Micronutrient Fortified Carbohydrate Supplementation and Speed, Agility and Power in Indian Adolescent Athletes

2017 ◽  
Vol 54 (1) ◽  
pp. 1
Author(s):  
Tessa E. Morris ◽  
Rachana Bhoite ◽  
Ritu Karwal ◽  
, Verma ◽  
, Bhavna ◽  
...  
Keyword(s):  
Intermittent Exercise ◽  
Cycle Ergometer ◽  
Adolescent Athletes ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Performance Impact ◽  
Treatment Groups ◽  
Before And After ◽  
The Difference ◽  
Mean Power Output

The positive performance impact of exogenous carbohydrate intake on prolonged endurance is well established. The effect on shorter duration activities has been less documented, in particular with adolescents. In this randomized, cross over study, thirty adolescent athletes (24 male and 6 female; age: 13.5 ± 1.0 yrs; height: 161.4 ± 8.1cm; weight: 50.4 ± 9.3 kg) performed the same sequence of procedures; baseline assessments, a treatment drink before and after a 45 min intermittent exercise protocol followed by post-baseline assessments. Participants were randomised to one of three blinded treatment drinks; micronutrient fortified carbohydrate (CHO), calorie-matched control (PRO) or water (WAT). The assessments involved repeated sprint and repeated agility tests (6 repetitions; 65 sec. provided to complete the repetition and recover prior to the next effort) and a repeated Wingate anaerobic test (3 x 30 sec) on a cycle ergometer. The Fatigue Index (FI) was calculated from the sprint and agility results and Mean Power Output (MPO) from the repeated Wingate results. The difference between the baseline and post-baseline results was then calculated and CHO, PRO and WAT treatment groups compared using Analysis of variance (ANOVA). No significant differences were found between speed, agility and power change from baseline results when CHO, PRO and WAT treatment groups were compared (p ≥ 0.05). Supplementation with a micronutrient fortified carbohydrate beverage does not increase repeated speed, agility or power in Indian adolescent team sport athletes.

scholarly journals Growth hormone responses to repeated maximal cycle ergometer exercise at different pedaling rates

2002 ◽  
Vol 92 (2) ◽  
pp. 602-608 ◽  
Author(s):  
K. A. Stokes ◽  
M. E. Nevill ◽  
G. M. Hall ◽  
H. K. A. Lakomy
Keyword(s):  
Growth Hormone ◽  
Area Under The Curve ◽  
Cycle Ergometer ◽  
Mean Power ◽  
Ergometer Exercise ◽  
Hormone Responses ◽  
Sprint Cycling ◽  
Mean Power Output ◽  
Male Subjects ◽  
Serum Gh

The present study examined the growth hormone (GH) response to repeated bouts of maximal sprint cycling and the effect of cycling at different pedaling rates on postexercise serum GH concentrations. Ten male subjects completed two 30-s sprints, separated by 1 h of passive recovery on two occasions, against an applied resistance equal to 7.5% (fast trial) and 10% (slow trial) of their body mass, respectively. Blood samples were obtained at rest, between the two sprints, and for 1 h after the second sprint. Peak and mean pedal revolutions were greater in the fast than the slow trial, but there were no differences in peak or mean power output. Blood lactate and blood pH responses did not differ between trials or sprints. The first sprint in each trial elicited a serum GH response (fast: 40.8 ± 8.2 mU/l, slow: 20.8 ± 6.1 mU/l), and serum GH was still elevated 60 min after the first sprint. The second sprint in each trial did not elicit a serum GH response ( sprint 1 vs. sprint 2, P < 0.05). There was a trend for serum GH concentrations to be greater in the fast trial (mean GH area under the curve after sprint 1vs. after sprint 2: 1,697 ± 367 vs. 933 ± 306 min · mU−1 · l−1; P = 0.05). Repeated sprint cycling results in an attenuation of the GH response.

Determination of aerobic work and power on a rope-braked cycle ergometer by direct measurement

2006 ◽  
Vol 31 (4) ◽  
pp. 392-397 ◽  
Author(s):  
Rae S. Gordon ◽  
Kathryn L. Franklin ◽  
Julien S. Baker ◽  
Bruce Davies
Keyword(s):  
Direct Measurement ◽  
Power Estimation ◽  
Cycle Ergometer ◽  
Mean Power ◽  
Physiological Assessment ◽  
Brake Force ◽  
The Mean ◽  
The Difference ◽  
Work Done

