Effects of Different Surfaces on Metabolic Cost During Repetitive Jumping: A Pilot Study

International Journal of Exercise Science 16(2): 866-874, 2023. The purpose of this pilot study was to determine if there is a difference in metabolic cost when jumping on platforms of varying thickness, as well as whether a difference exists in metabolic cost between genders exists on the different platforms. Fourteen participants (seven males and seven females) completed three repetitive jumping trials on the DigiJump machine. Each trial was performed at a cadence of 120 jumps per minute and at a minimum height of 1/2” per jump. Trials were completed on platforms of 1/2”, 3/8”, and 1/4” thickness. Participants were instructed to jump as long as possible while maintaining the prescribed cadence or until fifteen minutes had elapsed. There were no differences observed in metabolic cost or exertion for all participants or between genders as indicated by oxygen consumption, respiratory exchange ratio, upper leg RPE, or lower leg RPE. There were also no differences for durations of exercise the participants were able to sustain on the machine. However, when comparing data between genders, a significant interaction was observed in total body RPE across the three platforms (p = .009) and in HR on the 1/2” platform (p = .018). Results from this study indicate that metabolic cost is similar during repetitive jumping regardless of platform rigidity or gender. However, post-trial comments from participants did show preferences towards specific platforms, though this was not apparent in exercise duration

A VO2max Protocol for Young, Apparently Healthy Adults

International Journal of Exercise Science 16(4): 1257-1268, 2023. The Bruce and Astrand treadmill protocols are commonly utilized when assessing maximal oxygen consumption (VO2max). However, the steep grade implemented in the protocols often leads to localized muscular fatigue, potentially causing participants prematurely to terminate the test prior to reaching their true VO2max. The purpose of this study was to evaluate a Novel VO2max protocol that may be better suited for young, apparently healthy populations. The Novel protocol starts at a higher speed and lower initial grade to limit lower extremity fatigue. Fifteen participants performed the Bruce, Astrand, and Novel protocols with the following maximal values recorded from each: VO2max, maximal ventilation (VEmax), respiratory exchange ratio (RER), heart rate (HR), rating of perceived exertion (RPE) and time to exhaustion (TTE). The Novel protocol displayed substantial agreement with both criterion protocols. Mean absolute percent error (MAPE) was less than 10% indicating that the Novel protocol is a valid measurement for VO2max values. Bland-Altman analysis revealed that the Novel protocol exhibited a low degree of bias, with tight limits of agreement when compared to the Bruce (bias ±95% LOA = 0.824 ± 3.163) and Astrand protocols (-0.153 ± 3.528) for VO2max. A paired samples t-test revealed no significant differences between Novel and criterion protocols for VO2max. Paired samples t-tests revealed that the Novel protocol had significantly lower TTE when compared to the Bruce and Astrand protocols and produced similar VO2max values to that of the Bruce and Astrand. The Novel protocol may be considered a valid and time-efficient protocol

A Pilot Study on Cannabidiol (CBD) and Eccentric Exercise: Impact on Inflammation, Performance, and Pain

