Blood pressure rise with swimming versus walking in older women: the Sedentary Women Exercise Adherence Trial 2 (SWEAT 2)

Interventions Based on Behavior Change Techniques to Encourage Physical Activity or Decrease Sedentary Behavior in Community-Dwelling Adults Aged 50-70: Systematic Review With Intervention Component Analysis

Increasing physical activity (PA) and/or decreasing sedentary behaviors is important in the delay and prevention of long-term conditions. PA can help maintain function and independence and decrease the need for hospitalization/institutionalization. Activity rates often decline in later life resulting in a need for interventions that encourage uptake and adherence through the use of Behavior Change Techniques (BCTs). We conducted a systematic review of the evidence for interventions that included BCTs in community-dwelling adults with a mean age of 50-70. The review followed PRISMA guidelines. The interventions were psychosocial, nonpharmacological, and noninvasive interventions utilizing components based on BCTs that evaluated change in PA and/or sedentary behavior. Intervention Component Analysis (ICA) was used to synthesize effectiveness of intervention components. Twelve randomized controlled trials were included in this review. The mean sample age was 50-64. Thirteen BCTs were used across all studies, and the most commonly used techniques were goals and planning, feedback and monitoring, and natural consequences. Seven intervention components linked with BCTs were found: personalized goal setting, tailored feedback from facilitators, on-site and postintervention support, education materials and resources, reinforcing change on behavior and attitudes, self-reported monitoring, and social connectedness. All components, except for social connectedness, were associated with improved health behavior and PA levels. The interventions that use BCTs have incorporated strategies that reinforce change in behavior and attitudes toward PA.

Examining the relationship between arterial stiffness and swim-training volume in elite aquatic athletes

PURPOSE

Factors such as prone body position, hydrostatic pressure, and intermittent breath-holding subject aquatic athletes to unique physical and environmental stressors during swimming exercise. The relationship between exposure to aquatic exercise and both arterial stiffness and wave reflection properties is not well-understood. This study assessed central artery stiffness and wave reflection properties in elite pool-swimmers (SW), long-distance open-water swimmers (OW), and water polo players (WP) to examine the relationship between these variables and aquatic exercise.

METHODS

Athletes competing in SW, OW and WP events at the FINA World Championships were recruited. Carotid-femoral pulse wave velocity, and pulse wave analysis were used to quantify arterial stiffness, and central wave reflection properties.

RESULTS

Athletes undertook differing amounts of weekly swimming distance in training according to their discipline (SW: 40.2 ± 21.1 km, OW: 59.7 ± 28.4 km, WP: 11.4 ± 6.3 km; all p < 0.05). Pulse wave velocity (Males [SW: 6.0 ± 0.6 m/s, OW: 6.5 ± 0.8 m/s, WP: 6.7 ± 0.9 m/s], Females [SW: 5.4 ± 0.6 m/s, OW: 5.3 ± 0.5 m/s, WP: 5.2 ± 0.8 m/s; p = 0.4]) was similar across disciplines for females but was greater in male WP compared to male SW (p = 0.005). Augmentation index (Males [SW: - 3.4 ± 11%, OW: - 9.6 ± 6.4%, WP: 1.7 ± 10.9%], Females [SW: 3.5 ± 13.5%, OW: - 13.2 ± 10.7%, WP: - 2.8 ± 10.7%]) was lower in male OW compared to WP (p = 0.03), and higher in female SW compared to OW (p = 0.002). Augmentation index normalized to a heart rate of 75 bpm was inversely related to weekly swim distance in training (r = - 0.27, p = 0.004).

CONCLUSIONS

This study provides evidence that the central vasculature of elite aquatic athletes differs by discipline, and this is associated with training load.

Strategies to improve retention in randomised trials

BACKGROUND

Poor retention of participants in randomised trials can lead to missing outcome data which can introduce bias and reduce study power, affecting the generalisability, validity and reliability of results. Many strategies are used to improve retention but few have been formally evaluated.

OBJECTIVES

To quantify the effect of strategies to improve retention of participants in randomised trials and to investigate if the effect varied by trial setting.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Scopus, PsycINFO, CINAHL, Web of Science Core Collection (SCI-expanded, SSCI, CPSI-S, CPCI-SSH and ESCI) either directly with a specified search strategy or indirectly through the ORRCA database. We also searched the SWAT repository to identify ongoing or recently completed retention trials. We did our most recent searches in January 2020.

SELECTION CRITERIA

We included eligible randomised or quasi-randomised trials of evaluations of strategies to increase retention that were embedded in 'host' randomised trials from all disease areas and healthcare settings. We excluded studies aiming to increase treatment compliance.

DATA COLLECTION AND ANALYSIS

We extracted data on: the retention strategy being evaluated; location of study; host trial setting; method of randomisation; numbers and proportions in each intervention and comparator group. We used a risk difference (RD) and 95% confidence interval (CI) to estimate the effectiveness of the strategies to improve retention. We assessed heterogeneity between trials. We applied GRADE to determine the certainty of the evidence within each comparison.

MAIN RESULTS

We identified 70 eligible papers that reported data from 81 retention trials. We included 69 studies with more than 100,000 participants in the final meta-analyses, of which 67 studies evaluated interventions aimed at trial participants and two evaluated interventions aimed at trial staff involved in retention. All studies were in health care and most aimed to improve postal questionnaire response. Interventions were categorised into broad comparison groups: Data collection; Participants; Sites and site staff; Central study management; and Study design. These intervention groups consisted of 52 comparisons, none of which were supported by high-certainty evidence as determined by GRADE assessment. There were four comparisons presenting moderate-certainty evidence, three supporting retention (self-sampling kits, monetary reward together with reminder or prenotification and giving a pen at recruitment) and one reducing retention (inclusion of a diary with usual follow-up compared to usual follow-up alone). Of the remaining studies, 20 presented GRADE low-certainty evidence and 28 presented very low-certainty evidence. Our findings do provide a priority list for future replication studies, especially with regard to comparisons that currently rely on a single study.

AUTHORS' CONCLUSIONS

Most of the interventions we identified aimed to improve retention in the form of postal questionnaire response. There were few evaluations of ways to improve participants returning to trial sites for trial follow-up. None of the comparisons are supported by high-certainty evidence. Comparisons in the review where the evidence certainty could be improved with the addition of well-done studies should be the focus for future evaluations.

Chronic Physiological Effects of Swim Training Interventions in Non-Elite Swimmers: A Systematic Review and Meta-Analysis

BACKGROUND

Swimming is a popular and potentially health-enhancing exercise, but has received less scientific attention compared with other exercise modes.

OBJECTIVE

The objective of the study was to determine the chronic (long-term) effect of pool swim training on physiological outcomes in non-elite or non-competitive swimming participants.

DESIGN

This study was a systematic review with a meta-analysis.

DATA SOURCES

We searched the electronic databases PubMed, EMBASE and CENTRAL from inception to March 2017.