The purpose of this study was to compare the power and work outputs of a cycle ergometer using the manufacturer’s guidelines, with calculations using direct flywheel velocity and brake torque. A further aim was to compare the values obtained with those supplied by the manufacturer. A group of 10 male participants were asked to pedal a Monark 824E ergometer at a constant cadence of 60 r/min for a period of 3 min against a resistive mass of 3 kg. The flywheel velocity was measured using a tachometer. The brake force was determined by measuring the tension in the rope on either side of the flywheel. The calculated mean power was 147.45 ± 6.5 W compared with the Monark value of 183 ± 3.7 W. The difference between the methods for power estimation was 18% and was statistically significant (p < 0.01). The mean work done by the participants during the 3 min period was found to be 26 460 ± 1145 J compared with the Monark value of 33 067 ± 648 J (p < 0.01). The Monark formulae currently used to determine the power and work done by a participant overestimates the actual values required to overcome the resistance. There findings have far-reaching implications in the physiological assessment of athletic, sedentary, and diseased populations.

scholarly journals The Effect of Previous Wingate Performance Using one Body Region on Subsequent Wingate Performance Using a Different Body Region

2017 ◽  
Vol 56 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Leonie Harvey ◽  
Matthew Bousson ◽  
Chris McLellan ◽  
Dale Lovell
Keyword(s):  
Rest Period ◽  
Cycle Ergometer ◽  
Upper Body ◽  
Body Region ◽  
Power Indices ◽  
Lower Body ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Sprint Exercise ◽  
Braking Force

AbstractThe 30 second Wingate Anaerobic Test (WAnT) is the gold standard measure of anaerobic performance. The present investigation aimed to determine if a previous WAnT using one body region significantly affected a subsequent WAnT using a different body region. Twelve male university students (n = 12, 23 ± 2 years, 84 ± 16.1 kg, 178.5 ± 7.4 cm) volunteered to complete two repeated WAnT protocols (either lower body WAnT followed by an upper body WAnT or vice versa) on two separate testing occasions. The upper body WAnT was conducted on a modified electromagnetically braked cycle ergometer using a flywheel braking force corresponding to 5% bodyweight. The lower body WAnT was conducted on an electronically braked cycle ergometer using a flywheel braking force corresponding to 7.5% bodyweight. Participants had a 1 minute rest period for transition between WAnTs. Data are reported as mean ± standard deviation. No significant differences were identified in power indices for the lower body between 30 s WAnTs. When the upper body WAnT was performed 2nd, absolute peak power (p < 0.01), mean power (p < 0.001) and relative mean power (p < 0.001) were significantly lower compared to when the upper body WAnT was performed 1st. The value of maximum revolutions per minute was significantly lower (p < 0.001) when the upper body WAnT was performed after the lower body WAnT, compared to when it was performed 1st (193.3 ± 11.4 1st vs 179.8 ± 14.4 2nd). Previous upper body sprint exercise does not significantly affect lower body sprint exercise; however, previous lower body sprint exercise severely compromises subsequent upper body sprint performance.

scholarly journals Single and Combined Effects of Beetroot Crystals and Sodium Bicarbonate on 4-km Cycling Time Trial Performance

2017 ◽  
Vol 27 (3) ◽  
pp. 271-278 ◽  
Author(s):  
Marcus J. Callahan ◽  
Evelyn B. Parr ◽  
John A. Hawley ◽  
Louise M. Burke
Keyword(s):  
Sodium Bicarbonate ◽  
Latin Square ◽  
Time Trial ◽  
Cycle Ergometer ◽  
Combined Effects ◽  
Beetroot Juice ◽  
Mean Power ◽  
Cycling Time Trial ◽  
Plasma Nitrite ◽  
Mean Power Output

When ingested alone, beetroot juice and sodium bicarbonate are ergogenic for high-intensity exercise performance. This study sought to determine the independent and combined effects of these supplements. Eight endurance trained (VO2max 65 mL·kg·min-1) male cyclists completed four × 4-km time trials (TT) in a doubleblind Latin square design supplementing with beetroot crystals (BC) for 3 days (15 g·day-1 + 15 g 1 h before TT, containing 300 mg nitrate per 15 g), bicarbonate (Bi 0.3 g·kg-1 body mass [BM] in 5 doses every 15 min from 2.5 h before TT); BC+Bi or placebo (PLA). Subjects completed TTs on a Velotron cycle ergometer under standardized laboratory conditions. Plasma nitrite concentrations were significantly elevated only in the BC+Bi trial before the TT (1520 ± 786 nmol·L-1) compared with baseline (665 ± 535 nmol·L-1, p = .02) and the Bi and PLA conditions (Bi: 593 ± 203 nmol·L-1, p < .01; PLA: 543 ± 369 nmol·L-1, p < .01). Plasma nitrite concentrations were not elevated in the BC trial before the TT (1102 ± 218 nmol·L-1) compared with baseline (975 ± 607 nmol·L-1, p > .05). Blood bicarbonate concentrations were increased in the BC+Bi and Bi trials before the TT (BC+Bi: 30.9 ± 2.8 mmol·L-1; Bi: 31.7 ± 1.1 mmol·L-1). There were no differences in mean power output (386–394 W) or the time taken to complete the TT (335.8–338.1 s) between any conditions. Under the conditions of this study, supplementation was not ergogenic for 4-km TT performance.