International Journal of Exercise Science 16(2): 109-117, 2023. Cannabidiol (CBD) is a non-psychoactive cannabinoid purported to reduce symptoms of discomfort. Individuals are now using CBD to treat symptoms of multiple sclerosis, seizures, and chronic pain. Animal models indicate that CBD may be effective at reducing inflammation post fatiguing exercise. However, little evidence is available to evaluate these findings in humans. Therefore, the purpose of this investigation was to evaluate the impact of two doses of CBD oil on inflammation (IL-6), performance, and pain after an eccentric loading protocol. Participants (n = 4) participated in three conditions (placebo, low dose, and high dose), in this randomized, counterbalanced design. Each condition took 72 hours to complete, with a 1-week washout period between conditions. At the beginning of each week, participants were subjected to a loading protocol of six sets of ten eccentric only repetitions in the single-arm bicep curl. Participants consumed capsules of either a placebo, low dose (2mg/kg) or high dose (10mg/kg) of CBD oil immediately following the session and continued every twelve hours for 48 hours. Venipunctures were taken before exercise and repeated at 24, 48, and 72 hours post exercise. Blood samples were centrifuged for 15 minutes in gel and lithium heparin vacutainers. Plasma was separated from cells and stored at -80° until analysis. Samples were analyzed using an immunometric assay for IL-6 (ELISA). Data were analyzed using a three (condition) by four (time) repeated measure ANOVA. There were no differences in inflammation between conditions (F(2,6) = 0.726, p = 0.522, np2 = 0.195) or across time (F(3,9) = 0.752, p = 0.548, np2 = 0.200), handgrip strength between conditions (F(2,6) = 0.542, p = 0.607, np2 = .153) or across time (F(3,9) = 2.235, p = .153, np2 = .427), or bicep curl strength between conditions (F(2,6) = 0.675, p = 0.554, np2 = .184) or across time (F(3,9) = 3.513, p = .150, np2 = .539). There were no differences in pain between conditions (F(2,6) = 0.495, p = 0.633, np2 = .142), but there was a difference across time (F(3,9) = 7.028, p = .010, np2 = .701). There were no significant interactions to note. Although there was no statistical significance between conditions (likely due to the low sample size), there was a visible increase in IL-6 48 (4.88 ± 6.53) and 72 hours (3.12 ± 4.26) post exercise in the placebo condition which was not observed in the low (48: 0.35 ± 2.22; 72: 1.34 ± 5.6) and high dose condition (48: 1.34 ± 1.34; 72: -0.79 ± 5.34). Future investigations should consider implementing eccentric resistance training across a larger portion of the body to improve ecological validity of the exercise. A larger sample would reduce risk of researchers committing a type II statistical error and give strength to detecting differences between conditions

More than Body Composition: A Darwinian Theory of Somatotype, Applied to a DII Track and Field Outdoor Season

International Journal of Exercise Science 17(4): 1-12, 2024. This study presents somatotype data on a team sport with chronic and diverse sporting demands. The aims were to (1) characterize a somatotype profile for Division II (DII) track and field athletes (n=54) by sex, class, and events; (2) determine if somatotype changed across the season; (3) determine if changes differed based on class or sex; and, (4) assess potential differences in somatotype between sexes. Methods: Anthropometrics (height, weight, body composition, somatotype) were evaluated after a competitive indoor season and immediately before the outdoor conference championships (41 days). Body measurements were assessed using a bioelectrical impedance analysis device, skinfold assessment, boney breadths, and limb girths. Descriptive statistics are provided as well as results from two-way ANOVAs which evaluate differences in actual and change scores across sex and class. Results: Our DII track and field athletes were primarily endomorphic (scores displayed as ENDO, MESO, ECTO, respectively). Males were found to be primarily ENDO-MESO somatotypes (4.7, 4.1, 3.0), while females were dominantly ENDO (7.7, 2.9, 2.9). Upperclass were more ENDO-MESO balanced compared with lowerclass (5.8, 3.8, 2.8 vs 6.0, 3.5, 3.0). When investigated based on sex, class level, and event, the groups were similar. There was no meaningful change to ECTO scores across the season for males or females. Female athletes improved ENDO scores (-0.89%) and males and females improved MESO scores (14.29% and 5.29%, respectively), indicating adaptations can be accomplished despite the chronic demands of a competitive season. Conclusion: Our research offers practitioners information about the potential changes they may expect across a competitive track and field season

Effects of Heat Exposure on Body Water Assessed using Single-Frequency Bioelectrical Impedance Analysis and Bioimpedance Spectroscopy

International Journal of Exercise Science 10(7): 1085-1093, 2017. The purpose of this study was to determine if heat exposure alters the measures of total body water (TBW), extracellular water (ECW), and intracellular water (ICW) in both single-frequency bioelectrical impedance analysis (BIA) and bioimpedance spectroscopy (BIS). Additionally, we sought to determine if any differences exist between the BIA and BIS techniques before and after brief exposure to heat. Body water was evaluated for twenty men (age=24±4 years) in a thermoneutral environment (22°C) before (PRE) and immediately after (POST) 15 min of passive heating (35°C) in an environmental chamber. The mean difference and 95% limits of agreement at PRE demonstrated that BIS yielded significantly higher body water values than BIA (all p0.05; 0.2±1.5kg). Additionally, the ES of the mean differences at POST were trivial to small and the r-values were high (r≥0.96). When analyzing the changes in body water before and after heat exposure, POST values for BIS were significantly higher than PRE (all

