Heart rate processing algorithms and exercise duration on reliability and validity decisions in biceps-worn Polar Verity Sense and OH1 wearables.

Consumer wearable technology use is widespread and there is a need to validate measures obtained in uncontrolled settings. Because no standard exists for the treatment of heart rate data during exercise, the effect of different approaches on reliability (Coefficient of Variation [CV], Intraclass Correlation Coefficient [ICC]) and validity (Mean Absolute Percent Error [MAPE], Lin's Concordance Correlation Coefficient [CCC)] were determined in the Polar Verity Sense and OH1 during trail running. The Verity Sense met the reliability (CV < 5%, ICC > 0.7) and validity thresholds (MAPE < 5%, CCC > 0.9) in all cases. The OH1 met reliability thresholds in all cases except entire session average (ICC = 0.57). The OH1 met the validity MAPE threshold in all cases (3.3-4.1%), but not CCC (0.6-0.86). Despite various heart rate data processing methods, the approach may not affect reliability and validity interpretation provided adequate data points are obtained. It is also possible that a large volume of data will artificially inflate metrics.

Acute Handgrip Fatigue and Forearm Girth in Recreational Sport Rock Climbers.

Indoor sport rock climbing has been increasing in popularity both recreationally and competitively. Despite this increase in popularity, the physiological responses to sport climbing as an exercise to specific muscle groups are not well defined. The purpose of this study was to quantify the change in handgrip strength over a 30-minute bout of continuous climbing, specifically in intermediate-level sport climbers. Ten intermediate rock climbers (age = 27 ± 2 years; climbing experience: 7.3 ± 1.5 years) completed baseline handgrip strength and forearm girth measurements. Each participant ascended one of two 5.9 difficulty routes as many times as possible in 30 minutes. After each ascent, heart rate was obtained, and handgrip strength and forearm girth were measured. Data were analyzed using repeated-measures ANOVA with significance set at α < 0.05. Dominant arm handgrip strength decreased by 22%, and non-dominant handgrip strength reduced by 23%. Dominant and non-dominant forearm girth increased by 4.5% and 4.4%, respectively. Weak but significant negative correlations were observed between handgrip strength and forearm girth in dominant (r = -0.311, p = 0.001) and non-dominant limbs (r = -.491, p = 0.001). These results indicate a relationship between increased forearm girth and decreases in muscular strength. Since handgrip strength decreases substantially during a 30-min climb in intermediate rock climbers, this population would be advised to carefully monitor recovery time between bouts.

The acute effect of two massage techniques on functional capability and balance in recreationally trained older adult women: A cross-over study.

With aging comes a reduction in neuromuscular and neuromotor function. Different strategies have been used to mitigate these functional losses. Certain manual therapy techniques and interventions have been explored with regard to their ability to improve functional capability and balance in an older adult population. The purpose of this study was to analyze the acute effects of two massage techniques on functional capability and balance performance in recreationally trained older adult women. Twenty-eight older adult women (66.74 ± 4.61 years) completed three interventions: a) stick massage followed by functional capability and balance performance tests (MMS), b) manual massage followed by functional capability and balance performance tests (MM), c) no MMS or MM (control condition (CC)) - only performed the functional capability and balance performance tests. Functional capability was assessed by four tests that are part of the Senior Fitness Test: the 6-min walk (W6), the chair sit-and-reach (CSR), the 8-foot up-and-go (8FUG), and the 30s-chair stand (30s-CS). Balance was assessed using the Berg Balance Scale (BBS). Significant differences (p < 0.001) were observed between MM and MMS compared to CC among 30s-CS, W6, CSR, and 8FUG. BBS showed a significant difference between MM and CC (p = 0.041). Both MM and MMS demonstrated significant acute improvements in the functional capability of recreationally trained elderly women and may be included in an exercise program.

Effect of exercise in a desert environment on physiological and subjective measures.

