O'Kroy, Joseph A.

The purpose of this study was to evaluate the effectiveness of the American
Association of Cheerleading Coaches and Advisors (AACCA) certification in
reducing injuries associated with cheerleading. Participants were selected from a
list of AACCA certified coaches in the state of Florida and through state, county,
and district cheerleading coach directories in Delaware, Florida, Maryland, New
Jersey, Pennsylvania, Virginia and West Virginia. A total of approximately 575
questionnaires asking about number and types of injuries in 2003 -2004,
certifications held and other relevant information were distributed. One hundred
and two questionnaires were returned for a response rate of 16.5%. Contrary to
our hypothesis, AACCA certification was not associated with fewer reported
injuries. In contrast, holding other cheerleading certifications was negatively
correlated with total injuries suggesting that other certifications, but not AACCA
certification, are more effective in reducing injuries.

Effects of an external nasal dilator on the work of breathing was measured during exercise in 14 untrained students (age, 24 $\pm$ 3 yr.). Two maximal, incremental ergometer tests were performed to exhaustion. Subjects wore a placebo or an active nasal dilator strip, in random order, during each test. Measurement of inspiratory elastic work (inew), inspiratory resistive work (inrw), and expiratory resistive work (exrw) was done using an esophageal balloon. Measured variables included VO$\sb2$, V$\rm\sb{E}$, V$\rm\sb{T}$, frequency of breathing (f), inew, inrw, and exrw, (work expressed in joules). There were no significant differences in VO$\sb2$, V$\rm\sb{E}$, V$\rm\sb{T}$ or f between groups ($\rm p>0.05$). No significant difference was found at peak exercise between groups (mean $\pm$ SD; Placebo; inew, $1.1\pm0.6$ J, inrw, $1.4\pm0.8$ J, exrw $2.2\pm1.8$ J; Active; inew, $1.0\pm0.5$ J, inrw, $1.3\pm0.7$ J, exrw, $1.8\pm0.9$ J; $\rm p>0.05$). Wearing an external nasal dilator does not significantly reduce the work of breathing during exercise.

The purpose of this study was to determine the effects of an aerodynamic racing posture on the work of breathing during cycling. Nine moderately trained cyclists performed three maximal exercise tests on a cycle ergometer using three different commonly used riding positions. The positions used were vertical (V) with back upright and perpendicular to the ground, horizontal (H) with the upper third of the back parallel to the ground and elbows on the "aero-bars," and with hands on the drop bars and back at a 45-degree angle to the ground (45). Total work of breathing (WOB), oxygen consumption (VO$\sb2$), tidal volume (V$\sb{\rm T}$), minute ventilation (V$\sb{\rm E}$), and breathing frequency (f) were measured. There were no significant differences in WOB, VO$\sb2$, V$\sb{\rm T}$ V$\sb{\rm E}$, or f between any position at 70% of maximal exercise or at maximal exercise. Therefore, an aerodynamic posture is not associated with an increased work of breathing in cyclists.

The purpose of the present study was to cross-validate the BOD POD (BP) measurements of male high school athletes with those obtained from hydrostatic weighing (HW). Additionally, the percent body fat values measured via near-infrared interactance (NIR), bioelectrical impedance (BIA) and skinfold (SF) were compared to HW to determine the validity of these measures. Thirty male, high school athletes (mean age +/- SD = 15.8 +/- 1.0 yrs) volunteered to have their % fat estimated. The findings from the present study indicated that the NIR and BIA instruments resulted in total error values that were too large to be of practical value (TE = 11.0 and TE = 6.5% fat, respectively). The BP (TE = 3.8% fat) produced acceptable measures (TE < 4.0% fat), but compared to all SF (TE = < 3.5% fat) estimations, BP was higher. These data suggest that the BP can produce acceptable body fat measures for male high school athletes, but is not superior to SF.

The purpose of this study was to determine the effect of oxygenated water on endurance exercise performance. Subjects (N=15, VO2max 54.8 +/- 5.8 ml/kg/min) were tested using non-oxygenated water (PL) and oxygenated water (OW). Two maximal exercise tests and 2 submaximal tests were conducted. VO2max (3.28 +/- 0.81 L/min (OW) vs. 3.30 +/- 0.80 L/min (PL)) VE, VO2, or R were not different. Submaximal blood lactate values at 60%, 80% of VO 2max (4.2 +/- 2.1 mMol/L, 6.6 +/- 2.9 mMol/L (OW) vs. 3.8 +/- 1.8 mMol/L, 6.1 +/- 2.4 mMol/L (PL)) and HR (140 +/- 15 bpm, 162 +/- 11 bpm (OW) vs. 138 +/- 15 bpm, 163 +/- 13 bpm (PL)) were not different and neither was time to exhaustion at 90% of VO 2max (5.22 +/- 2.31 min (OW) vs. 6.80 +/- 2.93 min (PL)). Oxygen content of OW (13.1 +/- 1.5 mgO2L-1 ) was higher than PL (6.0 +/- 0.1 mgO2L -1) (p<0.05) but lower than manufacture's claims. Thus, superoxygenated water did not result in any improvements in endurance exercise performance.

Active-isolated (AI = 11) stretching was compared to static stretching (SS = 8), proprioceptive neuromuscular facilitation stretching (PNF = 10), and a control group (C = 9) at improving hamstring flexibility. Pre- and post-assessments of flexibility were performed with a goniometer on the right leg. All subjects performed a warm-up on an ergometer; after which, subjects in the stretching groups performed mode-specific stretching of both hamstrings 4 days per week for 4 weeks. A significant increase was found in flexibility after training for all stretching groups (p < 0.05). However, there were no significant differences in flexibility between groups (ANOVA: p > 0.05). It is possible the small number of subjects may have contributed to this finding.

The purpose of this investigation was to quantify the electrical activity in the pectoralis major during a supine dumbbell chest press while maintaining a fixed and non-fixed scapula. Fifteen neophyte male subjects between the ages of 18--45 participated in the investigation. Each subject performed five repetitions with 85% of their estimated 1RM in both a fixed (FI) and non-fixed (FL) scapulae position. Measurement of EMG activity was recorded from the shoulder girdle and localized musculature via pre-amplified bipolar skin surface electrodes for the duration of both testing bouts. Data analysis employed a repeated measures ANOVA (p < 0.05). No significant difference in measured electrical activity was noted for the pectoralis major between the two tested positions of the scapulae. Therefore, it appeared scapular positioning did not influence measured electrical activity in the pectoralis major.

The role of airflow limitation (AFL) in exercise-induced arterial hypoxemia (ElAH) was examined in six well-trained competitive cyclists. Two maximal cycle ergometer tests were performed, one while breathing room air (RA; 79% N2, 21% O2) and another breathing a mixture of heliox (He; 79% He, 21% O2) in random order. EIAH was estimated via pulse oximetry of HbSaO2. The results revealed no subject experienced AFL breathing RA or He. Despite a significant increase in V&dot;Emax (RA = 114.3 +/- 27.6 l/min; He = 129.2 +/- 25.5 l/min; p < 0.05) during He condition there was no difference in HbSaO2 during maximal exercise (RA = 95.3 +/- 1%; He = 96.7 +/- 1.5%; p > 0.05). In conclusion, our subject population failed to show any significant decrease in HbSaO2 breathing RA, which makes it difficult to determine if AFL plays a role in EIAH.