Physiological Performance Variables Research Articles

Effects of Inspiratory Muscle Training on Physiological Performance Variables in Women's Handball.

Inspiratory muscle training (IMT) has been used in different sports, although there is no consensus on its benefits. We investigated the effects of eight weeks of IMT in women's handball. Twenty-four players were randomly distributed into experimental (EXP; n = 13) and control (CON; n = 11) groups. Only the EXP group performed IMT using the POWERBreathe device, following indications of the manufacturers. Before and after the intervention, spirometric variables were evaluated at rest and during a graded test using direct analysis of respiratory gases. Perception of exertion at submaximal intensity was also determined. No significant differences were observed post- vs. pre-intervention (p ≥ 0.05) regarding forced vital capacity (FVC), forced expiratory volume in the 1st second (VEF1), FVC/VEF1, maximal expiratory flow at 50% of FVC or peak inspiratory flow. Post-intervention, only the CON group increased their absolute and relative VO2max (2.1 ± 0.2 L/min pre vs. 2.2 ± 0.3 L/min post; 33.6 ± 3.6 ml/kg∙min pre vs. 34.5 ± 3.2 ml/kg∙min post, respectively). No significant improvements (p ≥ 0.05) were observed in VO2 associated with ventilatory threshold 1 (VT1), nor in the intensity associated with VO2max and VT1. However, there was a tendency for the mentioned variables to decrease in the CON group, while in the EXP group the trend was to maintain or increase previous values. IMT did not determine an improvement in the perception of exertion at submaximal intensity. The use of POWERBreathe, as described in the present study, is feasible in terms of time and effort, although its benefits may not be significant.

Intensified training before Olympic-distance triathlon in recreational triathletes: "Less pain, more gain".

To examine 1) the contribution of physiological performance variables to Olympic-distance (OD) triathlon performance, and 2) the links between an 8-wk intensified training plus competition preceding the main OD triathlon race and the changes in the physiological status in triathletes. An observational longitudinal study. Endurance performance variables during maximal incremental running and cycling tests, and average velocity during an all-out 400-m swimming performance test (V400) were assessed before (T1) and after (T2) the intensified training in 7 recreational-level triathletes. Overall main OD triathlon time was extremely largely (r = -0.94; P = 0.01) correlated with peak running velocity (PRV). Best correlation magnitude between exercise modes' partial race times and the corresponding specific physiological criterion tests was observed for swimming (r = -0.97; P<0.001). Improvement in V400 (2.9%), PRV (1.5%) and submaximal running blood lactate concentration (17%) was observed along the training period, whereas no changes were observed in the cycling endurance performance variables. Higher volume of training plus competition at high intensity zones during cycling, running and swimming were associated with lower improvements or declines in their corresponding exercise mode-specific criterion performance variables (r = 0.81-0.90; P = 0.005-0.037). Results indicate that: 1) PRV is highly associated with overall OD triathlon performance, and 2) spending much time at high relative intensities during swimming, cycling or running may lead, in a dose-response manner, to lower improvements or decreases on those exercise-specific physiological performance variables. This may favor the emergence of overreaching or diminished performance.

Influence of COVID-19 Restrictions on Training and Physiological Characteristics in U23 Elite Cyclists.

PURPOSE: The COVID-19 pandemic and its associated mobility restrictions caused many athletes to adjust or reduce their usual training load. The aim of this study was to investigate how the COVID-19 restrictions affected training and performance physiology measures in U23 elite cyclists. METHODS: Twelve U23 elite cyclists (n = 12) participated in this study (mean ± SD: Age 21.2 ± 1.2 years; height 182.9 ± 4.7 cm; body mass 71.4 ± 6.5 kg). Training characteristics were assessed between 30 days pre, during, and post COVID-19 restrictions, respectively. The physiological assessment in the laboratory was 30 days pre and post COVID-19 restrictions and included maximum oxygen uptake (V̇O2max), peak power output for sprint (SprintPmax), and ramp incremental graded exercise (GXTPmax), as well as power output at ventilatory threshold (VT) and respiratory compensation point (RCP). RESULTS: Training load characteristics before, during, and after the lockdown remained statistically unchanged (p > 0.05) despite large effects (>0.8) with mean reductions of 4.7 to 25.0% during COVID-19 restrictions. There were no significant differences in maximal and submaximal power outputs, as well as relative and absolute V̇O2max between pre and post COVID-19 restrictions (p > 0.05) with small to moderate effects. DISCUSSION: These results indicate that COVID-19 restrictions did not negatively affect training characteristics and physiological performance measures in U23 elite cyclists for a period of <30 days. In contrast with recent reports on professional cyclists and other elite level athletes, these findings reveal that as long as athletes are able to maintain and/or slightly adapt their training routine, physiological performance variables remain stable.

Physiological Performance Measures as Indicators of CrossFit® Performance.

CrossFit® began as another exercise program to improve physical fitness and has rapidly grown into the “sport of fitness”. However, little is understood as to the physiological indicators that determine CrossFit® sport performance. The purpose of this study was to determine which physiological performance measure was the greatest indicator of CrossFit® workout performance. Male (n = 12) and female (n = 5) participants successfully completed a treadmill graded exercise test to measure maximal oxygen uptake (VO2max), a 3-minute all-out running test (3MT) to determine critical speed (CS) and the finite capacity for running speeds above CS (D′), a Wingate anaerobic test (WAnT) to assess anaerobic peak and mean power, the CrossFit® total to measure total body strength, as well as the CrossFit® benchmark workouts: Fran, Grace, and Nancy. It was hypothesized that CS and total body strength would be the greatest indicators of CrossFit® performance. Pearson’s r correlations were used to determine the relationship of benchmark performance data and the physiological performance measures. For each benchmark-dependent variable, a stepwise linear regression was created using significant correlative data. For the workout Fran, back squat strength explained 42% of the variance. VO2max explained 68% of the variance for the workout Nancy. Lastly, anaerobic peak power explained 57% of the variance for performance on the CrossFit® total. In conclusion, results demonstrated select physiological performance variables may be used to predict CrossFit® workout performance.