scholarly journals Effect of Combined Endurance Training and MitoQ on Cardiac Function and Serum Level of Antioxidants, NO, miR-126, and miR-27a in Hypertensive Individuals

2022 ◽  
Vol 2022 ◽  
pp. 1-13
Author(s):  
Yaser Masoumi-Ardakani ◽  
Hamid Najafipour ◽  
Hamid Reza Nasri ◽  
Soheil Aminizadeh ◽  
Shirin Jafari ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Endurance Training ◽  
Cardiovascular Health ◽  
Serum Levels ◽  
Cycle Ergometer ◽  
Moderate Intensity ◽  
Double Blind ◽  
Treatment Groups ◽  
Before And After ◽  
And Control

Objectives. Hypertension (HTN) is one of the most important risk factors for cardiovascular diseases. Despite advances in treatment and control of HTN, the prevalence of HTN is still increasing. MitoQ is a supplement that acts on mitochondria and attenuates reactive oxygen species (ROS), which plays an important role in cardiovascular health. miRNAs play an important role in the pathophysiology of HTN. We evaluated the effects of MitoQ supplementation and endurance training (ET), alone and in combination, on functional indices of the heart and serum levels of miR-126, miR-27a, antioxidants, and NO, in patients with HTN. Methods. In a double-blind randomized clinical trial, 52 male participants (age 40-55 years) were randomly divided into four groups ( n = 13 ) of placebo, MitoQ (20 mg/day, oral), ET (cycle ergometer, moderate intensity, 40-60% VO2 peak, heart rate 120-140 b/min, 45 min a day, three days/week for six weeks), and MitoQ+ET. Cardiac function indices were assessed by echocardiography before and after interventions. Results. Systolic blood pressure (SBP) significantly decreased in all intervention groups ( P < 0.001 ) while DBP ( P < 0.01 ) and LV hypertrophy ( P < 0.05 ) were significantly decreased only in the MitoQ+ET group. Serum levels of SOD, GPx, and NO and the level of miR-126 significantly increased in all treatment groups, while miR-27a reduced in the ET ( P < 0.05 ) and MitoQ+ET ( P < 0.01 ) groups. Conclusions. Compared to MitoQ and ET alone, their combination has more prominent improving effects on cardiac health and amelioration of BP in the patients with HTN. These effects are through miR-126 and miR-27a modulation and ameliorating mitochondrial ROS production.

scholarly journals Effects of creatine hydrochloride supplementation on physical performance and hormonal changes in soldiers

2021 ◽  
Vol 9 (1) ◽  
pp. 93-99
Author(s):  
Mohammad Milad Tayebi ◽  
Mitra Yousefpour ◽  
Laya Ghahari
Keyword(s):  
Physical Performance ◽  
Vertical Jump ◽  
Hormonal Changes ◽  
Power Performance ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Double Blind ◽  
Back Squat ◽  
Before And After ◽  
Army Soldiers

Purpose: The aim of this study was to examine the effects of 2 weeks of creatine hydrochloride (CrHCl) supplementation on physical performance and hormonal changes in army soldiers. Materials: Eighteen male army soldiers were randomly assigned in a double-blind fashion to either a CrHCl (n=9) or placebo (Pl) (n=9) groups. CrHCl group costumed 3g of creatine per day, whereas Pl group was given dextrose. Before and after supplementation period, the subjects performed a battery of performance tests including one repletion maximum (1RM) of bench press and back squat, vertical jump (VJ) and Wingate anaerobic test. In addition, blood samples were obtained to determine changes in testosterone and cortisol concentrations per and post supplementation. Results: There were significant increases in VJ, peak and mean power, and 1RM back squat test following the 2 weeks of CrHCl supplementation (p < 0.05) without any significant change for the Pl group. In addition significant changes were observed in testosterone and cortisol concentrations from before to after supplementation in CrHCl group (p < 0.05) and compared with Pl group (p=0.001). Conclusions: In conclusion, the present study indicates that CrHCl supplementation can improve VJ, power performance, 1RM back squat and hormonal changes in army soldiers.