ELIGIBILITY CRITERIA

The eligibility criteria included randomised controlled trials, quasi-randomised controlled trials and controlled trials of chronic (long-term) swimming interventions in non-elite or non-competitive swimming participants, with a physiological outcome measure.

RESULTS

Our search of 6712 records revealed 29 eligible studies. Swimming had a significant and clinically meaningful effect on maximal oxygen uptake compared with the control in an analysis including multiple populations (mean difference 6.32 mL/kg/min; 95% confidence interval 4.33-8.31), and subgroup analyses of healthy children/adolescents (mean difference 7.93 mL/kg/min; 95% confidence interval 3.31-12.55) and those with asthma (mean difference 9.67 mL/kg/min; 95% confidence interval 5.84-13.51) and healthy adults (mean difference 5.87 mL/kg/min; 95% confidence interval 2.93-8.81). Swimming also resulted in significant improvements in other cardiorespiratory fitness-related outcomes such as maximal minute ventilation (mean difference 0.61 L/min; 95% confidence interval 0.17-1.05), submaximal exercise performance (standardised mean difference 0.64; 95% confidence interval 0.14-1.13) and total exercise test time (mean difference 4.27 min; 95% confidence interval 2.11-6.42). Compared with the control, swimming had significant favourable effects on body mass (mean difference - 2.90 kg, 95% confidence interval - 5.02 to - 0.78), body fat percentage in multiple populations (mean difference - 1.92%; 95% confidence interval - 3.25 to - 0.60) and healthy children/adolescents (mean difference - 1.92%; 95% confidence interval - 4.64 to - 0.80) and lean mass (mean difference 1.96 kg; 95% confidence interval 0.21-3.71), but negative effects on waist circumference in a pooled analysis of two studies involving adults with hypertension (mean difference 4.03 cm; 95% confidence interval 2.58-5.49). Regarding lung function, significant effects of swimming vs. the control were found only for peak expiratory volume in analyses including children/adolescents combined with healthy adults (mean difference 58.74 L/min; 95% confidence interval 29.70-87.78) and children/adolescents with asthma alone (mean difference 63.49 L/min; 95% confidence interval 25.01-101.97). Based on limited data, swimming had similar effects to other exercise modes, except for higher post-intervention body mass index values with swimming vs. running in healthy adults (mean difference 1.18 kg/m²; 95% confidence interval 0.54-1.81).

CONCLUSIONS

Swimming may offer robust beneficial effects on cardiorespiratory fitness and body composition across multiple populations and effects may be comparable to other exercise modes. Future randomised controlled trials are required to establish the effectiveness of swimming on physiological outcomes in healthy populations and those with non-communicable disease.

A randomized controlled trial of physical activity with individual goal-setting and volunteer mentors to overcome sedentary lifestyle in older adults at risk of cognitive decline: the INDIGO trial protocol

BACKGROUND

Increasing physical activity (PA) effectively in those who are inactive is challenging. For those who have subjective memory complaints (SMC) or mild cognitive impairment (MCI) this is a greater challenge necessitating the need for more engaging and innovative approaches. The primary aim of this trial is to determine whether a home-based 6-month PA intervention with individual goal-setting and peer mentors (GM-PA) can significantly increase PA levels in insufficiently active older adults at increased risk of developing Alzheimer's disease (AD).

METHODS

Community living 60-80 year olds with SMC or MCI who do not engage in more than 60 min per week of moderate intensity PA will be recruited from memory clinics and the community via media advertisements to participate in this randomized, single-blind controlled trial. All participants will receive an individually tailored home-based PA program of 150 min of moderate intensity walking/week for 6 months. The intervention group will undertake individual goal-setting and behavioral education workshops with mentor support via telephone (GM-PA). Those randomized to the control group will have standard education workshops and Physical Activity Liaison (PAL) contact via telephone (CO-PA). Increase in PA is the primary outcome, fitness, cognitive, personality, demographic and clinical parameters will be measured and a health economic analysis performed. A saliva sample will be collected for APOE e4 genotyping. All participants will have a goal-setting interview to determine their PA goals. Active volunteers aged 50-85 years will be recruited from the community randomized and trained to provide peer support as mentors (intervention group) or PALS (control group) for the 6-month intervention. Mentors and PALS will have PA, exercise self-efficacy and mentoring self-efficacy measured. Participants in both groups are asked to attend 3 workshops in 6 months. At the first workshop, they will meet their allocated Mentor or PAL who will deliver their respective programs and support via 6 telephone calls during the intervention.

DISCUSSION

If the GM-PA program is successful in increasing the PA levels of the target group it will potentially provide another strategy and community resource that can be translated into practice.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry ACTRN12613001181796 . (29/10/2013) retrospectively registered.

Is Vigorous Exercise Training Superior to Moderate for CVD Risk after Menopause?

Postmenopausal women have an increased risk for cardiovascular disease through many factors, such as a sedentary lifestyle and reduced heart rate variability (HRV). Endurance training improves coronary risk but the role of exercise intensity is unclear. The purpose of this observational study was to evaluate the effects of moderate versus vigorous exercise on cardiovascular disease risk in postmenopausal women. Thirty-six postmenopausal women who self-reported training at moderate (3-5.9 METS; n=18; age 58.9±4.4yr) or vigorous intensities (>6 METS; n=18; age 59.7±5.2yr) participated. C-reactive protein (CRP), HRV, VO ₂ max, and stress (Perceived Stress Survey, Menopause Rating Scale) were measured. Groups were compared using independent samples t- tests, and associations of exercise intensities with CRP and HRV were assessed using multiple regression. CRP, HRV, and VO ₂ max were similar ( p >0.05). Vigorous exercise had lower stress subscale scores ( p <0.01) and higher counter-stress subscale scores compared to moderate ( p <0.05). There was a positive association between time spent in vigorous exercise and HRV ( p <0.05).Vigorous exercise may not confer additional benefits in CRP and HRV over moderate, except for stress reduction. However, more time spent in vigorous exercise was associated with higher HRV. Therefore, increased parasympathetic tone may provide cardioprotection after menopause.