Green exercise is beneficial to emotional and physiological measures, however, the US has large desert areas. We aimed to determine if exercise in a desert (brown) environment extends similar benefits to green. Participants (N = 10) completed baseline measures (PRE), 30-min seated rest (SIT), and 30-min self-paced walking (WALK) in: indoor, outdoor urban, green, and two brown environments. Heart rate (HR), blood pressure (BP), and measures of stress, comfort, and calm were obtained. After SIT, HR was elevated in urban vs green (p = 0.05). Systolic BP was lower after SIT compared to PRE and WALK (p = 0.05). Brown and green returned greater comfort and calm scores (p = 0.001). Stress was lower following WALK than PRE and SIT (p < 0.01). Comfort and calm were greatest in natural environments, and exercise significantly reduced perceived stress. Taken together, these data provide evidence that exercise in a desert environment is just a beneficial as the exercise performed in a green environment. Abbreviations: ANCOVA: analysis of covariance; ANOVA: analysis of variance; AU: arbitrary units; BP: blood pressure; BSL: below sea level; DBP: diastolic blood pressure; HR: heart rate; PRE: baseline measurement; PS: perceived stress; SBP: systolic blood pressure; SIT: measurement following 30-min seated rest; WALK: measurement following 30-min self-paced walking.

Concurrent heart rate validity of wearable technology devices during trail running.

Validation of heart rate responses in wearable technology devices is generally composed of laboratory-based protocols that are steady state in nature and as a result, high accuracy measures are returned. However, there is a need to understand device validity in applied settings that include varied intensities of exercise. The purpose was to determine concurrent heart rate validity during trail running. Twenty-one healthy participants volunteered (female n = 10, [mean (SD)]: age = 31 [11] years, height = 173.0 [7] cm, mass = 75.6 [13] kg). Participants were outfitted with wearable technology devices (Garmin Fenix 5 wristwatch, Jabra Elite Sport earbuds, Motiv ring, Scosche Rhythm+ forearm band, Suunto Spartan Sport watch with accompanying chest strap) and completed a self-paced 3.22 km trail run while concurrently wearing a criterion heart rate strap (Polar H7 heart rate monitor). The trail runs were out-and-back with the first 1.61 km in an uphill direction, and the 1.61 return being downhill in nature. Validity was determined through three methods: Mean Absolute Percent Error (MAPE), Bland-Altman Limits of Agreement (LOA), and Lin's Concordance Coefficient (rC). Validity measures overall are as follows: Garmin Fenix 5 (MAPE = 13%, LOA = -32 to 162, rC = 0.32), Jabra Elite Sport (MAPE = 23%, LOA = -464 to 503, rC = 0.38), Motiv ring (MAPE = 16%, LOA = -52 to 96, rC = 0.29), Scosche Rhythm+ (MAPE = 6%, LOA = -114 to 120, rC = 0.79), Suunto Spartan Sport (MAPE = 2%, LOA = -62 to 61, rC = 0.96). All photoplethysmography-based (PPG) devices displayed poor heart rate agreement during variable intensity trail running. Until technological advances occur in PPG-based devices allowing for acceptable agreement, heart rate in outdoor environments should be obtained using an ECG-based chest strap that can be connected to a wristwatch or other comparable receiver.

Reliability of Trail Walking and Running Tasks Using the Stryd Power Meter.

Footpod monitors are wearable devices attaching to the shoe with the ability to sense oscillations in leg movement; however, few studies provide reliability. The purpose was to provide reliability data for outdoor tasks as measured by the Stryd Power Meter, which is a footpod monitor. Young healthy individuals (N=20, male n=12, female n=8) completed two 5-min self-paced walks along a trail, and two 5-min trail runs. Reliability of the tasks was determined using Coefficient of Variation (CV), Intraclass Correlation (ICC), and 95% confidence intervals (CI). Measures during trail running that returned a CV less than 10%, met the ICC threshold of 0.70, and displayed good to excellent 95% CI included pace, average elapsed power, average elapsed form power, average elapsed leg spring, and vertical oscillation. The only variable during walking to meet these criteria was maximal power (CV=4.02%, ICC=0.968, CI=0.902, 0.989). Running tasks completed on a trail generally return more consistent measures for variables that can be obtained from the Stryd footpod device than walking tasks.

Acute Normobaric Hypoxia Exposure and Excess Post-Exercise Oxygen Consumption.

