Physical activity measurement : a primer for health promotion

As the importance of physical activity is recognised in health promotion, the task of measuring it becomes a central research and practice challenge. Measurement of physical activity is important to policy makers interested in population surveillance, as well as to practitioners interested in programme evaluation and research. This review outlines ‘best practice’ in physical activity measurement, and provides an inventory of established physical activity and related measures for use in health promotion programme evaluation, research and surveillance at the national and local level

Telephone interventions for physical activity and dietary behavior change : a systematic review

Background: Given the epidemic of lifestyle-related chronic diseases, building the evidence base for physical activity and dietary behavior change interventions with a wide population reach is of critical importance. For this purpose, telephone counseling interventions have considerable potential. Purpose: To systematically review the literature on interventions for physical activity and dietary behavior change in which a telephone was the primary method of intervention delivery, with a focus on both internal and external validity. Methods: A structured search of PubMed, Medline, and PsycInfo was conducted for studies published in English from 1965 to January 2006. Studies targeted primary or secondary prevention in adults, used randomized designs, and included physical activity and/or dietary behavior outcomes. Results: Twenty-six studies were reviewed, including 16 on physical activity, six on dietary behavior, and four on physical activity plus dietary behavior. Twenty of 26 studies reported significant behavioral improvements. Positive outcomes were reported for 69% of physical activity studies, 83% of dietary behavior studies, and 75% of studies addressing both outcomes. Factors associated with positive outcomes appear to be the length of intervention and the number of calls, with interventions lasting 6 to 12 months and those including 12 or more calls producing the most favorable outcomes. Data on the representativeness of participants, implementation of calls, and costs were reported much less frequently.Conclusions: There is now a solid evidence base supporting the efficacy of physical activity and dietary behavior change interventions in which the telephone is the primary intervention method. Thus, research studies on broader dissemination are necessary, and should address questions relevant to the translation of this body of work into population health practice

Website-delivered physical activity interventions : a review of the literature

Evidence-based physical activity interventions that can be delivered to large numbers of adults at an acceptable cost are a public health priority; website-delivered programs have this potential. The purpose of this study was to systematically review the research findings and outcomes of website-delivered physical activity interventions and to identify relationships of intervention attributes with behavioral outcomes. A structured search of PubMed, Medline, PsycInfo, and Web of Science was conducted for intervention studies published up to July 2006. Studies included in the review were those that (1) used websites or e-mail, (2) had physical activity behavior as an outcome measure, (3) had randomized controlled or quasi-experimental designs, (4) targeted adults, and (5) were published in English. Of the fifteen studies reviewed, improvement in physical activity was reported in eight. Better outcomes were identified when interventions had more than five contacts with participants and when the time to follow-up was short (≤3 months; 60% positive outcomes), compared to medium-term (3–6 months, 50%) and long-term (>6 months, 40%) follow-up. There were no clear associations of outcomes with other intervention attributes. A little over half of the controlled trials of website-delivered physical activity interventions have reported positive behavioral outcomes. However, intervention effects were short lived, and there was limited evidence of maintenance of physical activity changes. Research is needed to identify elements that can improve behavioral outcomes, the maintenance of change and the engagement and retention of participants; larger and more representative study samples are also needed

Associations of leisure-time internet and computer use with overweight and obesity, physical activity and sedentary behaviors : cross-sectional study

Background: Internet and computer use are increasingly common leisure-time sedentary behaviors, which have the potential to impact negatively on health outcomes. However, little is known about the extent to which adults’ Internet and computer use is associated with weight status and time spent in leisure-time physical activity. Objective: The objective is to examine associations of leisure-time Internet and computer use with overweight and obesity, leisure-time physical activity, and other sedentary behaviors. Methods: Participants (2650 adults living in Adelaide, Australia) completed a mail-back questionnaire including items on their height and weight, past seven day recall of leisure-time physical activity, Internet and computer use, and other leisure-time sedentary behaviors. Leisure-time Internet and computer use was categorized into no use, low use (less than three hours per week), or high use (three hours or more per week). Results: Participants with low leisure-time Internet and computer use had the highest levels of educational attainment and employment, and engaged in less other sedentary behaviors when compared to participants with no or high Internet and computer use. Multinomial logistic regression, adjusted for gender, age, employment, education, other sedentary behaviors and physical activity, determined that participants with a high leisure-time Internet and computer use were 1.46 (95% CI = 1.10 - 1.93) times more likely to be overweight (BMI≥25 and <30 kg/m2) and 2.52 times more likely (95% CI = 1.82 - 3.52) to be obese (BMI≥30 kg/m2), compared to those who reported no Internet and computer use in their leisure-time. Adults with high leisure-time Internet and computer use were more likely to be overweight or obese even if they were highly active in their leisure time (OR = 1.86; 95% CI = 1.21 - 2.88), as compared to participants who did not use the Internet or computer. Leisure-time physical activity levels were largely independent of Internet and computer use. Conclusion: These findings suggest that, apart from nutritional and physical activity interventions, it may also be necessary to decrease time spent in sedentary behaviors, such as leisure-time Internet and computer use, in order to reduce the prevalence of overweight and obesity. Future Internet interventions to reduce weight or increase physical activity may need to differentiate between participants with different levels of Internet use in order to increase their effectiveness. Longitudinal studies are required to examine further the potential causal relationships between the development of overweight and specific sedentary behaviors such as Internet and computer use

