scholarly journals Porovnání aktuálních metodik identifikace funkčních a anaerobních prahů na bicyklovém ergometru u triatlonistů

2015 ◽  
Vol 9 (2) ◽  
pp. 85-91
Author(s):  
Lenka Kovářová ◽  
Martin Berka ◽  
David Pánek
Keyword(s):  
Theoretical Calculation ◽  
Repeated Measures ◽  
Body Height ◽  
Time Trial ◽  
Pairwise Comparison ◽  
Test Method ◽  
Test Time ◽  
Motor Test ◽  
Bonferroni Test ◽  
Conconi Test

The aim of the study was to compare the currently methodics for identification functional and anaerobic thresholds on a bicycle ergometer by triathletes. The sample included triathletes (men), regular participants in the Czech triathlon cup (n = 10, age 35.89 ± 7.94 years, body height 181.83 ± 6.52 cm, weight 80.65 ± 6.53 kg). In the study, we compared the evaluation methodics using lactate curve, respiratory parameters, theoretical calculation, motor test and Conconi test. For statistical data processing we used the Repeated Measures, for evaluating the significance of differences between each test method then pairwise comparation (Bonferroni test). Results showed statistically significant differences (p = 0.000). Significantly higher values are reached in Conconi test (173 ± 14.2 beats.min–1, 313 ± 74.8 W). In pairwise comparison of methodics are differences between lactate and Conconi test in HR values (p = 0.037) as well as the difference between HR lactate test and theoretical calculation (p = 0.039). Most statistical variations in the watts evaluation is found again in connection with Conconi test (time trial: p = 0.039; lactate test: p = 0.013; spiroergometry: p = 0.041).

scholarly journals Examination of Construct Validity and Criterion-Related Validity of the German Motor Test in Egyptian Schoolchildren

2021 ◽  
Vol 18 (16) ◽  
pp. 8341
Author(s):  
Osama Abdelkarim ◽  
Julian Fritsch ◽  
Darko Jekauc ◽  
Klaus Bös
Keyword(s):  
Construct Validity ◽  
Physical Fitness ◽  
Large Scale ◽  
Body Height ◽  
Cross Sectional Study ◽  
Latent Factors ◽  
Cross Sectional ◽  
First Order ◽  
Motor Test ◽  
Health Related

Physical fitness is an indicator for children’s public health status. Therefore, the aim of this study was to examine the construct validity and the criterion-related validity of the German motor test (GMT) in Egyptian schoolchildren. A cross-sectional study was conducted with a total of 931 children aged 6 to 11 years (age: 9.1 ± 1.7 years) with 484 (52%) males and 447 (48%) females in grades one to five in Assiut city. The children’s physical fitness data were collected using GMT. GMT is designed to measure five health-related physical fitness components including speed, strength, coordination, endurance, and flexibility of children aged 6 to 18 years. The anthropometric data were collected based on three indicators: body height, body weight, and BMI. A confirmatory factor analysis was conducted with IBM SPSS AMOS 26.0 using full-information maximum likelihood. The results indicated an adequate fit (χ2 = 112.3, df = 20; p < 0.01; CFI = 0.956; RMSEA = 0.07). The χ2-statistic showed significant results, and the values for CFI and RMSEA showed a good fit. All loadings of the manifest variables on the first-order latent factors as well as loadings of the first-order latent factors on the second-order superordinate factor were significant. The results also showed strong construct validity in the components of conditioning abilities and moderate construct validity in the components of coordinative abilities. GMT proved to be a valid method and could be widely used on large-scale studies for health-related fitness monitoring in the Egyptian population.

scholarly journals Effect of Dietary Nitrate Supplementation on Swimming Performance in Trained Swimmers

2017 ◽  
Vol 27 (4) ◽  
pp. 377-384 ◽  
Author(s):  
Sam Lowings ◽  
Oliver Michael Shannon ◽  
Kevin Deighton ◽  
Jamie Matu ◽  
Matthew John Barlow
Keyword(s):  
Nitric Oxide ◽  
Repeated Measures ◽  
Swimming Performance ◽  
Time Trial ◽  
Mean Difference ◽  
Breath Hold ◽  
Double Blind ◽  
Nitric Oxide Concentration ◽  
Nitrate Supplementation ◽  
Maximal Effort

