Development of a rowing-specific VO2max field test.

The purpose of this study was to develop an aerobic capacity test for rowers using minimal equipment that could be used in the field. Thirty rowers (15 men and 15 women) between the ages of 18 and 26 years were recruited on a volunteer basis from the District of Columbia metro area. The testing protocol consisted of a maximum of 7 2-minute stages on a rowing ergometer, separated by 30-second breaks where lactic acid concentrations were analyzed. Starting intensity for men was 200 W, although women started at 150 W, and each stage increased by 50 W. Expired gasses were collected during the test, and athletes were asked to row until maximal volition so that the directly measured VO2max could be compared to predicted values. Peak heart rates from each completed stage were plotted, and regression equations were calculated to predict VO2max. Separate regression equations were calculated for men and women. The predicted VO2max values were approximately 23 and 25% lower than what was actually achieved for men and women, respectively. Heart rate was a stronger correlate of VO2max in men compared with in women. Among men, we observed a moderate and statistically significant correlation (r = 0.55; p = 0.05), whereas among women, no such agreement was observed (r = -0.05; p > 0.85). The principle finding of this study was that the test was adequate in predicting VO2max in men but was inadequate in its prediction in women. With slight modifications to the testing protocol, stronger correlations and a more accurate prediction of VO2max is expected in men.

Comparison of acute exercise responses between conventional video gaming and isometric resistance exergaming.

Exergaming is a relatively new type of entertainment that couples physical activity and video gaming. To date, research that has focused on the physiologic responses to exergaming has been focused exclusively on aerobic-type activities. The purpose of this project was to describe the acute exercise responses (i.e., oxygen uptake [VO(2)], heart rate, and rate of perceived exertion [RPE]) to exergaming using full-body isometric muscle resistance and to determine whether these responses are different during single- versus opponent-based play. Male subjects (n = 32) were randomly and equally divided into either an experimental (EXP) or control (CON) group. Acute exercise responses VO(2), heart rate, and RPE) were measured in all subjects during both solo- and opponent-based video game play. Subjects in the EXP group played using a controller that relied on full-body isometric muscle resistance to manipulate the on-screen character, whereas CON subjects used a conventional handheld controller. During solo play, the EXP group exhibited significantly higher values for VO(2) (9.60 +/-0.50 mL/kg/min) and energy expenditure (3.50 +/- 0.14 kcal/min) than the CON group VO(2) 5.05 +/- 0.16 mL/kg/min; energy expenditure 1.92 +/- 0.07 kcal/min). These changes occurred with no significant differences in RPE or heart rate between the groups. These results suggest that whole-body isometric exergaming results in greater energy expenditure than conventional video gaming, with no increase in perceived exertion during play. This could have important implications regarding long-term energy expenditure in gamers.

Ponderal somatogram analysis of girth measurements by position in division III college football players.

Ponderal somatograms assessed body composition in four groups of Division III collegiate football players: offensive line (OL), defensive line (DL), offensive backs (OB), and defensive backs (DB). Ponderal somatograms evaluate body size and shape by converting muscular (shoulders, chest, biceps, forearm, thigh, and calf) and nonmuscular (abdomen, hips, knee, ankle, and wrist) girths into ponderal equivalent (PE) values. Anthropometric measurements, including stature, body mass, girths, and percent body fat by densitometry were collected in 82 players (22 OL, 12 DL, 20 OB, and 28 DB) during preseason camp. PE values were calculated for each girth as PE, kilograms = (girth, cm / k) x stature, decimeters, where k = k constant from Behnke's reference man. PE values were compared to body mass to indicate overdevelopment (PE > body mass) and underdevelopment (PE < body mass). OL was significantly heavier than DL (+15.6 kg), OB (+25.2 kg), and DB (+22.4 kg). OL percent fat was significantly greater than DL (+5.9%), OB (+9.0%), and DB (+9.3%). Similar differences occurred in girths and PE values by position. Muscular components were generally overdeveloped, with the greatest overdevelopment in the biceps (OL + 16.0 kg, DL + 19 kg, OB + 14.2 kg, and DB + 16.2 kg). Nonmuscular abdomen, hips, and knee were generally overdeveloped, with the greatest overdevelopment in the OL abdomen (+19.3 kg). Nonmuscular ankle and wrist were underdeveloped. Ponderal somatograms provide a relatively quick and simple method to translate girth measurements into ponderal equivalent values that seem to be position-specific among offensive and defensive linemen and backs. Somatograms provide an appraisal of body composition that helps coaches and athletes monitor the effectiveness of strength and conditioning programs.

Changes in pain perception in women during and following an exhaustive incremental cycling exercise.

