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This study investigated how a time-restricted intermittent fasting for 6 weeks influences overweight and obese young adults. Twentyfive (n = 25) individuals between the ages of 18 and 29 were recruited through university banners and were randomly assigned to 2 Groups: Group A and Group B. Each Group fasted for 16 hours. Group A fasted from 8 p.m. to 12 p.m. and Group B fasted from 4 p.m. to 8 a.m. The following baseline measurements were determined before starting the trials: Body anthropometric measurements including body mass (BM, kg), body mass index (BMI, kg·m-2), waist circumference (cm), hip circumference (cm), waist to hip ratio, body fat percentage (%), and resting metabolic rate (mL·kg-1·min-1). Each subject was tested at baseline, at 2 weeks, at 4 weeks, and at 6 weeks (post-test) Statistical analysis included demographic mean (± standard deviation), an independent samples t-test for between Group differences at each measurement term, and a dependent samples t-test for within Group differences between measurement terms. Statistical significance was set at a P = 0.05. After 6 weeks, between Group differences were not statistically different while within Group comparisons indicated a decrease in weight (P = 0.002), BMI (P = 0.0006), waist circumference (P = 0.02), and hip circumference (P = 0.018). [ABSTRACT FROM AUTHOR]

The purpose was to compare a mathematical model of oxygen uptake and bioenergetic systems to an experimental protocol. Twelve (N = 12) noncyclists (NC), age (21.8 [+ or -] 1.4 years), and 8 (N = 8) cyclists (C), age (30.5 [+ or -] 5.7 years), were subjects. All subjects signed an informed consent. Oxygen consumption ([[??]o.sub.2], ml x [kg.sup.-1] x [min.sup.-1]) was measured with steady-state [[??]o.sub.2] requirements and responses determined using the mathematical model from the following equation: [[??]o.sub.2] (WR) = [[??]o.sub.2] (rest) + [[??]o.sub.2] (unloading pedaling) + [alpha]. WR; [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII]. Exercise means (SD) included the following: [[??]o.sub.2]NC(WR)=48.4 (16.6)[ml.sup.-1]. [min.sup.-1] for NCs and [[??]o.sub.2]C(WR)=56.4(24.95) [ml.sup.-1] x [min.sup.-1] for Cs; [DELTA][[??]o.sub.2]NC(t, WR)=6.38 [ml.sup.-1] x [min.sup.-1] for NCs and [DELTA][[??]o.sub.2]C(t, WR)=7.44 [ml.sup.-1] x [min.sup.-1] for Cs. The correlation between the mathematical model and actual measure was statistically significant (p < 0.01) with a coefficient of r = 0.947. The experimental protocol was significantly associated with the mathematical model. This allows for a quantitative analysis and safe prediction of steady-state oxygen uptake conditions on populations before exposure to exercising conditions. Through more precise analysis of conditions, greater specificity of training may lead to more predictable adaptation outcomes. KEY WORDS bioenergetic systems, prediction equation, oxygen capacity

Gregg, JS, Wyatt, FB, and Kilgore, JL. Determination of ventilatory threshold through quadratic regression analysis. J Strength Cond Res 24(9): 2512-2515, 2010--Ventilatory threshold ([V.sub.T]) has been used to measure physiological occurrences in athletes through models via gas analysis with limited accuracy. The purpose of this study is to establish a mathematical model to more accurately detect the ventilatory threshold using the ventilatory equivalent of carbon dioxide ([V.sub.E]/[??]C[O.sub.2]) and the ventilatory equivalent of oxygen ([V.sub.E]/[??][O.sub.2]). The methodology is primarily a mathematical analysis of data. The raw data used were archived from the cardiorespiratory laboratory in the Department of Kinesiology at Midwestern State University. Procedures for archived data collection included breath-by-breath gas analysis averaged every 20 seconds (ParVoMedics[TM], TrueMax 2400). A ramp protocol on a Velotron[TM] bicycle ergometer was used with increased work at 25 W x [min.sup.1] beginning with 150 W, until volitional fatigue. The subjects consisted of 27 healthy, trained cyclists with age ranging from 18 to 50 years. All subjects signed a university approved informed consent before testing. Graphic scatterplots and statistical regression analyses were performed to establish the crossover and subsequent dissociation of [[??].sub.E]/[??][O.sub.2] to [[??].sub.E]/[??]c[o.sub.2], A polynomial trend line along the scatterplots for [[??].sub.E]/[??][o.sub.2] and VE/[??]C[O.sub.2] was used because of the high correlation coefficient, the coefficient of determination, and trend line. The equations derived from the scatterplots and trend lines were quadratic in nature because they have a polynomial degree of 2. A graphing calculator in conjunction with a spreadsheet was used to find the exact point of intersection of the 2 trend lines. After the quadratic regression analysis, the exact point of [[??].sub.E]/[??][O.sub.2] and [[??].sub.E]/[??]C[O.sub.2] crossover was established as the [V.sub.T]. This application will allow investigators to more accurately determine the VT in subsequent research. KEY WORDS metabolic, polynomial trend line, mathematical model

