Effect of Wearing Surgical Face Masks During Exercise: Does Intensity Matter?

Face masks are widely recommended as means of controlling the coronavirus disease outbreak. This study aimed to examine the physiological and perceptual responses of wearing surgical face masks while exercising at different intensities. Thirteen healthy young adults (mean age, 21.9 ± 1.4 years) conducted randomized crossover trials with or without a surgical face mask. In each trial, participants completed an incremental treadmill protocol, with three 6-min stages (light, moderate, and vigorous at 25, 50, and 75% maximal oxygen uptake, respectively). Physiological outcomes (heart rate, blood lactate, and oxygen saturation level), perceived exertion and discomfort feeling were assessed. No significant differences were observed in physiological outcomes with or without masks at different exercise intensities (p > 0.05). However, the rating of perceived exertion (RPE) was significantly higher when exercising vigorously (mask: 15.5 ± 1.5 vs. no-mask: 14.2 ± 2.1, p < 0.05). Participants wearing masks reported marked discomfort, such as feeling hot, humid, and breathing resistance. Although face mask-wearing during exercise may not have detrimental effects on major physiological parameters, it can increase perceived exertion level and discomfort when the exercise intensity exceeds a certain threshold. Therefore, healthcare professionals should cautiously evaluate each person’s ability to exercise while wearing a mask and tailor their prescription accordingly.

The Effect of Motorized vs Non-Motorized Treadmills on Exercise Economy during Acute Sub-maximal Bouts in Collegiate Cross-Country Female Athletes

Background: Fitness equipment manufacturers have developed non-motorized treadmills (NMT) to better replicate overground running, a characteristic which motorized treadmills (MT) purportedly lack. Because NMTs are novel, limited empirical evidence exists regarding acute physiological and neuromuscular activity responses to its use. Objectives: The purpose of this investigation was to examine the effect of walking and running on an NMT and MT on exercise economy (EE), cardiometabolic responses, lower-body muscle activity, and rating of perceived exertion (RPE) in division II female cross-country athletes. Methods: Thirteen female cross-country athletes volunteered to complete a treadmill protocol that consisted of a warm-up walk, a 5-min walk, a 5-min run, and a 5-min cool-down walk on an NMT and MT on two separate occasions. During both treadmill conditions, VO2, RER, neuromuscular activity, HR, and RPE were recorded and analyzed every minute. Results: VO2 (NMT= 36.8 ± 10.0 ml/kg/min; MT= 27.4 ± 6.7 ml/kg/min), RER (NMT= 1.02 ± 0.14; MT= 0.89 ± 0.08), HR (NMT= 167 ± 18 bpm; MT= 142 ± 21 bpm), and RPE (NMT= 12 ± 2; MT= 9 ± 2) measures were significantly (p<0.05 for all) greater on the NMT than the MT in walking and running. Conclusions: The greater VO2, RER, and HR experienced on the NMT indicates higher physical exertion, and the greater RPE on the NMT indicates the participants’ perception of exertion correspond to the physiological responses. While cardiometabolic demand was greater on the NMT, thereby suggesting exercise economy was greater with the MT.

Purslane supplementation lowers oxidative stress, inflammatory and muscle damage biomarkers after high-intensity intermittent exercise in female runners

Background: The aim of this study was to determine the effect of purslane supplementation on oxidative stress, inflammation and muscle damage biomarkers after completing high-intensity interval exercise (HIIE). Methods: Nine healthy female runners completed a HIIE treadmill protocol comprising 1 min at 100% of the peak treadmill velocity attained in a preliminary exhaustive incremental treadmill test, interspersed by 1 min of passive recovery, until they had run for 2.5 km. Athletes repeated this test following 10 days of supplementation with 1000 mg per day of purslane. Results: At baseline (i.e., absence of purslane supplementation) the HIIE protocol increased 9-HODE (p < 0.001), 13-HODE (p < 0.001), IL-17 (p < 0.001), TNF-α (p < 0.001), and LDH (p < 0.001). After purslane consumption, resting 9-HODE, 13-HODE, IL-17, TNF-α, and LDH were lowered (p < 0.001) and IL-10 was increased (p < 0.001) compared to before purslane supplementation. After purslane consumption and following the HIIE protocol, the responses of these biomarkers were lower compared to baseline (p < 0.001). Conclusion: Ten days of purslane supplementation blunted the perturbation to biomarkers of oxidative stress, inflammation and muscle damage in female runners completing a HIIE protocol.

