Ryan Er Reid

Validity and reliability of Fitbit activity monitors compared to ActiGraph GT3X+ with female adults in a free-living environment

OBJECTIVES Inexpensive activity monitors have recently gained popularity with the general public. Researchers have evaluated these consumer-based monitors in laboratory-conditions. Given the current wide-spread consumer use of these devices, it is important to ensure users are attaining accurate information compared to previously validated measures. This study investigates the accuracy of Fitbit One and Flex activity monitors in measuring steps, sedentary time, and time spent in light, moderate, and vigorous intensity activities with ActiGraph GT3X+ with female adults in free-living conditions. DESIGN Cross-sectional study. METHODS Twenty-two women, 21.23±1.63 years, BMI: 22.35±2.34kg/m2 wore two Fitbit Ones (bra and waist), one Fitbit Flex on the wrist, and one ActiGraph GT3X+ on the waist for seven-consecutive days. Repeated measures ANOVA was used to explore differences in steps, sedentary time, and time spent in light, moderate and vigorous intensity activities among the four devices. RESULTS No differences were found in number of steps recorded across the four devices. Fitbit One, waist and bra, overestimated time spent in light intensity activities. Fitbit One (waist) and Fitbit Flex overestimated time spent in moderate intensity activities. Fitbit One, waist and bra, and Fitbit Flex overestimated time spent in vigorous intensity activities. All Fitbit activity monitors overestimated MVPA and underestimated sedentary time compared to the ActiGraph. CONCLUSIONS Regardless of wear-location all Fitbit devices provide similar activity monitoring and users can wear the devices wherever best accommodates their lifestyle or needs. Users should not rely solely on these monitors when tracking vigorous and MVPA activities.

Precision of the iDXA for visceral adipose tissue measurement in severely obese patients.

UNLABELLED A new measurement tool, the automated software CoreScan, for the GE Lunar iDXA, has been validated for measuring visceral adipose tissue (VAT) against computed tomography in normal-weight populations. However, no study has evaluated the precision of CoreScan in measuring VAT among severely obese patients. PURPOSE The purpose of the study was to evaluate the precision of CoreScan for VAT measurements in severely obese adults (body mass index > 40 kg·m(-2)). METHODS A total of 55 obese participants with a mean age of 46 ± 11 yr, body mass index of 49 ± 6 kg·m(-2), and body mass of 137.3 ± 21.3 kg took part in this study. Two consecutive iDXA scans with repositioning of the total body were conducted for each participant. The coefficient of variation, the root-mean-square averages of SD of repeated measurements, the corresponding 95% least significant change, and intraclass correlations were calculated. RESULTS Precision error was 8.77% (percent coefficient of variation), with a root-mean-square SD of 0.294 kg and an intraclass correlation of 0.96. Bland-Altman plots demonstrated a mean precision bias of -0.08 ± 0.41 kg, giving a coefficient of repeatability of 0.82 kg and a bias range of -0.890 to 0.725 kg. CONCLUSIONS When interpreting VAT results with the iDXA in severely obese populations, clinicians should be aware of the precision error for this important clinical parameter.

Seasonal Changes in Whole Body and Regional Body Composition Profiles of Elite Collegiate Ice-Hockey Players.

Abstract Prokop, NW, Reid, RER, and Andersen, RE. Seasonal changes in whole body and regional body composition profiles of elite collegiate ice-hockey players. J Strength Cond Res 30(3): 684–692, 2016—The monitoring of a collegiate hockey players body composition can reflect fitness characteristics and may help players, coaches, or strength and conditioning specialists optimize physiologic gains during an off-season, whereas simultaneously preventing performance decrements in-season. The purpose of the study was to investigate changes in whole-body and regional-body composition of fat and lean tissue. The body composition profiles of 19 elite Canadian collegiate hockey players were assessed using dual energy X-ray absorptiometry. Players completed end-of-season, preseason, and midseason assessments with questionnaires relating to their off-season and in-season training. Statistically significant changes in body composition profiles were observed between the different time points because players showed various tissue gains and losses depending on the region assessed. Overall, players gained (1.38 kg, p ⩽ 0.01) and lost (0.79 kg, p ⩽ 0.01) fat tissue during the off-season and in-season, respectively. Players also showed a significant gain of leg lean tissue (0.29 kg, p = 0.02) and loss of arm tissue mass (−0.25 kg, p = 0.02) during the first-half of the competitive season. Several correlations emerged that may provide insight into potential trends that could be more pronounced during longer and more demanding schedules. Collegiate hockey players show changes in body composition during the off-season and in-season. The understanding of body composition profiles, body composition fluctuations, and potential variables that may influence the composition of collegiate hockey players can help coaches and athletic programs tailor their teams training, nutrition, lifestyle, and informative resources to further support their athletes.

