Tommy Boone

Cardiovascular and thermal responses of triathlon performance.

Triathletes typically train each triathlon event separately. Therefore, to determine the cardiovascular and thermal differences between training and triathlon performance, nine male triathletes performed a simulated 75-min (40 km) control bike and a 40-min (10 km) control run at 70% of maximal oxygen uptake. Control data were compared to data derived from a simulated triathlon (0.8-km swim, 75-min bike, and 40-min run). Results demonstrated that prior swimming significantly decreased (P less than 0.05) triathlon cycling work output (191 +/- 4.2 to 159 +/- 7.6 W) producing mean differences (P less than 0.05) in oxygen uptake (3.18 +/- 0.1 to 3.01 +/- 0.11.min-1), ventilation (84.7 +/- 4 to 80.4 +/- 4.21.min-1), stroke volume (128 +/- 7.1 to 118 +/- 3.5 ml.min-1), cardiac output (20.7 +/- 1.2 to 18.9 +/- 0.8 l.min-1), mean arterial pressure (105 +/- 3.8 to 96 +/- 7.9 mm Hg) and rectal temperature (38.2 +/- 0.2 to 38.4 +/- 0.3 degrees C). Triathlon running, while performing identical control work output, elicited significant increases (P less than 0.05) in oxygen uptake (3.41 +/- 0.1 to 3.85 +/- 0.1 l.min-1), ventilation (91.3 +/- 3.3 to 104.2 +/- 2.8 l.min-1), heart rate (161 +/- 3.1 to 174 +/- 3.6 beats.min-1), arteriovenous oxygen difference (15.3 +/- 0.2 to 17.2 +/- 0.3 ml.100 ml-1) and rectal temperature (38.3 +/- 0.2 and 39.2 +/- 0.3 degrees C) with significantly lower (P less than 0.05) stroke volume (138 +/- 2.4 to 129 +/- 3.6 ml.min-1) and mean arterial pressure (102 +/- 11.2 to 89 +/- 5.5 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Qigong on Cardiorespiratory Changes: A Preliminary Study

Qigong, a special form of breathing exercise, was investigated to examine its effect on cardiorespiratory changes. Ten volunteers (five males and five females) participated in a 20-minute group instructional session for 10 consecutive days before testing of its treatment effects. The testing protocol followed a C1-T-C2 design, where C1, T, and C2 represented the first, treatment, and second control period, respectively. Each period consisted of a 5-minute interval, and thus each testing session consisted of 15 minutes. The results indicated there were no statistically significant differences (p > 0.05) in heart rate or tidal volume for the three 5-minute periods. There was a significant decrease (p < 0.05) in respiratory exchange ratio between T and C2. A significant increase in ventilatory efficiency for carbon dioxide production was found between C1 and T. Statistically significant differences (p < 0.05) were found in the volume of oxygen consumed and carbon dioxide produced, frequency of breath, expired ventilation, and ventilatory efficiency for oxygen produced between the T and the two control periods. This preliminary study of Qigong demonstrates that the subjects were able to learn the technique in a short period of time. The data also suggest that, with an improvement of nearly 20% in ventilatory efficiency for oxygen uptake and carbon dioxide production, this technique may have useful therapeutic value.

GENDER DIFFERENCES IN CARDIOVASCULAR RESPONSE TO ISOMETRIC EXERCISE IN THE SEATED AND SUPINE POSITIONS 999

ABSTRACT Donald R Melrose. Gender Differences In Cardiovascular Response To Isometric Exercise In The Seated And Supine Positions. JEP online . 2005;8(4):29-35. The purpose of this study was to 1) determine if the cardiovascular responses to isometric exercise differ between genders, and 2) determine if posture affects cardiovascular responses to isometric n women and 15 men (age 22.6±4.2 yrs) performed two randomized (seated or supine) maximal IHG trials at 40 %MVC one week apart. Blood pressure (BP) and heart rate (HR) measurements were collected at rest (RT), the first minute of exercise (M1), prior to failure (PF), and at 30 s of recovery following failure (RC). Mean arterial pressure (MAP), pulse pressure (PP), and rate pressure product (RPP) were calculated from BP and HR data. Analyses showed significant time by gender interactions for diastolic blood pressure (DBP) and MAP. Males had significantly higher DBP than females at M1 (105.46±14.97 vs. 92.59±13.14 mmHg), PF (122.46±11.23 vs. 109.50±13.72 mmHg) and RC (85.83±4.11 vs. 73.46 ± 8.35 mmHg) and higher MAP measurements than females at M1 (120.32 ± 13.76 vs. 105.43 ± 13.76 mmHg), PF (136.44 ± 8.65 vs. 24.31 ±13.34 mmHg), and RC (100.44 ±8.21 vs. 87.67 ±8.26 mmHg). DBP, MAP, and HR were significantly higher in the seated position than in the supine position for both genders. It was concluded that 1) men significantly increase MAP and DBP upon initiation of submaximal IHG exercise through recovery regardless of posture, 2) women have significantly lower blood pressure measurements than men during submaximal IHG exercise regardless of posture, and 3) posture has a significant affect on cardiovascular response during submaximal IHG exercise.

