP), whereas the other two emphasized slower exercise movements using 8- to 12-RM loads (TH, UH). The FLD group performed plyometric and partner exercises. Subjects were tested for body composition, strength, power, endurance, maximal and repetitive box lift, 2-mile loaded run, and U.S. Army Physical Fitness Tests before (T0) and after 3 (T3) and 6 months of training (T6). For comparison, untrained men (N = 100) (MEN) were tested once.

RESULTS

Specific training programs resulted in significant increases in body mass (TP), 1-RM squat (TP, TH, FLD), bench press (all except AER), high pull (TP), squat jump (TP, TH, FLD), bench throw (all except AER), squat endurance (all except AER), 1-RM box lift (all except aerobic), repetitive box lift (all), push-ups (all except AER), sit-ups (all except AER), and 2-mile run (all).

CONCLUSIONS

Strength training improved physical performances of women over 6 months and adaptations in strength, power, and endurance were specific to the subtle differences (e.g., exercise choice and speeds of exercise movement) in the resistance training programs (strength/power vs strength/hypertrophy). Upper- and total-body resistance training resulted in similar improvements in occupational task performances, especially in tasks that involved upper-body musculature. Finally, gender differences in physical performance measures were reduced after resistance training in women, which underscores the importance of such training for physically demanding occupations.

Identifying bone mass and muscular changes

The aim of this investigation was to examine the impact of a six-month high intensity strength-training program on lumbar bone mineral density (BMD), trunk and lower limb strength in a population of Australian women aged 50 years and over. A subject pool of 44 women were recruited and randomly allocated into either strength training (n = 19) or active control (n = 25) groups. All subjects trained twice weekly in either a 50 minute supervised strength training session that progressed from 60% one repetition maximum (1RM) to 90% 1RM or a 50 minute group walk session. Measurements included a lumbar (L2-L4) BMD scan: peak isokinetic trunk strength and a dynamic 1RM squat as a measure of lower body strength. No significant group differences in lumbar BMD were evident at the completion of training. However, a significant (p < 0.05) within group change was apparent for the active control group as lumbar BMD decreased 1.7% below baseline testing. A significant (p < 0.05) group difference was evident with the strength trained group increasing peak isokinetic trunk strength (19.3%) and 1RM squat strength (34.4%) above that of the active controls. It was concluded that strength training provides an effective means for increasing trunk and lower limb strength in women over 50 years. The impact of strength training on lumbar BMD was not conclusive in the present study.

Low-volume circuit versus high-volume periodized resistance training in women

PURPOSE

The purpose of this investigation was to determine the long-term training adaptations associated with low-volume circuit-type versus periodized high-volume resistance training programs in women.

METHODS

34 healthy, untrained women were randomly placed into one of the following groups: low-volume, single-set circuit (SSC; N = 12); periodized high-volume multiple-set (MS; N = 12); or nonexercising control (CON) group (N = 10). The SSC group performed one set of 8-12 repetitions to muscular failure 3 d x wk(-1). The MS group performed two to four sets of 3-15 repetitions with periodized volume and intensity 4 d x wk(-1). Muscular strength, power, speed, endurance, anthropometry, and resting hormonal concentrations were determined pretraining (T1), after 12 wk (T2), and after 24 wk of training (T3).

RESULTS

1-RM bench press and leg press, and upper and lower body local muscular endurance increased significantly (P < or = 0.05) at T2 for both groups, but only MS showed a significant increase at T3. Muscular power and speed increased significantly at T2 and T3 only for MS. Increases in testosterone were observed for both groups at T2 but only MS showed a significant increase at T3. Cortisol decreased from T1 to T2 and from T2 to T3 in MS. Insulin-like growth factor-1 increased significantly at T3 for SSC and at T2 and T3 for MS. No changes were observed for growth hormone in any of the training groups.

CONCLUSION

Significant improvements in muscular performance may be attained with either a low-volume single-set program or a high-volume, periodized multiple-set program during the first 12 wk of training in untrained women. However, dramatically different training adaptations are associated with specific domains of training program design which contrast in speed of movement, exercise choices and use of variation (periodization) in the intensity and volume of exercise.

Resistance training combined with bench-step aerobics enhances women's health profile

PURPOSE

The purpose of this study was to investigate the comprehensive physiological alterations that take place during the combination of bench-step aerobics (BSA) and resistance exercise training.