Nitrate supplementation appears to be most ergogenic when oxygen availability is restricted and subsequently may be particularly beneficial for swimming performance due to the breath-hold element of this sport. This represents the first investigation of nitrate supplementation and swimming time-trial (TT) performance. In a randomized double-blind repeated-measures crossover study, ten (5 male, 5 female) trained swimmers ingested 140ml nitrate-rich (~12.5mmol nitrate) or nitrate-depleted (~0.01mmol nitrate) beetroot juice. Three hours later, subjects completed a maximal effort swim TT comprising 168m (8 × 21m lengths) backstroke. Preexercise fractional exhaled nitric oxide concentration was significantly elevated with nitrate compared with placebo, Mean (SD): 17 (9) vs. 7 (3)p.p.b., p = .008. Nitrate supplementation had a likely trivial effect on overall swim TT performance (mean difference 1.22s; 90% CI -0.18–2.6s; 0.93%; p = .144; d = 0.13; unlikely beneficial (22.6%), likely trivial (77.2%), most unlikely negative (0.2%)). The effects of nitrate supplementation during the first half of the TT were trivial (mean difference 0.29s; 90% CI -0.94–1.5s; 0.46%; p = .678; d = 0.05), but there was a possible beneficial effect of nitrate supplementation during the second half of the TT (mean difference 0.93s; 90% CI 0.13–1.70s; 1.36%; p = .062; d = 0.24; possibly beneficial (63.5%), possibly trivial (36.3%), most unlikely negative (0.2%)). The duration and speed of underwater swimming within the performance did not differ between nitrate and placebo (both p > .30). Nitrate supplementation increased nitric oxide bioavailability but did not benefit short-distance swimming performance or the underwater phases of the TT. Further investigation into the effects of nitrate supplementation during the second half of performance tests may be warranted.

scholarly journals The Acute Effects of Different Forms of Suspension Push‐Ups on Oxygen Consumption, Salivary Testosterone and Cortisol and Isometric Strength

2018 ◽  
Vol 64 (1) ◽  
pp. 77-85 ◽  
Author(s):  
David Bellar ◽  
Cory Etheredge ◽  
Lawrence W. Judge
Keyword(s):  
Oxygen Consumption ◽  
Repeated Measures ◽  
Bench Press ◽  
Body Height ◽  
Isometric Strength ◽  
Exercise Session ◽  
Acute Effects ◽  
Hands And Feet ◽  
The Impact ◽  
Push Up

Abstract Suspension exercise systems are being used in strength and conditioning facilities, fitness centers, rehabilitation centers and home gyms. Though some evidence exists regarding the impact of training with these systems, more work is needed for a better understanding. The purpose of the present investigation was to examine the acute effects of an exercise session with 2 (hands only) and 4 straps (hands and feet) in the push-up exercise compared to a work-matched bench press exercise session. The participants for this repeated measures, cross-over investigation were 18 healthy college-aged males (age: 24.8 ± 3.5 yrs, body mass: 81.8 ± 7.8 kg, body height: 178.9 ± 4.5 cm). The conditions were 6 sets of 10 repetitions of suspension push-ups using two straps (DUAL) for the hands, fours straps (QUAD) for hands and feet and a traditional bench press exercise matched to the average resistance during the suspension push-up. The participants performed all repetitions at a controlled cadence. Expired gases, and heart rate were monitored continuously during the exercise session. Pre and post exercise saliva samples were collected to quantify changes in testosterone and cortisol. Upper body isometric strength tests ( UBIST) were performed (Post, 1 hr, 24 hr, 48 hr) to evaluate changes in force production during recovery. Data analysis via repeated measures ANOVA revealed a significant trend for increased oxygen consumption in the QUAD condition compared to the bench press (p = 0.019). Additionally, both suspension conditions resulted in a reduced respiratory exchange ratio as compared to the bench press (p < 0.05). A significant main effect was noted for time in all conditions regarding isometric strength (p < 0.001), but no differences between conditions were revealed. Testosterone and cortisol responses did not differ between conditions. Based upon these data, it appears that when matched for work, suspension exercise results in equivalent reductions in muscle force, but greater oxygen consumption compared to isotonic exercise.

