Athletes competing in contact sports commonly wear intra-oral dental mouthguards. Data are sparse concerning the influence of a mouthguard on breathing during exercise. We compared VE and VO2 during submaximal and maximal exercise on a skating treadmill (TM) while wearing an intra-oral dental mouthguard. Female varsity hockey players (n = 12) performed two skating tests on a TM with and without a mouthguard (WIPSS Jaw-Joint Protecto(TM)). The players wore the mouthguard during hockey practices prior to collection of ventilation data on the treadmill. Also, the players completed a questionnaire that examined their perceptions of the mouthguard in terms of ventilation, comfort and performance. A 10-point rating scale was used for this evaluation. Two performance tests on the skating treadmill examined the effect of the mouthguard on submaximal and maximal aerobic exercise. The subjects skated for 4 min at 2 submaximal velocities (14 and 16 km·h-1 ) separated by 5 min of passive recovery. A VO2 max test followed the submaximal tests and commenced at 18 km·h-1 with the velocity increasing by 1 km·h-1 every minute until volitional fatigue. VE, VO2, VCO 2 and RER were analyzed using a Sensor Medics 2900 metabolic cart. Two-way (2 conditions x 3 velocities) repeated measures ANOVAs were used to examine differences in VE, VO2 and HR. Ventilation was unchanged when skating at the two submaximal velocities. VO2 max was 48.8 ml·kg-1·min-1 using the intra-oral mouthguard and was 52.4 ml·kg-1·min -1 without a mouthguard. VE max was 108.5 L·min -1 using the intra-oral mouthguard and was 114.1 L·min -1 without a mouthguard. The results showed that VE max and VO2 max were lower using the mouthguard compared to the no mouthguard condition.

The objective of this study was to assess the oxygen cost of various intensities of steady-state cycling. VO2 (ml·min -1·kg-1) was measured at rest, during unloaded cycling (UL), 20 Watts, 50% (SS50) & 65% (SS65) of peak watts in 40 COPD patients (64 +/- 9 yrs; FEV1/FVC: 48 +/- 17 % predicted; FEV1:36 +/- 14 % predicted) and 28 age-matched healthy controls (CTRL). Despite higher VE (L·min -1) in COPD vs. CTRL (UL: 20.6 +/- 3.4 vs. 15.4 +/- 4.1; 20W: 24.3 +/- 4.5 vs. 17.8 +/- 4.2), VO2 at rest, at UL and 20W was not higher in COPD compared to CTRL. In addition, comparable slope and intercept coefficients for the VO2 vs. Watt relationship were obtained in COPD and CTRL for submaximal cycling of low to moderate intensity. (Abstract shortened by UMI.)

Purpose. To examine the outcome of a 6-month treatment with carvedilol or metoprolol on peak and submaximal exercise performance and ventilatory efficiency in patients with heart failure (HF). / Methods. 27 patients with HF were randomized to receive either metoprolol or carvedilol for 6 months and compared with 12 healthy controls. Maximal exercise capacity was assessed at baseline and after 6 months with a symptom limited incremental treadmill protocol (RAMP). Submaximal exercise was determined to be the portion of exercise below a respiratory exchange ratio of 1.0. Peak heart rate (HR), oxygen uptake (VO2), and ventilatory equivalent for O2 and CO2 were recorded. The slopes of the VE vs. VCO2, VE vs. VO2 and VE/VCO2 vs. VO2 relationships were calculated for each subject from submaximal values. / Results. Resting HR decreased to similar extent in both treatment groups. There were no other significant changes in resting hemodynamics or ventricular function. Peak VO2 and HR decreased significantly in both treatment groups. Peak VE/VCO2 and submaximal VCO 2 vs. VE slope were not changed significantly after therapy. / Conclusion. beta-blocker treatment with either metoprolol or carvedilol does not decrease the slope of the VCO2 vs. VE relationship. The present observations may suggest that the exaggerated ventilatory response of patients with moderate HF is not mediated by beta-adrenergic receptors.

Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 7 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 5 uppsatser.

Thesis (M.S.)--The University of North Carolina at Greensboro, 2008. / Directed by Paul Davis; submitted to the Dept. of Kinesiology. Title from PDF t.p. (viewed Jul. 20, 2010). Includes bibliographical references (p. 104-112).

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