The Effect of Physiological Performance Variables on 3000m Times in Collegiate Mid-Distance and Distance Runners

Collegiate mid-distance (MD) runners and distance (D) runners compete in the 3000m. Previous research has identified VO2max, velocity at lactate threshold (vLT), %VO2max at lactate threshold, and running economy (RE) to correlate with 3000m performance. Research is lacking on if differences in these variables, and pacing strategy, affects 3000m performance between groups. PURPOSE: To identify how physiological performance variables relate to 3000m time, and if differences in these variables, and pacing strategies, occurs between groups. METHODS: 11 male NCAA Division II runners (5 MD, 6 D) were used. Subjects completed a 3000m time trial on a synthetic 200m indoor track, where 3000m time and split times were recorded using a single-beam timing gate. A discontinuous 3-minute stage lactate threshold protocol was used to measure vLT, lactate threshold (LT), and running economy at 14.5km/h, 16km/h, and 17.5 km/h (RE14.5, RE16, RE17.5). A modified Astrand VO2max test was used to assess VO2max, with the speed set at 16.1km/h and grade increasing 2% every two minutes. RESULTS: VO2max (r=-.629), RE14.5 (r=.632), RE16 (r=.756), %VO2max at LT (r=0.675), 600-1200m time (r=.784), 1200-1800m time (r=.962), and 1800-2400m time (r=.719) significantly correlated to 3000m time (p<0.05), when merging subjects. In the D group, %VO2max at LT (r=.875), RE16 (r=.853), 600-1200m time (r=.882), and 1200-1800m time (r=.965) significantly correlated to 3000m time (p<0.05). In the MD group, 1200-1800m time (r=.932) significantly correlated to 3000m time (p<0.05), and VO2max had a trend towards significance with 3000m time (r=-.829, p=.083). Statistically different mean differences in VO2max (D=67.00±2.64 vs MD=63.56±1.52ml/kg/min), and vLT (D=15.10±0.19 vs MD=14.33±0.35km/h) was observed between groups (p<0.05). A graphical difference in pacing strategy was observed between groups. CONCLUSION: 1200-1800m time is the most important split time for 3000m performance. VO2max was the best physiological performance indicator in MD runners, and RE16 was the best physiological performance indicator in D runners. Runners should be trained differently according to their training status, to improve 3000m performance.

Effect of dietary fatty acid composition on fatty acid profiles of polar and neutral lipid tissue fractions in zebra finches, Taeniopygia guttata

The growing awareness that the fatty acid (FA) composition of the diets of birds, and ultimately their tissues, influence physiological performance variables, such as aerobic capacity, thermosensitivity, digestive efficiency, etc., underscores the need to understand how differences in dietary fatty acid composition actually translate into differences in the fatty acid composition of specific tissues. We quantified the fatty acid profiles of polar and neutral lipid fractions of several tissues in zebra finches ( Taeniopygia guttata) and compared these profiles among birds fed either a control diet of only hulled millet, or one of two experimental diets of hulled millet supplemented with either 8% (by mass) sunflower seed oil (ω6-enriched diet) or linseed oil (ω3-enriched diet). We found that different lipid fractions vary widely in their diversity and complexity of FA composition, with neutral lipids being much less structurally diverse than those of polar lipids, for example, and that the fatty acid compositions of different organs exhibited different propensities to be altered by the diet, with brain and cardiac tissues having lower levels of flexibility than skeletal muscle and liver. We also present evidence suggesting that adipose tissue may be used to sequester essential FAs when they occur in the diet at levels that exceed immediate requirements. We conclude that the fatty acid composition of adipose tissue may not be a particularly useful indicator of the dietary FA composition of birds, and suggest that future studies investigating the relationships between the FA profiles of bird tissues and bird diets and/or physiological performance variables examine multiple tissues and distinguish between neutral and polar lipid fractions.

Scaling physiological measurements for individuals of different body size.

This paper examines how selected physiological performance variables, such as maximal oxygen uptake, strength and power, might best be scaled for subject differences in body size. The apparent dilemma between using either ratio standards or a linear adjustment method to scale was investigated by considering how maximal oxygen uptake (l.min-1), peak and mean power output (W) might best be adjusted for differences in body mass (kg). A curvilinear power function model was shown to be theoretically, physiologically and empirically superior to the linear models. Based on the fitted power functions, the best method of scaling maximum oxygen uptake, peak and mean power output, required these variables to be divided by body mass, recorded in the units kg 2/3. Hence, the power function ratio standards (ml.kg-2/3.min-1) and (W.kg-2/3) were best able to describe a wide range of subjects in terms of their physiological capacity, i.e. their ability to utilise oxygen or record power maximally, independent of body size. The simple ratio standards (ml.kg-1.min-1) and (W.kg-1) were found to best describe the same subjects according to their performance capacities or ability to run which are highly dependent on body size. The appropriate model to explain the experimental design effects on such ratio standards was shown to be log-normal rather than normal. Simply by taking logarithms of the power function ratio standard, identical solutions for the design effects are obtained using either ANOVA or, by taking the unscaled physiological variable as the dependent variable and the body size variable as the covariate, ANCOVA methods.