scholarly journals Effects of Different Forms of Extrinsic Feedback on the Accuracy of Force Production and to Differentiate this Force in the Simple Cyclic Movements of the Upper and Lower Limb

2020 ◽  
Vol 72 (3) ◽  
pp. 39-56
Author(s):  
Stefan Szczepan ◽  
Zofia Wróblewska ◽  
Andrzej Klarowicz ◽  
Ryszard Błacha ◽  
Marek Rejman
Keyword(s):  
Lower Limb ◽  
Retention Test ◽  
Repeated Measures ◽  
Body Height ◽  
Force Production ◽  
Lower Limbs ◽  
Verbal Feedback ◽  
Physically Active ◽  
Cyclic Movements ◽  
Extrinsic Feedback

Abstract Background: This study aimed to assess the accuracy of force production by the limbs and to identify the ability to differentiate this force during a progressively increasing value, in response to different types of extrinsic feedback. Material and methods: The study involved nineteen healthy and physically active boys and girls aged 12.82±0.34 years, body height 157.05±9.02 cm, and body mass 44.89±7.89 kg. The tasks were to perform a series of right and left upper limb pulls and pushes with increasing force using the levers of the kinesthesiometer and a series of lower limb presses on the pedal of the kinesthesiometer. The tasks were completed in three feedback conditions: no feedback, sound feedback, verbal feedback, and the retention test was used. To assess the level of accuracy of force production, the novel index of force production accuracy (FPAIndex) was used. Results: The outcomes expressing the value of FPAIndex on the point scale indicated that the highest level of kinesthetic differentiation was observed when no feedback was provided (1.17 points), and the lowest kinesthetic differentiation was recorded when verbal feedback was provided (3.33 points). However, they were devoid of statistical value. The repeated-measures analysis of variance ANOVA with the Tukey post-hoc test (HSD) indicated a significant lowest (p=0.0402) level of accuracy of FPA (x̄ 36.12±18.29 [N]) only for the act of left lower limb press (LL PRESS) in the retention test, while no feedback was provided to the subjects. Conclusions: The results of this study showed that verbal and sound extrinsic feedback did not affect the accuracy of force production by the upper and lower limbs and the ability to differentiate this force in simple movements among children.

A Development of a New Life Test Procedure for Fan Motors

2006 ◽  
Vol 321-323 ◽  
pp. 1539-1542
Author(s):  
Wae Gyeong Shin ◽  
Soo Hong Lee ◽  
Young Sik Song
Keyword(s):  
Automotive Industry ◽  
Field Condition ◽  
Test Procedure ◽  
Test Method ◽  
Accelerated Life Test ◽  
Test Time ◽  
Life Test ◽  
Dc Motors ◽  
Accelerated Life ◽  
Automotive Parts

Reliability of automotive parts has been one of the most interesting fields in the automotive industry. Especially small DC motor was issued because of the increasing adoption for passengers’ safety and convenience. For several years, small DC motors have been studied and some problems of a life test method were found out. The field condition was not considered enough in the old life test method. It also needed a lot of test time. For precise life estimation and accelerated life test, new life test procedure was developed based on measured field condition. First, vibration condition on vehicle and latent force on fan motor shaft were measured and correlated with each other. Second, test condition was decided by obtained data. Finally, life of fan motors was estimated by new life test method in shorter test time.

scholarly journals Acetazolamide does not alter endurance exercise performance at 3,500-m altitude

