Lisa K. Lloyd

The metabolic cost of hatha yoga.

To determine the metabolic and heart rate (HR) responses of hatha yoga, 26 women (19–40 years old) performed a 30-minute hatha yoga routine of supine lying, sitting, and standing asanas (i.e., postures). Subjects followed identical videotaped sequences of hatha yoga asanas. Mean physiological responses were compared to the physiological responses of resting in a chair and walking on a treadmill at 93.86 m·min-1 [3.5 miles per hour (mph)]. During the 30-minute hatha yoga routine, mean absolute oxygen consumption (VO2), relative VO2, percentage maximal oxygen consumption (%VO2R), metabolic equivalents (METs), energy expenditure, HR, and percentage maximal heart rate (%MHR) were 0.45 L·min-1, 7.59 ml·kg-1·min-1, 14.50%, 2.17 METs, 2.23 kcal·min-1, 105.29 b·min-1, and 56.89%, respectively. When compared to resting in a chair, hatha yoga required 114% greater O2 (L·min-1), 111% greater O2(ml·kg-1·min-1), 4,294% greater %VO2R, 111% greater METs, 108% greater kcal·min-1, 24% greater HR, and 24% greater %MHR. When compared to walking at 93.86 m·min-1, hatha yoga required 54% lower O2(L·min-1), 53% lower O2(ml·kg-1·min-1), 68% lower %VO2R, 53% lower METs, 53% lower kcal·min-1, 21% lower HR, and 21% lower %MHR. The hatha yoga routine in this study required 14.50% VO2R, which can be considered a very light intensity and significantly lighter than 44.8% VO2R for walking at 93.86 m·min-1 (3.5 mph). The intensity of hatha yoga may be too low to provide a training stimulus for improving cardiovascular fitness. Although previous research suggests that hatha yoga is an acceptable form of physical activity for enhancing muscular fitness and flexibility, these data demonstrate that hatha yoga may have little, if any, cardiovascular benefit.

The effects of caffeine on athletic agility.

Caffeine has been shown to improve sprint time, anaerobic power, and reaction time, all integral aspects of agility. The purpose of this study was to determine whether an acute caffeine dose would enhance agility and anaerobic power. Sixteen subjects participated in a randomized, double-blind experiment and performed the proagility run and the 30-second Wingate test 60 minutes after ingestion of caffeine (6 mg·kg−1) or placebo. No significant change was observed in the proagility run after caffeine ingestion compared with placebo. Also, no significant change was observed in peak power, mean power, or percent power decrease. Agility is an integral component of athletic skill and any reasonable method for enhancing agility would benefit active individuals. However, results from this study indicate that a 6 mg·kg−1 dose of caffeine does not impact agility as measured by the proagility run test or power output as measured by the 30-second Wingate test in recreationally active young adult males who are not habituated to caffeine.

The Influence of Body Size and Composition on FITNESSGRAM(r) Test Performance and the Adjustment of FITNESSGRAM(r) Test Scores for Skinfold Thickness in Youth

This study was designed to (a) determine the influence of body composition on the performance of FITNESSGRAM(r) test items and (b) evaluate the impact of adjusting FITNESSGRAM(r) scores for the effect of body composition on percentile ranks and the achievement of criterion-referenced standards (CRS). Male and female children (N = 200; ages 10-12 years) were administered a battery of FITNESSGRAM(r) tests. Body composition measurements had significant moderate negative correlations with PACER, curl-up, and push-up scores (r = -.30 to -.49). After the performance scores were adjusted for sum of skinfolds (SSF) by regression analysis for each of these tests, CRS classifications were altered in 4.5-22.7% of the participants. Adjusting the performance scores for SSF also resulted in differences of greater than 10 percentile ranks in 41-45% of the participants. The relationship between SSF and PACER, curlup, and push-up scores appears to be sufficient to justify the use of adjusted scores for evaluating cardiorespiratory endurance and upper-body muscular strength and endurance independent of SSF. The use of adjusted scores may permit a more unbiased assessment of health-related fitness independent of body size and composition.

