Search Results

You are looking at 101 - 110 of 558 items for :

  • "anaerobic" x
Clear All
Restricted access

Khalid S. Almuzaini

The main purpose of the present study was to determine isokinetic strength and endurance, isometric strength, and anaerobic power for untrained healthy Saudi children and adolescents. The secondary purpose was to evaluate the effects of age in relation to anthropometric characteristics on strength and anaerobic performances. Forty-four (untrained) 11- to 19-year-old boys were grouped by age: 11-13 years, 14–16 years, and 17–19 years. All participants underwent anthropometric measurements, a flexibility test, a vertical jump test, a grip strength test, isokinetic strength measurements (Cybex Norm), and a Wingate anaerobic power test. Oneway ANOVA results indicated age-related increases in muscle strength and power. High correlation coefficients that were found among age and strength and anaerobic power indices almost disappeared when fat-free mass (FFM) was controlled for, indicating that the amount of variance in these indices that was explained by age is mostly shared by FFM. In addition, stepwise linear regression models indicated that FFM was the main predictor of strength and power performances. Thus, FFM was the best scaling variable for body size when comparing these age groups of Saudis. Until wide-range normal representative values for isokinetic strength and anaerobic power for Saudi children and adolescents are available, the present study’s results can serve as a reference for these indices.

Restricted access

Eric Small, Oded Bar-Or, Edgar Van Mil and Saroj Saigal

This study compared the anaerobic performance and the muscle strength between extremely low birthweight (> 1,000 g = ELBW) 11- to 17-year-old adolescents and normal birthweight (< 2,500 g = NEW) controls. Seventeen ELBW (9 females and 8 males) and 17 NEW (9 females and 8 males) subjects took part. ELBW had lower anaerobic performance, as manifested in mean (p = .03) and peak (p < .001) mechanical power per kg body mass (Wingate Anaerobic Test). In absolute units mean power and peak power tended (p = .06 and .08, respectively) to be lower in the ELBW group, but there were no inter-group differences in the isokinetic strength of knee extensors or flexors (Kin Com dynamometer). ANOVA revealed no interaction between the effects of low birthweight and gender. We propose that dynamic, but not static, muscle performance in ELBW is still somewhat inferior in adolescence. This may reflect deficient neuromuscular control.

Restricted access

David W. Hill, Robert P. Steward Jr. and Cindy J. Lane

The purpose of this study was to evaluate use of the critical power concept with swimmers ages 8 to 18 years. Critical velocity (CV) and anaerobic swimming capacity (ASC) were determined from the results of three short time trials (n = 86) or competition swims (n = 60). Data fit the critical power model well, as evidenced by high R2 and low SEE of CV and ASC estimates. CV was correlated with velocity in an endurance swim (r ≥ 0.86) and ASC was correlated with peak lactate (r ≥ 0.69). Thus, even in very young swimmers, CV and ASC provide mode-specific indices of endurance and anaerobic capacity, respectively.

Restricted access

David Criswell, Scott Powers, John Lawler, John Tew, Stephen Dodd, Yryik Iryiboz, Richard Tulley and Keith Wheeler

This study compared the efficacy of a 7% glucose polymer beverage containing electrolytes (GP) versus a nonnutrient, nonelectrolyte placebo (P) in maintaining blood homeostasis during recovery from football and determined whether consumption of the GP beverage improved anaerobic performance immediately after football competition when compared with the placebo. Forty-four high school football players participated in a 50-play scrimmage designed to simulate game conditions. At each of six periods before and during the scrimmage, players consumed 170 ml of the GP or P beverage. Eight maximal-effort 40-yd sprints (40-sec rest intervals) were performed before and after the scrimmage to assess the decrement in anaerobic performance from the scrimmage. Venous blood samples were drawn before and after the scrimmage and analyzed. The pre- to postscrimmage differences in mean and peak sprint velocities did not differ between treatments, nor did body weight and plasma. In contrast, the percent decrease in plasma volume was significantly greater in the P group. Postscrimmage increases in glucose and insulin were greater in the GP group. These data suggest that CHO-electrolyte drinks do not prevent a decline in anaerobic performance when compared to water, but a CMO-electrolyte drink is more effective in maintaining PV than water during recovery from anaerobic exercise.

Restricted access

Richard B. Kreider, Dawn Hill, Greg Horton, Michael Downes, Sarah Smith and Beth Anders

The purpose of this study was to determine the effects of carbohydrate supplementation during intense training on dietary patterns, psychological status, and markers of anaerobic and aerobic performance. Seven members of the U.S. National Field Hockey Team were matched to 7 team counterparts (N = 14). One group was blindly administered a carbohydrate drink containing 1 g·kg−1 of carbohydrate four times daily, while the remaining group blindly ingested a flavored placebo during 7 days of intense training. Subjects underwent pre- and posttraining aerobic and anaerobic assessments, recorded daily diet intake, and were administered the Profile of Mood States (POMS) psychological inventory prior to and following each practice. Results revealed that the carbohydrate-supplemented group had a greater (p < .05) total energy intake, carbohydrate intake, and change (pre vs. post) in time to maximal exhaustion following training while reporting less postpractice psychological fatigue. However, no significant differences were observed in remaining psychological, physiological, or performance-related variables.

