John Saxton

The ABC of Physical Activity for Health: A consensus statement from the British Association of Sport and Exercise Sciences

Absract Our understanding of the relationship between physical activity and health is constantly evolving. Therefore, the British Association of Sport and Exercise Sciences convened a panel of experts to review the literature and produce guidelines that health professionals might use. In the ABC of Physical Activity for Health, A is for All healthy adults, B is for Beginners, and C is for Conditioned individuals. All healthy adults aged 18–65 years should aim to take part in at least 150 min of moderate-intensity aerobic activity each week, or at least 75 min of vigorous-intensity aerobic activity per week, or equivalent combinations of moderate- and vigorous-intensity activities. Moderate-intensity activities are those in which heart rate and breathing are raised, but it is possible to speak comfortably. Vigorous-intensity activities are those in which heart rate is higher, breathing is heavier, and conversation is harder. Aerobic activities should be undertaken in bouts of at least 10 min and, ideally, should be performed on five or more days a week. All healthy adults should also perform muscle-strengthening activities on two or more days a week. Weight training, circuit classes, yoga, and other muscle-strengthening activities offer additional health benefits and may help older adults to maintain physical independence. Beginners should work steadily towards meeting the physical activity levels recommended for all healthy adults. Even small increases in activity will bring some health benefits in the early stages and it is important to set achievable goals that provide success, build confidence, and increase motivation. For example, a beginner might be asked to walk an extra 10 min every other day for several weeks to slowly reach the recommended levels of activity for all healthy adults. It is also critical that beginners find activities they enjoy and gain support in becoming more active from family and friends. Conditioned individuals who have met the physical activity levels recommended for all healthy adults for at least 6 months may obtain additional health benefits by engaging in 300 min or more of moderate-intensity aerobic activity per week, or 150 min or more of vigorous-intensity aerobic activity each week, or equivalent combinations of moderate- and vigorous-intensity aerobic activities. Adults who find it difficult to maintain a normal weight and adults with increased risk of cardiovascular disease or type 2 diabetes may in particular benefit from going beyond the levels of activity recommended for all healthy adults and gradually progressing towards meeting the recommendations for conditioned individuals. Physical activity is beneficial to health with or without weight loss, but adults who find it difficult to maintain a normal weight should probably be encouraged to reduce energy intake and minimize time spent in sedentary behaviours to prevent further weight gain. Children and young people aged 5–16 years should accumulate at least 60 min of moderate-to-vigorous-intensity aerobic activity per day, including vigorous-intensity aerobic activities that improve bone density and muscle strength.

Randomized Trial of Exercise Therapy in Women Treated for Breast Cancer

PURPOSE To examine the effects of aerobic exercise therapy on quality of life (QoL) and associated outcomes in women treated for breast cancer. Evidence suggests that exercise may be beneficial, but no trial has included an exercise-placebo and a usual-care group to control for the attention effects that might be associated with aerobic exercise interventions in cancer patients. PATIENTS AND METHODS A total of 108 women who had been treated for breast cancer 12 to 36 months previously were randomly assigned to supervised aerobic exercise therapy (n = 34), exercise-placebo (body conditioning; n = 36), or usual care (n = 38). Exercise therapy and exercise-placebo sessions took place three times per week for 8 weeks. Outcomes included QoL, depression, exercise behavior, aerobic fitness; outcomes were assessed at baseline and at the 8- and 24-week follow-up. RESULTS Analyses of covariance revealed a significant mean difference of 9.8 units in Functional Assessment of Cancer Therapy-General (primary outcome) favoring aerobic exercise therapy at 8 weeks, relative to usual care. Significant differences that favored aerobic exercise therapy relative to usual care were recorded for Functional Assessment of Cancer Therapy-Breast, social/family well-being, functional well-being, and breast cancer subscale scores at 8-week follow-up. Psychological health outcomes improved modestly for both intervention groups; these improvements were sustained for several end points. CONCLUSION Exercise therapy had large, clinically meaningful, short-term beneficial effects on QoL in women treated for breast cancer; this finding cannot be attributable to attention, given that the exercise-placebo group did not report similar effects relative to usual care.