METHODS

Thirty-five healthy, active women were randomly assigned to one of four groups that either a) performed 25 min of BSA only (SA25); b) performed a combination of 25 min of BSA and a multiple-set upper and lower body resistance exercise program (SAR); c) performed 40 min of BSA only (SA40); or d) served as a control group (C), only performing activities of daily living. Direct assessments for body composition, aerobic fitness, muscular strength, endurance, power, and cross-sectional area were performed 1 wk before and after 12 wk of training.

RESULTS

All training groups significantly improved peak VO(2) (3.7 to 5.3 mL O(2).kg(-1).min(-1)), with the greatest improvement observed in the SAR group (P = 0.05). Significant reductions in preexercise heart rates (8-9 bpm) and body fat percent (5--6%) were observed in all training groups after training. Significant reductions in resting diastolic blood pressure were observed for the SAR and SA40 groups (6.7 and 5.8 mm Hg, respectively). Muscular strength and endurance only improved significantly in the SAR group (21 and 11% respectively). All groups demonstrated increased lower body power (11--14%), but only the SAR group significantly improved upper body power (32%). Thigh muscle cross-sectional areas measured via magnetic resonance imaging (MRI) increased primarily for the SAR group.

CONCLUSION

BSA is an exercise modality effective for improving physical fitness and body composition in healthy women. The addition of resistance exercise appears to enhance the total fitness profile by improving muscular performances, muscle morphology, and cardiovascular fitness greater than from performing BSA alone. Therefore, the inclusion of both modalities to an exercise program is most effective for improving total body fitness and a woman's health profile.

The effect of heavy resistance exercise on the circadian rhythm of salivary testosterone in men

Circadian rhythms of serum testosterone concentrations in men have been shown, in general, to be highest in the morning and lowest in the evening. Thus, the purpose of this investigation was to determine the effects of acute resistance exercise upon the waking circadian rhythm of salivary testosterone over 2 days (with or without resistance exercise). The subjects included ten resistance-trained men (with at least 1 year of lifting experience) with the following characteristics [mean (SD)]: age 21.6 (1.1) years; height 177.8 (9.5) cm; body mass 80.5 (11.5) kg; percent body fat 7.9 (1.7)%. A matched, randomized, crossover study design was used such that each subject was tested under both the resistance exercise and control (no exercise) conditions. The resistance exercise protocol consisted of ten exercises performed for three sets of ten repetitions maximum with 2 min of rest between sets. Saliva sample 1 was collected at 0615 hours and resistance exercise began immediately afterwards at approximately 0620 hours, and sample 2 was collected at 0700 hours, which corresponded approximately to a mid-exercise (or control) time point. Saliva samples were then obtained every hour on the hour from 0800 hours until 2200 hours. No significant differences were observed between the exercise and resting conditions for salivary testosterone, with the exception of a significant decrease at 0700 hours during the resistance exercise protocol. The results of this investigation indicate that resistance exercise does not affect the circadian pattern of salivary testosterone secretion over a 16-h waking period in resistance-trained men.

Changes in myosin heavy chain composition with heavy resistance training in 60- to 75-year-old men and women

The purpose of this investigation was to assess the myosin heavy chain (MHC) expression in the vastus lateralis muscle from elderly men and women, and to determine whether heavy resistance training influences its expression. Twenty healthy, mildly physically active subjects gave their informed consent to participate in the study. The experimental group consisted of seven men and seven women [mean (SD) age 65.5 (4.1) years] and the control group consisted of three men and three women [mean (SD) age 62.3 (3.6) years]. The 6-month resistance training program was divided into two phases with weeks 1-12 consisting of high-intensity resistance training, and weeks 13-24 involving power training. Muscle biopsy samples were taken from the vastus lateralis muscle at week 0 and week 24 using the needle biopsy technique. The male and female experimental groups both exhibited a significant decrease (P < or = 0.05) in the percentage of MHC IIb, while the experimental female group also demonstrated a significant increase (P < or = 0.05) in the expression of MHC IIa, after 24 weeks of heavy resistance training. There was no change in MHC expression within the control group. The male [130.4 (25.3) kg vs 171.1 (30.5) kg] and female [58.2 (8.3) kg vs 77.9 (11.1) kg] experimental groups exhibited a significant increase (P < or = 0.05) in the maximal strength values for the 1 repetition maximum (1RM) squat exercise. The control group showed no change in strength for the 1RM squat exercise for either the male [115.8 (35.10 kg vs 123.8 (47.2) kg] or female [57.5 (99.0) kg vs 58.3 (2.9) kg] groups. The results clearly show that elderly subjects undergoing heavy resistance training have the ability to produce a similar shift in the expression of MHC isoforms from MHC IIb to MHC IIa, as has been shown to occur in younger subjects. This highlights the plasticity of human skeletal muscle in response to heavy resistance training, even at older ages.