Validity of the Polar Vantage M watch when measuring heart rate at different exercise intensities

Background The use of wrist worn wearable fitness trackers has been growing rapidly over the last decade. The growing popularity can be partly attributed to the improvements in technology, making activity trackers more affordable, comfortable and convenient for use in different fitness and environmental applications. Fitness trackers typically monitor activity level, track steps, distance, heart rate (HR), sleep, peripheral capillary oxygen saturation and more, as the technology continuously is advancing. In terms of measuring HR, photoplethysmography (PPG) is a relatively new technology utilised in wearables. PPG estimates HR through an optical technique that monitors changes in blood volume beneath the skin. With these new products becoming available it is important that the validity of these devices be evaluated. Therefore, the aim of this study was to assess the validity of the Polar Vantage M (PVM) watch to measure HR compared to medical grade ECG on a healthy population during a range of treadmill exercise intensities. Methods A total of 30 healthy participants (n = 17 males, n = 13 females) were recruited for this study. The validity of the PVM watch to measure HR was compared against the gold standard 5-lead ECG. The study was conducted on 2 separate testing days with 24–48 h between sessions. Participants completed the Bruce Treadmill Protocol, and HR was measured every 30 s. Validation of the PVM watch in comparison to the ECG was measured with an Intraclass Correlation Coefficient (ICC) and associated 95% confidence intervals (CI) and levels of agreement were identified with Bland–Altman plots with 90% limits of agreement. Linear regression analysis was performed to calculate the value of r2 computing the variation of HR obtained by the PVM watch and ECG. Results In total, 30 participants completed the protocol, with data from 28 participants utilised for statistical analysis (16 males, 14 females, 26.10 ± 3.39 years, height 52.36 m ± 7.40 cm, mass 73.59 ± 11.90 kg). A strong and significant correlation was found between the PVM watch and ECG, demonstrating good criterion validity (p < 0.05, r2 = 0.87). Good validity was seen for day 1 and day 2 for stage 0 (ICC = 0.83; 95% CI [0.63–0.92], ICC = 0.74; 95% CI [0.37–0.88]), stage 1 (ICC = 0.78; 95% CI [0.52–0.90], ICC = 0.88; 95% CI [0.74–0.95]), and stage 2 (ICC = 0.88; 95% CI [0.73–0.94], ICC = 0.80; 95% CI [0.40–0.92]). Poor validity was demonstrated on day 1 and day 2 for stages 3–5 (ICC < 0.50). Conclusion This study revealed that the PVM watch had a strong correlation with the ECG throughout the entire Bruce Protocol, however the level of agreement (LoA) becomes widely dispersed as exercise intensities increased. Due to the large LoA between the ECG and PVM watch, it is not advisable to use this device in clinical populations in which accurate HR measures are essential for patient safety; however, the watch maybe used in settings where less accurate HR is not critical to an individual’s safety while exercising.

Is the Polar M430 a Valid Tool for Estimating Maximal Oxygen Consumption in Adult Females?