Effect of lifestyle interventions on cardiovascular risk factors among adults without impaired glucose tolerance or diabetes: A systematic review and meta-analysis

Structured lifestyle interventions can reduce diabetes incidence and cardiovascular disease (CVD) risk among persons with impaired glucose tolerance (IGT), but it is unclear whether they should be implemented among persons without IGT. We conducted a systematic review and meta-analyses to assess the effectiveness of lifestyle interventions on CVD risk among adults without IGT or diabetes. We systematically searched MEDLINE, EMBASE, CINAHL, Web of Science, the Cochrane Library, and PsychInfo databases, from inception to May 4, 2016. We selected randomized controlled trials of lifestyle interventions, involving physical activity (PA), dietary (D), or combined strategies (PA+D) with follow-up duration ≥12 months. We excluded all studies that included individuals with IGT, confirmed by 2-hours oral glucose tolerance test (75g), but included all other studies recruiting populations with different glycemic levels. We stratified studies by baseline glycemic levels: (1) low-range group with mean fasting plasma glucose (FPG) <5.5mmol/L or glycated hemoglobin (A1C) <5.5%, and (2) high-range group with FPG ≥5.5mmol/L or A1C ≥5.5%, and synthesized data using random-effects models. Primary outcomes in this review included systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and triglycerides (TG). Totally 79 studies met inclusion criteria. Compared to usual care (UC), lifestyle interventions achieved significant improvements in SBP (-2.16mmHg[95%CI, -2.93, -1.39]), DBP (-1.83mmHg[-2.34, -1.31]), TC (-0.10mmol/L[-0.15, -0.05]), LDL-C (-0.09mmol/L[-0.13, -0.04]), HDL-C (0.03mmol/L[0.01, 0.04]), and TG (-0.08mmol/L[-0.14, -0.03]). Similar effects were observed among both low-and high-range study groups except for TC and TG. Similar effects also appeared in SBP and DBP categories regardless of follow-up duration. PA+D interventions had larger improvement effects on CVD risk factors than PA alone interventions. In adults without IGT or diabetes, lifestyle interventions resulted in significant improvements in SBP, DBP, TC, LDL-C, HDL-C, and TG, and might further reduce CVD risk.

Effect of lifestyle interventions on glucose regulation among adults without impaired glucose tolerance or diabetes: A systematic review and meta-analysis

This study systematically assessed the effectiveness of lifestyle interventions on glycemic indicators among adults (⩾18years) without IGT or diabetes. Randomized controlled trials using physical activity (PA), diet (D), or their combined strategies (PA+D) with follow-up ⩾12months were systematically searched from multiple electronic-databases between inception and May 4, 2016. Outcome measures included fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), fasting insulin (FI), homeostasis model assessment-estimated insulin resistance (HOMA-IR), and bodyweight. Included studies were divided into low-range (FPG <5.5mmol/L or HbA1c <5.5%) and high-range (FPG ⩾5.5mmol/L or HbA1c ⩾5.5%) groups according to baseline glycemic levels. Seventy-nine studies met inclusion criteria. Random-effect models demonstrated that compared with usual care, lifestyle interventions achieved significant reductions in FPG (-0.14mmol/L [95%CI, -0.19, -0.10]), HbA1c (-0.06% [-0.09, -0.03]), FI (%change: -15.18% [-20.01, -10.35]), HOMA-IR (%change: -22.82% [-29.14, -16.51]), and bodyweight (%change: -3.99% [-4.69, -3.29]). The same effect sizes in FPG reduction (0.07) appeared among both low-range and high-range groups. Similar effects were observed among all groups regardless of lengths of follow-up. D and PA+D interventions had larger effects on glucose reduction than PA alone. Lifestyle interventions significantly improved FPG, HbA1c, FI, HOMA-IR, and bodyweight among adults without IGT or diabetes, and might reduce progression of hyperglycemia to type 2 diabetes mellitus.

Aquatic High Intensity Interval Training for Cardiometabolic Health: Benefits and Training Design

High-intensity interval training (HIIT) has emerged as an attractive alternative to traditional continuous exercise training (CT) programs for clinical and healthy populations who find that they can achieve equal or greater fitness benefits in less time. Land-based HIIT may not be an appropriate choice for some participants. Few studies have explored the acute responses and chronic adaptations of HIIT in an aquatic environment, and no study has compared the cardiometabolic responses of an aquatic-based program to a land-based HIIT program. Shallow-water aquatic exercise (AE) programs utilizing HIIT have elicited comparable and, in some cases, greater physiological responses compared with constant-intensity or continuous AE regimens. Factors that may explain why HIIT routines evoke greater cardiometabolic responses than CT protocols may be based on the types of exercises and how they are cued to effectively manipulate hydrodynamic properties for greater intensities. Favorable aquatic HIIT protocols such as the S.W.E.A.T. system may serve as a beneficial alternative to land-based HIIT programs for clinical, and athletic populations, potentially reducing the likelihood of associated musculoskeletal and orthopedic complications. Hence, the purpose of this review is to examine the role of AE as an alternative safe and effective HIIT modality.

Arterial stiffness in young adult swimmers

PURPOSE

Habitual Aerobic exercise reduces arterial stiffness, but effects of habitual swimming on arterial stiffness are not yet fully understood. Swimming can also increase systolic blood pressure (BP) in normotensive individuals. Accordingly, this cross-sectional study aimed to investigate arterial stiffness in young adult swimmers after considering the influence of BP.

METHODS

Participants comprised 41 men (18-21 years), including 15 untrained controls (C), 11 competitive cyclists (aerobic-trained athletes; A), and 15 competitive swimmers (S). Arterial stiffness was assessed by brachial-ankle pulse-wave velocity (baPWV), heart-ankle pulse-wave velocity (haPWV), and cardio-ankle vascular index (CAVI). CAVI is the measurement of arterial stiffness that is theoretically adjusted by BP.

RESULTS

Although physical characteristics and handgrip strength did not differ between groups, peak oxygen uptake was significantly greater in A and S than in C. A tendency towards higher systolic BP and a significantly higher pulse pressure were found in S as compared to C and A. Most importantly, baPWV was significantly lower in A than in C or S, and no significant difference in baPWV was observed between C and S (C, 1027 ± 25; A, 852 ± 23; S, 1032 ± 24 cm/s). No significant difference in haPWV was observed. However, CAVI was significantly lower in A and S than in C, and did not differ significantly between A and S (C, 5.8 ± 0.2; A, 5.1 ± 0.2; S, 5.3 ± 0.2 unit).

CONCLUSION

These findings indicate that arterial stiffness in young adult swimmers is lower than in age-matched sedentary controls and similar to land-based aerobic-exercise individuals, after considering the influences of BP.

Evaluation of Global Health in Master Swimmers Involved in French National Championships

BACKGROUND

Swimming is often recommended as a means of increasing physical activity and gaining health benefits. The present study examined the psychological, social, and physical health states in competitive swimmers engaged in long-term training.

METHODS

The study took place during the 4 days of the French master championships in France in 2011 (from 10 to 13 March). Global health parameters were evaluated and compared with general values reported in studies aiming to describe health standard values in France or Europe. All swimmers selected for the event were invited to participate in the study. Setting questionnaires concerning mental and social health (short form 36), physical activity (International Physical Activity Questionnaire), and medication were administered. Peak expiratory flow (l.min-1) was measured, and body mass index (kg.m-2) was calculated from height (m) and body mass (kg). Prevalence of overweight and obesity was calculated by age and gender. Chi-squared tests were used to compare prevalence of overweight and obesity between participants and reference values. Short form 36 scores and physical activity (met.h.week-1) were compared with reference values by single t-tests. Two-way ANOVA was used to compare peak flow results with standard values. The level of significance was set at p < 0.05.