Neuromuscular dysfunction following eccentric exercise.

This study examined the effects of exercise-induced muscle damage on tremor and proprioception components of neuromuscular function. Six male and six female volunteers (aged 18-30 yr) performed 50 maximal eccentric muscle actions using the forearm flexors of the nondominant arm. Forearm flexor tremor and perception of voluntary force and joint position were monitored to assess changes in neuromuscular function. Data were analyzed using REANOVA. Serum creatine kinase activity increased from a baseline value of 68 +/- 13 IU.l-1 to 2849 +/- 852 IU.l-1 5 d after exercise (P < 0.05). This was accompanied by prolonged impaired joint range of motion (P < 0.01) and reduced maximum strength (P < 0.01). Muscle soreness peaked 3 d postexercise (P < 0.01; Wilcoxon test). Tremor amplitude was increased (P < 0.01) until 48 h after exercise, whereas the power frequency spectrum was unaffected. Perception of joint position at elbow angles of 1.57 rad (P < 0.01) and 2.09 rad (P < 0.05) and perception of force (P < 0.01) were significantly impaired when the control arm acted as the reference. Joint positions were more accurately reproduced when the experimental arm acted as its own reference. The increase in tremor amplitude and loss of proprioceptive function in the days after damage-inducing eccentric exercise suggest significant impairment of neuromuscular function.

Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer

IntroductionBreast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice.MethodsMore than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer ‘stem’ cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account.ResultsThe 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working.ConclusionsWith resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years.

Indices of free-radical-mediated damage following maximum voluntary eccentric and concentric muscular work.

This study monitored plasma and skeletal muscle markers of free-radical-mediated damage following maximum eccentric and concentric exercise, to examine the potential role of free radicals in exercise-induced muscle damage. Fourteen male volunteers performed either (1) a bout of 70 maximum eccentric and a bout of 70 maximum concentric muscle actions of the forearm flexors (the bouts being separated by 4 weeks; n = 8) or (2) a bout of 80 maximum eccentric and a bout of 80 maximum concentric muscle actions of the knee extensors (the bouts being separated by 1 week; n=6). Plasma markers of lipid peroxidation, thiobarbituric acid-reactive substances (TBARS) and diene-conjugated compounds (DCC) were monitored in the arm protocol and skeletal muscle markers of oxidative lipid and protein damage, malondialdehyde (MDA) and protein carbonyl derivatives (PCD) respectively, were monitored in the leg protocol. In both protocols, the contralateral limb was used for the second bout and the order of the bouts was randomised between limbs. Repeated measures ANOVA indicated significant changes from baseline following eccentric arm work on the measures of serum creatine kinase activity (P < 0.05), maximum voluntary torque production (P < 0.01) and relaxed arm angle (P < 0.01). Subjective muscle soreness peaked 2 days after eccentric arm work (P < 0.05, Wilcoxon test). However, there were no changes in the plasma levels of TBARS or DCC following the eccentric or concentric arm exercise. Immediately after concentric leg exercise, skeletal muscle PCD concentrations was significantly higher than that observed immediately after eccentric work (P < 0.05). However, no significant difference between the eccentric and concentric knee extensor bouts was observed on the measure of skeletal muscle MDA concentration. The results of this study offer no support for the involvement of oxygen free radicals in exercise-induced muscle damage.

Lifestyle changes for improving disease-specific quality of life in sedentary men on long-term androgen-deprivation therapy for advanced prostate cancer: a randomised controlled trial

