Craig J. Cisar

Pre-exercise carbohydrate meals: application of glycemic index.

Purpose: The purpose of this study was to compare postprandial glycemic, insulinemic, and physiologic responses to a pre-exercise meal calculated to have a low glycemic index (LGI) with one calculated to have a moderately high glycemic index (HGI); each meal provided three foods totaling 1.5 g carbohydrate/kg body weight. Methods: After an overnight fast, 10 trained cyclists consumed one of the test meals or water 30 min before cycling 2 h at 70% of maximum oxygen uptake (VO 2max ), followed by cycling to exhaustion at 100% of VO 2max . Results: Plasma insulin levels were significantly lower (P< 0.05) after LGI than after HGI through 20 min of exercise. Significantly higher (P < 0.05) respiratory exchange ratios were observed after HGI than after LGI until 2 h of exercise. At that time plasma glucose levels were significantly higher and ratings of perceived exertion lower (P < 0.05) after LGI compared with after HGI. Time to exhaustion was 59% longer after LGI (206.5 ± 43.5 s) than after HGI (129.5 ± 22.8 s). Conclusions: These results suggest a pre-exercise LGI may positively affect maximal performance following sustained exercise. The LGI maintained higher plasma glucose levels at the end of 2 h of strenuous exercise than the HGI, which may have better supported subsequent maximal effort.

Strength and anaerobic responses of elite young female sprint and distance runners.

The purpose of this study was to assess the strength and anaerobic responses of elite young female runners, in order to determine the relationship of these characteristics to age and high proficiency in sprint events. Thirty-one national junior-level sprint and middle distance runners were evaluated for isokinetic peak torque for leg extension at velocities ranging for 30 degrees to 300 degrees X s-1, anaerobic power and capacity based on the Wingate test, and body composition based on underwater weighing. Age-related and event-related differences were noted for both the peak torque and anaerobic response measures. Peak torques were greater for the older (greater than 11.67 yr) runners and greater for the sprinters when measured at the higher testing velocities. Anaerobic power and capacity were also greater for the older runners, but event-related differences only appeared when anaerobic power was adjusted for fat-free weight (adjusted anaerobic power was greater in the older sprinters). These results indicate that both age and fat-free weight influence strength and anaerobic responses in young female runners and that exceptional levels of such characteristics only appear for sprinters within the upper age groups of youth competition.

Isokinetic leg flexion and extension strength of elite adolescent female track and field athletes

Abstract Sixty-two elite adolescent (age: 16.39 ± 1.62 yrs) female track and field athletes volunteered to be measured isokinetically for peak torque of the leg flexors and extensors. The sample included 16 throwers, 11 jumpers, 12 middle-distance runners (> 400 m), and 23 sprinters. A Cybex II isokinetic dynamometer was used to measure dominant leg strength at 180°/sec. One-way ANOVA revealed significant between group differences for absolute flexion and extension (Nm), extension/body weight (Nm/Kg), and extension/lean body weight (Nm/Kg). Scheffe post-hoc comparisons showed that, for absolute leg extension strength, throwers were stronger than middle-distance runners (by 54.4%), sprinters (35.6%), and jumpers (23.6%). For absolute leg flexion movements, throwers were stronger than middle distance runners (37.4%) and sprinters (32.1%). Jumpers had greater extension peak torque values than middle-distance runners relative to body weight (14.0%), and throwers were stronger than middle-distance runners for ...

Yearly changes in the body composition and muscular strength of high school wrestlers

Abstract The purpose of this investigation was to determine the yearly changes in body composition as well as absolute and relative isokinetic forearm flexion and extension strength of high school wrestlers. Evaluations of body composition (underwater weighing) were performed on 27 high school wrestlers prior to three consecutive seasons. In addition, isokinetic forearm flexion and extension strength values at 180°/s (Cybex II) were available for 20 of the subjects. The mean ages at the times of laboratory testing were 15.5 (± .5), 16.5 (± .5), and 17.5 (± .5) years. Repeated measures ANOVA or ANCOVA with Tukey post-hoc comparisons were used to locate significant (p<.05) differences across age for height, body weight, relative fat, body density, fat weight, fat-free weight, absolute muscular strength, and muscular strength covaried for body weight and fat-free weight. There were yearly increases in all variables except fat weight, forearm flexion covaried for fat-free weight and forearm extension covaried...

Effects of Kettlebell Training on Aerobic Capacity.

Abstract Falatic, JA, Plato, PA, Holder, C, Finch, D, Han, K, and Cisar, CJ. Effects of kettlebell training on aerobic capacity. J Strength Cond Res 29(7): 1943–1947, 2015—This study examined the effects of a kettlebell training program on aerobic capacity. Seventeen female National Collegiate Athletic Association Division I collegiate soccer players (age: 19.7 ± 1.0 years, height: 166.1 ± 6.4 cm, weight: 64.2 ± 8.2 kg) completed a graded exercise test to determine maximal oxygen consumption (V[Combining Dot Above]O2max). Participants were assigned to a kettlebell intervention group (KB) (n = 9) or a circuit weight-training (CWT) control group (n = 8). Participants in the KB group completed a kettlebell snatch test to determine individual snatch repetitions. Both groups trained 3 days a week for 4 weeks in addition to their off-season strength and conditioning program. The KB group performed the 15:15 MVO2 protocol (20 minutes of kettlebell snatching with 15 seconds of work and rest intervals). The CWT group performed multiple free-weight and dynamic body-weight exercises as part of a continuous circuit program for 20 minutes. The 15:15 MVO2 protocol significantly increased V[Combining Dot Above]O2max in the KB group. The average increase was 2.3 ml·kg−1·min−1, or approximately a 6% gain. There was no significant change in V[Combining Dot Above]O2max in the CWT control group. Thus, the 4-week 15:15 MVO2 kettlebell protocol, using high-intensity kettlebell snatches, significantly improved aerobic capacity in female intercollegiate soccer players and could be used as an alternative mode to maintain or improve cardiovascular conditioning.