Effect of training on muscle metabolism during treadmill sprinting

1989 ◽  
Vol 67 (6) ◽  
pp. 2376-2382 ◽  
Author(s):  
M. E. Nevill ◽  
L. H. Boobis ◽  
S. Brooks ◽  
C. Williams
Keyword(s):  
Vastus Lateralis ◽  
Muscle Metabolism ◽  
Plasma Norepinephrine ◽  
Sprint Training ◽  
Mean Power ◽  
Muscle Lactate ◽  
Group 4 ◽  
Before And After ◽  
Muscle Buffering Capacity ◽  
Mean Power Output

Sixteen subjects volunteered for the study and were divided into a control (4 males and 4 females) and experimental group (4 males and 4 females, who undertook 8 wk of sprint training). All subjects completed a maximal 30-s sprint on a nonmotorized treadmill and a 2-min run on a motorized treadmill at a speed designed to elicit 110% of maximum oxygen uptake (110% run) before and after the period of training. Muscle biopsies were taken from vastus lateralis at rest and immediately after exercise. The metabolic responses to the 110% run were unchanged over the 8-wk period. However, sprint training resulted in a 12% (P less than 0.05) and 6% (NS) improvement in peak and mean power output, respectively, during the 30-s sprint test. This improvement in sprint performance was accompanied by an increase in the postexercise muscle lactate (86.0 +/- 26.4 vs. 103.6 +/- 24.6 mmol/kg dry wt, P less than 0.05) and plasma norepinephrine concentrations (10.4 +/- 5.4 vs. 12.1 +/- 5.3 nmol/l, P less than 0.05) and by a decrease in the postexercise blood pH (7.17 +/- 0.11 vs. 7.09 +/- 0.11, P less than 0.05). There was, however, no change in skeletal muscle buffering capacity as measured by the homogenate technique (67.6 +/- 6.5 vs. 71.2 +/- 4.5 Slykes, NS).

Effects of Traditional and Simplified Methods of Rhythm-Reading Instruction

1982 ◽  
Vol 30 (2) ◽  
pp. 107-119 ◽  
Author(s):  
Muriel J. Bebeau
Keyword(s):  
Reading Instruction ◽  
Traditional Approach ◽  
Third Graders ◽  
Traditional Group ◽  
General Application ◽  
Treatment Groups ◽  
Rhythm Reading ◽  
Before And After ◽  
The Difference ◽  
Early Training

Two experiments were conducted to compare the effectiveness of teaching rhythm reading using a traditional approach versus a simplified speech cue method. Results of the first experiment indicated the superiority of the speech cue method. Experiment 2 was conducted to determine whether the speech cue method could be used effectively with minimal teacher training. A 23-item rhythm-reading test was administered to 107 third graders before and after rhythm instruction by each method. In both experiments, the speech cue group made significantly greater gains than the traditional group. The difference between pretest and posttest scores was significant for both treatment groups. The findings have general application for rhythm-reading instruction using the speech cue method for early training.

scholarly journals Lactate threshold predicting time-trial performance: impact of heat and acclimation

2011 ◽  
Vol 111 (1) ◽  
pp. 221-227 ◽  
Author(s):  
Santiago Lorenzo ◽  
Christopher T. Minson ◽  
Tony G. Babb ◽  
John R. Halliwill
Keyword(s):  
Exercise Performance ◽  
Lactate Threshold ◽  
Time Trial ◽  
Heat Acclimation ◽  
Mean Power ◽  
Performance Impact ◽  
Time Trial Performance ◽  
Threshold Test ◽  
Before And After ◽  
Trial Performance

The relationship between exercise performance and lactate and ventilatory thresholds under two distinct environmental conditions is unknown. We examined the relationships between six lactate threshold methods (blood- and ventilation-based) and exercise performance in cyclists in hot and cool environments. Twelve cyclists performed a lactate threshold test, a maximal O2 uptake (V̇o2max) test, and a 1-h time trial in hot (38°C) and cool (13°C) conditions, before and after heat acclimation. Eight control subjects completed the same tests before and after 10 days of identical exercise in a cool environment. The highest correlations were observed with the blood-based lactate indexes; however, even the indirect ventilation-based indexes were well correlated with mean power during the time trial. Averaged bias was 15.4 ± 3.6 W higher for the ventilation- than the blood-based measures ( P < 0.05). The bias of blood-based measures in the hot condition was increased: the time trial was overestimated by 37.7 ± 3.6 W compared with only 24.1 ± 3.2 W in the cool condition ( P < 0.05). Acclimation had no effect on the bias of the blood-based indexes ( P = 0.51) but exacerbated the overestimation by some ventilation-based indexes by an additional 34.5 ± 14.1 W ( P < 0.05). Blood-based methods to determine lactate threshold show less bias and smaller variance than ventilation-based methods when predicting time-trial performance in cool environments. Of the blood-based methods, the inflection point between steady-state lactate and rising lactate (INFL) was the best method to predict time-trial performance. Lastly, in the hot condition, ventilation-based predictions are less accurate after heat acclimation, while blood-based predictions remain valid in both environments after heat acclimation.

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