BACKGROUND: Excess postexercise oxygen consumption (EPOC) is an elevation in oxygen consumption (Vo2) following exercise. Altitude decreases maximal oxygen uptake; however, studies are equivocal concerning the effect on resting metabolic rate. The EPOC response has not been studied with normobaric hypoxia. The purpose was to observe EPOC following constant-load cycling in normobaric hypoxia.METHODS: Subjects (N = 7 women, 7 men) completed resting metabolic rate testing between 06:00 and 08:30. Constant workload cycle exercise was performed (10 min at 100 W) while breathing air from an altitude simulator under the following conditions: normoxic control (CON), 3353 m (11,001 ft; HI), and 6401 m (21,001 ft; EXT). Subjects completed remaining conditions in a counterbalanced order. Upon completion, participants were reconnected to the metabolic system until a running 5-min average of Vo2 values returned to baseline (EPOC duration). Magnitude was determined by summing the net oxygen consumption each minute during the EPOC period. Data were analyzed using 2 × 3 repeated measures ANOVA.RESULTS: No sex differences were detected for any variable. EPOC duration increased significantly at each simulated altitude increase (CON = 15.2 ± 1.9 vs. HI = 20.7 ± 1.7 min) (HI vs. EXT = 28.1 ± 2.6 min). Likewise, EPOC magnitude increased significantly at each simulated altitude (CON = 73.5 ± 9.9 vs. HI = 99.1 ± 9.3 ml O2) (HI vs. EXT = 139.7 ± 14.3 ml O2).DISCUSSION: The EPOC response to simulated altitude represents elevated caloric expenditure that must be accounted for. Individuals who are active at altitude must consider the increased caloric deficit despite a loss of appetite that is common with altitude exposure.Navalta JW, Tanner EA, Bodell NG. Acute normobaric hypoxia exposure and excess post-exercise oxygen consumption. Aerosp Med Hum Perform. 2018; 89(12):1031-1035.

Sex and Age Differences in Trail Half Marathon Running.

Female participation is growing in trail running races. The purpose was to evaluate sex and age differences in top finishers of a trail running half marathon. Velocity differences between males (M) and females (F) were determined for the top 10 finishers of the Moab Trail Half Marathon from 2012 - 2015 across age, and by finishing place. Differences between age category and between sexes were determined through ANOVA with significance accepted at P < 0.05. A significant difference for running velocity was present between sexes at each age category (20-29 yr F = 2.9±0.3, M = 3.4±0.4 m·sec-1; 30-39 yr F = 2.8±0.3, M = 3.3±0.3; 40-49 yr F = 2.7±0.3, M = 3.0±0.5; 50-59 yr F = 2.3±0.2, M = 2.8±0.3; 60-69 yr F = 1.6±0.3, M = 2.2±0.4; P < 0.0001). Sex difference in trail running velocity was consistent (~13%) among all age categories with exception of the oldest group (33%, P = 0.0001). There were significantly greater female finishers in every age category (20 - 29 yr F = 107±18, M = 56±1;, 30 - 39 yr F = 150±34, M = 84±21; 40 - 49 yr F = 112±17, M = 64±16; P < 0.01) until 50 - 59 yr (F = 48±13, M = 41±14; P = 0.50). These data indicate that the widening gap in sex differences observed in road races are ameliorated in a trail running environment that has a larger number of female participants.

90 Minutes of Moderate-Intensity Exercise does not Attenuate Postprandial Triglycerides in Older Adults.

To determine whether 90 minutes of moderate-intensity exercise, prior to a high fat meal, attenuates postprandial triglycerides (PPT) in older adults. Eight sedentary older adult volunteers (mean ± SD age = 58 ± 8 years, BMI 26.5 ± 4.2); completed two trials consisting of exercise and a no-exercise control. Exercise trials involved 90 minutes of moderate-intensity exercise 60% heart rate reserve (HRR). Following exercise, an overnight fast of 12-16 hours was performed. Participants were given a high fat meal that consisted of 146 grams of CHO, and 92 grams of fat and instructed to rest. Lipid levels were collected at pre-feeding, 1, 2, 3, and 4 hours post feeding. The control trial involved no exercise, performed an overnight fast of 12-16 hours, and was given the high fat meal followed by four hours of rest and data collection. There was no difference in PPT between the control and exercise trials (p < 0.05). Triglycerides (TG) increased in both trials over pre-feeding values (pre-feeding 123.13 ± 65.03 con. 111 ± 53.9 ex., 1hr 161.50 ± 83.77 con. 149 ± 71.03 ex., 2hrs 208.25 ± 120.69 con. 177 ± 97.29 ex., 3hrs 228 ± 146.99 con. 147.25 ± 87.64 ex., 4hrs 211.75 ± 140.15 con. 169.5 ± 68.14 ex). No difference in triglycerides over time was observed among older adults between the exercise and control trials.