The Potential Role of Objective Activity Monitoring in Off-Site Follow-Ups Post-Bariatric Surgery

Title: The Potential Role of Objective Activity Monitoring in Off-Site Follow-Ups Post-Bariatric Surgery. Background: Weight gain and attendance at follow-up visits after bariatric surgery are of great concern for the multidisciplinary care team. Geography and schedules make attending follow-up visits increasingly difficult as time after surgery goes on. Recently, inexpensive commercially available activity monitors have become more common place, making information concerning physical activity and sedentary behaviours deliverable online, allowing for important patient lifestyle information to be transmitted to the multidisciplinary care team. The purpose of this study was to determine if off-site objectively monitored physical activity and sedentary time can describe health measures such as total body fat, abdominal adipose tissue (AAT), and weight maintenance long-term post-bariatric surgery. Methods and findings: 59 individuals who had undergone bariatric surgery wore an ActivPAL for seven consecutive days, monitoring physical activity and sedentary time and underwent one DXA scan to determine body composition. Linear regression shows that (moderate-to-vigorous physical activity (MVPA) explained 18.8% of variance in body fat (p=0.019) and 11.3% of the variance in AAT (p=0.033). Conclusions: Objective monitoring could offer beneficial information concerning patients’ health at post-surgical follow-up visits.

Transfer of Off-Ice Agility to On-Ice Performance in Elite Canadian Collegiate Hockey Players: 3014 Board #79 June 3, 3: 30 PM - 5: 00 PM.

METHODS: Wingate test results from the summer training periods and 1500m performances during the subsequent winter were analyzed over a 3-year period, in 5 female and 8 male elite speed skaters. Regression analyses using generalized estimating equations (GEE) were used to estimate the relation between Wingate test variables and 1500m performance. Wingate peak power (PP), mean power (MP) and fatigue index (FI) were used to predict 1500m time, split times and lap times. RESULTS: The results indicate that an improvement of 1 W/kg on PP and MP in women predict an improvement of -0.75s and -2.05s, respectively, on 1500m time (World Record 111.79s). In men, PP and MP were also associated with performance, predicting improvements of -0.2s and -2.33s on 1500m time per 1 W/kg (World Record 101.04s). Split times on the 1500m in women were also associated with Wingate PP and MP. CONCLUSION: These data indicate that Wingate tests performed during the summer training period are a good predictor of 1500m speed skating performance in the subsequent winter. Relative to the World Records on 1500m, a 1 W/kg improvement in MP predicts a 2% improvement in performance.

Affordable Activity Monitors Can Improve Post-Surgical Care in Bariatric Surgery Patients

Bariatric surgery is an effective method of dramatically reducing weight and minimizing the appearance of comorbidities in several obese individuals. Regardless of weight lost post-surgically, some patients fail to increase their amount of physical activity and remain overly sedentary. Furthermore, in the years following surgery, certain patients re-gain some of the weight that they had initially lost. A proposed explanation for this lack of long-term weight loss maintenance is the lack of attendance to long-term post-surgical follow-up visits. If health care providers are unable to monitor the progress of their patients post-surgically, it is impossible for them to provide new strategies that will promote better long-term weight loss success. Recently, new and more affordable activity monitoring devices have become accessible with the ability to log information about physical activity and nutrition wirelessly to web based software. This software enables the information to be accessed by anyone with internet access and the correct password. These devices give the opportunity for patients to communicate with their health care providers without the need for in person follow-up visits and offer an affordable option for better and more reliable long-term follow-up care after bariatric surgery.