Cordyceps sinensis (Cs) and Rhodiola rosea (Rr) are herbs used in traditional Chinese medicine to treat a multitude of ailments as well as to enhance performance. The purpose of this research was to examine the effects of a formula containing Cs and Rr (Cs-Rr) on circulatory dynamics, specifically muscle tissue oxygen saturation (St[O.sub.2]), in male subjects during maximal exercise. This study followed a double blind, randomized, placebo-treatment, pre-post test design. Capsules were administered to 8 subjects who were randomly assigned to 1 of 2 groups. The treatment group received Cs-Rr, and the control group received a placebo. All subjects performed 2 exercise stress tests to volitional fatigue on a cycle load ergometer. There were no significant (p [less than or equal to] 0.05) differences in St[O.sub.2] slope, St[O.sub.2] threshold (St[O.sub.2T]), V[O.sub.2]max, ventilatory threshold ([V.sub.T]), or time to exhaustion ([T.sub.E]) between or within the treatment or control group. In conclusion, Cs-Rr did not significantly enhance St[O.sub.2]. KEY WORDS. herb, vasodilation, blood flow, oxygen delivery

This study determined the mechanisms of muscle glycogen depletion and replenishment. A systematic literature review and meta-analysis research design was used. Inclusion and exclusion criteria consisted of the following: Glycogen depletionreplenishment studies; subjects in studies had no pathologies; human and animal studies were accepted; studies with diet manipulation were accepted; articles accepted for coding were peer reviewed, original publications. Coded studies were summarized and statistically analyzed. Coded variables were presented as means and standard deviations (±SD). Muscle glycogen depletion and replenishment were analyzed with Cohen's d effect size (ES). Fourteen studies were coded allowing for a total sample size of N=149. Subject demographics were: age, 29.0 ± 2.9 yrs; height, 180.4 ± 5) cm; and weight, 74.7 ± 3.6 kg. Pre-Post depletion rate ES was 10.29, which was considered huge. Post replenishment rate ES was 4.39, which was considered large. High intensity work led to the greatest depletion rates. High carbohydrates, with high kcal per meal showed the greatest replenishment rates. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess heart rate variability, slope of heart rate response, and heart rate threshold between cycling groups of differing fitness status. Male and female cyclists (N=115) were placed into two groups, competitive and recreational cyclists. Each subject performed a maximal test to exhaustion on the cycle ergometer. During this time, oxygen consumption (VO2), carbon dioxide production (VCO2) in L·min-1 and mL·kg-1·min-1, and heart rate (beats·min-1) were determined. Based on maximal oxygen consumption (VO2 max), the competitive cyclists were placed in quartiles with 1 being the least fit and quartile 4 being the most fit. These quartiles were compared between groups, and to recreational cyclists considered "average fit". A trend line of best fit was assigned to each phase of heart rate response. Thresholds of noted heart rate change were determined for comparisons between the groups. Additionally, heart rate variation was determined through heart rate changes every 20 sec throughout the test. From the assessment of heart rate slope, variability and thresholds, differences were seen primarily between the fit quartiles and the recreational group. Threshold occurrences were similar across groups. Heart rates were higher at threshold with the low fit group as compared to lower threshold in the fit group. However, while heart rate slope was not different between quartiles, it was significantly steeper in the recreational group. In conclusion, in comparing groups within a very fit category and those within a fit, recreational classification, heart rate response measured through various means is notable. [ABSTRACT FROM AUTHOR]