Anthropometric and body build variables as discriminators of event participation in elite adolescent male track and field athletes

Abstract The purpose of this study was to determine the extent to which anthropometric and body build measures discriminated between elite adolescent male athletes competing in different track and field events. One hundred and six national‐level Junior Olympic male athletes (mean age ± s.d. = 17.7±0.7 yr) volunteered as subjects. The sample included 26 middle distance runners, 24 sprinters/hurdlers, 39 jumpers and 17 throwers. The body build variables measured included fat‐free body weight/height (FFB/Ht), the sum of 6 skinfolds (SUM‐SF), the sum of 12 diameters (SUM‐D), the sum of 11 circumferences (SUM‐C), biacromial diameter/bi‐iliac diameter (BA/BI) and the bidimensional somatotype rating components X (ectomorphic rating—endomorphic rating) and Y [twice the mesomorphic rating — (endomorphic+ ectomorphic rating)]. Multiple discriminant analysis revealed three significant (P<0.05) discriminant functions (DF1, DF2, DF3). Validation of the discriminant functions revealed an overall value of 76.8% of subje...

Validity of Anthropometric Estimations of Body Composition in High School Wrestlers

The purpose of this study was to determine the validity of 23 anthropometric equations for estimating body composition and minimal wrestling weight in high school wrestlers. A total of 409 high school wrestlers (M age +/- SD = 16.42 +/- 1.03 yrs) volunteered for this study. Twenty-three anthropometric measures including eight skinfolds, nine circumferences, and six diameters were obtained from each subject. The mean body density, determined from underwater weighing, was 1.0748 +/- 0.0100 g.cm-3. The crossvalidation analyses indicated that the quadratic skinfold equation of Lohman resulted in the most accurate estimation of body density. The total error, constant error, standard error of estimate, and r for this equation were 0.0077 g.cm-3, -0.0003 g.cm-3, 0.0076 g.cm-3 and .65, respectively. Furthermore, the results of this investigation indicated that the minimal wrestling weight equations of Tcheng and Tipton resulted in total error values (5.54 to 6.06 kg) which were too large to be of practical use for high school wrestlers.

Basic Conditioning Principles for High School Wrestlers.

In brief: Tired wrestlers bore the crowd and disappoint themselves and their coaches. By contrast, skilled, aggressive wrestlers who are conditioned to attack and defend throughout a six-minute match can generate excitement equal to that of any athletic contest. To maintain the appropriate fitness required to perform at this level, a specific conditioning program is needed. This article describes a conditioning program based on a year-round schedule that helps wrestlers achieve and maintain their highest possible level of performance.

The effects of age and body weight on anthropometric estimations of minimal wrestling weight in high school wrestlers

The purpose of this study was to determine the effects of age and body weight on anthropometric estimations of minimal wrestling weight (MWW) in high school wrestlers. Five hundred and twenty-two high school wrestlers (M age +/- SD = 16.45 +/- 1.03 years) volunteered as subjects for this study. The total sample (N = 522) was dichotomized by age (less than 16 years, n = 171; greater than or equal to 16 years, n = 351) and body weight (less than or equal to 62.60 kg, n = 252; greater than 62.60 kg, n = 270). Cross-validation analyses included examination of the constant error (CE), standard error of estimate (SEE), r, and total error (TE). The results indicated that the quadratic skinfold equation of Lohman (EQ1; Table 2) most accurately estimated MWW in each group. Furthermore, it was recommended that MWW be calculated from EQ1 using the conversion constants of Lohman ([(5.03/BD)-4.59] x 100) to estimate relative fat from body density.

Preexercise Carbohydrate Meals: Application of Glycemic Index

Abstract LEARNING OUTCOME: To list physiologic and performance differences following consumption of two preexercise meals of varying glycemic indices. The lowering of plasma glucose can contribute to fatigue in subjects performing strenuous endurance exercise. Plasma glucose may be maintained by preexercise carbohydrate meals. A low glycemic index meal (LGI) may offer an advantage by providing a source of glucose to the blood for a long period of time accompanied by a minimal insulin surge. The purpose of this study was to compare postprandial metabolic, physiologic, and performance responses to a LGI and a moderately high GI meal (HGI), each providing three foods totaling 1.5g carbohydrate per kg body weight. After an overnight fast, 10 male endurance trained cyclists consumed one of the test meals or water 30min prior to cycling 2h at 70% of maximum oxygen uptake (VO2 max) followed by cycling to exhaustion at 100% of VO2 max. Data were analyzed using two-way ANOVA for repeated measures (P