RESULTS

Out of 1554 master swimmers, 490 participated in this study (rates of participation = 44.8 and 23.5 % for females and males, respectively). Data showed inequality of health indexes as compared with reference values, despite a significantly higher level of physical activity including swimming activity. The prevalence of obesity was significantly lower (p < 0.05), and peak expiratory flow values were higher among female swimmers (from 7.6 to 17 % higher according to the age, p < 0.05). Perception of vitality was significantly higher for all female swimmers and the older age groups of male swimmers (p < 0.05). Perception of bodily pain indicated significantly lower scores for swimmers than the reference values (p < 0.05). Significantly lower prevalence of swimmers taking medication was noted in comparison with the French national values (p = 0.012).

CONCLUSIONS

Compared with reference data from various sources, master competitive swimmers used less medication, had lower rates of obesity in most age groups, had greater peak expiratory flow values suggesting improved lung function, had higher levels of total physical activity, and had more favorable scores for various subscales of the SF-36. The results argue in favor of competitive swimming for its positive effects on health outcomes.

KEY POINTS

French master swimmers involved in national championships have many positive health outcomes in terms of weight management, respiratory function, and vitality. However, the very high physical activity level in this competitive context did not result in significantly better levels on all parameters in comparison with their national counterparts (pain perception, social, emotional, and mental health).Positive health outcomes were higher for female master swimmers in terms of weight management, respiratory function, and vitality.The fact that these benefits were not linked with medication consumption could be interesting in an economic context aimed at controlling expenditures on health. Based on these data, we can argue for promoting this form of physical activity across the lifespan.

Comportamento da pressão arterial em homens pré-hipertensos participantes em um programa regular de natação

INTRODUÇÃO: A natação tem sido recomendada como tipo de atividade física para a prevenção, tratamento e controle da hipertensão arterial. OBJETIVO: Analisar os efeitos da prática regular de natação sobre a pressão arterial de adultos pré-hipertensos. MÉTODOS: A amostra foi composta por 36 homens pré-hipertensos divididos em dois grupos: Experimental - GE (n=24, 40,60±9,36 anos) e Controle - GC (n=12, 40,57±8,05 anos). O GE realizou um programa regular de natação, com três sessões semanais de 45 min, durante 12 semanas, enquanto o GC não alterou seus hábitos alimentares e permaneceu sem praticar atividade física no período. O procedimento estatístico utilizado para verificar as diferenças entre as médias antes e depois de 12 semanas do programa regular de natação foi o teste-t de Student. O estudo admitiu o nível de p < 0.05 para a significância estatística. RESULTADOS: O grupo GE apresentou diferenças estatisticamente significativas nas variáveis analisadas quando comparadas com o GC, tanto na pressão arterial sistólica, PAS (Δ = - 5,89 mmHg, p = 0,00), como na pressão arterial diastólica, PAD (Δ = - 5,15mmHg, p = 0,00). CONCLUSÃO: Os resultados mostram que um programa regular de natação provoca reduções significativas na pressão arterial em repouso em homens pré-hipertensos.

Is there evidence that walking groups have health benefits? A systematic review and meta-analysis

OBJECTIVE

To assess the health benefits of outdoor walking groups.

DESIGN

Systematic review and meta-analysis of walking group interventions examining differences in commonly used physiological, psychological and well-being outcomes between baseline and intervention end.

DATA SOURCES

Seven electronic databases, clinical trial registers, grey literature and reference lists in English language up to November 2013.

ELIGIBILITY CRITERIA

Adults, group walking outdoors with outcomes directly attributable to the walking intervention.

RESULTS

Forty-two studies were identified involving 1843 participants. There is evidence that walking groups have wide-ranging health benefits. Meta-analysis showed statistically significant reductions in mean difference for systolic blood pressure -3.72 mm Hg (-5.28 to -2.17) and diastolic blood pressure -3.14 mm Hg (-4.15 to -2.13); resting heart rate -2.88 bpm (-4.13 to -1.64); body fat -1.31% (-2.10 to -0.52), body mass index -0.71 kg/m(2) (-1.19 to -0.23), total cholesterol -0.11 mmol/L (-0.22 to -0.01) and statistically significant mean increases in VO(2max) of 2.66 mL/kg/min (1.67-3.65), the SF-36 (physical functioning) score 6.02 (0.51 to 11.53) and a 6 min walk time of 79.6 m (53.37-105.84). A standardised mean difference showed a reduction in depression scores with an effect size of -0.67 (-0.97 to -0.38). The evidence was less clear for other outcomes such as waist circumference fasting glucose, SF-36 (mental health) and serum lipids such as high-density lipids. There were no notable adverse side effects reported in any of the studies.

CONCLUSIONS

Walking groups are effective and safe with good adherence and wide-ranging health benefits. They could be a promising intervention as an adjunct to other healthcare or as a proactive health-promoting activity.

Heart rate variability and swimming

BACKGROUND AND OBJECTIVES

Professionals in the domain of swimming have a strong interest in implementing research methods in evaluating and improving training methods to maximize athletic performance and competitive outcome. Heart rate variability (HRV) has gained attention in research on sport and exercise to assess autonomic nervous system activity underlying physical activity and sports performance. Studies on swimming and HRV are rare. This review aims to summarize the current evidence on the application of HRV in swimming research and draws implications for future research.

METHODS

A systematic search of databases (PubMed via MEDLINE, PSYNDEX and Embase) according to the PRISMA statement was employed. Studies were screened for eligibility on inclusion criteria: (a) empirical investigation (HRV) in humans (non-clinical); (b) related to swimming; (c) peer-reviewed journal; and (d) English language.

RESULTS

The search revealed 194 studies (duplicates removed), of which the abstract was screened for eligibility. Fourteen studies meeting the inclusion criteria were included in the review. Included studies broadly fell into three classes: (1) control group designs to investigate between-subject differences (i.e. swimmers vs. non-swimmers, swimmers vs. other athletes); (2) repeated measures designs on within-subject differences of interventional studies measuring HRV to address different modalities of training or recovery; and (3) other studies, on the agreement of HRV with other measures.

CONCLUSIONS

The feasibility and possibilities of HRV within this particular field of application are well documented within the existing literature. Future studies, focusing on translational approaches that transfer current evidence in general practice (i.e. training of athletes) are needed.

Strategies to improve retention in randomised trials

BACKGROUND

Loss to follow-up from randomised trials can introduce bias and reduce study power, affecting the generalisability, validity and reliability of results. Many strategies are used to reduce loss to follow-up and improve retention but few have been formally evaluated.

OBJECTIVES

To quantify the effect of strategies to improve retention on the proportion of participants retained in randomised trials and to investigate if the effect varied by trial strategy and trial setting.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PreMEDLINE, EMBASE, PsycINFO, DARE, CINAHL, Campbell Collaboration's Social, Psychological, Educational and Criminological Trials Register, and ERIC. We handsearched conference proceedings and publication reference lists for eligible retention trials. We also surveyed all UK Clinical Trials Units to identify further studies.

