The Feasibility of a Telehealth Exercise Program Aimed at Increasing Cardiorespiratory Fitness for People After Stroke

Background: Accessing suitable fitness programs post-stroke is difficult for many. The feasibility of telehealth delivery has not been previously reported.Objectives: To assess the feasibility of, and level of satisfaction with home-based telehealth-supervised aerobic exercise training post-stroke.Methods: Twenty-one ambulant participants (?3 months post-stroke) participated in a home-based telehealth-supervised aerobic exercise program (3 d/week, moderate-vigorous intensity, 8-weeks) and provided feedback via questionnaire postintervention. Session details, technical issues, and adverse events were also recorded.Results: Feasibility was high (83% of volunteers met telehealth eligibility criteria, 85% of sessions were conducted by telehealth, and 95% of participants rated usability favourably). Ninety-five percent enjoyed telehealth exercise sessions and would recommend them to others. The preferred telehealth exercise program parameters were: frequency 3 d/week, duration 20-30 min/session, program length 6-12 weeks.Conclusion: The telehealth delivery of exercise sessions to people after stroke appear

Effects of Virtual Reality During Rowing Ergometry on Metabolic and Performance Parameters

Physical activity and moderate or intense exercise improve musculoskeletal and metabolic health; however, approximately 80% of Americans do not meet the minimum exercise recommendations from the American College of Sports Medicine (ACSM) or the Centers for Disease Control (CDC). Exercise intensity may be the most important factor in eliciting positive physical outcomes with exercise. PURPOSE: To assess the effectiveness of a proprietary virtual reality (VR) interface to increase metabolic and physical performance during rowing ergometry. METHODS: A novel VR software program for rowing ergometry was developed. Subsequently, sixteen apparently healthy, recreationally active individuals (12M, 4F; 35.5 ± 13.9 y; 174.5 ± 10.1 cm; 80.4 ± 12.8 kg; VO2max: 38.1 ± 5.6 mL/kg/min) were familiarized with the rowing ergometer and VR software, and then completed a VO2max test during two separate sessions. Finally, subjects performed four, 30-min rowing sessions in a randomized, counterbalanced order at maximal voluntary intensity in four different conditions: 1) no augmented visual or audio stimuli (CON), 2) no augmented visual stimuli with self-selected music (MUS), 3) screen-based environmental display (SB), and 4) a virtual reality environment (VR). Oxygen consumption, ventilation, heart rate, and the respiratory exchange ratio (RER) were measured continuously during the four experimental sessions; these data were then averaged over each 30-min testing period. Power output (W) and distance rowed (m) were measured and similarly reduced. Data (mean ± SD) were analyzed by repeated measures ANOVA and appropriate Tukey’s post hoc tests. Alpha was set at P \u3c 0.05. RESULTS: Oxygen consumption (CON: 2.23 ± 0.63 L/min; MUS: 2.30 ± 0.63 L/min; SB: 2.23 ± 0.71 L/min; VR: 2.19 ± 0.69 L/min), ventilation (CON: 74.2 ± 21.0 L/min; MUS: 77.5 ± 20.5 L/min; SB: 73.4 ± 23.9 L/min; VR: 71.7 ± 23.8 L/min), heart rate (CON: 154 ± 16 bpm; MUS: 156 ± 17 bpm; SB: 152 ± 23 bpm; VR: 154 ± 17 bpm), and RER (CON: 0.94 ± 0.04; MUS: 0.95 ± 0.04; SB: 0.94 ± 0.04; VR: 0.93 ± 0.05) were not different between conditions (all P \u3e 0.05). Performance outcomes also did not differ between conditions (CON: 126 ± 40 W, 6337 ± 763 m; MUS: 130 ± 42 W, 6486 ± 617 m; SB: 128 ± 46 W, 6358 ± 862 m; VR: 124 W ± 44 W, 6294 ± 849 m; all P \u3e 0.05). CONCLUSION: The pilot version of the VR software for rowing ergometry did not increase voluntary effort as determined by metabolic or physical performance outputs. Added features, such as greater immersion for reluctant exercisers, and competitive elements for highly motivated individuals, may elicit greater voluntary exertion with VR in rowing ergometry. Moreover, such applications may be more beneficial and improve exercise enjoyment in less experienced exercises who are not accustomed to high exercise intensities