Exercise has been found to alter pain sensitivity with a hypoalgesic response (i.e., diminished sensitivity to pain) typically reported during and/or following high intensity exercise. Most of this research, however, has involved the testing of men. Thus, the purpose of the following investigation was to examine changes in pain perception in women during and following exercise. Seventeen healthy female subjects (age 20.47±.87; VO2 peak 36.77± 4.95) volunteered to undergo pain assessment prior to, during, and after a graded exhaustive VO2 peak cycling challenge. Heart Rate (HR) and Oxygen Uptake (VO2) were monitored along with electro-diagnostic assessments of Pain Threshold (PT) and Pain Tolerance (PTOL) at: 1) baseline (B), 2) during exercise (i.e., 120 Watts), 3) at exhaustive intensity (VO2 peak), and 4) 10 minutes into recovery (R). Data were analyzed using repeated measures ANOVA to determine differences across trials. Significant differences in PT and PTOL were found across trials (PT, p = 0.0043; PTOL p = 0.0001). Post hoc analyses revealed that PT were significantly elevated at VO2 peak in comparison to B (p = 0.007), 120 Watts (p = 0.0178) and R (p = 0.0072). PTOL were found to be significantly elevated at 120 Watts (p = 0.0247), VO2 peak (p < 0.001), and R (p = 0.0001) in comparison to B. In addition, PTOL were found to be significantly elevated at VO2 peak in comparison to 120 Watts (p = 0.0045). It is concluded that exercise-induced hypoalgesia occurs in women during and following exercise, with the hypoalgesic response being most pronounced following exhaustive exercise. Key PointsExercise-induced hypoalgesia (i.e., elevated PT and PTOL) was found to occur in women during and following exercise, with the hypoalgesic response being most pronounced during exhaustive exercise.

Ponderal somatograms assess changes in anthropometric measurements over an academic year in Division III collegiate football players.

Ponderal somatograms evaluate body size and shape by converting muscular (shoulders, chest, biceps, forearm, thigh, calf) and nonmuscular (abdomen, hips, knee, ankle, wrist) girths into ponderal equivalent (PE) values. Anthropometric measurements, including stature, body mass, girths, and percent body fat by densitometry were collected in 54 Division III football players in preseason camp (fall) and at the beginning (winter) and end (spring) of the team strength and conditioning program. PE values were calculated for each girth as PE, kg = (girth, cm / k)(2) x stature, dm, where k = k constant from Behnke's reference man. PE values were compared to body mass to indicate overdevelopment (PE > body mass) and underdevelopment (PE < body mass) at specific girth sites. From fall to winter, body mass (+1.6 kg), percent fat (+1.3%), fat mass (+1.6 kg), nonmuscular abdominal and hip girths (+2.1 cm, +1.5 cm), and PE values (+5.3 kg, +2.6 kg) increased significantly (p < 0.05). From winter to spring, percent fat (-1.5%), fat mass (-1.4 kg), nonmuscular abdominal girth (-1.0 cm), and PE value (-2.5 kg) decreased significantly (p < 0.05). Fat-free mass (+1.5 kg), muscular biceps girth (+0.4 cm), and PE value (+2.6 kg) increased significantly (p < 0.05) from winter to spring. Ponderal somatogram muscular components were generally overdeveloped, with the greatest overdevelopment at the biceps in fall (+14.7 kg), winter (+14.9 kg), and spring (+17.4 kg). Nonmuscular components generally were underdeveloped, except abdomen and hips that were overdeveloped. The abdomen remained the greatest nonmuscular overdevelopment in fall (+6.8 kg), winter (+10.5 kg), and spring (+7.9 kg). Ponderal somatograms provide a relatively simple, practical method to track specific changes in body size and shape over time.

The effects of isokinetic contraction velocity on concentric and eccentric strength of the biceps brachii.

The purpose of this investigation was to determine the influence of contraction velocity on the eccentric (ECC) and concentric (CON) torque production of the biceps brachii. After performing warm-up procedures, each male subject (n = 11) completed 3 sets of 5 maximal bilateral CON and ECC isokinetic contractions of the biceps at speeds of 90, 180, and 300 degrees x s(-1) on a Biodex System 3 dynamometer. The men received a 3-minute rest between sets and the order of exercises was randomized. Peak torque (Nm) values were obtained for CON and ECC contractions at each speed. Peak torque scores (ECC vs. CON) were compared using a t-test at each speed. A repeated measures analysis of variance was used to determine differences between speeds. ECC peak torque scores were greater than CON peak torque scores at each given speed: 90 degrees x s(-1), p = 0.0001; 180 degrees x s(-1), p = 0.0001; and 300 degrees x s(-1), p = 0.0001. No differences were found between the ECC peak torque scores (p = 0.62) at any of the speeds. Differences were found among the CON scores (p = 0.004). Post hoc analysis revealed differences between 90 degrees x s(-1) (114.61 +/- 23) and 300 degrees x s(-1) (94.17 +/- 18). These data suggest that ECC contractions of the biceps brachii were somewhat resistant to a force decrement as the result of an increase in velocity, whereas CON muscular actions of the biceps brachii were unable to maintain force as velocity increased.