Effects of Respiratory Resistance Training With a Concurrent Flow Device on Wheelchair Athletes

Abstract Background/Objective: To determine the effect of respiratory resistance training (RRT) with a concurrent flow respiratory (CFR) device on respiratory function and aerobic power in wheelchair athletes. Methods: Ten male wheelchair athletes (8 with spinal cord injuries, 1 with a neurological disorder, and 1 with postpolio syndrome), were matched by lesion level and/or track rating before random assignment to either a RRT group (n = 5) or a control group (CON, n = 5). The RRT group performed 1 set of breathing exercises using Expand-a-Lung, a CFR device, 2 to 3 times daily for 10 weeks. Pre/posttesting included measurement of maximum voluntary ventilation (MW), maximum inspiratory pressure (MIP), and peak oxygen consumption (Vo2peak). Results: Repeated measures ANOVA revealed a significant group difference in change for MIP from pre- to posttest (P < 0.05). The RRT group improved by 33.0 cm H2O, while the CON group improved by 0.6 cm H2O. Although not significant, the MW increased for the RRT group and decreased for the CON group. There was no significant group difference between Vo2peak for pre/posttesting. Due to small sample sizes in both groups and violations of some parametric statistical assumptions, nonparametric tests were also conducted as a crosscheck of the findings. The results of the nonparametric tests concurred with the parametric results. Conclusions: These data demonstrate that 10 weeks of RRT training with a CFR device can effectively improve MIP in wheelchair athletes. Further research and a larger sample size are warranted to further characterize the impact of Expand-a-Lung on performance and other cardiorespiratory variables in wheelchair athletes.

A Review of Fluid Replacement for Workers in Hot Jobs

Prolonged work in hot environments leads to progressive water and electrolyte loss from the body. The rate of sweating varies among individuals and depends on the environmental conditions, but in protective clothing and very hot environments rates can reach 2.25 L/hour. Because hypohydration will impair work performance and increases the risk of heat injury, consumption of fluids is necessary to prevent dehydration and enhance performance. Much of the research on rehydration has been conducted in athletic settings. The purpose of this review is to interpret the existing research literature on hydration in a way that is useful to industrial hygienists and safety experts. The authors hope to provide industrial hygienists and safety professionals with scientific bases for making recommendations regarding beverage availability and hydration practices. Although water is a very common beverage, some previous research has reported that drinks containing low to moderate levels of electrolytes and carbohydrates may provide some significant advantages in industrial situations. In general these studies seem to support the use of electrolyte-carbohydrate beverages as a supplement to water or as a replacement for water.

The Impact of Seasonality on Changes in Body Weight and Physical Activity in Mexican-American Women

This 12-month, longitudinal panel study examined seasonal variability in body weight and physical activity in Mexican-American women. Fifty-nine women (20 to 63 years of age) were measured five times at intervals of three months between March 2010 and March 2011. Complete data were collected for all measures at all times on 36 women. Repeated measures multivariate analysis of variance with follow-up univariate repeated measures analysis of variance revealed that body weight increased on average by 1.36 kg (p < .01), with the greatest increase occurring during the fall (+0.80 kg). Changes in vigorous-intensity aerobic activity were statistically significant, with the greatest increase occurring in the spring (+51.99 min/week) and the greatest decline occurring in the fall (–30.11 min/week). Significant changes were observed in muscle-strengthening activity during the summer (–32.38 min/week). Moderate-intensity aerobic activity remained relatively stable. The decline in muscle-strengthening activity during the summer and subsequent decline in vigorous-intensity aerobic activity in the fall likely led to the observed increase in body weight during the fall. Thus, weight management interventions should consider the time of year when Mexican-American womens physical activity declines and include strategies specifically designed to prevent weight gain during the fall season.

Effects of Concurrent Respiratory Resistance Training on Health-Related Quality of Life in Wheelchair Rugby Athletes: A Pilot Study

PURPOSE To compare the effects of 9 weeks of training with a concurrent flow resistance (CFR) device versus a concurrent pressure threshold resistance (CPTR) device on health-related quality of life (HRQoL) in wheelchair rugby (WR) athletes. METHOD Twenty-four male WR athletes (22 with tetraplegia, 1 with a spastic cerebral palsy, and 1 with congenital upper and lower limb deformities) were matched by lesion level, completeness of injury, and rugby classification prior to being randomly assigned to 1 of 3 groups: (1) CPTR (n=8), (2) CFR (n=8), or (3) controls (CON, n=8). Pre/post testing included assessment of HRQoL as measured by the Short-Form Health Survey Version 2.0 (SF-36v2). Manufacturer protocol guidelines for the CFR and CPTR groups were followed for breathing exercises. RESULTS Sixteen participants completed the study (CPTR=4, CFR=5, CON=7). The Mann-Whitney U rank order revealed significantly greater reductions in bodily pain (P = .038) and improvements in vitality (P = .028) for CFR versus CON. CONCLUSION Results from this study suggest that training with a CFR device improves some aspects of HRQoL (eg, vitality and bodily pain) in WR athletes. Further research with a larger sample size is needed to examine the impact of these devices on improving HRQoL for wheelchair athletes.