Background: Previous research studies have found that heart rate monitors that predict maximal oxygen consumption () are valid for males but overestimate in females. Inaccurate self-reported physical activity (PA) levels may affect the validity of the prediction algorithm used to predict . Purpose: To investigate the validity of the Polar M430 in predicting among females with varying PA levels. Methods: Polar M430 was used to predict () for 43 healthy female study participants (26.9 ± 1.3 years), under three conditions: the participant’s self-selected PA category (sPA), one PA category below the sPA (sPA − 1), and one category above the sPA (sPA + 1). Indirect calorimetry was utilized to measure () via a modified Astrand treadmill protocol. Repeated-measures analyses of covariance using age and percentage of body fat as covariates were used to detect differences between groups. Bland–Altman plots were used to assess the precision of the measurement. Results: was significantly correlated with (r = .695, p < .001). The mean values for and were 44.58 ± 9.29 and 43.98 ± 8.76, respectively. No significant differences were found between , , sPA – 1, and sPA + 1 (p = .492). However, the Bland–Altman plots indicated a low level of precision with the estimate. Conclusions: The Polar M430 was a valid method to predict across different sPA levels in females. Moreover, an under/overestimation in sPA had little effect on the predicted .

Kinematic Gait Adjustments to Virtual Environments on Different Surface Conditions: Do Treadmill and Over-Ground Walking Exhibit Different Adaptations to Passive Virtual Immersion?

Background. The aim of this study was to examine the kinematic gait adjustments performed in response to passive and photorealistic virtual reality environment (VRE) demands during over-ground and treadmill walking conditions and determine whether the surface presentation order affects the gait adjustments in response to different VREs. Methods. Twenty young participants divided into two groups performed two virtual reality (VR) walking protocols which included two different VREs (snowy and crowded conditions). Group A performed the VR over-ground protocol (four natural walking (NW), seven VR snowy, and seven VR crowded trials) followed by the VR treadmill protocol (four NW, one VR snowy, and one VR crowded trials); Group B performed the VR treadmill protocol (four NW, seven VR snowy, and seven VR crowded trials) followed by the VR over-ground protocol (four NW, one VR snowy, and one VR crowded trials). Center of mass (COM) excursion angles and mediolateral (ML) COM excursions were analyzed and used as outcome measures. Results. Group A showed higher COM excursion angles and ML-COM excursion on over-ground VR trials compared to NW trials ( p < 0.05 ), while Group B only showed kinematic changes for the crowded VRE compared to NW trials during the treadmill walking protocol ( p < 0.05 ). Post over-ground exposure, Group A showed greater COM excursion angle and ML-COM excursions on VR trials compared to NW trials during the treadmill walking protocol ( p < 0.05 ). Post treadmill exposure, Group B only showed higher COM excursion angles for the snowy VRE compared to NW trials during the over-ground walking protocol ( p < 0.01 ). Conclusion. Results showed that higher kinematic gait adjustments in response to VRE demands were observed during over-ground walking. Additionally, higher sensorimotor responses to VRE demands were observed when the VR protocol was first performed on the over-ground surface and followed by the treadmill walking condition (Group A) compared to the opposite (Group B).

Evaluating the Accuracy of Step Tracking and Fall Detection in the Starkey Livio Artificial Intelligence Hearing Aids: A Pilot Study

Purpose The primary purpose of this study was to examine the efficacy and the effectiveness of Starkey Livio Artificial Intelligence hearing aids in tracking step count. A secondary purpose was to investigate the accuracy of the fall detection and alert system of Livio hearing aids in detecting fall maneuvers. Method A participant wore Binaural Starkey Livio receiver-in-the-canal style hearing aids, a Sportline pedometer, and a Fitbit Charge 3 concurrently during both real-world and treadmill walking conditions. The real-world condition was conducted over a 5-day period. Step count for the treadmill protocol was assessed at six different treadmill speeds (2 mph, 2.5 mph, 3 mph, 3.5 mph, 4 mph, 4.5 mph, and 5 mph). The fall detection and alert system were assessed through falling maneuvers of activities of daily living. Results In the real-world condition, Livio, Sportline, and Fitbit recorded steps within 1 SD of each other. In addition, Livio recorded the most accurate steps compared to actual physical steps taken. In the treadmill condition, Livio recorded the least number of steps across all walking paces compared to the rest of the devices. Also, Livio hearing aids detected majority of the engaged falling maneuvers. Conclusions The Livio was found to be feasible, consistent, and sensitive in detecting steps and falls. Further research of higher sample size and recruitment of individuals with hearing loss are suggested.