Neuromuscular responses to explosive and heavy resistance loading

The EMG power spectrum may shift towards higher frequencies with higher movement velocities. Fatigue, on the other hand, can cause a decrease in the frequency components. The purpose of this study was to examine acute effects of explosive (EE) and heavy resistance (HRE) concentric leg press exercise on muscle force, EMG and blood lactate. The EE included five sets of ten repetitions with 40+/-6% of the isometric maximum at a 100 degrees knee angle performed as explosively as possible. The same number of repetitions was performed in HRE but with a heavier load (67+/-7% of the isometric maximum at a 100 degrees knee angle). Maximal isometric and single concentric actions of different loads, and an isometric fatigue test were measured before and after both exercises. Surface EMG was recorded from the vastus medialis muscles for analyses of average EMG (aEMG) and EMG power spectrum. Muscle fiber composition of the vastus lateralis was determined and blood lactate measured throughout the exercises. Mean power frequency and median frequency were higher during EE than during HRE (P<0.05). They increased during EE (P<0.05) as the exercise progressed, whereas during HRE no change or even slight decreases were observed. Signs of fatigue after pure concentric work were not observed after EE, and even after HRE, possibly due to the relatively small range of motion and short duration of action time, the fatigue was not that extensive. The relative number of fast twitch fibers was correlated (r=0.87, P<0.05) with the change in blood lactate in HRE. It was concluded that there may be a greater use of fast twitch motor units in explosive movements and that instead of fatigue, the present number of concentric actions in explosive exercise seems to have facilitated the neuromuscular system.

Neuromuscular adaptation during prolonged strength training, detraining and re-strength-training in middle-aged and elderly people

Effects of a 24-week strength training performed twice weekly (24 ST) (combined with explosive exercises) followed by either a 3-week detraining (3 DT) and a 21-week re-strength-training (21 RST) (experiment A) or by a 24-week detraining (24 DT) (experiment B) on neural activation of the agonist and antagonist leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris, maximal isometric and one repetition maximum (1-RM) strength and jumping (J) and walking (W) performances were examined. A group of middle-aged (M, 37-44 years, n = 12) and elderly (E, 62-77, n = 10) and another group of M (35-45, n = 7) and E (63-78, n = 7) served as subjects. In experiment A, the 1-RM increased substantially during 24 ST in M (27%, P<0.001) and E (29%, P<0.001) and in experiment B in M (29%, P<0.001) and E (23%, P<0.01). During 21 RST the 1-RM was increased by 5% at week 48 (P<0.01) in M and 3% at week 41 in E (n.s., but P<0.05 at week 34). In experiment A the integrated electromyogram (IEMG) of the vastus muscles in the 1-RM increased during 24 ST in both M (P<0.05) and E (P<0.001) and during 21 RST in M for the right (P<0.05) and in E for both legs (P<0.05). The biceps femoris co-activation during the 1-RM leg extension decreased during the first 8-week training in M (from 29+/-5% to 25+/-3%, n.s.) and especially in E (from 41+/-11% to 32+/-9%, P<0.05). The CSA increased by 7% in M (P<0.05) and by 7% in E (P<0.001), and by 7% (n.s.) in M and by 3% in E (n.s.) during 24 ST periods. Increases of 18% (P<0.001) and 12% (P<0.05) in M and 22% (P<0.001) and 26% (P<0.05) in E occurred in J. W speed increased (P<0.05) in both age groups. The only decrease during 3 DT was in maximal isometric force in M by 6% (P<0.05) and by 4% (n.s.) in E. During 24 DT the CSA decreased in both age groups (P<0.01), the 1-RM decreased by 6% (P<0.05) in M and by 4% (P<0.05) in E and isometric force by 12% (P<0.001) in M and by 9% (P<0.05) in E, respectively, while J and W remained unaltered. The strength gains were accompanied by increased maximal voluntary neural activation of the agonists in both age groups with reduced antagonist co-activation in the elderly during the initial training phases. Neural adaptation seemed to play a greater role than muscle hypertrophy. Short-term detraining led to only minor changes, while prolonged detraining resulted in muscle atrophy and decreased voluntary strength, but explosive jumping and walking actions in both age groups appeared to remain elevated for quite a long time by compensatory types of physical activities when performed on a regular basis.