2020 ◽  
Vol 128 (2) ◽  
pp. 390-396 ◽  
Author(s):  
Karleigh E. Bradbury ◽  
Beau R. Yurkevicius ◽  
Katherine M. Mitchell ◽  
Kirsten E. Coffman ◽  
Roy M. Salgado ◽  
...  
Keyword(s):  
Sea Level ◽  
Endurance Exercise ◽  
Exercise Performance ◽  
Repeated Measures ◽  
Acute Mountain Sickness ◽  
Time Trial ◽  
Peak Oxygen Consumption ◽  
Repeated Measures Design ◽  
Hypoxic Environment ◽  
The Impact

Acetazolamide (AZ) is a medication commonly used to prevent acute mountain sickness (AMS) during rapid ascent to high altitude. However, it is unclear whether AZ use impairs exercise performance; previous literature regarding this topic is equivocal. The purpose of this study was to evaluate the impact of AZ on time-trial (TT) performance during a 30-h exposure to hypobaric hypoxia equivalent to 3,500-m altitude. Ten men [sea-level peak oxygen consumption (VO2peak): 50.8 ± 6.5 mL·kg−1·min−1; body fat %: 20.6 ± 5.2%] completed 2 30-h exposures at 3,500 m. In a crossover study design, subjects were given 500 mg/day of either AZ or a placebo. Exercise testing was completed 2 h and 24 h after ascent and consisted of 15-min steady-state treadmill walking at 40%–45% sea-level VO2peak, followed by a 2-mile self-paced treadmill TT. AMS was assessed after ~12 h and 22 h at 3,500 m. The incidence of AMS decreased from 40% with placebo to 0% with AZ. Oxygen saturation was higher ( P < 0.05) in AZ versus placebo trials at the end of the TT after 2 h (85 ± 3% vs. 79 ± 3%) and 24 h (86 ± 3% vs. 81 ± 4%). There was no difference in time to complete 2 miles between AZ and PL after 2 h (20.7 ± 3.2 vs. 22.7 ± 5.0 min, P > 0.05) or 24 h (21.5 ± 3.4 vs. 21.1 ± 2.9 min, P > 0.05) of exposure to altitude. Our results suggest that AZ (500 mg/day) does not negatively impact endurance exercise performance at 3,500 m. NEW & NOTEWORTHY To our knowledge, this is the first study to examine the impact of acetazolamide (500 mg/day) versus placebo on self-paced, peak-effort exercise performance using a short-duration exercise test in a hypobaric hypoxic environment with a repeated-measures design. In the present study, acetazolamide did not impact exercise performance after 2-h or 24-h exposure to 3,500-m simulated altitude.

scholarly journals Effect of neuromuscular resistance training on the performance of 5-km runners

Kinesiology ◽  
2020 ◽  
Vol 52 (1) ◽  
pp. 64-71
Author(s):  
Miller P. Guimarães ◽  
Yuri A.C. Campos ◽  
Hiago L.R. de Souza ◽  
Gaspar P. da Silva ◽  
Claudio Hernández-Mosqueira ◽  
...  
Keyword(s):  
Resistance Training ◽  
Body Height ◽  
Time Trial ◽  
Distance Runners ◽  
Fat Percentage ◽  
Leg Press ◽  
Baseline Values ◽  
Incremental Protocol ◽  
Fourth Session ◽  
Training Protocol

The study aimed to identify the effect of a neuromuscular resistance training protocol (NRTP) on the performance of 5-km distance runners. This study included 18 male runners (age=29.3±3.2 years, fat percentage=11.3±2.6%, body height=1.77±.04 m, body mass=73.4±4.4 kg, time in 5 km=20.6±2.4 min, training years=4.3±0.7 years). First, volunteers were anthropometrically evaluated, and they performed one-repetition maximum (1RM) 45º leg press (LP) strength test. Second, they performed an incremental protocol in the 45º LP to acquire the electromyographic threshold. Third, they completed a 5-km time trial run (5 km basal). In the fourth session, they performed NRTP in LP. And fifth, the 5-km time trial run was performed at 30 min, 48 h, 96 h, and 144 h post the NRTP intervention. A significant decrease (p≤.05) was observed when baseline values were compared with post 30 min and post 48 h (p=.02 and p=.04, respectively). However, there were significant positive differences in performance (p=.04 for time) when baseline values and post 144 h were analyzed. Therefore, it is concluded that the NRTP can be used by 5-km distance runners to improve their performance with a break of one week between the intervention and test.