COVID-19 atypical Parsonage-Turner syndrome: a case report

Background Neurological manifestations of Sars-CoV-2 infection have been described since March 2020 and include both central and peripheral nervous system manifestations. Neurological symptoms, such as headache or persistent loss of smell and taste, have also been documented in COVID-19 long-haulers. Moreover, long lasting fatigue, mild cognitive impairment and sleep disorders appear to be frequent long term neurological manifestations after hospitalization due to COVID-19. Less is known in relation to peripheral nerve injury related to Sars-CoV-2 infection. Case presentation We report the case of a 47-year-old female presenting with a unilateral chest pain radiating to the left arm lasting for more than two months after recovery from Sars-CoV-2 infection. After referral to our post-acute outpatient service for COVID-19 long haulers, she was diagnosed with a unilateral, atypical, pure sensory brachial plexus neuritis potentially related to COVID-19, which occurred during the acute phase of a mild Sars-CoV-2 infection and persisted for months after resolution of the infection. Conclusions We presented a case of atypical Parsonage-Turner syndrome potentially triggered by Sars-CoV-2 infection, with symptoms and repercussion lasting after viral clearance. A direct involvement of the virus remains uncertain, and the physiopathology is unclear. The treatment of COVID-19 and its long-term consequences represents a relatively new challenge for clinicians and health care providers. A multidisciplinary approach to following-up COVID-19 survivors is strongly advised

THE EFFECT OF DISC GOLF ON PHYSICAL AND PSYCHOLOGICAL WELL-BEING

BACKGROUND: In the past five years, disc golf has grown exponentially in its media attention and popularity. Disc golf is like traditional golf in that it involves periods of walking interspersed by brief periods where an object is being advanced towards a goal. These brief, goal-oriented moments can be thought of as distractions towards exercise. Enjoyable distractions from exercise can further enhance the already positive influence exercise has on mood. It may be that the distraction that throwing a disc provides may enhance the psychological benefits over non-distracting exercise and, thus, increase the likelihood for continuing the behavior. The purpose of the proposed study will be to assess the psychological and physical health benefits of disc golf and compare those to a more traditional form of physical activity. METHODS: We will recruit college-aged individuals with and without prior disc golf experience. The study will consist of 2 conditions (disc golf and walking) taking place over consecutive weeks. Each condition will take place across the same days of the week to attempt to control for differences in step counts across different days of the week. Conditions will last 3 days with days 1 and 3 being purely observational with experimental manipulation occurring on day 2. Day 2 for the disc golf condition will consist of 9 holes of disc golf and day 2 for the walking conditioning will consist of a matched amount of PA (steps) recorded during the disc golf condition. Physical activity (steps) will be measured all 3 days of each condition via a triaxial accelerometer along with positive and negative affect using the Positive and Negative Affect Schedule (PANAS). Additionally, session RPE and outdoor physical activity enjoyment and will be queried using the Physical Activity Enjoyment Scale (PACES) 15 minutes following the cessation of exercise. Heart rate will be collected continuously and averaged to compare internal loads between conditions. ANTICIPATED RESULTS: It is hypothesized that PA levels in both conditions to be similar across all days, with disc golf having better PACES and PANAS scores when compared to the walking condition

The Predictability of Peak Oxygen Consumption Using Submaximal Ratings of Perceived Exertion in Adolescents

International Journal of Exercise Science 11(4): 1173-1183, 2018. Rating of perceived exertion (RPE) extrapolation involves mathematically extending the submaximal relationship between RPE and oxygen consumption (VO2) to maximal intensity. This technique allows practitioners to forego, potentially dangerous, maximal exertion testing while attaining accurate measures of maximal oxygen consumption used for exercise prescription. This method has been proven accurate in adults, but much less in known when applied to an adolescent population. The purpose of this study was to assess the accuracy of the RPE extrapolation as method for estimating VO2max in adolescents. Twenty-two healthy, asymptomatic adolescents performed a graded exercise test (GXT) to exhaustion. Heart rate and VO2 were recorded throughout the bout with RPE being queried every two minutes using the Borg (6-20) RPE scale. Individual regression lines were fitted for each subject using RPE and VO2 for RPE values up to 13,15, and 17. Theoretical maximal RPE values of 20 and 19 were entered into the equation to calculate an estimated VO2max. Repeated measures ANOVA with planned contrasts showed that all VO2max estimation methods significantly overpredicted measured VO2max (p \u3c .001). Error analysis via Bland-Altman plots revealed large limits of agreement between the all methods, indicating large variability in error between estimated and measured VO2max. The results suggest that submaximal RPE values using the Borg scale cannot be used to predict VO2max in children due to the amount of error in the prediction equations. These inaccuracies could lead to potential under or over-prescription of exercise intensity and adverse effects on the person’s health