SELECTION CRITERIA

We included eligible retention trials of randomised or quasi-randomised evaluations of strategies to increase retention that were embedded in 'host' randomised trials from all disease areas and healthcare settings. We excluded studies aiming to increase treatment compliance.

DATA COLLECTION AND ANALYSIS

We contacted authors to supplement or confirm data that we had extracted. For retention trials, we recorded data on the method of randomisation, type of strategy evaluated, comparator, primary outcome, planned sample size, numbers randomised and numbers retained. We used risk ratios (RR) to evaluate the effectiveness of the addition of strategies to improve retention. We assessed heterogeneity between trials using the Chi(2) and I(2) statistics. For main trials that hosted retention trials, we extracted data on disease area, intervention, population, healthcare setting, sequence generation and allocation concealment.

MAIN RESULTS

We identified 38 eligible retention trials. Included trials evaluated six broad types of strategies to improve retention. These were incentives, communication strategies, new questionnaire format, participant case management, behavioural and methodological interventions. For 34 of the included trials, retention was response to postal and electronic questionnaires with or without medical test kits. For four trials, retention was the number of participants remaining in the trial. Included trials were conducted across a spectrum of disease areas, countries, healthcare and community settings. Strategies that improved trial retention were addition of monetary incentives compared with no incentive for return of trial-related postal questionnaires (RR 1.18; 95% CI 1.09 to 1.28, P value < 0.0001), addition of an offer of monetary incentive compared with no offer for return of electronic questionnaires (RR 1.25; 95% CI 1.14 to 1.38, P value < 0.00001) and an offer of a GBP20 voucher compared with GBP10 for return of postal questionnaires and biomedical test kits (RR 1.12; 95% CI 1.04 to 1.22, P value < 0.005). The evidence that shorter questionnaires are better than longer questionnaires was unclear (RR 1.04; 95% CI 1.00 to 1.08, P value = 0.07) and the evidence for questionnaires relevant to the disease/condition was also unclear (RR 1.07; 95% CI 1.01 to 1.14). Although each was based on the results of a single trial, recorded delivery of questionnaires seemed to be more effective than telephone reminders (RR 2.08; 95% CI 1.11 to 3.87, P value = 0.02) and a 'package' of postal communication strategies with reminder letters appeared to be better than standard procedures (RR 1.43; 95% CI 1.22 to 1.67, P value < 0.0001). An open trial design also appeared more effective than a blind trial design for return of questionnaires in one fracture prevention trial (RR 1.37; 95% CI 1.16 to 1.63, P value = 0.0003).There was no good evidence that the addition of a non-monetary incentive, an offer of a non-monetary incentive, 'enhanced' letters, letters delivered by priority post, additional reminders, or questionnaire question order either increased or decreased trial questionnaire response/retention. There was also no evidence that a telephone survey was either more or less effective than a monetary incentive and a questionnaire. As our analyses are based on single trials, the effect on questionnaire response of using offers of charity donations, sending reminders to trial sites and when a questionnaire is sent, may need further evaluation. Case management and behavioural strategies used for trial retention may also warrant further evaluation.

AUTHORS' CONCLUSIONS

Most of the retention trials that we identified evaluated questionnaire response. There were few evaluations of ways to improve participants returning to trial sites for trial follow-up. Monetary incentives and offers of monetary incentives increased postal and electronic questionnaire response. Some other strategies evaluated in single trials looked promising but need further evaluation. Application of the findings of this review would depend on trial setting, population, disease area, data collection and follow-up procedures.

Effects of moderate-intensity aerobic cycling and swim exercise on post-exertional blood pressure in healthy young untrained and triathlon-trained men and women

Aerobic exercises such as running, walking and cycling are known to elicit a PEH (post-exercise hypotensive) response in both trained and UT (untrained) subjects. However, it is not known whether swim exercise produces a similar effect in normotensive individuals. The complex acute physiological responses to water immersion suggest swimming may affect BP (blood pressure) differently than other forms of aerobic exercises. We tested the hypothesis that an acute bout of swimming would fail to elicit a PEH BP response compared with an equivalent bout of stationary cycling, regardless of training state. We studied 11 UT and ten triathlon-trained young healthy normotensive [SBP/DBP (systolic BP/diastolic BP) <120/80 mmHg)] men and women (age 23±1 years) who underwent 30 min of intensity-matched cycling and swimming sessions to assess changes in BP during a 75-min seated recovery. CO (cardiac output), SV (stroke volume), TPR (total peripheral resistance), HR (heart rate), HRV (HR variability) and core and skin temperature were also assessed. In UT subjects, PEH was similar between cycling (-3.1±1 mmHg) and swimming (-5.8±1 mmHg), with the greater magnitude of PEH following swimming, reflecting a significant fall in SV between modalities (P<0.05). Trained individuals did not exhibit a PEH response following swimming (0.3±1 mmHg), yet had a significant fall in SBP at 50 min post-cycling exercise (-3.7±1 mmHg) (P<0.05). The absence of PEH after swimming in the trained group may reflect a higher cardiac sympathetic outflow [as indicated by the LF (low-frequency) spectral component of HRV) (25 and 50 min) (P<0.05)] and a slower return of vagal tone, consistent with a significant increase in HR between modalities at all time points (P<0.05). These results suggest that training may limit the potential for an effective post-exertional hypotensive response to aerobic swimming.

Remote and web 2.0 interventions for promoting physical activity

BACKGROUND

Remote and web 2.0 interventions for promoting physical activity (PA) are becoming increasingly popular but their ability to achieve long term changes are unknown.

OBJECTIVES

To compare the effectiveness of remote and web 2.0 interventions for PA promotion in community dwelling adults (aged 16 years and above) with a control group exposed to placebo or no or minimal intervention.

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, and some other databases (from earliest dates available to October 2012). Reference lists of relevant articles were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared remote and web 2.0 PA interventions for community dwelling adults with a placebo or no or minimal intervention control group. We included studies if the principal component of the intervention was delivered using remote or web 2.0 technologies (for example the internet, smart phones) or more traditional methods (for example telephone, mail-outs), or both. To assess behavioural change over time, the included studies had a minimum of 12 months follow-up from the start of the intervention to the final results. We excluded studies that had more than a 20% loss to follow-up if they did not apply an intention-to-treat analysis.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the quality of each study and extracted the data. Non-English language papers were reviewed with the assistance of an interpreter who was an epidemiologist. Study authors were contacted for additional information where necessary. Standardised mean differences (SMDs) and 95% confidence intervals (CIs) were calculated for the continuous measures of self-reported PA and cardio-respiratory fitness. For studies with dichotomous outcomes, odds ratios and 95% CIs were calculated.