The influence of direct supervision of resistance training on strength performance

PURPOSE

The purpose of this study was to compare changes in maximal strength, power, and muscular endurance after 12 wk of periodized heavy-resistance training directly supervised by a personal trainer (SUP) versus unsupervised training (UNSUP).

METHODS

Twenty moderately trained men aged 24.6 +/- 1.0 yr (mean +/- SE) were randomly assigned to either the SUP group (N = 10) or the UNSUP group (N = 8). Both groups performed identical linear periodized resistance training programs consisting of preparatory (10-12 repetitions maximum (RM)), hypertrophy (8 to 10-RM), strength (5 to 8-RM), and peaking phases (3 to 6-RM) using free-weight and variable-resistance machine exercises. Subjects were tested for maximal squat and bench press strength (1-RM), squat jump power output, bench press muscular endurance, and body composition at week 0 and after 12 wk of training.

RESULTS

Mean training loads (kg per set) per week were significantly (P < 0.05) greater in the SUP group than the UNSUP group at weeks 7 through 11 for the squat, and weeks 3 and 7 through 12 for the bench press exercises. The rates of increase (slope) of squat and bench press kg per set were significantly greater in the SUP group. Maximal squat and bench press strength were significantly greater at week 12 in the SUP group. Squat and bench press 1-RM, and mean and peak power output increased significantly after training in both groups. Relative local muscular endurance (80% of 1-RM) was not compromised in either group despite significantly greater loads utilized in bench press muscular endurance testing after training. Body mass, fat mass, and fat-free mass increased significantly after training in the SUP group.

CONCLUSION

Directly supervised, heavy-resistance training in moderately trained men resulted in a greater rate of training load increase and magnitude which resulted in greater maximal strength gains compared with unsupervised training.

Effect of exercise intensity on bone density, strength, and calcium turnover in older women

PURPOSE

This study examined the effects of 24 wk of high intensity strength training or low intensity walking on lumbar bone mineral density (BMD), muscular strength, and calcium turnover in Australian women either taking hormone replacement therapy (HRT) or not taking HRT.

METHODS

A subject pool of 64 women between 45-65 yr and randomly allocated into weights (N = 21), walking (N = 20), weightsHRT (N = 14), and walkingHRT (N = 9) groups completed this study. All subjects trained twice weekly in either a 50-min walking or weight-training program (60-90% IRM). Measurements included maximal isometric knee strength, IRM bench press, IRM squat, isokinetic back strength, lumbar (L2-L4) BMD, serum osteocalcin, and urinary deoxypyridinoline crosslinks (Dpd).

RESULTS

No significant group differences in BMD were evident at the completion of training. However, a significant (P < 0.05) within group change was apparent for the walking group since BMD decreased 1.3% below baseline testing. Osteocalcin levels increased significantly (P < 0.05) in the walking (22%) group. Maximal bench press and squat strength improved significantly (P < 0.05) in the weights (25.8% and 37.7%) and weightsHRT (25.4% and 35.7%) groups. The weights group also increased significantly (P < 0.05) in isokinetic back strength (22.2%).

CONCLUSION

It was concluded that short-term high intensity resistance training provides an effective means for increasing muscular strength in women between 45 and 65 yr. The training effects on lumbar BMD were not apparent in the present study.

Training for muscular power

In sport and everyday activities, the most important attribute of skeletal muscle is the ability to generate power, a product of strength and speed of movement. Many factors influence the muscle's ability to generate power. Training for muscular power requires special care in developing the proper exercise prescription. The need for muscular power runs across a spectrum of people from elite athletes attempting to optimize sports performance to the frail elderly trying to perform simple tasks. Power development is paramount to optimal neuromuscular function.

