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Official Journal of the American College of Sports Medicine 1275 Board #221 May 30, 8:00 AM - 9:30 AM a Multivariable Index for Grading Exercise Gas Exchange severity in Patients with Pulmonary arterial hypertension and heart Failure Chul-Ho Kim, Steve Anderson, Dean McMacarter, Bruce D. Johnson. Mayo Clinic, Rochester, MN. (No relationships reported) Patients with pulmonary arterial hypertension (PAH) and heart failure (HF) display a number of abnormalities in respiratory gas exchange with exercise. These abnormalities track disease severity and are associated with prognosis. However, there are limitations due to the large number of variables and difficulty in interpretation. PurPOsE. To develop a multivariable gas exchange index (MVI) that integrates key variables obtained during submaximal exercise and to demonstrate its utility clinical populations. METhOds. 1) Normal values and ranges of 6 gas exchange variables (Rest PetCO2, Delta PetCO2, SaO2, OUES, VE/VCO2 and PCAP) that are associated with a higher risk in PAH and HF were obtained from previous literature and used to develop a score. 2) To test the MVI score, the gas exchange data from 3 populations (42-PAH, 47-HF, 25-controls) were gathered. Each variable was scored based on severity (=4=very severe) in HF or PAH and was calculated into a weighted cumulative individual variable index score which was then divided by total number of variables to get the MVI. Relationships between individual gas exchange measures, calculated MVI, cardiac Index (CI), New York Heart Association (NYHA), Right Ventricular Systolic Pressure (RVSP) and WHO classification were examined. rEsuLTs. We developed a model to integrate gas exchange variables using a weighted classification system that categorized disease severity based on the final MVI outcome. A MVI value of
<strong>Thursday</strong>, May 30, 2013 S248 Vol. 45 No. 5 Supplement 1279 Board #225 May 30, 8:00 AM - 9:30 AM Comparison Of Oxygen utilization during Magnetic Muscle stimulation With That during handgrip Exercise Tadashi Saitoh, Kyuichi Niizeki. Yamagata University, Yonezawa, Japan. (No relationships reported) PurPOsE: This study aimed to investigate the dynamics of oxygen utilization during intermittent muscle contraction induced by magnetic stimulation compared with that during handgrip exercise. METhOds: This study included 7 healthy volunteers (means ± SD: age, 24.4 ± 5.6 yr; height, 167.9 ± 3.8 cm; body mass, 63.3 ± 6.4 kg). After a 2-minute rest, the volunteers received magnetic stimuli with a magnitude of 0.4 kV in the flexor digitorum superficialis muscle or performed handgrip exercise for 2 min at 1 Hz, followed by a 2-minute rest. The intensity of the handgrip exercise was controlled so that its amplitude, as measured by mechanomyography, matched that of the magnetic stimulation. Pulmonary gas exchange rates, ventilation level, and heart rate were measured breath by breath. Hemoglobin concentrations were measured at 1 Hz using near-infrared spectroscopy. rEsuLTs: During the handgrip exercise, oxygen uptake and heart rate immediately increased to 407.6 ± 117.7 ml/min (baseline, 196.6 ± 47.3 ml/min) and 76.6 ± 8.6 beats/min (baseline, 66.2 ± 7.0 beats/min), respectively. Moreover, deoxyhemoglobin levels exponentially increased at an amplitude of 15.4 μM. On the other hand, during the magnetic stimulation, oxygen uptake, heart rate, and the levels of oxyhemoglobin, deoxyhemoglobin, and total hemoglobin remained constant. CONCLusIONs: This experiment showed that oxygen utilization did not increase during the intermittent muscle contraction induced by magnetic stimulation. The data also suggest that the aTP-PCr system served as the primary energy supply system for contraction during magnetic stimulation, or that muscle contraction during magnetic stimulation did not require aTP. 1280 Board #226 May 30, 8:00 AM - 9:30 AM Effects of stretch shortening Cycle Warm-up on Cycling Performance in Females Jessica W. Chow1 , David Heikkinen2 , Elaina Mertens3 , Tracey D. Matthews3 , Vincent J. Paolone, FACSM3 . 1Brooklyn College, Brooklyn, NY. 2Fitchburg State University, Fitchburg, MA. 3Springfield College, Springfield, MA. (No relationships reported) Respiratory muscle fatigue has been recognized to be a contributing factor to the termination of high intensity exercise performance due to a sympathetically mediated vasoconstriction response in the peripheral muscles. Inspiratory muscle specific warmup (2 x 30 repetitions) has been reported to improve performance in several high intensity activities. PurPOsE: To determine the effects of performing 2 x 30 stretch shortening cycling (SSC) respiratory muscle warm-up on cycling performance. METhOds:Fifteen highly fit female subjects (VO2peak: 51.70 ± 6.67 ml·kg-1·min-1) participated in the study. The control trial involved a 5 min whole body warm-up cycling at 40% of peak power output. The experimental trial consisted of 2 x 30 breathing exercises following the 5 min whole body warm-up. Maximum expiratory volume (MEV) and maximum inspiratory volume (MIV) were assessed after the warm-up routines and post exercise. Subjects exercised at 85% of peak power output until volitional fatigue. During the exercise test minute