scholarly journals The Effects of Inhaled Terbutaline on 3-km Running Time-Trial Performance

2019 ◽  
Vol 14 (6) ◽  
pp. 822-828 ◽  
Author(s):  
John Molphy ◽  
John W. Dickinson ◽  
Neil J. Chester ◽  
Mike Loosemore ◽  
Gregory Whyte
Keyword(s):  
Repeated Measures ◽  
Time Trial ◽  
Endurance Performance ◽  
Forced Expiratory Volume ◽  
Concentration Data ◽  
Running Performance ◽  
Running Time ◽  
Time Trial Performance ◽  
Repeated Measures Design ◽  
Trial Performance

Terbutaline is a prohibited drug except for athletes with a therapeutic use exemption certificate; terbutaline’s effects on endurance performance are relatively unknown. Purpose: To investigate the effects of 2 therapeutic (2 and 4 mg) inhaled doses of terbutaline on 3-km running time-trial performance. Methods: A total of 8 men (age 24.3 [2.4] y; weight 77.6 [8] kg; and height 179.5 [4.3] cm) and 8 women (age 22.4 [3] y; weight 58.6 [6] kg; and height 163 [9.2] cm) free from respiratory disease and illness provided written informed consent. Participants completed 3-km running time trials on a nonmotorized treadmill on 3 separate occasions following placebo and 2- and 4-mg inhaled terbutaline in a single-blind, repeated-measures design. Urine samples (15 min postexercise) were analyzed for terbutaline concentration. Data were analyzed using 1-way repeated-measures analysis of variance, and significance was set at P < .05 for all analyses. Results: No differences were observed for completion times (1103 [201] s, 1106 [195] s, 1098 [165] s; P = .913) for the placebo or 2- and 4-mg inhaled trials, respectively. Lactate values were higher (P = .02) after 4 mg terbutaline (10.7 [2.3] mmol·L−1) vs placebo (8.9 [1.8] mmol·L−1). Values of forced expiratory volume in the first second of expiration (FEV1) were greater after inhalation of 2 mg (5.08 [0.2]; P = .01) and 4 mg terbutaline (5.07 [0.2]; P = .02) compared with placebo (4.83 [0.5] L) postinhalation. Urinary terbutaline concentrations were mean 306 (288) ng·mL−1 and 435 (410) ng·mL−1 (P = .2) and peak 956 ng·mL−1 and 1244 ng·mL−1 after 2 and 4 mg inhaled terbutaline, respectively. No differences were observed between the male and female participants. Conclusions: Therapeutic dosing of terbutaline does not lead to an improvement in 3-km running performance despite significantly increased FEV1. The findings suggest that athletes using inhaled terbutaline at high therapeutic doses to treat asthma will not gain an ergogenic advantage during 3-km running performance.

scholarly journals The Effect of 1,3-Butanediol on Cycling Time-Trial Performance

2019 ◽  
Vol 29 (5) ◽  
pp. 466-473 ◽  
Author(s):  
David M. Shaw ◽  
Fabrice Merien ◽  
Andrea Braakhuis ◽  
Daniel Plews ◽  
Paul Laursen ◽  
...  
Keyword(s):  
Steady State ◽  
Body Mass ◽  
Repeated Measures ◽  
Average Power ◽  
Gastrointestinal Symptoms ◽  
Time Trial ◽  
Endurance Performance ◽  
Carbon Dioxide Production ◽  
Serum Glucose ◽  
Cycling Time Trial