Effects of exercise and alkalosis on serum insulin-like growth factor I and IGF-binding protein-3

This investigation examines the effects of orally induced alkalosis on serum IGF-I and IGFBP3 concentrations in response to an acute 90-s bout of high intensity cycle exercise. Ten healthy, active men, ages 24.60 +/- 4.90 years, participated in a randomized, double-blind, counterbalanced trial order with a cross-over design. Subjects ingested an experimental bicarbonate solution or a placebo solution. Blood was sampled at baseline; pre-exercise; and 0, 5, 10, and 30 min postexercise. The pH between groups for pre-exercise and postexercise time points differed significantly (p < or = .05) in the experimental condition (from 7.42 +/- 0.01 to 7.35 +/- 0.02) versus the placebo condition (from 7.36 +/- 0.01 to 7.25 +/- 0.03). Increases in IGF-I over resting conditions occurred with placebo conditions at 5 and 10 min postexercise and in the experimental condition at 5 min postexercise. Concentrations of IGFBP3 were elevated above baseline at IP in both experimental and placebo conditions.

Basal concentrations and acute responses of serum hormones and strength development during heavy resistance training in middle-aged and elderly men and women

Effects of 6 months of heavy resistance training combined with explosive exercises on both basal concentrations and acute responses of total and free testosterone, growth hormone (GH), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), cortisol and sex hormone-binding globulin (SHBG), as well as voluntary neural activation and maximal strength of knee extensors were examined in 10 middle-aged men (M40; 42 +/- 2 years), 11 middle-aged women (W40; 39 +/- 3 years), 11 elderly men (M70; 72 +/- 3 years), and in 10 elderly women (W70; 67 +/- 3 years). The maximal integrated electromyographic (iEMG) and 1 repetition maximum (RM) knee-extension values remained unaltered in all groups during a 1-month control period with no strength training. During the 6-month training the 1RM values increased in M40 by 27 +/- 9% (p < .001), in M70 by 16 +/- 6% (p < .001), in W40 by 28 +/- 11% (p < .001), and in W70 by 24 +/- 10% (p < .001). The iEMGs of the vastus lateralis and medialis muscles increased(p < .05-.001) in M40, M70, W40, and W70. No systematic changes occurred during the experimental period in the mean concentrations of serum total and free testosterone, DHEA, DHEAS, GH, cortisol, or SHBG. However, the mean levels of individual serum free testosterone in W70 and serum testosterone in the total group of women correlated with the individual changes recorded in strength during the training (r = .55,p <.05; and r = .43,p <.05). The single exercise session both before and after the training resulted in significant responses in serum total and free testosterone concentrations in both male groups (p <.05-.01), but not in the female groups, as well as in serum GH levels in all groups (p <.05-.01) except W70 (ns). In summary, the present strength training led to great increases in maximal strength not only in middle-aged but also in elderly men and women. The strength gains were accompanied by large increases in the maximal voluntary activation of the trained muscles. None of the groups showed systematic changes in the mean serum concentrations of hormones examined. However, a low level of testosterone, especially in older women, may be a limiting factor in strength development and testosterone could mediate interactions with the nervous system contributing to strength development. The physiological significance of the lack of acute responsiveness of serum GH to heavy resistance exercise in older women for their trainability during prolonged strength training requires further examination.

The relationship between dynamic, isokinetic and isometric strength and bone mineral density in a population of 45 to 65 year old women

This study investigated the relationship between age, lumbar spine bone mineral density (LS BMD) and muscular strength of peri and postmenopausal women between 45 and 65 years either taking or not taking hormone replacement therapy (HRT). Ninety six women were tested for LS BMD (L2-L4), one repetition maximum (1RM) bench press and squat, maximal voluntary isometric contraction (MVC) of the knee extensors and peak torque of back extensor muscles at a speed of 30 degrees s(-1). Bone and strength data were analysed to evaluate the relationships in incrementing five year age groups and based on groups either taking or not taking HRT. ANOVA revealed significant differences in LS BMD between the 45-49 and 55-59 (F[3,92]=2.6411, p<0.05; -8%) age groups amounting to an annual bone loss of 0.8% for this Australian based population. Non significant LS BMD results were evident after controlling for the influence of age and menopausal status on the groups either taking or not taking HRT. Significant differences between the 45-49 and 60-64 (F[3,92]=2.7463, p<0.05) age groups for 1RM bench press and the 45-49 and 60-64, 50-54 and 60-64, and, 55-59 and 60-64 (F[3,92]=4.2816, p<0.05) age groups for 1RM squat amounting to an 18.8% and 37.5% loss of dynamic upper and lower body strength, respectively. Group correlation coefficients ranged between (r=-0.20 and -0.34, p<0.05) for LS BMD, strength and age. The conclusions demonstrate a concomitant decline in maximal muscle strength and bone density between women 45 and 65 years irrespective of HRT. These results also demonstrate a 50% greater decline in lower body strength compared to upper body strength between women 45 and 65 years.