BACKGROUND Prostate cancer is a key driver of cancer-related global disability-adjusted life-years. Androgen-deprivation therapy (ADT) for advanced disease is linked to fatigue, reduced physical function, and quality of life (QoL). OBJECTIVE To evaluate the effect of a lifestyle intervention on disease-specific QoL, diastolic blood pressure, and cancer-related fatigue in sedentary men receiving long-term ADT for advanced prostate cancer. DESIGN, SETTING, AND PARTICIPANTS A total of 100 hundred sedentary men with locally advanced or metastatic prostate cancer on long-term ADT were randomised to an intervention or usual care group. INTERVENTION A 12-wk lifestyle intervention consisting of aerobic and resistance exercise with parallel dietary advice. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Disease-specific QoL was measured using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and Functional Assessment of Cancer Therapy-Fatigue (FACT-F) questionnaires at 12 wk postintervention and at 6 mo following withdrawal of support. Analysis of covariance and mixed regression were conducted. RESULTS AND LIMITATIONS Clinically relevant improvements in FACT-P were seen at 12 wk in the intervention group compared with controls (mean difference: 8.9 points; 95% confidence interval [CI], 3.7-14.2; adjusted p=0.001). No difference was apparent at 6 mo (mean difference: 3.3 points; 95% CI, -2.6 to 9.3; adjusted p=0.27). No difference in diastolic blood pressure was seen at either follow-up (all p > 0.05). Clinically relevant improvements in FACT-F were seen at 12 wk (mean difference: 5.3 points; 95% CI, 2.7-7.9; adjusted p<0.001) and maintained following withdrawal of supervision (mean difference: 3.9 points; 95% CI, 1.1-6.8; adjusted p=0.007). Improvements in exercise tolerance and behaviour were maintained at 6 mo (adjusted p<0.001 and 0.038). CONCLUSIONS A lifestyle intervention resulted in a clinically meaningful improvement in disease-specific QoL that was not maintained postintervention. No effect on blood pressure occurred. Durability of response was seen in fatigue and exercise behaviour. Further evaluation of support structures is essential. TRIAL REGISTRATION ISRCTN88605738.

Risk determination and prevention of breast cancer

Breast cancer is an increasing public health problem. Substantial advances have been made in the treatment of breast cancer, but the introduction of methods to predict women at elevated risk and prevent the disease has been less successful. Here, we summarize recent data on newer approaches to risk prediction, available approaches to prevention, how new approaches may be made, and the difficult problem of using what we already know to prevent breast cancer in populations. During 2012, the Breast Cancer Campaign facilitated a series of workshops, each covering a specialty area of breast cancer to identify gaps in our knowledge. The risk-and-prevention panel involved in this exercise was asked to expand and update its report and review recent relevant peer-reviewed literature. The enlarged position paper presented here highlights the key gaps in risk-and-prevention research that were identified, together with recommendations for action. The panel estimated from the relevant literature that potentially 50% of breast cancer could be prevented in the subgroup of women at high and moderate risk of breast cancer by using current chemoprevention (tamoxifen, raloxifene, exemestane, and anastrozole) and that, in all women, lifestyle measures, including weight control, exercise, and moderating alcohol intake, could reduce breast cancer risk by about 30%. Risk may be estimated by standard models potentially with the addition of, for example, mammographic density and appropriate single-nucleotide polymorphisms. This review expands on four areas: (a) the prediction of breast cancer risk, (b) the evidence for the effectiveness of preventive therapy and lifestyle approaches to prevention, (c) how understanding the biology of the breast may lead to new targets for prevention, and (d) a summary of published guidelines for preventive approaches and measures required for their implementation. We hope that efforts to fill these and other gaps will lead to considerable advances in our efforts to predict risk and prevent breast cancer over the next 10 years.

Lifestyle intervention in men with advanced prostate cancer receiving androgen suppression therapy: a feasibility study

