Determination of the physiological responses of female fire fighters while working in the heat

This study determined the physiological responses of female fire fighters to two similar bouts of work in the heat. Peak heart rates (HR), peak oxygen consumption (VO2), peak rectal temperatures (Trec), peak mean skin temperature (MST), and ratings of perceived exertion (RPE) were compared between two work bouts which were separated by a standard recovery period. Seven female fire fighters walked for twenty minutes in complete fire fighting ensembles at 50% of their VO2max in a 40°C environment. After the first work bout (WB1), subjects removed their protective clothing, rehydrated and rested in front of a fan until their Trec returned to baseline levels. Then, they completed a second work bout (WB 2) similar to WB1. The differences in Trec and HR between WB1 and WB2 were significantly higher during WB2. Although Trec was higher in WB2 , the difference was small (0.38°C); the difference in HR was twelve beats per minute

Maximal Running Speed and Critical Speed Are Positively Related to Phase Angle in Healthy Young Adults

International Journal of Exercise Science 17(4): 405-417, 2024. Phase Angle (PhA), derived from bioelectrical impedance analysis, is a measurement of cellular resistance to electrical current and a non-invasive tool to monitor neuromuscular performance. The relationship between PhA and components of athletic performance is not fully understood. The purpose of this study was to determine if maximal running speed, critical speed (CS), and/or D prime (D’) derived from a 3-minute all-out-test (3MAOT) correlates to PhA, reactance (Xc), or resistance (R). Sixty-one (male n=35, female n=26) healthy young adults (23.4±3.9 years) completed bioelectrical impedance analysis (Inbody770) and a 3MAOT. The correlations between PhA, Xc, and R and 3MAOT results were evaluated using correlations. Simple and multiple linear-regressions were used to test if results from the 3MAOT (maximum running speed, CS, D’) could predict PhA. Linear regression analysis indicated that maximum running speed and CS alone explained 32% and 9% of the variance in PhA, respectively (R2=0.32, p\u3c0.05; R2=0.09, p\u3c0.05). Multiple linear regression indicated that maximum running speed, CS, and D’ explained 35% of the variance in PhA (R2=0.35; p\u3c0.05). Only maximum running speed remained a significant predictor of PhA after controlling for age (β=0.45; p\u3c0.05), but not after controlling for both age and sex (β=0.14; p\u3e0.05). Since maximum running speed was a stronger predictor of PhA compared to CS (proxy for endurance performance), practitioners should use discernment when using PhA as a readiness tool to monitor endurance performance

Standardized Total Fitness Scores and Phase Angle in Cancer Survivors

Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 20, 2023. Cancer treatment can lead to decrement in all components of fitness. Exercise can attenuate these effects and build fitness. Exercise program design for this population continues to evolve with high-intensity interval training at the forefront. Phase angle (PhA) is an indirect measure of cellular health and function and is associated with fitness, health, and reduced disease severity. Continued exploration spurs an emerging question: What type of training should be used to maximize improvements in PhA? We provide a visualization of a cancer rehabilitation fitness profile and present the relationship between standardized fitness scores and PhA

The Effects of Different Training Types on Phase Angle in Men - An Exploratory Study

Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 12, 2023. Phase Angle (PhA) has emerged as a valuable measure in clinical and sports settings due to its predictive relationship with health and sports performance. Fitness is related to PhA, but the type of exercise training that is most influential over PhA has yet to be determined. The purpose was to explore the effects of endurance training (ET), strength-based resistance training (RT), and sprint-interval training (SIT) on PhA, resistance (R), and reactance (Xc) in men. Thirty-five recreationally-trained healthy young adult males (24±4 years) were randomly assigned to one of three training groups or a control group. All interventions were performed 3 times/week, for 4 weeks, with 48 hours between sessions. Training sessions for ET, RT, and SIT included 30 minutes of moderate-intensity (85% critical speed) treadmill running, 4 sets of 5 repetitions of the barbell back squat at 85% 1 repetition-maximum (1RM), or 4 sets of repeated inclined treadmill sprints designed to induce fatigue in 30-60 seconds, respectively. Baseline and post-intervention tests were performed using bioelectrical impedance analysis, the 3-minute all-out exercise test, and the back squat 1RM. ET significantly increased critical speed (Δ=5.16%; p\u3c0.005), but subjects in this group exhibited lower PhA and Xc values. These changes were not significant (PhA: Cohen’s d=-0.44; Δ=-3.01%, p\u3e0.005; Xc: Cohen’s d=-0.48; Δ=-4.82%, p\u3e0.005). RT significantly increased muscular strength (Δ=12.92%; p\u3c0.005) and this coincided with a trend for increased PhA and Xc values, but this was not significant (PhA: Cohen’s d=0.44, Δ=2.55%, p\u3e0.005; Xc: Cohen’s d=0.20, Δ=3.52%, p\u3e0.005). Exploratory data from this study showed that ET tended to decrease PhA and Xc, whereas RT tended to positively affect PhA and Xc in healthy young adult males. Future research should examine to see if these trends remain true because it has the potential to impact the way we optimize exercise prescriptions