Comparison of Electromyographical Signal Analyses for Estimating Lactate Threshold

Background: Currently, no published literature exists comparing the most appropriate and efficient filtering methods of electromyographical (EMG) analyses to estimate the workload at which lactate threshold (LT) occurs. Purpose: The purpose of this investigation was to evaluate and compare EMG transformations and time windows to predict LT. Methods: Participants (n=14) completed a maximal exercise test on a cycle ergometer until exhaustion. Blood lactate was measured every minute, while EMG was recorded continuously at the vastus lateralis. EMG signaling was then transformed and filtered using two time-segment windows (i.e., 10 and 60 seconds), as well as three signal conversions (i.e., root mean square, smoothing, and peak amplitude averaging). Results: Results indicated no mean differences between the EMG thresholds, for any of the filtering methods or time-segment windows, when compared to the LT criterion. Moderate correlations were seen when comparing the lactate and EMG time-curves ranging from 0.69 – 0.79. Conclusions: EMG may be a useful tool to estimate the work rate associated with LT. Averaging EMG over a minute of time and continual 10-second recordings demonstrate comparable readings and allow an easier application of EMG threshold in the field

Reliability of Lactate Threshold Following a Fatiguing Bout of Exercise

Background: Assessment and monitoring of lactate threshold (LT) are important factors to monitor to prioritize which metabolic system is being stressed. LT training is a popular form of training due to its ability improve anaerobic performance. Furthermore, training below this intensity can be extremely advantageous for producing adaptations to aid in aerobic performance. However, accumulation of fatigue has been shown to precipitate changes to muscle recruitment strategies and metabolic pathways. These changes could then lower the intensity at which lactate begins to accumulate. The purpose of this study was to evaluate the reliability of LT threshold following a bout of exhaustive exercise. Methods: Eleven healthy, asymptomatic adults completed two graded exercises tests (GXT) interspersed with a 30-min fatiguing cycling session. The GXT started at 80 watts followed by increases of 40 W every three minutes at a cadence of 80 rpm. The GXT was ended upon volitional exhaustion or if cadence dropped below 75 rpm. Oxygen consumption was recorded throughout the GXT trials, while lactate was recorded every minute. The thirty minute fatiguing trial was completed at one stage above LT. Raw lactate values from the GXT tests were then input into a Dmax calculator in order to obtain threshold values and the corresponding stages in which they occurred. Results: A paired samples T-test found revealed significant differences in baseline lactate values from when comparing the pre-fatigue trial (1.55 ± 0.49 mmol.L-1) to the post fatigue trial (3.44 ± 2.04 mmol.L-1; p = 0.09, Cohen’s d = 1.27). No significant mean differences were seen in lactate values threshold during the pre-fatigue trial (3.56 ± 0.84 mmol.L-1) versus the post fatigue trial (3.50 ± 1.99 mmol.L-1). However, when expressed as a wattage, LT occurred at a significantly higher wattage in the pre-fatigue trial than the post fatigue trial (128 vs. 104 watts; p = 0.03). Half of the participants reached LT during the same stage of the GXT, while four participants had an LT that occurred one stage lower in the post fatigue trial than the pre-fatigue trial. When expressed as %VO2peak, there were no significant mean differences between pre-fatigue LT compared to post fatigue LT (p = 0.19; Cohen’s d = 0.75). LT with poor reliability (ICC = -0.36; 95% CI = -3.32 to 0.637; p = 0.69). Furthermore, there were no significant mean differences in LT when data was expressed as %HRmax (p = 0.74, Cohen’s d = 0.17). Conclusions: A fatiguing bout of exercise does not mediate LT when examining blood lactate levels, or when LT is represented as a percentage of maximal heart rate and peak oxygen consumption. However, it appears that the power output needed to achieve LT is significantly lower after fatigue has set in. Practical Application: Lactate threshold is an important metric for prescribing exercise intensity for optimal athletic performance. Practitioners need to confirm that the athlete is adequately recovered before measuring LT to ensure an accuracy of the work output measure. Furthermore, LT training should be prescribed as a %HRmax or %VO2peak rather than a raw power to help control for the effect of fatigue on the measure