Objective: We examined changes in youth cardiometabolic risk following a lifestyle intervention. Methods: Forty-five participants had indices of obesity, blood pressure (BP), and biomarkers assessed pre- and post-intervention. We assessed changes in outcome measures between groups across time. Results: Results from the ANCOVA indicated a statistically significant effect of the intervention on post-intervention HDL-C after controlling for baseline HDL-C, F(1, 24) = 4.98, p = .03, and there was a statistically significant effect of the intervention on post-intervention LDL-C after controlling for baseline LDL-C, F(1, 23) = 35.43, p < .001. Conclusions: Whereas this intervention resulted in improvements across multiple outcomes, no changes in BMI occurred. An intervention of longer duration may be necessary for improvement in a wider range of cardiometabolic markers. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the cardiovascular responses during sustained power output comparing low cadence (LC) high force (HF) vs. high cadence (HC) Low force (LF) cycle ergometry. Nine participants (N = 9) volunteered for this study. Participants signed a Human Participants consent form. A power output of 150 watts (W) for 20 minutes was estimated as the sustainable workload. Participants were instructed to pedal steadily at 50 rpm (LC) or 100 rpm (HC) with resistance adjusted to sustain 150 W. The following measures were obtained each minute during the 20-minute protocol: average heart rate (b*min.-1), blood pressure (mmHg) and Rate Pressure Product (i.e. RPP= (SBP * HR)*100-1). Randomization was used to counterbalance both protocols (HC vs. LC) and demographic controls (N=9). Means and standard deviations (SD) were determined for age (36 ± 13.64 years), resting heart rate (68.83 ± 11.95 b*min-1), resting blood pressure (126.42 ± 13.27 mmHg), body fat percentage (male: 14.7 ± 4.3 %; female 20.6 ± 1.3 %) and height (157.80 ± 10.04 cm). A Repeated Measures Analysis of Variance (RM-ANOVA) was utilized to compare exercising values between test protocols. A Pearson Product Correlation Coefficient was utilized to determine bivariate associations between variables. A Tukey Post Hoc analysis was performed to analyze differences in LC HR and RPP. Statistical significance was set a priori at p ⩽ 0.05. There were statistical differences among LC ±HR (130.51 ± 3.36), HC HR (150.83±6.49), LC RPP (204.63± 11.45), and HC RPP (245.57±25.70) Between the HC and LC protocols, the use of HC protocol elicited an increase in HR and RPP. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the physiological characteristics of competitive, collegiate female cyclists (CFC) to data of elite female cyclists (EFC) obtained from a meta-analytic review. Eleven (n=11) CFC volunteered as subjects. Subjects signed a university approved informed consent. Means and standard deviation (± SD) were obtained from the following measurements: age (y), 22.5 ± 5.1; height (cm) 167.22 ± 6.2; body mass (kg) 63.78 ± 9.71; body fat (%) 22.9 ± 3.6. Subjects performed a maximal cycling ergometer test to volitional fatigue. Maximal oxygen consumption (VO2 max, mL*kg-1*min.-1) was analyzed using a gas analyzer. VO2 max, maximal blood lactate (mM), maximal power (W), lactate threshold (mM), ventilatory threshold (VT, % of maximal) and heart rate threshold (HRT, % of maximal) were used to compare the performance of CFC to the data of EFC. An independent samples t-Test compared measures of the CFC vs. EFC. Alpha was set a priori at p ≤ 0.05. Results indicate comparisons between CFC vs. EFC, respectively: body fat %, 22.9 (3.6)* vs 15.2( 3.3); VO2 max (mL/kg/min), 58.07(6.94)* vs 52.5 (5.5); max power (W) 275.0( 42.5 ) vs 450.7( 256)* ;lactate threshold (mM) 3.74(0.79)* vs 2.8 ( 0.28); VT (%) 87.0( 4.1)* vs 73.2 ( 9.8) and HRT (% max) 93.1( 2.2)* vs 79.7. There were significant differences *(p ≤ 0.05) in the aforementioned measures. Results indicate differences between CFC vs. EFC. These differences were favorable in relation to performance with both CFC and EFC. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine if fit adolescent males and females indicate myocardial morphology changes outside normal values. Twenty-two young adults 15 to 18 yrs of age acted as subjects. Resting measures included: age (yrs), height (ht, cm), weight (wt, kg), systolic blood pressure (SBP, mmHg), diastolic blood pressure (DBP, mmHg), percentage body fat (%BF), body mass index (BMI, kg·m-2), waist circumference (WC, cm), waist/hip (W/H, ratio). A resting echocardiogram was used to determine the subjects' myocardial morphology, which included left ventricular mass (LVM, gm), left ventricular internal diameter end-diastolic (LVIDd, cm), left ventricular internal diameter end-systolic (LVIDs, cm), septal wall thickness (SWT, cm), and posterior wall thickness (PWT, cm). The subjects ran the Aerobic Fitness Shuttle Test and took the Physical Activity Questionnaire (PAQ). Statistical procedures included mean (±SD) for group measures. A Pearson Product R Correlation Coefficient determined bi-variate associations. Post hoc regression analyses established prediction equations between associated variables. The statistical significance was set at P=0.05. Left ventricular internal diameter end-diastolic significantly associated with ht, wt, WC, LVIDs, LVM, and PWT. Posterior wall thickness, LM, and ST showed significant predictive qualities to the Aerobic Shuttle Test through regression analyses. Linear regression analyses determined specific myocardial morphologies can be determined through weight and fitness status. These include LVIDd, PWT, SWT, and LVM. [ABSTRACT FROM AUTHOR]