Influence of exercise training on physiological and performance changes with weight loss in men

PURPOSE

The purpose of this study was to examine the physiological effects of a weight-loss dietary regimen with or without exercise.

METHODS

Thirty-five overweight men were matched and randomly placed into either a control group (C; N = 6) or one of three dietary groups; a diet-only group (D; N = 8), a diet group that performed aerobic exercise three times per week (DE; N = 11); and a diet group that performed both aerobic and strength training three times per week (DES; N = 10).

RESULTS

After 12 wk, D, DE, and DES demonstrated a similar and significant (P < or = 0.05) reduction in body mass (-9.64, -8.99, and -9.90 kg, respectively) with fat mass comprising 69, 78, and 97% of the total loss in body mass, respectively. The diet-only group also demonstrated a significant reduction in fat-free mass. Maximum strength, as determined by 1-RM testing in the bench press and squat exercise was significantly increased for DES in both the bench press (+19.6%) and squat exercise (+32.6%). Absolute peak O2 consumption was significantly elevated in DE (+24.8%) and DES (+15.4%). There were no differences in performance during a 30-s Wingate test for the DE and DES, whereas D demonstrated a significant decline in peak and mean power output. Resting metabolic rate (RMR) (kcal x d(-1)) was not significantly different for any of the groups except for the DE group. There were no significant changes in basal concentrations of serum glucose, BUN, cortisol, testosterone, and high density lipoprotein (HDL) cholesterol for any of the groups. Serum total cholesterol and low density lipoprotein (LDL) cholesterol were significantly decreased for all dietary groups. Serum triglycerides were significantly reduced for D and DES at week 6 and remained lower at week 12 for D, while triglycerides returned to baseline values for DES.

CONCLUSIONS

These data indicate that a weight-loss dietary regimen in conjunction with aerobic and resistance exercise prevents the normal decline in fat-free mass and muscular power and augments body composition, maximal strength, and maximum oxygen consumption compared with weight-loss induced by diet alone.

Effects of heavy-resistance training on hormonal response patterns in younger vs. older men

To examine the adaptations of the endocrine system to heavy-resistance training in younger vs. older men, two groups of men (30 and 62 yr old) participated in a 10-wk periodized strength-power training program. Blood was obtained before, immediately after, and 5, 15, and 30 min after exercise at rest before and after training and at rest at -3, 0, 6, and 10 wk for analysis of total testosterone, free testosterone, cortisol, growth hormone, lactate, and ACTH analysis. Resting values for insulin-like growth factor (IGF)-I and IGF-binding protein-3 were determined before and after training. A heavy-resistance exercise test was used to evaluate the exercise-induced responses (4 sets of 10-repetition maximum squats with 90 s of rest between sets). Squat strength and thigh muscle cross-sectional area increased for both groups. The younger group demonstrated higher total and free testosterone and IGF-I than the older men, training-induced increases in free testosterone at rest and with exercise, and increases in resting IGF-binding protein-3. With training the older group demonstrated a significant increase in total testosterone in response to exercise stress along with significant decreases in resting cortisol. These data indicate that older men do respond with an enhanced hormonal profile in the early phase of a resistance training program, but the response is different from that of younger men.

Effects of ballistic training on preseason preparation of elite volleyball players

PURPOSE

The purpose of this study was to determine whether ballistic resistance training would increase the vertical jump (VJ) performance of already highly trained jump athletes.

METHODS

Sixteen male volleyball players from a NCAA Division I team participated in the study. A Vertec was used to measure standing vertical jump and reach (SJR) and jump and reach from a three-step approach (AJR). Several types of vertical jump tests were also performed on a Plyometric Power System and a forceplate to measure force, velocity, and power production during vertical jumping. The subjects completed the tests and were then randomly divided into two groups, control and treatment. All subjects completed the usual preseason volleyball on-court training combined with a resistance training program. In addition, the treatment group completed 8 wk of squat jump training while the control group completed squat and leg press exercises at a 6RM load. Both groups were retested at the completion of the training period.