Comparison of 3 Methods to Assess Urine Specific Gravity in Collegiate Wrestlers.

OBJECTIVE: To investigate the reliability and validity of refractometry, hydrometry, and reagent strips in assessing urine specific gravity in collegiate wrestlers. DESIGN AND SETTING: We assessed the reliability of refractometry, hydrometry, and reagent strips between 2 trials and among 4 testers. The validity of hydrometry and reagent strips was assessed by comparison with refractometry, the criterion measure for urine specific gravity. SUBJECTS: Twenty-one National Collegiate Athletic Association Division III collegiate wrestlers provided fresh urine samples. MEASUREMENTS: Four testers measured the specific gravity of each urine sample 6 times: twice by refractometry, twice by hydrometry, and twice by reagent strips. RESULTS: Refractometer measurements were consistent between trials (R =.998) and among testers; hydrometer measurements were consistent between trials (R =.987) but not among testers; and reagent-strip measurements were not consistent between trials or among testers. Hydrometer (1.018 +/- 0.006) and reagent-strip (1.017 +/- 0.007) measurements were significantly higher than refractometer (1.015 +/- 0.006) measurements. Intraclass correlation coefficients were moderate between refractometry and hydrometry (R =.869) and low between refractometry and reagent strips (R =.573). The hydrometer produced 28% false positives and 2% false negatives, and reagent strips produced 15% false positives and 9% false negatives. CONCLUSIONS: Only the refractometer should be used to determine urine specific gravity in collegiate wrestlers during the weight-certification process.

An investigation of the tri-bar gripping system on isometric muscular endurance.

Recently, a new product called the Tri-Bar has been introduced as an alternative to the standard round weightlifting bar. The Tri-Bar has the same weight, length, and circumference as a standard weightlifting bar and differs only in that the shape of the bar is formed like a triangle with rounded edges. Theoretically, the shape of the bar will enhance gripping comfort and increase muscular endurance. We studied 32 moderately trained males who were free from upper-body injury or limitation. Each participant completed 4 visits to the lab as part of 2 separate investigations. The first investigation was a comparison of straight-arm hang times while grasping a standard Olympic bar or a Tri-Bar attached to the top of a power rack. The second investigation involved grasping a standard revolving cable handle or a Tri-Bar revolving handle attached to a weight equal to half the subject's body weight. In both investigations, time was used as a measure of isometric muscular endurance. Differences were determined using a dependent t-test, and a level of significance was set at p < 0.05. Mean hang times were significantly longer when the men hung from the Tri-Bar (107.6 seconds) versus the standard bar (95.4 seconds) (p = 0.015). Conversely, in the investigation using the revolving handles, the round bar produced longer grasping times (71.5 seconds) than the Tri-Bar (62.6 seconds) (p = 0.000). The results of this investigation indicate that a fixed and stable Tri-Bar may help to increase hang time, but a Tri-Bar free to rotate within the grasp may decrease grasping time in comparison to a standard round handle. With regard to exercises that require isometric grasping, the Tri-Bar may be an effective alternative to the standard bar for increasing isometric grasping endurance.

Effect of load position on physiological and perceptual responses during load carriage with an internal frame backpack.

The purpose of this study was to determine the effect of load position in an internal frame backpack on physiological and perceptual variables. Ten female participants walked on a level treadmill for 10 min carrying 25% of their body weight in a high, central, or low position. The variables measured included oxygen consumption (VO2), heart rate (HR), respiratory exchange ratio (R), respiratory rate (RR), minute ventilation (VE), and rating of perceived exertion (RPE). VO2, VE, and RPE were significantly lower in the high position (18.6 +/- 2.3 ml/kg/min, 31.7 +/- 5.0 l/min, 2.8 +/- 0.8, respectively) compared to the low position (22.2 +/- 3.0 ml/kg/min, 38.6 +/- 7.5 l/min, 3.7 +/- 1.0, respectively). HR, R, and RR did not change significantly as the load was moved from the high (129.8 +/- 16.8, 0.89 +/- 0.06, 30.3 +/- 4.2, respectively) to the low position (136.0 +/- 25.3, 0.92 +/- 0.04, 33.8 +/- 5.2, respectively). The results of this study suggest that load placement is an important factor in the physiological and perceptual responses to load carriage, and that packing heavy items high in the backpack may be the most energy efficient method of carrying a load on the back.