This study investigated the effect of the racemic β-hydroxybutyrate (βHB) precursor, R,S-1,3-butanediol (BD), on time-trial (TT) performance and tolerability. A repeated-measures, randomized, crossover study was conducted in nine trained male cyclists (age, 26.7 ± 5.2 years; body mass, 69.6 ± 8.4 kg; height, 1.82 ± 0.09 m; body mass index, 21.2 ± 1.5 kg/m2; VO2peak,63.9 ± 2.5 ml·kg−1·min−1; Wmax, 389.3 ± 50.4 W). Participants ingested 0.35 g/kg of BD or placebo 30 min before and 60 min during 85 min of steady-state exercise, which preceded a ∼25- to 35-min TT (i.e., 7 kJ/kg). The ingestion of BD increased blood D-βHB concentration throughout exercise (0.44–0.79 mmol/L) compared with placebo (0.11–0.16 mmol/L; all p < .001), which peaked 1 hr following the TT (1.38 ± 0.35 vs. 0.34 ± 0.24 mmol/L; p < .001). Serum glucose and blood lactate concentrations were not different between trials (all p > .05). BD ingestion increased oxygen consumption and carbon dioxide production after 20 min of steady-state exercise (p = .002 and p = .032, respectively); however, no further effects on cardiorespiratory parameters were observed. Within the BD trial, moderate to severe gastrointestinal symptoms were reported in five participants, and low levels of dizziness, nausea, and euphoria were reported in two participants. However, this had no effect on TT duration (placebo, 28.5 ± 3.6 min; BD, 28.7 ± 3.2 min; p = .62) and average power output (placebo, 290.1 ± 53.7 W; BD, 286.4 ± 45.9 W; p = .50). These results suggest that BD has no benefit for endurance performance.

Cycling Time Trial Performance 4 Hours After Glycogen-Lowering Exercise Is Similarly Enhanced by Recovery Nondairy Chocolate Beverages Versus Chocolate Milk

2016 ◽  
Vol 26 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Adam U. Upshaw ◽  
Tiffany S. Wong ◽  
Arash Bandegan ◽  
Peter W.R. Lemon
Keyword(s):  
Repeated Measures ◽  
Time Trial ◽  
Chocolate Milk ◽  
Double Blind ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Repeated Measures Design ◽  
Dairy Milk ◽  
Cycling Time ◽  
Trial Performance

Postexercise chocolate milk ingestion has been shown to enhance both glycogen resynthesis and subsequent exercise performance. To assess whether nondairy chocolate beverage ingestion post–glycogen-lowering exercise can enhance 20-km cycling time trial performance 4 hr later, eight healthy trained male cyclists (21.8 ± 2.3y, VO2max = 61.2 ± 1.4 ml·kg-1·min-1; M ± SD) completed a series of intense cycling intervals designed to lower muscle glycogen (Jentjens & Jeukendrup, 2003) followed by 4 hr of recovery and a subsequent 20-km cycling time trial. During the first 2 hr of recovery, participants ingested chocolate dairy milk (DAIRYCHOC), chocolate soy beverage (SOYCHOC), chocolate hemp beverage (HEMPCHOC), low-fat dairy milk (MILK), or a low-energy artificially sweetened, flavored beverage (PLACEBO) at 30-min intervals in a double-blind, counterbalanced repeated-measures design. All drinks, except the PLACEBO (247 kJ) were isoenergetic (2,107 kJ), and all chocolate-flavored drinks provided 1-g CHO·kg body mass-1·h-1. Fluid intake across treatments was equalized (2,262 ± 148 ml) by ingesting appropriate quantities of water based on drink intake. The CHO:PRO ratio was 4:1, 1.5:1, 4:1, and 6:1 for DAIRYCHOC, MILK, SOYCHOC, and HEMPCHOC, respectively. One-way analysis of variance with repeated measures showed time trial performance (DAIRYCHOC = 34.58 ± 2.5 min, SOYCHOC = 34.83 ± 2.2 min, HEMPCHOC = 34.88 ± 1.1 min, MILK = 34.47 ± 1.7 min) was enhanced similarly vs PLACEBO (37.85 ± 2.1) for all treatments (p = .019) These data suggest that postexercise macronutrient and total energy intake are more important for same-day 20-km cycling time trial performance after glycogen-lowering exercise than protein type or protein-to-carbohydrate ratio.

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