RESULTS

The treatment group produced a significant increase in both SJR and AJR of 5.9+/-3.1% and 6.3+/-5.1%. respectively. These increases were significantly greater than the pre- to postchanges produced by the control group, which were not significant for either jump. Analysis of the data from the various other jump tests suggested increased overall force output during jumping, and in particular increased rate of force development were the main contributors to the increased jump height.

CONCLUSIONS

These results lend support to the effectiveness of ballistic resistance training for improving vertical jump performance in elite jump athletes.

Changes in muscle morphology, electromyographic activity, and force production characteristics during progressive strength training in young and older men

Effects of a 10-week progressive strength training program composed of a mixture of exercises for increasing muscle mass, maximal peak force, and explosive strength (rapid force production) were examined in 8 young (YM) (29+/-5 yrs) and 10 old (OM) (61+/-4 yrs) men. Electromyographic activity, maximal bilateral isometric peak force, and maximal rate of force development (RFD) of the knee extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF), muscle fiber proportion, and fiber areas of types I, IIa, IIb, and IIab of the vastus lateralis were evaluated. Maximal and explosive strength values remained unaltered in both groups during a 3-week control period with no training preceding the strength training. After the 10-week training period, maximal isometric peak force increased from 1311+/-123 N by 15.6% (p <.05) in YM and from 976+/-168 N by 16.5% (p <.01) in OM. The pretraining RFD values of 4049+/-791 N*s(-1) in YM and 2526+/-1197 N*s(-1) in OM remained unaltered. Both groups showed significant increases (p < .05) in the averaged maximum IEMGs of the vastus muscles. The CSA of the QF increased from 90.3+/-7.9 cm2 in YM by 12.2% (p <.05) and from 74.7+/-7.8 cm2 in OM by 8.5% (p <.001). No changes occurred in the muscle fiber distribution of type I during the training, whereas the proportion of subtype IIab increased from 2% to 6% (p < .05) in YM and that of type IIb decreased in both YM from 25% to 16% (p < .01) and in OM from 15% to 6% (p < .05). The mean fiber area of type I increased after the 10-week training in YM (p < .001) and OM (p < .05) as well as that of type IIa in both YM (p < .01) and OM (p < .01). The individual percentage values for type I fibers were inversely correlated with the individual changes recorded during the training in the muscle CSA of the QF (r=-.56, p < .05). The present results suggest that both neural adaptations and the capacity of the skeletal muscle to undergo training-induced hypertrophy even in older people explain the gains observed in maximal force in older men, while rapid force production capacity recorded during the isometric knee extension action remained unaltered during the present mixed strength training program.

The effects of short-term resistance training on endocrine function in men and women

This investigation examined hormonal adaptations to acute resistance exercise and determined whether training adaptations are observed within an 8-week period in untrained men and women. The protocol consisted of a 1-week pre-conditioning orientation phase followed by 8 weeks of heavy resistance training. Three lower-limb exercises for the quadriceps femoris muscle group (squat, leg press, knee extension) were performed twice a week (Monday and Friday) with every other Wednesday used for maximal dynamic 1 RM strength testing. Blood samples were obtained pre-exercise (Pre-Ex), immediately post-exercise (IP), and 5 min post-exercise (5-P) during the first week of training (T-1), after 6 weeks (T-2) and 8 weeks (T-3) of training to determine blood concentrations of whole-blood lactate (LAC), serum total testosterone (TT), sex-hormone binding globulin (SHBG), cortisol (CORT) and growth hormone (GH). Serum TT concentrations were significantly (P < or = 0.05) higher for men at all time points measured. Men did not demonstrate an increase due to exercise until T-2. An increase in pre-exercise concentrations of TT were observed both for men and women at T-2 and T-3. No differences were observed for CORT between men and women; increases in CORT above pre-exercise values were observed for men at all training phases and at T-2 and T-3 for women. A reduction in CORT concentrations at rest was observed both in men and women at T-3. Women demonstrated higher pre-exercise GH values than men at all training phases; no changes with training were observed for GH concentrations. Exercise-induced increases in GH above pre-exercise values were observed at all phases of training. Women demonstrated higher serum concentrations of SHBG at all time points. No exercise-induced increases were observed in men over the training period but women increased SHBG with exercise at T-3. SHBG concentrations in women were also significantly higher at T-2 and T-3 when compared to T-1 values. Increases in LAC concentrations due to exercise were observed both for men and women for all training phases but no significant differences were observed with training. These data illustrate that untrained individuals may exhibit early-phase endocrine adaptations during a resistance training program. These hormonal adaptations may influence and help to mediate other adaptations in the nervous system and muscle fibers, which have been shown to be very responsive in the early phase of strength adaptations with resistance training.