Effects of Virtual Reality During Rowing Ergometry on Presence, Perceived Exertion, and Exercise Enjoyment

Physical inactivity is associated with a host of negative health outcomes. Approximately 80% of Americans do not meet minimum levels of recommended physical activity. Virtual reality (VR) may improve exercise outcomes by enhancing presence, decreasing perceived exertion, and increasing exercise enjoyment. PURPOSE: To assess the effects of a proprietary VR interface on presence, perceived exertion, and exercise enjoyment during rowing ergometry. METHODS: First, we developed a novel VR software program for rowing ergometry. Subsequently, sixteen apparently healthy, recreationally active individuals (12M, 4F; 35.5 ± 13.9 y; 174.5 ± 10.1 cm; 80.4 ± 12.8 kg; VO2max: 38.1 ± 5.6 mL/kg/min) were familiarized with the rowing ergometer and VR software, and then completed a VO2max test during two separate sessions. Finally, subjects performed four, 30-min rowing sessions in a randomized, counterbalanced order at maximal voluntary intensity in four different conditions: 1) no augmented visual or audio stimuli (CON), 2) no augmented visual stimuli with self-selected music (MUS), 3) screen-based environmental display (SB), and 4) a virtual reality environment (VR). Presence (Spatial Presence Experience Scale), perceived exertion (Borg 6-20 scale), and enjoyment (Exercise-Induced Feelings Inventory) were assessed using questionnaires. Data (mean ± SD) were analyzed by repeated measures ANOVA and appropriate Tukey’s post hoc tests. Alpha was set at P \u3c 0.05. RESULTS: Eight of twenty spatial presence items indicated an enhanced experience in VR vs. SB (P \u3c 0.05). Perceived exertion (CON: 14.7 ± 2.1; MUS: 14.9 ± 2.0; SB: 15.2 ± 2.5; VR: 14.9 ± 1.7) and exercise-induced feelings were not different between conditions (P \u3e 0.05). CONCLUSION: The pilot version of the VR software for rowing ergometry did not reduce perceived exertion or increase exercise enjoyment in recreationally active individuals, although it did facilitate improved user presence compared to a screen-based enhanced environment. Added features, such as better coupling of rowing intensity to boat velocity in VR may further enhance presence and immersion, thereby decreasing perceived exertion and increasing exercise enjoyment

Heart Rate Responses to Unaided Orion Side Hatch Egress in the Neutral Buoyancy Laboratory

NASA is developing the Orion capsule as a vehicle for transporting crewmembers to and from the International Space Station (ISS) and for future human space exploration missions. Orion and other commercial vehicles are designed to splash down in the ocean where nominally support personnel will assist crewmembers in egressing the vehicle. However, off-nominal scenarios will require crewmembers to egress the vehicle unaided, deploy survival equipment, and ingress a life raft. PURPOSE: To determine the heart rate (HR) responses to unaided Orion side hatch egress and raft ingress as a part of the NASA Crew Survival Engineering Team's evaluation of the PORT Orion mockup in the Neutral Buoyancy Laboratory (NBL). METHODS: Nineteen test subjects, including four astronauts (N=19, 14 males/5 females, 38.6+/-8.4 y, 174.4+/-9.6 cm, 75.7+/-13.1 kg), completed a graded maximal test on a cycle ergometer to determine VO2peak and HRpeak and were divided into five crews of four members each; one subject served on two crews. Each crew was required to deploy a life raft, egress the Orion vehicle from the side hatch, and ingress the life raft with two 8 kg emergency packs per crew. Each crew performed this activity one to three times; a total of ten full egresses were completed. Subjects wore a suit that was similar in form, mass, and function to the Modified Advanced Crew Escape Suit (MACES) including helmet, gloves, boots, supplemental O2 bottles, and a CO2-inflated life preserver (approx.18 kg); subjects began each trial seated supine in the PORT Orion mockup with seat belts and mockup O2 and communication connections and ended each trial with all four crewmembers inside the life raft. RESULTS: VO2peak was 40.8+/-6.8 mL/kg/min (3.1+/-0.7 L/min); HRpeak was 181+/-10 bpm. Total egress time across trials was 5.0+/-1.6 min (range: 2.8-8.0 min); all subjects were able to successfully complete all trials. Average maximum HR at activity start, at the hatch opening, in the water, and in the raft, was 108, 137, 147, and 153 bpm, respectively; these values corresponded to 59+/-10%, 73+/-8%, 82+/-3%, and 84+/-6% of HRpeak, respectively. The highest HRs were seen after raft ingress and ranged from 72-99% HRpeak. Across all trials, cumulative averages of 5.4, 3.0, 1.1, and 0.2 min were spent at HRs >60%, >70%, >80%, and >90% HRpeak, respectively. CONCLUSION: Unaided Orion side hatch egress in the NBL is a relatively short-duration activity that elicits a high HR response for several min. Although all crewmembers successfully completed this activity, additional factors such as high seas, poor visibility, an incapacitated crewmember, neurovestibular perturbation, and neuromuscular deconditioning characteristic of a true operational environment may increase the physiologic demand (or decrease crewmembers' physiologic capacity) of unaided Orion side hatch egress. Additionally, landing conditions may require the crewmembers to egress from the top hatch, which is expected to be even more physiologically demanding; this condition will be evaluated in subsequent collaborative testing with the NASA Crew Survival Engineering Team