Monitoring Readiness Using the Hooper Index in American Football Players: Defining Flagging Thresholds

Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 18, 2023. The purpose of this article is to illustrate how the Hooper Index, which to our knowledge has not been utilized in American Football, can notify the practitioner when to modify training or apply recovery interventions throughout the season

Adding Context to Monitoring Neuromuscular Status in High-Performance Sport

Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 19, 2023. Utilizing performance tests alone without the contextualization of other information may mislead practitioners in the decision-making process. Thus, the purpose of this Topic Brief is to provide practitioners a decision tree and systematic triangulation approach for adding context to assessing neuromuscular status, which provides a clear picture of how to prepare an athlete for competition

Exercise Based Cancer Rehabilitation Program Improves Phase Angle in Breast Cancer Survivors

International Journal of Exercise Science 15(3): 1444-1456, 2022. Phase angle (PhA) is an index of cell membrane integrity and prognostic indicator of survival and quality of life in cancer survivors. The efficacy of exercise-based cancer rehabilitation programs (ExCR) on PhA is unknown. To assess the effect of ExCR on PhA in breast cancer survivors. Fifty-nine female breast cancer survivors (61 ± 9 years) were referred to the ExCR by their oncologist and participated in one-on-one exercise-based training for 90 minutes, 3 times a week, for 12 weeks. Training sessions included 45 minutes of resistance training at intensities between 40-85% of 1-repetition maximum with a rate of perceived exertion (RPE) between 3-8, 30 minutes of cardiorespiratory training at intensities between 40-85% of heart rate reserve with an RPE between 3-8, and 15 minutes of flexibility training. Participants completed pre- and post-measurements of body composition, cardiorespiratory endurance, flexibility, muscular endurance, muscular strength, and PhA (Inbody 770). PhA significantly increased (p \u3c 0.05) after ExCR (PhApre = 4.56; PhApost = 4.64; Δ = 1.8%). Changes in measures of muscular strength have a weak but significant positive relationship (r = 0.20-0.39; p \u3c 0.05) with changes in PhA. There was no relationship between changes in PhA and changes in cardiorespiratory endurance or muscular endurance. A 12-week ExCR significantly improves PhA in breast cancer survivors. Training muscular strength may be an integral component of ExCR with the objective of improving PhA

Muscular Strength Predicts Phase Angle in Breast Cancer Survivors

Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 4, 2023. Phase angle (PhA) has emerged as a prognostic indicator of survival and quality of life (QOL) in cancer patients. Identifying measures of physical fitness that correlate with PhA can provide guidance toward optimizing cancer rehabilitation programs and future research. The purpose was to examine the relationship between PhA and physical fitness in breast cancer survivors. Sixty-three breast cancer survivors (60 ± 9 years, PhA 4.59±0.52, mean±SD) completed assessments for muscular strength, muscular endurance, cardiorespiratory endurance, flexibility, and body composition. PhA and body composition were measured using bioimpedance analysis (Inbody 770) at 50 KHz. The correlations between phase angle and measures of fitness were evaluated using Pearson coefficients. Simple and multiple linear regression was used to test if measures of muscular strength, muscular endurance, and cardiorespiratory endurance predict PhA. Linear regression analysis showed that incline bench press 1-RM alone explains 28% (r2 = 0.28; P2peak explain 32% (r2 =0.32; PThe prioritization of muscular strength for improving PhA in exercise-based cancer rehabilitation programs may be of importance