Genesis of an Employee Wellness Program at a Large University

University employee wellness programs have potential to support positive changes in employee health, thereby improving productivity and mitigating the rise in health care costs. The purpose of this article is to describe a theory-driven approach to systematically planning, developing, and implementing a comprehensive university employee wellness program. Long-term program goals were to improve employee health, well-being, and productivity by focusing on decreasing sedentary behavior, increasing physical activity, improving dietary habits, and reducing stress. An ecological approach was taken to identify levels of influence specific to a university setting: intrapersonal, interpersonal, department/college/division, and university. This framework guided the development of program components and strategies, which were grounded in several health behavior change theories. Input from supervisors and employees was incorporated throughout program development. A 15-week trial run, involving 514 employees, was evaluated to fine-tune services. Participation and feedback were positive, demonstrating that the program was valued. Support from upper administration is evidenced by continued funding. Critical factors to the successful launch of the program included a supportive administration, leverage of existing facilities and equipment, leadership provided by faculty, and service delivery by students.

Is the Polar F6 heart rate monitor less accurate during aerobic bench stepping because of arm movements

Abstract Lloyd, LK, Crixell, SH, and Price, LR. Is the polar F6 heart rate monitor less accurate during aerobic bench stepping because of arm movements? J Strength Cond Res 28(7): 1952–1958, 2014—Because of the well-documented linear relationship between heart rate and oxygen consumption (V[Combining Dot Above]O2), heart rate is commonly used to estimate energy expenditure during exercise. However, previous research suggests that heart rate increases without a concomitant rise in V[Combining Dot Above]O2 when arm movements are added to exercise. If so, this could impact the accuracy of heart rate monitors in estimating energy expenditure during combined arm and leg exercise. This study compared the cardiorespiratory responses to a bench step aerobics routine performed with and without arm movements and evaluated whether the accuracy of the Polar F6 heart rate monitor in predicting energy expenditure was impacted by the inclusion of arm movements. Thirty-two women performed the same routine with and without arm movements while stepping up and down off of a 15.24-cm bench at a cadence of 128 b·min−1. Heart rate and V[Combining Dot Above]O2 increased, whereas oxygen pulse (V[Combining Dot Above]O2·heart rate−1) decreased when arm movements were added (p < 0.001). However, the differences between the energy expenditure estimated by the Polar F6 heart rate monitor and the energy expenditure measured by indirect calorimetry were similar during the same aerobic bench stepping routine performed with and without arms (&Dgr;∼2 kCal·min−1, p ≥ 0.05). Results confirm that arm movements during aerobic bench stepping elicit a disproportionate rise in heart rate relative to V[Combining Dot Above]O2. However, results do not support that these movements increase the prediction error in energy expenditure, as the Polar F6 heart rate monitor over predicted energy expenditure when arm movements were involved and when they were not involved.

Effect of group health behaviour change coaching on psychosocial constructs associated with physical activity among university employees

Lifestyle behaviours are a contributing factor in approximately 80% of chronic diseases, making them a primary target for employee wellness programmes (EWPs). To effectively change health behaviours, EWPs should implement evidence-based strategies. One strategy is health behaviour change coaching, which is often delivered in a one-on-one format. While limited research exists, group health behaviour change coaching (group coaching) has potential to be an efficient alternative, impacting more people. The purpose of this study was to determine whether group health coaching improved psychological constructs related to physical activity and physical fitness among university employees in an EWP. Employees (n = 100) were randomly selected from a pool of volunteers who registered for the EWP, were overweight/obese, and at risk for cardiovascular disease. The intervention consisted of three group coaching sessions based on the Transtheoretical Model and Self-Determination Theory. Paired t-tests compared pre/post-measures of psychological constructs related to physical activity and physical fitness. Additionally, multivariate regression analysis with post-coaching self-efficacy as the dependent variable was performed. Overall, 84 participants (83% female, average BMI = 31.2) completed the intervention, attending an average of 2.26 sessions. Stages of change, seven processes of change, self-efficacy, perceived competence, and the health care climate score improved. Attending group coaching sessions predicted post-test self-efficacy. All but one measure of physical fitness improved. Group coaching can be effective in improving physical fitness and psychological constructs related to physical activity behaviour. In programmes with limited funds, group coaching has potential to be an important EWP component to support health behaviour change.