Background: Healthy lifestyle behaviors could have a role in ameliorating some of the adverse effects of androgen suppression therapy (AST) in men with prostate cancer. The primary aim of this study was to assess the feasibility of a tapered supervised exercise program in combination with dietary advice in men with advanced prostate cancer receiving AST. Methods: Advanced prostate cancer patients receiving AST for a minimum of 6 months were randomized to a 12-week lifestyle program comprising aerobic and resistance exercise, plus dietary advice (n = 25), or standard care (n = 25). Exercise behavior, dietary macronutrient intake, quality of life, fatigue, functional fitness, and biomarkers associated with disease progression were assessed at baseline, after the intervention, and at 6 months. Results: The lifestyle group showed improvements in exercise behavior (P < 0.001), dietary fat intake (P = 0.001), total energy intake (P = 0.005), fatigue (P = 0.002), aerobic exercise tolerance (P < 0.001), and muscle strength (P = 0.033) compared with standard care controls. Although a high rate of attrition (44%) was observed at 6 months, the improvements in key health outcomes were sustained. No effects on clinical prostate cancer disease markers were observed. Conclusions: This preliminary evidence suggests that pragmatic lifestyle interventions have potential to evoke improvements in exercise and dietary behavior, in addition to other important health outcomes in men with advanced prostate cancer receiving AST. Impact: This study shows for the first time that pragmatic lifestyle interventions are feasible and could have a positive impact on health behaviors and other key outcomes in men with advanced prostate cancer receiving AST. Cancer Epidemiol Biomarkers Prev; 20(4); 647–57. ©2011 AACR.

Comparison of eccentric knee extensor muscle actions at two muscle lengths on indices of damage and angle-specific force production in humans.

In this study, we investigated the effects of knee extensor length during eccentric exercise on indices of muscle damage and adaptation. Subjects (n = 7) performed two bouts of 75 maximal voluntary eccentric muscle actions at a knee joint angular velocity of 1.57 rad s(-1). One bout was performed at a short muscle length (bout S) with a knee joint range of motion of 2.79 to 1.40 radians (160 degrees to 80 degrees), and a second with the contralateral knee extensors at a long muscle length (bout L) with a range of motion of 2.01 to 0.7 radians (120 degrees to 40 degrees). The maximum voluntary contractile force (MVC) was measured before and 5 min after exercise, and again on days 3, 5, 7, 10 and 12, at knee angles of 160 degrees, 120 degrees and 80 degrees. Muscle soreness was measured before exercise and on each day after exercise. Serum creatine kinase activity was measured before exercise and on days 3, 5, 7, 10 and 12 post-exercise. The MVC declined after each bout (P < 0.01), with a greater decline after bout L (P < 0.05). Muscle soreness was higher relative to bout S on days 1, 2, 3, 5 and 6 (P < 0.05). Although serum creatine kinase activity was elevated after both exercise bouts (P < 0.01), there was no difference between bouts. Functional muscle damage markers and muscle soreness suggest greater damage after bout L. Post-exercise angle-specific force decrements suggest a transient increase in muscle length after bout L but not bout S.

Pragmatic Lifestyle Intervention in Patients Recovering From Colon Cancer: A Randomized Controlled Pilot Study

OBJECTIVE To investigate the feasibility of a pragmatic lifestyle intervention in patients who had recently completed surgery and chemotherapy for colon cancer and to obtain preliminary data of its impact on important health outcomes. DESIGN A prospective, randomized, controlled pilot trial. SETTING University rehabilitation facility. PARTICIPANTS Eighteen (N=18) colon cancer survivors (mean age=69y; range, 52-80y), Dukes stage A to C. INTERVENTIONS Participants were randomized 6 to 24 months postoperatively to either a 12-week program of combined exercise and dietary advice or standard treatment. MAIN OUTCOME MEASURES Exercise and dietary behavior, fatigue, health-related quality of life (QOL), aerobic exercise tolerance, functional capacity, muscle strength, and anthropometery were assessed at baseline and immediately after the intervention. RESULTS Adherences to supervised and independent exercise during the intervention were 90% and 94%, respectively, and there was low attrition (6%). The lifestyle intervention elicited improvements in exercise behavior (P=.068), fatigue (P=.005), aerobic exercise tolerance (P=.010), chair sit-to-stand performance (P=.003), and waist-to-hip ratio (P=.002). A positive change in dietary fiber intake (P=.044) was also observed in the intervention group. No change in QOL was observed (P=.795). CONCLUSIONS These preliminary results suggest that a pragmatic lifestyle intervention implemented 6 to 24 months after primary treatment for colon cancer was feasible. We observed a significant impact on dietary behavior, fatigue, aerobic exercise tolerance, functional capacity, and waist-to-hip ratio. These findings need to be confirmed with a larger-scale definitive randomized controlled trial.