Search

This investigation examined the validity of newly developed Adult OMNI Elliptical Ergometer Ratings of Perceived Exertion Scales. 60 men and women performed a graded exercise test on an elliptical ergometer. Oxygen consumption (V[O.sub.2]), heart rate (HR), and ratings of perceived exertion were recorded at each stage from the Borg 15 Category scale and two different OMNI scales. One scale employed an elliptical ergometer format of the OMNI Picture System of Perceived Exertion. The second scale modified verbal, numerical, and pictorial descriptors at the low end of the response range. Concurrent and construct validity were established by the positive relation between ratings of perceived exertion from each OMNI scale with V[O.sub.2], HR, and Borg scale ratings of perceived exertion (men, r= .94-.97; women, r = .93-.98). Validity was established for both OMNI scales, indicating either metric can be used to estimate ratings of perceived exertion during partial weight-bearing exercise. DOI 10.2466/05.06.PMS.111.6.848-862

The purpose of this study was to compare the effects of warm-up protocols using either whole-body vibration (WBV) or cycle ergometry (CE) on peak torque at 3 different isokinetic speeds and on fatigue in the knee extension exercise. Twenty-seven recreationally trained (age = 23.59 [+ or -] 3.87 years) men (n = 14) and women (n = 13) were tested at 3 different isokinetic speeds (60, 180, 300[degrees] x [s.sup.-1]) after either WBV or CE warm-up. The WBV consisted of intermittent bouts of 30 seconds of isometric squats at various degrees of hip and knee flexion for a total of 5 minutes. The CE consisted of 5 minutes of pedaling a cycle ergometer at 65-85% of age-predicted max heart rate. Comparisons between the warm-up conditions were analyzed using repeated measures analysis of variance. For the fatigue comparison, subjects completed 50 continuous concentric knee extensions at 240[degrees] x [s.sup.-1]. Means from the first 3 repetitions were compared to means from the final 3 repetitions to establish a fatigue index. Conditions were compared through an independent T-test. No significant (p > 0.05) differences were discovered between warm-up conditions at any speed or on the fatigue index. Means were virtually identical at 60[degrees] x [s.sup.-1] (WBV = 142.14 [+ or -] 43.61 ft [lb.sup.-1]; CE = 140.64 [+ or -] 42.72 ft [lb.sup.-1]), 180[degrees] [s.sup.-1] (WBV = 93.88 [+ or -] 35.18 ft [lb.sup.-1]; CE = 96.36 [+ or -] 31.53 ft [lb.sup.-1]), and 300[degrees] x [s.sup.-1] (WBV = 78.36 [+ or -] 26.04 ft [lb.sup.-1]; CE = 80.13 [+ or -] 26.08), and on fatigue percentage (WBV = 51.14 [+ or -] 10.06%; CE = 52.96 [+ or -] 9.19%). These data suggest that the more traditional 5-minute cycle ergometer warm-up elicits results comparable to a less common vibration warm-up. The findings of this study are that these modalities are comparable under the tested conditions. KEY WORDS strength, peak torque, fatigue

Enhancing the acute quality of the resistance training stimulus is the goal of many research and applied professionals. To that end, many methods have been proposed and a variety of training strategies and ergogenic supplements have been investigated. Postactivation potentiation is one phenomenon that has been frequently examined, offering some promise in this regard. Though never previously applied in the strength and conditioning profession, dental research on jaw clenching, studies examining the Jendrassik maneuver and remote voluntary contractions and research on motor overflow together make a compelling case for the existence of a concurrent activation potentiation phenomenon and the acute ergogenic advantage associated with the simultaneous activation of muscles other than the prime mover or synergists. Evidence demonstrates that this advantage is accrued via activation of the H reflex and through cortical overflow. Ultimately, through research and practical application, athletes may be taught to optimize the type, timing, and magnitude of remote muscle actions in order to gain an ergogenic advantage and increase the acute response of the prime movers. This strategy may be especially useful during the most difficult portion of a resistance training repetition and during the most difficult repetitions of a resistance training set. KEY WORDS. Jendrassik maneuver, remote voluntary contractions, motor overflow, strength

The purpose of this study was to examine the effects of 28 days of beta-alanine (b-Ala) and creatine monohydrate (CrM) supplementation on the onset of neuromuscular fatigue by using the physical working capacity at neuromuscular fatigue threshold ([PWC.sub.FT]) test in untrained men. Fifty-one men (mean age [+ or -] SD = 24.5 [+ or -] 5.3 years) volunteered to participate in this 28-day, double-blind, placebo-controlled study and were randomly assigned to 1 of 4 groups: placebo (PLA; 34 g dextrose; n = 13), CrM (5.25 g CrM plus 34 g dextrose; n = 12), b-Ala (1.6 g b-Ala plus 34 g of dextrose; n = 12), or b-Ala plus CrM (CrBA; 5.25 g CrM plus 1.6 g b-Ala plus 34 g dextrose; n = 14). The supplement was ingested 4 times per day for 6 consecutive days, then twice per day for 22 days before posttesting. Before and after the supplementation, subjects performed a continuous incremental cycle ergometry test while a surface electromyographic signal was recorded from the vastus lateralis muscle to determine [PWC.sub.FT]. The adjusted mean posttest [PWC.sub.FT] values (covaried for pretest [PWC.sub.FT] values) for the b-Ala and CrBA groups were greater than those for the PLA group (p [less than or equal to] 0.05). However, there were no differences between the CrM vs. PLA, CrBA vs. b-Ala, CrM vs. b-Ala, or CrM vs. CrBA groups (p > 0.05). These findings suggested that b-Ala supplementation may delay the onset of neuromuscular fatigue. Furthermore, there appeared to be no additive or unique effects of CrM vs. b-Ala alone on [PWC.sub.FT] KEY WORDS. carnosine, ergogenic aids, electromyography, cycle ergometry