Reliability of Strength Testing using the Advanced Resistive Exercise Device and Free Weights

The Advanced Resistive Exercise Device (ARED) was developed for use on the International Space Station as a countermeasure against muscle atrophy and decreased strength. This investigation examined the reliability of one-repetition maximum (1RM) strength testing using ARED and traditional free weight (FW) exercise. Methods: Six males (180.8 +/- 4.3 cm, 83.6 +/- 6.4 kg, 36 +/- 8 y, mean +/- SD) who had not engaged in resistive exercise for at least six months volunteered to participate in this project. Subjects completed four 1RM testing sessions each for FW and ARED (eight total sessions) using a balanced, randomized, crossover design. All testing using one device was completed before progressing to the other. During each session, 1RM was measured for the squat, heel raise, and deadlift exercises. Generalizability (G) and intraclass correlation coefficients (ICC) were calculated for each exercise on each device and were used to predict the number of sessions needed to obtain a reliable 1RM measurement (G . 0.90). Interclass reliability coefficients and Pearson's correlation coefficients (R) also were calculated for the highest 1RM value (1RM9sub peak)) obtained for each exercise on each device to quantify 1RM relationships between devices

Effects of Reduced Strength on Self-Selected Pacing for Long-Duration Activities

Strength and aerobic capacity are predictors of astronaut performance for extravehicular activities (EVA) during exploration missions. It is expected that astronauts will selfselect a pace below their ventilatory threshold (VT). PURPOSE: To determine the percentage of VT that subjects selfselect for prolonged occupational tasks. METHODS: Maximal aerobic capacity and a variety of lowerbody strength and power variables were assessed in 17 subjects who climbed 480 rungs on a ladder ergometer and then completed 10 km on a treadmill as quickly as possible using a selfselected pace. The tasks were performed on 4 days, with a weighted suit providing 0% (suit fabric only), 40%, 60%, and 80% of additional bodyweight (BW), thereby altering the strength to BW ratio. Oxygen consumption and heart rate were continuously measured. Repeated measures ANOVA and posthoc comparisons were performed on the percent of VT values under each suited condition. RESULTS: Subjects consistently selfpaced at or below VT for both tasks and the pace was related to suit weight. At the midpoint for the ladder climb the 80% BW condition elicited the lowest metabolic cost (19+/-14% below VT), significantly different than the 0% BW (3+/-16%, P=0.002) and the 40% BW conditions (5+/-22%, P=0.023). The 60% BW condition (13+/-19%) was different than the 40% BW condition (P=0.034). Upon completion of the ladder task there were no differences among the conditions (0%BW: 3+/-18%; 40%BW: 3+/-21%; 60%BW: 8+/-25%; 80%BW: 10+/-18%). All subjects failed to complete 5km at 80%BW. At the midpoint of the treadmill test the three remaining conditions were all significantly different (0%BW: 20+/-15%; 40%BW: 33+/-15%; 60%BW: 41+/-19%). Upon completion of the treadmill test the 60% BW condition (38+/-12%) was significantly different than the 40% BW (28+/-15%, P=0.024). CONCLUSIONS: Decreasing relative strength results in progressive and disproportionate decreases (relative to VT) in selfselected pacing during longduration activities. Thus, during prolonged, endurancetype activities, large reductions in strength cause notable performance decrements despite no changes in aerobic capacity. These data highlight the importance of both aerobic capacity and muscle strength to the performance of prolonged EVA in exploration mission scenarios