Test-retest reliability of four physical activity measures used in population surveys

Accurate monitoring of prevalence and trends in population levels of physical activity (PA) is a fundamental public health need. Test-retest reliability (repeatability) was assessed in population samples for four self-report PA measures: the Active Australia survey (AAN=356), the short Physical Activity Questionnaire (IPAQ, N=104), the physical activity items in the Behavioral Risk Factor Surveillance System (BRFSS, N=127) and in the Australian National health Survey (NHS, N=122). Percent agreement and Kappa statistics were used to assess reliability of classification of activity status as 'active', 'insufficiently active' or 'sedentary'. Interclass correlations (ICCs) were used to assess agreement on minutes of activity reported for each item of each survey and for total minutes. Percent agreement scores for activity status were very good on all four instruments, ranging from 80% for the NHS to 79% for the IPAQ. Corresponding Kappa statistics ranged from 0.40 (NHS) to 0.52 (AA). For individual items, ICCs were highest for walking (0.45 to 0.78) and vigorous activity (0.22 to 0.64) and lowest for moderate questions (0.16 to 0.44). All four measures provide acceptable levels of test-retest reliability for assessing activity status and sedentariness, and moderate reliability for assessing total minutes of activity

Reliability and detecting change following short-term creatine supplementation : comparison of two-component body composition methods

The purpose of the present study was twofold: firstly, to assess the reliability of various body composition methods, and secondly, to determine the ability of the methods to estimate changes in fat-free mass (FFM) following creatine (Cr) supplementation. Fifty-five healthy male athletes (weight 78.3 +/- 10.3 kg, age 21 +/- 1 years) gave informed consent to participate in this study. Subjects' FFM was estimated by hydrostatic weighing (HW), air-displacement plethysmography (ADP), bioelectrical impedance analysis (BIA), near-infrared spectroscopy (NIR), and anthropometric measurements (ANTHRO). Measurements were taken on 2 occasions separated by 7 days to assess the reliability of the methods. Following this, 30 subjects returned to the laboratory for an additional test day following 7 days of Cr supplementation (20 g.d(-1) Cr + 140 g.d(-1) dextrose) to assess each method's ability to detect acute changes in FFM. In terms of reliability, we found excellent test-retest correlations for all 5 methods, ranging from 0.983 to 0.998 (p < 0.001). The mean biases for the 5 methods were close to 0 (range -0.1 to 0.3 kg) and their 95% limits of agreement (LOAs) were within acceptable limits (HW = -1.1 to 1.7 kg; ADP = -1.1 to 1.2 kg; BIA = -1.0 to 1.0 kg; NIR = -1.4 to 1.4 kg); however, the 95% LOAs were slightly wider for ANTHRO (-2.4 to 2.6 kg). Following Cr supplementation there was a significant increase in body mass (from 77.9 +/- 10.1 kg to 78.9 +/- 10.3 kg, p = 0.000). In addition, all 5 body composition techniques detected the change in FFM to a similar degree (mean change: HW = 0.9 +/- 0.6 kg; ADP = 0.9 +/- 0.6 kg; BIA = 0.9 +/- 0.6 kg; NIR = 0.8 +/- 0.5 kg; ANTHRO = 1.0 +/- 0.7 kg; intraclass correlation coefficient = 0.962). We conclude that between-day differences in FFM estimation were within acceptable limits, with the possible exception of ANTHRO. In addition, all 5 methods provided similar measures of FFM change during acute Cr supplementation

Complex training in professional rugby players : influence of recovery time on upper-body power output

After a bout of heavy resistance training (HRT), skeletal muscle is in both a fatigued and potentiated state. Subsequent muscle performance depends on the balance between these 2 factors. To date, there is no uniform agreement about the recovery time required between the HRT and subsequent muscle performance to gain performance benefits in the upper body. The aim of the present study was to determine the recovery time required to observe enhanced upper-body muscle performance after HRT (i.e., complex training). Twenty-six professional rugby players performed a ballistic bench press (BBP) at baseline and at approximately 15 seconds and 4, 8, 12, 16, 20, and2 4 minutes after HRT (3 sets of 3 repetitions at 87% 1 repetition maximum). Peak power output (PPO) and throw height were determined for all BBPs. A significant time effect with regard to PPO (F = 29.145, partial Eta2 = 0.538, p , 0.01) and throw height (F = 17.362, partial Eta2 = 0.410, p , 0.01) was observed. Paired comparisons indicated a significant decrease in PPO and throw height in the BBP performed approximately 15 seconds after the HRT compared with the baseline BBP. After 8 minutes of recovery from the HRT, both PPO and throw height were significantly higher than the PPO and throw height recorded at baseline (e.g., PPO: 879 6 100 vs. 916 6 116 W,p , 0.01). It was concluded that muscle performance can be significantly enhanced after bouts of HRT during a BBP providing that adequate recovery (8 min) is given between the HRT and the explosive activity