The purpose of this study was to examine 10 weeks of creatine monohydrate (Cr) supplementation coupled with resistance training on body composition and strength in women trainees. Twenty-six subjects ingested Cr (n = 13) or a placebo (Pl) (n = 13) at a dose of 0.3 g x [kg.sup.-1] and 0.03 g x [kg.sup.-1] body mass for the initial 7 days and subsequent 9 weeks, respectively, while performing a resistance training program 4 days per week. Significant increases (p < 0.05) occurred in both groups for lean body mass and 1 repetition maximum (1RM) bench press and incline leg press. There was a significant main effect for training, but there was no significant difference in the total number of repetitions completed after 5 sets of multiple repetitions to exhaustion at 70% of 1RM for bench press and incline leg press for both groups or in the ability to perform a greater training volume (sets X repetitions X load) in the Cr vs. P1 groups over the 10 weeks. The results indicate that Cr supplementation combined with 10 weeks of concurrent resistance training may not improve strength or lean body mass greater than training only. These findings may be a result of nonresponders due to gender differences or a varying biological potential to uptake Cr within the muscle. KEY WORDS. ergogenic aid, training, female trainees

The aims of this study were to examine (a) the relationship between maximal oxygen uptake ([Vo.sub.2]max) and several performance indices of multiple sprint cycling; (b) the relationship between maximal accumulated oxygen deficit (MAOD) and those same performance indices; and (c) the influence of recovery duration on the magnitude of those relationships. Twenty-five physically active men completed a [Vo.sub.2]max test, a MAOD test, and 2 maximal intermittent (20 x 5 seconds) sprint cycling tests with contrasting recovery periods (10 seconds or 30 seconds). Mean [+ or -] SD for age, height, and body mass were 20.6 [+ or -] 1.5 years, 177.2 [+ or -] 5.4 cm, and 78.2 [+ or -] 8.2 kg, respectively. All tests were conducted on a friction-braked cycle ergometer with subsequent data normalized for body mass. Moderate (0.3 [less than or equal to] r < 0.5) positive correlations were observed between power output data and MAOD (range, 0.31-0.46; 95% confidence limits, -0.10 to 0.72). Moderate to large positive correlations also were observed between power output data and [Vo.sub.2]max, the magnitude of which increased as values were averaged across all sprints (range, 0.45-0.67; 95% confidence limits 0.07-0.84). Correlations between fatigue and [Vo.sub.2]max were greater in the intermittent protocol with 30-second recovery periods (r = -0.34; 95% confidence limits, 0.06 to -0.65). The results of this study reflect the complex energetics associated with multiple sprint work. Though the findings add support to the idea that multiple sprint sports demand a combination of speed and endurance, further longitudinal research is required to confirm the relative importance of these parameters. KEY WORDS. correlation, intermittent exercise, repeated bouts, performance indices

This study examined differentiated rating of perceived exertion (RPE), heart rate, and heart-rate variability during light cycle ergometry exercise at two different pedal rates. 30 healthy men (22.6 [+ or -] 0.9 yr.) were recruited from a student population and completed a continuous 20-min. cycle ergometry exercise protocol, consisting of a 4-min. warm-up (60 rev./min, 30 Watts), followed by four bouts of 4 min. at different combinations of pedal rate (40 or 80 rev./min.) and power output (40 or 80 Watts). The order of the four combinations was counterbalanced across participants. Heart rate was measured using a polar heart-rate monitor, and parasympathetic balance was assessed through time series analysis of heart-rate variability. Measures were compared using a 2 (pedal rate) x 2 (power output) repeated-measures analysis of variance. RPE was significantly greater (p

This study evaluated the validity and reliability of the Chinese-translated (Cantonese) versions of the Borg 6-20 Rating of Perceived Exertion (RPE) scale and the Children's Effort Rating Table (CERT) during continuous incremental cycle ergometry with 10- to 11-yr.-old Hong Kong school children. A total of 69 children were randomly assigned, with the restriction of groups being approximately equal, to two groups using the two scales, CERT (n=35) and RPE (n=34). Both groups performed two trials of identical incremental continuous cycling exercise (Trials 1 and 2) 1 wk. apart for the reliability test. Objective measures of exercise intensity (heart rate, absolute power output, and relative oxygen consumption) and the two subjective measures of effort were obtained during the exercise. For both groups, significant Pearson correlations were found for perceived effort ratings correlated with heart rate (rs [greater than or equal to] .69), power output (rs [greater than or equal to] .75), and oxygen consumption (rs [greater than or equal to] .69). In addition, correlations for CERT were consistently higher than those for RPE. High test-retest intraclass correlations were found for both the effort (R = .96) and perceived exertion (R = .89) groups, indicating that the scales were reliable. In conclusion, the CERT and RPE scales, when translated into Cantonese, are valid and reliable measures of exercise intensity during controlled exercise by children. The Effort rating may be better than the Perceived Exertion scale as a measure of perceived exertion that can be more validly and reliably used with Hong Kong children.