Effects Of Community-Based Exercise Training Among Older Individuals With Metabolic Disease, Cardiovascular Disease, Or Muscle Atrophy

Exercise training is associated with increased health benefits such as improved quality of life, mental health, and physical functioning. PURPOSE: The purpose of this study is to quantify the effects of structured aerobic and resistance exercise training on body composition, functional tests, and quality of life in older individuals in a community-based facility. We hypothesized that at least moderate participation in the program would decrease fat mass, improve outcomes on grip and timed movement tests, and increase quality of life. METHODS: Twenty subjects who were members from a community-based institute participated in the study (7M:13F; 69.10 ± 6.40 yrs [mean ± sd]; 166.88 ± 10.52 cm; 76.40 ± 16.42 kg) and had metabolic or cardiovascular disease, or muscle atrophy. Subjects were expected to participate in 3, 30-min sessions/week for 8 weeks. The program was 30 min aerobic conditioning of intervals and 6–7 full-body resistance exercises and basic stretches. We measured height (cm), weight (kg), fat mass (kg), lean mass (kg), grip strength (kg), timed-up-go (TUG, s), 10-meter walk forwards (s), 10-meter walk backwards (a novel movement) (s), 6-minute walk tests (m), the Health-Related Quality of Life (CDC HRQOL-4) survey, and 36-Item Short-Form Health (SF-36), before and after the completion of exercise training. We performed paired t-tests on testing variables and the 8 subsections of the SF-36 and one-sample t-tests on the delta of questions on the HRQOL-4. Alpha \u3c0.05. RESULTS: There were no significant differences in any of the SF-36 subsections or testing variables (p \u3e 0.05) except for increased right-hand grip strength (2.02 ± 4.35 kg, p = 0.05) and decreased time in the backwards 10-meter walk (0.52 ± 0.88 s, p = 0.02). Concerning the HRQOL-4, no members had fair to poor self-rated health before or after the program, more members experienced fewer but non-significant physically unhealthy days (delta = -3.61 ± 8.67 days, p = 0.10), and a similar number of mentally unhealthy days and days when poor mental/physical health kept them from usual activities (p \u3e 0.05). CONCLUSION: These preliminary findings suggest that there may be clinically meaningful improvements in strength and novel movement in these older individuals after an 8-week prescribed and training program in the community setting. Different measurements of quality of life in this population should be explored