Restricted access

James A. Padfield, Patricia A. Eisenman, Maurie J. Luetkemeier and Sally S. Fitt

A physiological profile of 40 early adolescent female dancers was completed to investigate the characteristics of dancers this age and the possible physical fitness benefits of high levels of dance training. Of those physical fitness variables studied, the only significant difference between performing (high level) and recreational (low level) dancers was the degree of hip flexibility (p<.01). Both groups exhibited lean body density (combined mean of 1.069 g ml−1) as well as moderate aerobic (combined mean of 45.8 ml kg−1 min−1) and anaerobic power (combined mean of 6.5 Watt kg−1). These data suggest that early adolescent dance training encourages a certain level of physical fitness, but higher levels or duration of dance training do not result in or demand exceptional aerobic or anaerobic power.

Restricted access

Dominic Micklewright, Murray Griffin, Valerie Gladwell and Ralph Beneke

A within subjects experimental design (N = 16) was used where participants performed a 30-s Wingate anaerobic cycling test (WAnT) after 30-min rest and after 30-min back massage. Mood State was measured before and after each intervention and after the WAnTs. No significant change in mood was detected following rest or massage. However, WAnT performance was better following massage compared to rest. Mood disturbance increased following the WAnT in both the rest and massage conditions. The results suggest that preperformance massage had no effect on mood state yet seemed to facilitate enhanced WAnT performance. The relationship between massage and anaerobic performance remains unclear, however is almost certainly mediated by preperformance psychological factors other than mood state.

Restricted access

James N. Roemmich and John P. Frappier

This study compared successful (n=19) and less successful (n=19) varsity wrestlers matched for age, weight, height, and wrestling experience on physiological variables important for wrestling success using field tests available to a high school wrestling coach. Significant (P<0.05) differences in favor of the successful wrestlers were found for mean left and right grip strength, flexibility of the low back and hamstrings, completed sit-ups, pull-ups, and push-ups. Successful wrestlers also covered a greater distance during a 12min run test and had significantly greater relative anaerobic power (Margaria step test). The groups did not differ significantly in the sum-of-six skinfolds. In conclusion, successful wrestlers had significantly more muscular strength, muscular endurance, flexibility of the low back and hamstrings, aerobic fitness, and relative anaerobic power than less successful wrestlers. It is suggested less successful wrestlers engage in regular training sessions that include stretching, cardiovascular, and strength/power components.

Restricted access

Martin Buchheit, Roberto Solano and Grégoire Paul Millet

The aim of the present investigation was to compare the accuracy of the heart-rate (HR) deflection point (HRDP) and the second HR variability threshold (HRVTh2) to predict anaerobic threshold in boys. HRDP was determined from slope trends of successive linear regressions. HRVTh2 was determined from the high frequency’s peak and power-density trends. The second ventilatory threshold (VTh2) corresponding to the first decrease in PETCO2, with an increase in VE/VCO2, was used as the reference measure of AnT. Results show that VO2 and HR were similar at HRDP, HRVTh2, and VTh2. HRVTh2 and HRDP were highly correlated. It appears that HRVTh2 is a good alternative to HRDP for assessing anaerobic threshold. HRVTh2 and HRDP might rely on similar mechanisms.

Restricted access

Pavle Mikulic

Purpose:

To examine variations in physical, physiological, and performance parameters over an annual training cycle in a world champion rowing crew.

Methods:

Four world-class rowers, all of them members of the men’s heavyweight quadruple sculls squad who are current world rowing champions, were assessed 3 times at regular 4-mo intervals during the 2011 season (November 2010, March 2011, and July 2011). Physical assessments included stature, body mass, body composition, whereas physiological and performance assessments obtained during an incremental rowing ergometer test to exhaustion included maximum oxygen uptake and anaerobic gas-exchange threshold with corresponding power output values.

Results:

Body mass (∼95 kg) and body composition (∼12% body fat) remained stable over the annual training cycle. Power output at anaerobic gas-exchange threshold increased +16% from November to July, whereas the corresponding oxygen uptake, expressed as a percentage of maximum oxygen uptake, increased from 83% to 90%. Maximum oxygen uptake decreased from 6.68 L/min in November to 6.10 L/min in March before rising to 6.51 L/min in July. The corresponding power output increased steadily from 450 W to 481 W.

Conclusion:

Seasonal variation in body mass and body composition of 4 examined world-class rowers was minimal. Oxygen uptake and power output corresponding to anaerobic threshold continuously increased from off-season to peak competition season. Seasonal variation in maximum oxygen uptake reached ∼10%; however, it remained above 6 L/min, that is, the value consistently observed in top caliber heavyweight rowers regardless of the time of the assessment.