MAIN RESULTS

A total of 11 studies recruiting 5862 apparently healthy adults met the inclusion criteria. All of the studies took place in high-income countries. The effect of the interventions on cardiovascular fitness at one year (two studies; 444 participants) was positive and moderate with significant heterogeneity of the observed effects (SMD 0.40; 95% CI 0.04 to 0.76; high quality evidence). The effect of the interventions on self-reported PA at one year (nine studies; 4547 participants) was positive and moderate (SMD 0.20; 95% CI 0.11 to 0.28; moderate quality evidence) with heterogeneity (I2 = 37%) in the observed effects. One study reported positive results at two years (SMD 0.20; 95% CI 0.08 to 0.32; moderate quality evidence). When studies were stratified by risk of bias, the studies at low risk of bias (eight studies; 3403 participants) had an increased effect (SMD 0.28; 95% CI 0.16 to 0.40; moderate quality evidence). The most effective interventions applied a tailored approach to the type of PA and used telephone contact to provide feedback and to support changes in PA levels. There was no evidence of an increased risk of adverse events (seven studies; 2892 participants). Risk of bias was assessed as low (eight studies; 3060 participants) or moderate (three studies; 2677 participants). There were no differences in effectiveness between studies using different types of professionals delivering the intervention (for example health professional, exercise specialist). There was no difference in pooled estimates between studies that generated the prescribed PA using an automated computer programme versus a human, nor between studies that used pedometers as part of their intervention compared to studies that did not.

AUTHORS' CONCLUSIONS

We found consistent evidence to support the effectiveness of remote and web 2.0 interventions for promoting PA. These interventions have positive, moderate sized effects on increasing self-reported PA and measured cardio-respiratory fitness, at least at 12 months. The effectiveness of these interventions was supported by moderate and high quality studies. However, there continues to be a paucity of cost effectiveness data and studies that include participants from varying socioeconomic or ethnic groups. To better understand the independent effect of individual programme components, longer term studies, with at least one year follow-up, are required.

Face-to-face interventions for promoting physical activity

BACKGROUND

Face-to-face interventions for promoting physical activity (PA) are continuing to be popular but their ability to achieve long term changes are unknown.

OBJECTIVES

To compare the effectiveness of face-to-face interventions for PA promotion in community dwelling adults (aged 16 years and above) with a control exposed to placebo or no or minimal intervention.

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, and some other databases (from earliest dates available to October 2012). Reference lists of relevant articles were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared face-to-face PA interventions for community dwelling adults with a placebo or no or minimal intervention control group. We included studies if the principal component of the intervention was delivered using face-to-face methods. To assess behavioural change over time the included studies had a minimum of 12 months follow-up from the start of the intervention to the final results. We excluded studies that had more than a 20% loss to follow-up if they did not apply an intention-to-treat analysis.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the quality of each study and extracted data. Non-English language papers were reviewed with the assistance of an interpreter who was an epidemiologist. Study authors were contacted for additional information where necessary. Standardised mean differences (SMDs) and 95% confidence intervals (CIs) were calculated for continuous measures of self-reported PA and cardio-respiratory fitness. For studies with dichotomous outcomes, odds ratios (ORs) and 95% CIs were calculated.

MAIN RESULTS

A total of 10 studies recruiting 6292 apparently healthy adults met the inclusion criteria. All of the studies took place in high-income countries. The effect of interventions on self-reported PA at one year (eight studies; 6725 participants) was positive and moderate with significant heterogeneity (I² = 74%) (SMD 0.19; 95% CI 0.06 to 0.31; moderate quality evidence) but not sustained in three studies at 24 months (4235 participants) (SMD 0.18; 95% CI -0.10 to 0.46). The effect of interventions on cardiovascular fitness at one year (two studies; 349 participants) was positive and moderate with no significant heterogeneity in the observed effects (SMD 0.50; 95% CI 0.28 to 0.71; moderate quality evidence). Three studies (3277 participants) reported a positive effect on increasing PA levels when assessed as a dichotomous measure at 12 months, but this was not statistically significant (OR 1.52; 95% CI 0.88 to 2.61; high quality evidence). Although there were limited data, there was no evidence of an increased risk of adverse events (one study; 149 participants). Risk of bias was assessed as low (four studies; 4822 participants) or moderate (six studies; 1543 participants). Any conclusions drawn from this review require some caution given the significant heterogeneity in the observed effects. Despite this, there was some indication that the most effective interventions were those that offered both individual and group support for changing PA levels using a tailored approach. The long term impact, cost effectiveness and rates of adverse events for these interventions was not established because the majority of studies stopped after 12 months.

AUTHORS' CONCLUSIONS

Although we found evidence to support the effectiveness of face-to-face interventions for promoting PA, at least at 12 months, the effectiveness of these interventions was not supported by high quality studies. Due to the clinical and statistical heterogeneity of the studies, only limited conclusions can be drawn about the effectiveness of individual components of the interventions. Future studies should provide greater detail of the components of interventions, and assess impact on quality of life, adverse events and economic data.

Face-to-face versus remote and web 2.0 interventions for promoting physical activity

BACKGROUND

Face-to-face interventions for promoting physical activity (PA) are continuing to be popular as remote and web 2.0 approaches rapidly emerge, but we are unsure which approach is more effective at achieving long term sustained change.

OBJECTIVES

To compare the effectiveness of face-to-face versus remote and web 2.0 interventions for PA promotion in community dwelling adults (aged 16 years and above).

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, and some other databases (from earliest dates available to October 2012). Reference lists of relevant articles were checked. No language restrictions were applied.

SELECTION CRITERIA

Randomised trials that compared face-to-face versus remote and web 2.0 PA interventions for community dwelling adults. We included studies if they compared an intervention that was principally delivered face-to-face to an intervention that had principally remote and web 2.0 methods. To assess behavioural change over time, the included studies had a minimum of 12 months follow-up from the start of the intervention to the final results. We excluded studies that had more than a 20% loss to follow-up if they did not apply an intention-to-treat analysis.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed the quality of each study and extracted the data. Non-English language papers were reviewed with the assistance of an interpreter who was an epidemiologist. Study authors were contacted for additional information where necessary. Standardised mean differences (SMDs) and 95% confidence intervals (CIs) were calculated for continuous measures of cardio-respiratory fitness.

MAIN RESULTS

One study recruiting 225 apparently healthy adults met the inclusion criteria. This study took place in a high-income country. From 27,299 hits, the full texts of 193 papers were retrieved for examination against the inclusion criteria. However, there was only one paper that met the inclusion criteria. This study reported the effect of a PA intervention on cardio-respiratory fitness. There were no reported data for PA, quality of life, or cost effectiveness. The difference between the remote and web 2.0 versus face-to-face arms was not significant (SMD -0.02; 95% CI -0.30 to 0.26; high quality evidence). The risk of bias in the included study was assessed as low, and there was no evidence of an increased risk of adverse events.

AUTHORS' CONCLUSIONS

There is insufficient evidence to assess whether face-to-face interventions or remote and web 2.0 approaches are more effective at promoting PA.