Hypoxia has been defined as conditions with lower than normal oxygen availability. Altitude exposure and acclimatization have been areas of research for a considerable time. The immediate (acute) effects of lowered ambient pressure of oxygen (PO2) pertaining to the human response and the adaptations to prolonged exposure (chronic) are complex. Several systems (i.e., cardiovascular, pulmonary, and endocrine) react to the hypoxia associated with altitude exposure. Adding to the complexity, these systems rarely react in isolation but rather interact to allow the work of the individual to be accomplished in this type of environment. While generalities exist relating to acute and chronic adaptations (acclimatization) to altitude exposure, current evidence indicates individual responses may facilitate or hinder the acclimatization process. Responders and non-responders have been identified in the literature during attempts to understand the human response to a lowered partial pressure of oxygen. This review summarizes the affects of acute and chronic exposure to altitude as it relates to exercise and work output. Several sub-categories will be addressed. Included in these categories are the following: (a) acute and chronic exposure; (b) performance and length of events; (c) substrate utilization; and (d) various adaptations associated with various increasing altitudes. While much research has been conducted regarding living high/training low (LHTL) scenarios, this review will only discuss findings associated with acute and chronic exposure to altitude. Thus, the purpose of this brief review is to summarize two basic tenets of altitude and exercise: (a) acute exposure response; and (b) chronic adaptations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to establish mathematical regression trend lines for segmental changes in heart rate (HR) response to increased work in 10 male subjects with a mean (±SD) age of 29.6 ± 8.1 yrs. Pre-exercise testing included height (cm), weight (kg), age (yrs), percent body fat (%), and seated resting HR. The subjects were classified as fit given their mean (±SD) VO2 max of 70.3 ± 6.03 mL·kg-1·min-1. Each subject began the bicycle ergometer test by pedalling at 150 watts (w) of work at a pedal rate of 80 to 90 rev·min-1 for the first 5 min followed by an increase in work of 25 w·min-1 until volitional fatigue. The following measurements were taken during the test: expired ventilation (VE), oxygen consumption (VO2), carbon dioxide (VCO2), and HR. Statistical analysis included the descriptive mean (±SD) of subjects and group test results, and the mean (±SD) values across subjects for HR at each measure. Statistical significance was set at P⩽0.05. Segments of change for each phase were determined using logarithmic and linear regression analysis of group mean HR. Trend lines of best fit were used for each of the phases. Phase I indicates the withdrawal of the parasympathetic nervous system. Phase II indicates sympathetic influence, and Phase III indicates peripheral afferent signalling. Three phases accompany the subjects' HR response during the incremental bicycle ergometer test. Each phase indicates an established physiological response of the subjects' HR in a sequence of an initial rapid rise, a slower steady rise, and a final rise with a plateau from the onset of exercise to volitional fatigue. [ABSTRACT FROM AUTHOR]