Reliability and detecting change following short-term creatine supplementation : comparison of two-component body composition methods

The purpose of the present study was twofold: firstly, to assess the reliability of various body composition methods, and secondly, to determine the ability of the methods to estimate changes in fat-free mass (FFM) following creatine (Cr) supplementation. Fifty-five healthy male athletes (weight 78.3 +/- 10.3 kg, age 21 +/- 1 years) gave informed consent to participate in this study. Subjects' FFM was estimated by hydrostatic weighing (HW), air-displacement plethysmography (ADP), bioelectrical impedance analysis (BIA), near-infrared spectroscopy (NIR), and anthropometric measurements (ANTHRO). Measurements were taken on 2 occasions separated by 7 days to assess the reliability of the methods. Following this, 30 subjects returned to the laboratory for an additional test day following 7 days of Cr supplementation (20 g.d(-1) Cr + 140 g.d(-1) dextrose) to assess each method's ability to detect acute changes in FFM. In terms of reliability, we found excellent test-retest correlations for all 5 methods, ranging from 0.983 to 0.998 (p < 0.001). The mean biases for the 5 methods were close to 0 (range -0.1 to 0.3 kg) and their 95% limits of agreement (LOAs) were within acceptable limits (HW = -1.1 to 1.7 kg; ADP = -1.1 to 1.2 kg; BIA = -1.0 to 1.0 kg; NIR = -1.4 to 1.4 kg); however, the 95% LOAs were slightly wider for ANTHRO (-2.4 to 2.6 kg). Following Cr supplementation there was a significant increase in body mass (from 77.9 +/- 10.1 kg to 78.9 +/- 10.3 kg, p = 0.000). In addition, all 5 body composition techniques detected the change in FFM to a similar degree (mean change: HW = 0.9 +/- 0.6 kg; ADP = 0.9 +/- 0.6 kg; BIA = 0.9 +/- 0.6 kg; NIR = 0.8 +/- 0.5 kg; ANTHRO = 1.0 +/- 0.7 kg; intraclass correlation coefficient = 0.962). We conclude that between-day differences in FFM estimation were within acceptable limits, with the possible exception of ANTHRO. In addition, all 5 methods provided similar measures of FFM change during acute Cr supplementation

Influence of recovery time on post-activation potentiation in professional rugby players

Following a bout of heavy resistance training, the muscle is in both a fatigued and potentiated state with subsequent muscle performance depending on the balance between these two factors. To date, there is no uniform agreement about the optimal acute recovery required between the heavy resistance training and subsequent muscle performance to gain performance benefits. The aim of the present study was to determine the recovery time required to observe enhanced muscle performance following a bout of heavy resistance training. Twenty professional rugby players performed a countermovement jump at baseline and approximately 15 s, 4, 8, 12, 16, 20, and 24 min after a bout of heavy resistance training (three sets of three repetitions at 87% one-repetition maximum squat). Power output, jump height, and peak rate of force development were determined for all countermovement jumps. Despite an initial decrease in countermovement jump performance after the heavy resistance training (P<0.001), participants' performance increased significantly following 8 min recovery (P<0.001) (i.e. jump height increased by 4.9%, s=3.0). The findings suggest that muscle performance during a countermovement jump can be markedly enhanced following bouts of heavy resistance training provided that adequate recovery (approximately 8 min) is allowed between the heavy resistance training and the explosive activity

Rise and Recharge: Exploring Employee Perceptions of and Contextual Factors Influencing an Individual-Level E-Health Smartphone Intervention to Reduce Office Workers’ Sedentary Time at Work

This feasibility study explored the contextual factors influencing office workers’ adherence to an e-health intervention targeting total and prolonged sedentary time over 12 weeks. A three-arm quasi-randomized intervention included prompts at 30 or 60 min intervals delivered via a smartphone application, and a no-prompt comparison arm. Fifty-six office workers completed baseline (64% female) and 44 completed the 12 week follow-up (80% retention). Ecological momentary assessments (EMA) captured contextual data, with 82.8 ± 24.9 EMA prompt questionnaires completed weekly. Two focus groups with n = 8 Prompt 30 and 60 participants were conducted one-month post-intervention to address intervention acceptability and feasibility. Contextual findings indicate that when working on a sedentary task (i.e., reading or screen-based work) and located at an individual workstation, hourly prompts may be more acceptable and feasible for promoting a reduction in total and prolonged sedentary time compared to 30 min prompts. Interpersonal support also appears important for promoting subtle shifts in sedentary working practices. This novel study gives a real-time insight into the factors influencing adherence to e-health prompts. Findings identified unique, pragmatic considerations for delivering a workplace e-health intervention, indicating that further research is warranted to optimize the method of intervention delivery prior to evaluation of a large-scale intervention