ventilation (VE), relative volume of oxygen consumption (VO2/kg), tidal volume (VT), breathing frequency (F), rating of perceived breathlessness (RPE-B), respiratory exchange ratio (RER), and breathing economy (VE/VO2) were measured every minute. Time to exhaustion (TEX) was also measured to assess performance. Multiple statistical analyses were used including one paired sample t-test, three analysis of variance (ANOVA), and one multivariate analysis of variance (MANOVA) to assess for statistical differences. rEsuLTs: No significant differences were observed between the treatment and MEDICINE & SCIENCE IN SPORTS & EXERCISE ® control for MIV, MEV, VE, VO2/kg, VT, F, RPE-B, RER, and VE/VO2 (p > .05). Expected exercise physiological responses were observed over time for VE, VO2/ kg, VT, F, RPE-B, RER and VE/VO2. No significant differences were observed for MIV (2.425 L ±.104 vs. 2.358 L ±.084, p > .05). MEV was significantly reduced post exercise (3.168 L ± 0.151 vs. 2.994 L ± 0.127, p < .05). CONCLusIONs:Performing the 2 x 30 repetition of SSC warm-up breathing exercises with whole body warm-up appeared to have an ergolytic effect on cycling performance by exasperating respiratory muscle fatigue,inducing the sympathetically mediated vasoconstriction response in the peripheral muscles. 1281 Board #227 May 30, 8:00 AM - 9:30 AM Effects of acute Oleic acid-induced Lung Injury on aerobic Capacity James H. Jones, George H. Crocker. University of California, Davis, CA. (No relationships reported) Soldiers in combat, rescue workers and miners may receive blast injuries that reduce pulmonary diffusing capacity for O2 (DLO2) and aerobic capacity (VO2max), jeopardizing their ability to escape to safety. PurPOsE: We tested the hypothesis that we could simulate acute lung injury that reduces DLO2 with oleic acid (OA) infusion and that it would decrease VO2max. METhOds: We infused OA (0.05 ml/kg) coupled with high-velocity saline through a dual-lumen catheter into the right atria of five goats to evenly distribute OA throughout their lungs. At 2-h and 24-h post-OA infusion or without OA infusion (control), goats ran on a treadmill at speeds eliciting VO2max while we measured O2 consumption, heart rate (fH) and sampled arterial and mixed-venous blood. We measured pulmonary diffusing capacity for CO (DLCO) using a rebreathing method both pre-infusion and pre-exercise. rEsuLTs: The DLCO returned to control values within ~3 days post-OA. Compared to control, VO2max decreased by 33% at 2-h and 24% at 24-h post-OA (P = 0.007), although VO2max did not differ between times (P = 0.319). The fH decreased by 29%, stroke volume (VS) did not change and cardiac output (Q) tended to decrease post-OA (fH, P = 0.009; VS, P = 0.155; Q, P = 0.073). However, OA also reduced arterio-mixed venous [O2] difference by 17% (P < 0.001) because arterial [O2] (CaO2) decreased by 17% (P < 0.001) with only a tendency for mixed-venous [O2] to do so (P = 0.080). Decreased CaO2 resulted from O2 saturation decreasing by 21% (P < 0.001) due to hypoxemia from impaired gas exchange (alveolar-arterial O2 partial pressure (PO2) difference increased by 32 Torr (P < 0.001)), not hypoventilation (P = 0.899). We tested whether fH decreased due to direct OA effect or due to hypoxemia by running the goats on the treadmill post-OA while breathing hyperoxic gas (30% O2) to defend arterial PO2. The fH remained lower in hyperoxia, not different from breathing normoxic gas (P = 0.803), suggesting OA directly affects fH. CONCLusIONs: The OA decreased pulmonary diffusing capacity, fH, CaO2 and VO2max, supporting our hypothesis. Infusion of OA may provide a reproducible and repeatable model of acute lung injury for animals in exercise studies. Supported by the U.S. Army Medical Research and Materiel Command (Contract No. W81XWH- 11-D-0011) through L-3/Jaycor. C-38 Free Communication/Poster - Upper Extremity Mechanics May 30, 2013, 7:30 AM - 12:30 PM Room: Hall C 1282 Board #228 May 30, 9:00 AM - 10:30 AM Vibration Exercise With Or Without Xco-trainer In Epicondylitis (VIBEs) - a randomized study Karsten Knobloch, Berit Schiffke. Sports Private Practice Prof. Karsten Knobloch, FACS, Hannover, Germany. (No relationships reported) PurPOsE: To study the effect of vibration training with or without a dynamic mass training (XCO-Trainer) on lateral epicondylitis. Hypothesis: A proprioceptive training with a dynamic mass device (XCO-Trainer) intervention is beneficial in terms of pain reduction and improvement of function in lateral epicondylitis. METhOds: We performed a randomized study and included a total number of 72 patients with unilateral lateral elbow tendinopathy and randomized in a 1:1 allocation to two groups: •Group A (n=40, final analysis n=29): Flexi-Bar only: vibration training only over 12 weeks with three distinct exercises and 10min training twice daily •Group B (n=32, final analysis n=28): Flexi-Bar+XCO Trainer: Combination intervention using vibration device Flexi-Bar and XCO-Trainer (oscillating mass within a tube moved during running 40-60min/week with reactive impact technology) The primary outcome parameter wa pain on visual analogue scale (VAS 0=no pain, ACSM May 28 - June 1, 2013 Indianapolis, Indiana
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