Energy expenditure, cardiorespiratory, and perceptual responses to shallow-water aquatic exercise in young adult women

INTRODUCTION

Aquatic exercise (AE) is a popular form of physical activity, yet few studies have assessed the individual's energy expenditure (EE) associated with a continuous bout of AE. Studies using indirect calorimetry to measure EE have reported limitations associated with test methodology and the ability to control individual's exercise intensity or tempo.

PURPOSE

To evaluate EE and cardiorespiratory (CR) responses during a 40-minute shallow-water AE session in young adult women.

METHODS

Twenty-one healthy women (aged 21.7 ± 3.4 years) completed an orientation practice session and a 40-minute shallow-water AE session using a traditional exercise class format and the SWEAT video-based instructional cuing program. The high-intensity interval format included the following segments: 1) warm-up (3 minutes); 2) CR segment ( 22 minutes); 3) muscular endurance segment (ME; 10 minutes); and 4) cool-down (5 minutes). Subject oxygen consumption (VO2; mL/kg/min), heart rate (HR) and OMNI overall ratings of perceived exertion (RPE-O) were assessed each minute. Average kcal/min1, metabolic equivalents (METs; 1 MET = 3.5 mL/kg/min), and total kcals per segment and for the overall session were calculated.

RESULTS

The total subject EE throughout the 40-minute trial (including warm-up and cool-down segments) was 264 kcals, with an overall average of 6.3 kcals/min (5.6 METs).The average kcals/min expended throughout CR segments 2 through 6 was 8.05 (7.1 METs), with the Hoverjog segment producing the greatest average kcals/min at 8.3 (7.3 METs). The CR portion (22 min) contributed 65% of the total EE (171 kcals) of the 40-minute AE trial. For the overall AE trial, the highest and average subject VO2 achieved were 33.3 and 19.7 mL/kg/min, respectively. The average highest subject heart rate achieved was 177 beats per minute (bpm), equivalent to 90% of the participant's age-predicted HRmax.

CONCLUSION

Energy expenditure during a 40-minute AE session met national recommendations for a daily moderate-to-vigorous bout of physical activity offering a viable alternative to land-based exercise. Because AE serves as a partial-weight bearing modality, future studies are needed to clarify the EE of shallow-water AE in apparently healthy and clinical populations.

Swimming and the heart

Exercise training is accepted to be beneficial in lowering morbidity and mortality in patients with cardiac disease. Swimming is a popular recreational activity, gaining recognition as an effective option in maintaining and improving cardiovascular fitness. Swimming is a unique form of exercise, differing from land-based exercises such as running in many aspects including medium, position, breathing pattern, and the muscle groups used. Water immersion places compressive forces on the body with resulting physiologic effects. We reviewed the physiologic effects and cardiovascular responses to swimming, the cardiac adaptations to swim training, swimming as a cardiac disease risk factor modifier, and the effects of swimming in those with cardiac disease conditions such as coronary artery disease, congestive heart failure and the long-QT syndrome.

The effects of a 10-week water aerobic exercise on the resting blood pressure in patients with essential hypertension

PURPOSE

To investigate the effects of a 10-week water aerobic exercise on the resting blood pressure in patients with stage 1 or 2 hypertension referring to Tehran University Clinics.

METHODS

Forty men with stage 1 or 2 essential hypertension were assigned to two groups of intervention [n = 12; aged 48.33±10.74 years (mean±SD)] and control [n = 28; aged 46.96±11.58 years (mean±SD)]. Subjects in the intervention group participated in a supervised 10-week water aerobic training program of 55 min sessions, 3 days per week on alternate days, while those in the control group were not involved in any regular training program during this period. Blood pressure of the participants was recorded and compared at the beginning and at the end of the study (48 hours after the last training session).

RESULTS

Exercise lowered systolic blood pressure and mean arterial pressure by 11.71 (95% confidence interval: 5.07 to 18.35) and 5.90 (95% confidence interval: 1.17 to 10.63) mm Hg respectively. The lowering effect of exercise on diastolic blood pressure was neither statistically significant nor clinically important (0.55 mm Hg; P. value = 0.8). There was no significant effect of age, baseline body mass index and stage of hypertension on the exercise-induced changes in blood pressure.

CONCLUSION

A 10-week course of water aerobic exercise markedly reduced the systolic and mean arterial blood pressure of patients with essential hypertension and is especially recommended for the obese and the elderly who have orthopedic problems or bronchospasm.

A long-term, comprehensive exercise program that incorporates a variety of physical activities improved the blood pressure, lipid and glucose metabolism, arterial stiffness, and balance of middle-aged and elderly Japanese

A 6-month, twice-a-week exercise program emphasizing swimming was conducted for 11 men (57-73 years) and 24 women (51-68 years). The control group comprised 11 male (59-70 years) and 11 female (53-70) volunteers. The exercise program significantly improved the systolic and diastolic blood pressure (SBP/DBP) and lipid and glucose metabolism, with no change in the controls. Brachial-ankle pulse wave velocity (baPWV), as an index of systemic arterial stiffness, was measured during medical examinations before and after each exercise session using a volume-plethysmographic apparatus. SBP and DBP of the extremities were significantly decreased after exercise, but did not change in the controls. Average baPWV decreased significantly in the exercise group, from 1661±50 to 1581±40 cm per sec. No change was seen in the controls. The sway path of the center of balance was analyzed using a force plate. The length of postural sway, the length of postural sway per sec and the area of postural sway were measured with eyes open and eyes closed, and the rectangular area was calculated. The eyes open/eyes closed ratio (Romberg sign) was also calculated. All parameters of body sway were significantly lower after 6 months in the exercise group, with no change in the controls. The Romberg sign did not change for either group. In addition to promoting better health, as shown by the clinical data, this type of exercise program improves balance function, which could help prevent falls of the elderly.

The curious question of exercise-induced pulmonary edema

The question of whether pulmonary edema develops during exercise on land is controversial. Yet, the development of pulmonary edema during swimming and diving is well established. This paper addresses the current controversies that exist in the field of exercise-induced pulmonary edema on land and with water immersion. It also discusses the mechanisms by which pulmonary edema can develop during land exercise, swimming, and diving and the current gaps in knowledge that exist. Finally, this paper discusses how these fields can continue to advance and the areas where clinical knowledge is lacking.