The overtraining (OT) syndrome has been studied extensively with little agreement as to reliable markers for detection. The purpose of this meta-analysis was to provide summary quantitative findings of markers (e.g., blood, physiological, and psychological) associated with the OT syndrome. A meta-analytic research design was utilized to investigate selected studies allowing for a coding process to record data. Thirteen studies met the inclusion/exclusion criteria. Markers included samples taken with the subjects in the normal (N) condition and during the OT. The biomarkers consisted of glutamine (um), glutamate (um), cortisol (nmo·L-1), IL-6 (nm), testosterone (mg·dL-1), total cholesterol (mg·dL-1), glucose (mg·dL-1), leptin (ng·mL-1), hematocrit (%), hemoglobin (g·L-1), norepinephrine (pg·mL-1), epinephrine (pg·mL-1), and creatine kinase (u·L-1). Cardiovascular variables included resting heart rate (RHR, beats·min.-1), and resting diastolic and systolic blood pressure (DBP and SBP, mmHg). Psychological measures included tension, anger, fatigue, confusion, depression, vigor, sleep, stress, and self-perceptions of physical status. Selected variables (i.e., anger, depression, etc.) were noted in terms of direction (+, -) of change in the OT state compared to the N state. To determine magnitude of difference between N and OT, the effect size calculation of M2-M1/SD1 was used where M2 is the mean of the OT sample, M1 was the mean of the N sample and SD1 is the standard deviation of the N sample. Combined sample size (N) was 238 subjects with the mean time in OT of 6.6 wks. The following are mean (SD) of the combined subject demographics: height (cm) 175.4 (2.4); weight (kg) 71.7 (2.6); body fat (%) 11.8 (0.9); age (yrs) 23.5 (2.03); VO2 max (mL·kg-1·min-1) 55.4 (0.8). Mean (SD) biomarker changes from the N state to the OT state were glutamine -56.3 (-2); glutamate 49.7 (2); cortisol -89.7 (-12.2); IL 6 -0.52 (0.12); testosterone -88.9 (-30); cholesterol 4.6 (-1.6); glucose -13.3 (1.9); leptin 0.15 (-0.11); hematocrit -0.83 (-0.4); hemoglobin -20; norepinephrine 36 (-4.1); epinephrine -2.2 (-3.5); creatine kinase 29.2 (8.5). Effect size calculations for the above biomarkers were considered large for the following: glutamine (-4.02), glutamate (8), cortisol, (-1.4), IL 6 ( -5.2), glucose (-1.1). Mean (SD) cardiovascular changes and direction of change (+, -) were the following: RHR, -1.9 (-0.22); resting SBP, -2 (-2); resting DBP, 0 (1). Effect size calculations for the above measures were -0.95, -0.33 and 0, respectively. Three articles reported decreases in tension at OT, and one noted increases at MW. Fatigue increased at OT in 6 studies and showed n o change in a separate study. Confusion did not change in two studies, increased at OT in another, and increased at MW and, then, declined at OT in a final article. Vigor reportedly remained stable in two studies and decreased in two other studies. Anger did not change in 2 articles, decreased in another, and increased in a different study with its peak at MW. There was no change in depression in three studies, but a decrease was reported in a separate article at OT with an increase at MW. Studies reported impaired sleep patterns, increased wakefulness, and decrements and stability in sleep quality. Two studies indicated increased levels of stress with one specifying stress related to training, sleep, and health. Findings showed a decreased perception of strength, decreased perception of recovery, and no change in perception of muscle soreness. From this analysis, the noted biomarker changes and direction of change (+, -) indicates considerable immune-suppression and increased stress with athletes experiencing the OT syndrome. A negative effect size for HR and SBP indicates questionable alterations from N to OT in subjects. Increased sympathetic and/or decreased sympathetic influence may be affected in the OT state. However, low effect size calculations allow for non-determinant conclusions related to cardiovascular indicators of the OT syndrome. Lastly, athletes in the OT state are likely to experience disturbances in sleep, self-perception, and mood factors. [ABSTRACT FROM AUTHOR]

Physiological thresholds have been identified as disproportionate changes as work rate increases proportionately. Purpose: We sought to identify whether the accumulation of metabolites in exercising muscle was associated with the ventilation threshold (VT) and heart rate threshold (HRT). Methods: Twenty-four men and women aged 26.5 ± 0.8 years (y), height of 179.4 ± 1.6 (cm), weight of 78.1 ± 1.6 (kg) performed two incremental work rate cycle ergometer exercise tests to volitional fatigue. Test 1 was performed without venous occlusion cuffs (CON) and test 2 was performed with leg venous occlusion cuffs inflated to 90 mmHg (CUFF). The order of the CON and CUFF tests was randomly assigned to each subject. Breath-by-breath measures of ventilation (VMM), expired respiratory gases (MASSPEC) and beat-to-beat heart rate were collected on a dedicated PC using customized data acquisition software. The VT and HRT were identified using a logarithmic transformation of the breath-by-breath expired carbon dioxide and beat-to-beat heart rate records, respectively. Results: The V̇O2 of the VT and HRT were not significantly different during either control or cuff conditions. However, the application of venous occlusion cuffs significantly reduced the V̇O2 of the VT and HRT when compared to control data. Conclusion: These data suggest altered ventilatory and heart rate responses to venous blood leg occlusion, possibly through direct afferent signalling to the sympathetic nervous system. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the cardiopulmonary parameters in a cross section of fit, aging cyclists to determine the associations between age, heart rate and ventilation on exercise time to exhaustion. Subjects were twenty-seven (N=27) males age 21 to 74 yrs. Each subject performed a maximal test on a cycle ergometer to volitional fatigue. Cardiopulmonary measures included; maximal oxygen consumption (VO2max,mL/kg/min, L/min), expired minute ventilation (VE, L/min), carbon dioxide production (VCO2, L/min),respiratory rate (RR) in breaths per minute (b/min), percent (%) O2 expired and % CO2 expired, ventilatory equivalents for O2 (VE/VO2) and CO2 (VE/VCO2), maximal heart rate (MHR, beats/min), ventilatory threshold (VT), heart rate threshold (HRT) and time to exhaustion (TE) in minutes (min). Through regression analyses with age as the independent variable, the following measures significantly declined with age: VO2, VE, VCO2, RR, MHR, VT, HRT and TE. Expired percent O2 and CO2, along with VE/VO2 and VE/VCO2 showed low coefficient values indicating little change between subjects with age. In conclusion, age decrements in cardiopulmonary related variables appear to be caused by diminished exercise capacities causing lowered maximal exercise intensities. The poor correlation between VE/VO2 and VE/VCO2 and age reveal that ventilatory capacities and function contribute little to the diminished exercise tolerance due to aging. [ABSTRACT FROM AUTHOR]