Stance Time and Impact Loading Rates are Significant Predictors of Critical Speed During a 3-Minute All-Out Running Test

International Journal of Exercise Science 17(4): 115-128, 2024. The addition of wearable technology during a 3-minute all-out overground running test (3MAOT) could provide additional insights to guide training and coaching strategies. The purpose of this study was to explore the relationships between critical speed (CS) and biomechanical parameters (cadence, stride length, vertical oscillation, stance time, form power, leg spring stiffness, and impact loading rate), and changes in biomechanical parameters throughout the 3MAOT. Sixty-three (male, n=37, female, n=26) recreationally active college-aged (23.4±3.9 years) subjects completed a 3MAOT while wearing a Stryd foot-pod. The correlations between CS and biomechanical parameters were evaluated using Pearson coefficients. Stepwise multiple linear regressions were used to test if biomechanical parameters could predict CS. Stance time and impact loading rate explained 69% and 63% of the variance in CS, respectively (R2=0.69, p\u3c0.05; R2=0.63, p\u3c0.05). Step-wise multiple linear regression analysis indicated that vertical oscillation, stance time, form power, leg spring stiffness, and impact loading rate explained 90% of the variance in CS (R2=0.90, p\u3c0.05). Throughout the 3MAOT, changes in cadence (-29%), stride length (57%), vertical oscillation (-8%), stance time (82%), form power (-5%), leg spring stiffness (-24%), and impact loading rate (-48%) were observed. Interventions such as auditory cueing or training designed to improve CS should focus on maintaining large impact loading rates and short stance times, and efforts should be made to enhance an athlete\u27s ability to maintain cadence, leg spring stiffness, vertical oscillation, and form power throughout the 3MAOT

Preliminary Findings from a Pediatric Physical Activity Program for Children with Cancer

It is critical for pediatric patients diagnosed with cancer to engage in physical activity (PA) as it is associated with positive psychosocial outcomes and may improve physical function. However, physical activity opportunities for pediatric cancer patients are limited. PURPOSE: To test the feasibility and adherence of pediatric cancer patients to a virtual PA program. METHODS: Pediatric patients undergoing cancer treatment were referred to the Pediatric Physical Activity program (PePA) by the Children’s Hospital’s oncology team using rolling recruitment. The target sample size was 20-25 patients. Patients enrolled in an online 12-week PA intervention with similar-aged peers (2x/week, 60 min/session). Patients completed surveys which shared their hobbies and interests. They were given PA equipment (i.e., yoga ball, mat). Trained undergraduate Kinesiology students designed and delivered the PA lessons which included yoga, dancing, calisthenics and Pilates. PA duration (visual inspection of recorded sessions, system for observing fitness instruction time, SOFIT), intensity (wrist-based heart rate monitors) and focus group data were used to assess program feasibility. RESULTS: Nine patients enrolled in the study (5, 5-7 years-olds; 4, 13-16 year-olds). One patient from each group completed 95% and 79% of the 24 sessions, respectively. These 2 patients reported improved balance and enjoyment of the program. PA leaders led the 5-7-year-old and 13-16-year-old groups through 27.6±4.9 and 33.0±9.4 minutes of PA, respectively. Average PA intensity was 26±6% heart rate reserve (HRR) and varied based upon activity. Patients rated their perceived exertion (RPE) of the PA as 2-7 on a scale of 1-10. During the session, children aged 5-7 years and 13-16 years engaged in 14.6±9.1 and 27.2±14.4 minutes of fitness, respectively (SOFIT coding). Three-fourths through the program, the duration for the 5-7 year olds was reduced to 45 minutes to match energy levels. Patients and parent-proxies of the younger children reported that they liked the session duration and type of PA performed. CONCLUSION: PA intensity fell at the lower end of the recommended 30-45% HRR range for adult patients undergoing cancer treatment. Program adherence was difficult to achieve, but those who completed the program reported physical benefit