Reliability of Unilateral Isometric and Dynamic Leg Press Force and Power

Strength and power are critical components of athletic performance. Athletes commonly perform sport-specific movements off a single leg, but there are few reliable, easily administered unilateral leg force and power assessments. PURPOSE: To determine 1) the reliability of unilateral leg press maximal isometric force (MIF) and peak power tests and 2) the percentage of MIF that elicits unilateral peak power during a dynamic throw. We hypothesized that the tests would be reliable for the assessment of unilateral MIF and peak power and that unilateral peak power would be achieved at 50% of MIF. METHODS: Eighteen apparently healthy, recreationally active adults (17M: 1F; 27.4 ± 5.0 years; 1.78 ± 0.01 m; 93.5 ± 22.5 kg; 3159 ± 807 N bilateral MIF) completed three testing sessions. After a brief standardized warm-up, each subject performed three maximal unilateral isometric leg presses (MIF) with each leg at 90° of knee flexion on a modified leg press sled equipped with a force plate, linear encoder, and magnetic brake. Subsequently, the sled was unlocked and loaded in ascending fashion with 30%, 40%, 50%, 60%, and 70% of MIF; with an initial knee angle of 90°, subjects used maximal effort to throw each load twice, unilaterally, with each leg. Subjects rested and reset for 10-30 s between efforts. Data were sampled at 300 Hz, low pass filtered at 4 Hz, and peak instantaneous power (W) was calculated for each throw using the measured sled force and velocity. Intraclass correlation coefficients (ICC) were computed for the highest force and power repetition at each load across the three sessions. The ICC (95% CI) and peak power output were determined for both right and left legs. ICCs were considered excellent if ≥ 0.95, high if ≥ 0.90, good if ≥ 0.80, fair if ≥ 0.70, poor if ≤ 0.70, and very poor if ≤ 0.40. RESULTS: MIF showed good reliability between sessions [ICC: 0.85 (0.62, 0.94; left leg); 0.86 (0.58, 0.95; right leg)]. Unilateral peak power also showed good to high reliability between sessions across all loads: ICC (left leg) 30%: 0.91 (0.81, 0.96); 40%: 0.91 (0.81, 0.96); 50%: 0.95 (0.88, 0.98); 60%: 0.93 (0.86, 0.97); 70%: 0.81 (0.64, 0.92); (right leg) 30%: 0.95 (0.89, 0.98); 40%: 0.94 (0.87, 0.97); 50%: 0.92 (0.84, 0.97); 60%: 0.92 (0.84, 0.97); 70%: 0.90 (0.80, 0.96). Across all three sessions, peak power by the left leg was achieved at: 30% (11 of 18 participants); 40% (6 of 18); 50% (1 of 18). Peak power by the right leg was achieved at: 30% (13 of 18 participants); 40% (4 of 18); 50% (1 of 18). CONCLUSION: Unilateral leg press MIF and peak power can be reliably assessed with a modified leg press equipped with a force plate, linear encoder, and magnetic brake in a recreationally active population. Sport teams and coaches can use single leg isometric presses and throws as reliable methods to test their athletes’ unilateral force and peak power, respectively, with loads of 30-50% MIF appropriate for peak power measurement

The Interaction of HVEM-Generated Point-Defects With Dissociated Dislocations

This paper describes experiments we have performed to investigate the mechanisms of interaction of IIVEM-generated point-defects with dissociated dislocations in a series of austenitic Fe-Ni-Cr alloys and review earlier work in Cu-Al alloys and in Ag. In the Fe-Ni-Cr alloys interstitial climb was observed only at favorable sites such as pre-existing jogs, while vacancies clustered near dislocations to form stacking-fault tetrahedra. These observations are similar to those in Ag; the complex climb mechanisms seen in Cu-Al alloys were not found. The differences between materials is believed to be due to differences in the case of interstitial pipe diffusion. 28 refs., 9 figs

Direct Measurement of Perchlorate Exposure Biomarkers in a Highly Exposed Population: A Pilot Study

Exposure to perchlorate is ubiquitous in the United States and has been found to be widespread in food and drinking water. People living in the lower Colorado River region may have perchlorate exposure because of perchlorate in ground water and locally-grown produce. Relatively high doses of perchlorate can inhibit iodine uptake and impair thyroid function, and thus could impair neurological development in utero. We examined human exposures to perchlorate in the Imperial Valley among individuals consuming locally grown produce and compared perchlorate exposure doses to state and federal reference doses. We collected 24-hour urine specimen from a convenience sample of 31 individuals and measured urinary excretion rates of perchlorate, thiocyanate, nitrate, and iodide. In addition, drinking water and local produce were also sampled for perchlorate. All but two of the water samples tested negative for perchlorate. Perchlorate levels in 79 produce samples ranged from non-detect to 1816 ppb. Estimated perchlorate doses ranged from 0.02 to 0.51 µg/kg of body weight/day. Perchlorate dose increased with the number of servings of dairy products consumed and with estimated perchlorate levels in produce consumed. The geometric mean perchlorate dose was 70% higher than for the NHANES reference population. Our sample of 31 Imperial Valley residents had higher perchlorate dose levels compared with national reference ranges. Although none of our exposure estimates exceeded the U. S. EPA reference dose, three participants exceeded the acceptable daily dose as defined by bench mark dose methods used by the California Office of Environmental Health Hazard Assessment