Deals with a study which determined whether heart rate is a predictor of power output for cyclists. Methods; Results; Discussion.

The article presents research on the association between power, change of direction (COD) performance and strength in college football players in Australia. Results of the study indicate the positive relation between COD, strength and power in football players, the development of maximal strength to boost sprinting and COD tasks, and the possible adaptations in power after training.

The purpose of this study was to investigate if fitness status in female runners, based on maximal oxygen consumption, affects electrical activity of the myocardium as noted in electrocardiographic readings. A VO2 max was performed on nine (n=9) elite female endurance runners (18 to 22 yrs of age) to obtain fitness status ranking (Moderate VO2 max or High VO2 max), while a standard 12-lead electrocardiogram (ECG) was performed for determination of sinus rhythm and resting hart rate (RHR). There was a significant difference (P=0.02) in VO2 max values between the high VO2 max group (59.7 ± 2.7 mL∙kg-1∙min-1) and the moderate VO2 max group (54.2 ± 1.4 mL∙kg-1∙min-1). From the 12-lead ECG, we gathered that some changes due to heightened resting vagal tone and changes associated with physiological cardiac remodeling were present. There were negative correlations between sinus bradycardia and RHR (r = -0.81), sinus bradycardia and recovery hear rate (r = -0.71), MHR and increased QRS voltage (r = -0.75), and between RHR and early repolarization (r = -0.72). There was a positive correlation between VO2 max and time to exhaustion TE (r = 0.86). It is important to recognize the difference between pathological and physiological adaptations when evaluating an athlete's ECG and the understanding that changes in myocardium may also be present in female athletes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate, through a literature review process, the utilization of regression analysis in Exercise Physiology and to provide a step by step account leading to prediction equations. This investigation used a literature review process for obtaining information pertaining to regression analysis and prediction equations. The format followed the statistical process that begins with an initial procedure of bivariate correlation analysis. This is followed by simple bivariate regression analysis using the equation: Y = a + bX. Examples of each process are given with eventual multi-variate regression analysis. Established statistical significance in regression analyses were then indicated through trend-line analysis. Trend-line examples were both linear and non-linear. Examples of various prediction equations and trend-lines were presented as well as future areas of study for establishing prediction equations. In summary, this study provides a sequential order for determining variables inherent in Exercise Physiology that have been used, and may be used for statistical regression analyses and eventual prediction equations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate associations between aerobic capacity and resting heart rate. Sixteen recreational cyclists (18 to 65 yrs of age) underwent aerobic performance (VO2 max) testing on a cycle ergometer, and an electrocardiograph (ECG) was used to measure resting heart rate. VO2 max was determined by a plateau in VO2 during the progressive incremental test until exhaustion. There was a significant (P=0.05) relationship between age (45.1 ± 10.7 yrs) and maximum heart rate (177.3 ± 11.9 beats∙min-1). Although a significant relationship was not found between VO2 max (44.2 ± 6.1 mL∙kg-1∙min-1) and resting heart rate (69.0 ± 9.0 beats∙min-1), understanding how endurance exercise training enhances the cardiovascular and pulmonary system can be beneficial for the prevention of cardiovascular disease. [ABSTRACT FROM AUTHOR]