Comparison of central artery elasticity in swimmers, runners, and the sedentary

Although swimming is one of the most popular, most practiced, and most recommended forms of physical activity, little information is available regarding the influence of regular swimming on vascular disease risks. Using a cross-sectional study design, key measurements of vascular function were performed in middle-aged and older swimmers, runners, and sedentary controls. There were no group differences in age, height, dietary intake, and fasting plasma concentrations of glucose, total cholesterol, and low-density lipoprotein cholesterol. Runners and swimmers were not different in their weekly training volume. Brachial systolic blood pressure and pulse pressure were higher (p <0.05) in swimmers than in sedentary controls and runners. Runners and swimmers had lower (p <0.05) carotid systolic blood pressure and carotid pulse pressure than sedentary controls. Carotid arterial compliance was higher (p <0.05) and β-stiffness index was lower (p <0.05) in runners and swimmers than in sedentary controls. There were no significant group differences between runners and swimmers. Cardiovagal baroreflex sensitivity was greater (p <0.05) in runners than in sedentary controls and swimmers and baroreflex sensitivity tended to be higher in swimmers than in sedentary controls (p = 0.07). Brachial artery flow-mediated dilation was significant greater (p <0.05) in runners compared with sedentary controls and swimmers. In conclusion, our present findings are consistent with the notion that habitual swimming exercise may be an effective endurance exercise for preventing loss in central arterial compliance.

A comparison of the effects of swimming and walking on body weight, fat distribution, lipids, glucose, and insulin in older women--the Sedentary Women Exercise Adherence Trial 2

All types of aerobic exercise are assumed to affect cardiovascular risk similarly. There are few studies of swimming, but complex responses to water-based exercise suggest its potential for differential effects. The aim of the study was to compare the effects of swimming and walking on fitness, body weight, lipids, glucose, and insulin in older women. Sedentary women aged 50 to 70 years (N = 116), randomly assigned to swimming or walking plus usual care or a behavioral intervention, completed 3 sessions per week of moderate-intensity exercise, supervised for 6 months then unsupervised for 6 months. After 6 months, 1.6-km walk time decreased in walkers and swimmers, with greater improvement in walkers (1.0 vs 0.6 minute, P = .001). In swimmers, but not walkers, distance swum in 12 minutes increased (78.1 vs -2.2 m, P = .021). Waist and hip circumferences (80.8 vs 83.1 cm and 101.8 vs 102.4 cm; P = .023 and P = .042, respectively) and insulin area under the curve (oral glucose tolerance test) (5128 vs 5623 μU/[L 120 min], P < .05) were lower with swimming. Lipids did not differ between groups. At 12 months, fitness was maintained. Relative to walking, swimming reduced body weight by (1.1 kg, P = .039) and resulted in lower total and low-density lipoprotein cholesterol (0.3 and 0.2 mmol/L; P = .040 and P = .049, respectively). The magnitude of the difference in the reduction of insulin area under the curve between swimming and walking was greater at 12 months; however, the significance was attenuated (4677 vs 5240 μU/[L 120 min], P = .052). Compared with walking, swimming improved body weight, body fat distribution, and insulin in the short term and, in the longer term, body weight and lipid measures. These findings suggest that the type of exercise can influence health benefits.

Swimming exercise: impact of aquatic exercise on cardiovascular health

Swimming is an exercise modality that is highly suitable for health promotion and disease prevention, and is one of the most popular, most practiced and most recommended forms of physical activity. Yet little information is available concerning the influence of regular swimming on coronary heart disease (CHD). Exercise recommendations involving swimming have been generated primarily from unjustified extrapolation of the data from other modes of exercise (e.g. walking and cycling). Available evidence indicates that, similarly to other physically active adults, the CHD risk profile is more favourable in swimmers than in sedentary counterparts and that swim training results in the lowering of some CHD risk factors. However, the beneficial impact of regular swimming may be smaller than land-based exercises. In some cases, regular swimming does not appear to confer beneficial effects on some CHD risk factors. Moreover, swimming has not been associated with the reduced risks of developing CHD. Thus, extrapolation of research findings using land-based exercises into swimming cannot be justified, based on the available research. Clearly, more research is required to properly assess the effects of regular swimming on CHD risks in humans.

Health benefits of physical activity in older patients: a review

As the number of elderly persons in our country increases, more attention is being given to geriatric healthcare needs and successful ageing is becoming an important topic in medical literature. Concept of successful ageing is in first line on a preventive approach of care for older people. Promotion of regular physical activity is one of the main non-pharmaceutical measures proposed to older subjects as low rate of physical activity is frequently noticed in this age group. Moderate but regular physical activity is associated with a reduction in total mortality among older people, a positive effect on primary prevention of coronary heart disease and a significant benefit on the lipid profile. Improving body composition with a reduction in fat mass, reducing blood pressure and prevention of stroke, as well as type 2 diabetes, are also well established. Prevention of some cancers (especially that of breast and colon), increasing bone density and prevention of falls are also reported. Moreover, some longitudinal studies suggest that physical activity is linked to a reduced risk of developing dementia and Alzheimer's disease in particular.

Short and long-term adherence to swimming and walking programs in older women--the Sedentary Women Exercise Adherence Trial (SWEAT 2)

OBJECTIVE

To examine in previously sedentary older women the effects of exercise mode and a behavioural intervention on short and long-term retention and adherence.

METHODS

Healthy, sedentary women aged 50-70 years (N=116) were randomly assigned to a supervised 6-month swimming or walking program 3 sessions a week. They were further randomised to usual care or a behavioural intervention. The same program was further continued unsupervised for 6 months. We assessed retention, adherence, stage of exercise behaviour and changes in fitness.

RESULTS

One hundred women (86%) completed 6 months and 86 (74%) continued for 12 months. Retention rates were similar for both exercise modes at 6 and 12 months. Adherence to swimming or walking was similar after 6 months (76.3 (95% CI: 69.5, 83.1)% vs. 74.3 (67.7, 80.9)%) and 12 months (65.8 (57.9, 73.8)% vs. 62.2 (54.6, 70.0)%). The behavioural intervention did not enhance retention or adherence. Fitness improved for both exercise modes after 6 months and was maintained at 12 months.

CONCLUSIONS

Either swimming or walking programs initiated with careful supervision over 6 months resulted in similar high retention and adherence rates by highly motivated older women over 12 months. Behavioural intervention in this setting did not improve these rates further.

EXERCISE AND BLOOD PRESSURE: APPLYING FINDINGS FROM THE LABORATORY TO THE COMMUNITY SETTING

1. During the 1980s, there was growing epidemiological evidence that aerobic training lowered blood pressure (BP). Early intervention studies had not always supported this conclusion. Such studies were limited by methodological shortcomings. Few studies had used normotensive individuals or women alone. 2. Exercise training is an attractive lifestyle strategy in the prevention of hypertension. In our studies in men, vigorous intensity cycling did not lower resting BP. 3. Vigorous exercise reduces day time ambulatory BP and, in combination with calorie restriction, had a synergist effect to reduce night-time and 24 h BP. 4. Exercise is a positive and effective adjunct to other lifestyle measures in the prevention of hypertension. Adherence to either supervised or unsupervised moderate-intensity exercise is sufficient to reduce BP in the short and long term. 5. Further studies need to be performed to evaluate the clinical significance and mechanisms for the increase in resting BP observed in older women. 6. Older individuals with hypertension should be monitored when taking up a swimming programme. 7. Exercise induced changes in BP seen in the laboratory are also observed in the community setting.