Metabolic cost of walking with and without a shoe-lift on the contralateral foot of an immobilised extended knee

The purpose of the present study was to determine the metabolic cost of walking with and without a shoe-lift on the contralateral foot of an immobilised extended knee. Eight male subjects were randomly allocated and participated in both the treatment (walking with a 2.5 cm shoe-lift) and control (walking without a shoe-lift) conditions. Cardiac output (Q) and related cardiovascular measurements were analysed to determine the effect of a shoe-lift on central (heart rate (HR); stroke volume (SV)) and peripheral (arteriovenous oxygen difference (a-vO2 diff)) components of oxygen consumption (VO2). A metabolic analyser was used to determine VO2 (ml x kg(-1) x min(-1)), which was converted to oxygen cost (ml x kg(-1) x m(-1)). The shoe-lift had no significant (p > 0.05) effect on VO2 or oxygen cost. There were no significant differences in Q, HR, SV, a-vO2 diff, systemic vascular resistance, carbon dioxide production, respiratory exchange ratio, expired ventilation, tidal volume and respiratory rate between the two walking conditions with and without a shoe-lift. These findings demonstrate that a shoe-lift added to the contralateral foot of an immobilised extended knee does not produce clinically important effects on oxygen cost or efficiency during walking.

Effects of a 10-Minute Back Rub on Cardiovascular Responses in Healthy Subjects

This study determined the cardiovascular responses to a 10-minute back rub. Twelve healthy, college-age males and females (mean age = 22 years) volunteered to participate as subjects. Using an ABA design, the subjects tested for 10 minutes (Control #1) on a padded plinth lying on one side. During the Treatment period, the back rub was administered, which was followed by Control #2. Oxygen consumption (VO2) was determined via the Medical Graphics CPX/D metabolic analyzer, which also estimated cardiac output (Q) using the CO2 rebreathing (equilibrium) method. A repeated measures ANOVA was performed to statistically compare the cardiovascular responses across the three periods. The back rub, when compared to Control #1, had no significant effect on VO2, but the central and peripheral components of VO2 were changed. Cardiac output was decreased as a result of the decreased stroke volume (SV), as a function of the increased peripheral vascular resistance (PVR). We also found an increase in the extraction of oxygen (a-vO2 diff) in the peripheral tissues. These results indicate that the VO2 response during the back rub was achieved by reciprocal central (SV,Q) and peripheral (a-vO2 diff) adjustments. Following the back rub, (i.e., Control #2 vs. Treatment), the decrease in VO2, VCO2, Ve, and a-vO2 diff appears to indicate that it was effective in inducing relaxation. Since HR, SV, and Q were unchanged, the VO2 response was a result of the decreased a-vO2 diff. Hence, the findings suggest certain positive implications for the health care industry.

Influence of a 36‐h fast on the central and peripheral components of VO2 during submaximal exercise and peak oxygen uptake

To determine if a 36-h fast affects the central and peripheral components of VO2 during submaximal exercise and peak oxygen uptake (VO2 peak), 10 physically healthy males exercised first for 10 min at approximately 60% of their VO2 peak and then to fatigue. Their cardiovascular responses were compared with those of 10 physically healthy controls (males) who were individually matched by VO2 peak values. Fasting had no significant effect on the central (heart rate, HR; stroke volume, SV; cardiac output, Q) and peripheral (arteriovenous oxygen content difference, a-vO2 diff.) components of VO2 during submaximal exercise. The respiratory exchange ratio (RER) during submaximal exercise was significantly decreased in the fasted subjects. Based on the RER, fasting altered substrate utilization of the muscle and thereby increased the contribution of fat during submaximal exercise. Fasting had no significant effect on VO2 peak, HR or O2 pulse, but RER was significantly lower during incremental exercise to fatigue. These results demonstrate that VO2 during submaximal exercise in fasted subjects is achieved by similar central and peripheral responses as found in non-fasted subjects, and that fasting does not reduce VO2 peak.

Carotid palpation at two exercise intensities.

It remains unclear whether carotid palpation (CP) should be used to count post-exercise heart rate (HR). We hypothesized that the carotid sinus, when stretched or compressed by external pressure, results in an increased nerve activity to the cardiovascular areas in the brain stem, with a resultant increase in parasympathetic activity and a decrease in sympathetic activity. The primary purpose of this study was to investigate the effects of CP and no CP on post-exercise HR determination at two exercise intensities. The secondary purposes were to investigate whether CP during exercise would elicit a decrease in HR and the effects of CP on post-exercise blood pressure. Twenty-one healthy females served as subjects. During the final min of each exercise intensity, two 10-s HRs were recorded by continuous ECG (i.e., 10 s without palpation and 10 s with palpation). Immediately post-exercise at each intensity, the carotid artery was either palpated (Phase I) or not palpated (Phase II). At 60 and 80% intensity, with 10-s CP, post-exercise HR decreased 12.4 and 7 beats . min-1, respectively (both were significant: P less than 0.05). At 60 and 80% intensity, without CP, post-exercise HR decreased 6.1 and 3.3 beats . min-1 in 10-s, respectively (both were significant; P less than 0.05). CP during exercise did not elicit a carotid sinus reflex, and post-exercise CP did not alter blood pressure readings. These findings were generally contrary to previous research on CP and were determined to be important in that the correct technique was used by the investigators.(ABSTRACT TRUNCATED AT 250 WORDS)

The Therapeutic Insights of Poetry Writing.

AbstractThis brief report is about the use of poetry writing in expressing and/or resolving feelings that may otherwise be too difficult to talk about. As a result, instead of feeling helpless, a person learns to grow in hope and understanding.