Changes in agonist-antagonist EMG, muscle CSA, and force during strength training in middle-aged and older people

Effects of 6 mo of heavy-resistance training combined with explosive exercises on neural activation of the agonist and antagonist leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris, as well as maximal and explosive strength were examined in 10 middle-aged men (M40; 42 +/- 2 yr), 11 middle-aged women (W40; 39 +/- 3 yr), 11 elderly men (M70; 72 +/- 3 yr) and 10 elderly women (W70; 67 +/- 3 yr). Maximal and explosive strength remained unaltered during a 1-mo control period with no strength training. After the 6 mo of training, maximal isometric and dynamic leg-extension strength increased by 36 +/- 4 and 22 +/- 2% (P < 0. 001) in M40, by 36 +/- 3 and 21 +/- 3% (P < 0.001) in M70, by 66 +/- 9 and 34 +/- 4% (P < 0.001) in W40, and by 57 +/- 10 and 30 +/- 3% (P < 0.001) in W70, respectively. All groups showed large increases (P < 0.05-0.001) in the maximum integrated EMGs (iEMGs) of the agonist vastus lateralis and medialis. Significant (P < 0.05-0.001) increases occurred in the maximal rate of isometric force production and in a squat jump that were accompanied with increased (P < 0.05-0. 01) iEMGs of the leg extensors. The iEMG of the antagonist biceps femoris muscle during the maximal isometric leg extension decreased in both M70 (from 24 +/- 6 to 21 +/- 6%; P < 0.05) and in W70 (from 31 +/- 9 to 24 +/- 4%; P < 0.05) to the same level as recorded for M40 and W40. The CSA of the quadriceps femoris increased in M40 by 5% (P < 0.05), in W40 by 9% (P < 0.01), in W70 by 6% (P < 0.05), and in M70 by 2% (not significant). Great training-induced gains in maximal and explosive strength in both middle-aged and elderly subjects were accompanied by large increases in the voluntary activation of the agonists, with significant reductions in the antagonist coactivation in the elderly subjects. Because the enlargements in the muscle CSAs in both middle-aged and elderly subjects were much smaller in magnitude, neural adaptations seem to play a greater role in explaining strength and power gains during the present strength-training protocol.

Acute hormone responses to heavy resistance lower and upper extremity exercise in young versus old men

Acute hormone responses of growth hormone (GH), total and free testosterone (TT and FT) and cortisol (C) to heavy resistance isometric exercise were examined in ten young men [YM 26.5 (SD 4.8) years] and ten old men [OM 70.0 (SD 3.7) years]. Loading conditions of the same relative intensity were created for the lower and upper extremity actions separately as well as for both of them together lower extremity exercise (LE; knee extension), upper extremity exercise (UE; bench press extension), and lower and upper extremity exercise (LUE) performed simultaneously in a seated position. Single voluntary maximal isometric actions lasting for 5 s were performed repeatedly for ten repetitions (with a recovery of 5 s) for a total of four sets. The recovery time between the sets was 1 min. Each exercise led to large acute decreases in maximal isometric force in both YM (P < 0.001) and OM (P < 0.001) ranging from 41% to 26% with no significant differences between the groups. Serum GH concentrations increased in both YM (P < 0.05-0.01) and OM (P < 0.05) but the postexercise value in YM during LE was greater (P < 0.05) than for OM. The TT increased (P < 0.01-0.001) in YM in all three exercises, while in OM the increase occurred only during LE (P < 0.01). The exercises led to increases in FT in YM (P < 0.05 for LE and LUE), while in OM the increase occurred only during LUE (P < 0.05). The pre and postexercise FT were greater in YM (P < 0.001) than in OM. No significant changes occurred in C either in YM or in OM. The blood lactate concentrations increased during the exercises in both YM (P < 0.001) and OM (P < 0.05-0.001) but the postexercise values during LE and LUE in YM were greater (P < 0.05) than in OM. The present data would indicate that the responses of GH, TT and FT to heavy resistance isometric exercise are lowered with increasing age. The reduced acute hormone response together with the lowered basal values in FT in the older men compared to the young men may indicate decreased anabolic effects on muscles and may explain in part the loss of muscle mass and strength associated with aging.