scholarly journals Oxygen Consumption at 30 W of Exercise Is Surrogate for Peak Oxygen Consumption in Evaluation of Cardiorespiratory Fitness in Young-Adult African-American Females

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Richard M. Millis ◽  
Vernon Bond ◽  
M. Sadegh Asadi ◽  
Georges E. Haddad ◽  
Richard G. Adams

Body mass index (BMI) is negatively correlated with cardiorespiratory fitness, measured by maximal or peak oxygen consumption (VO2peak). VO2peak measurements require heavy aerobic exercise to near exhaustion which increases the potential for adverse cardiovascular events. This study tests the hypothesis that VO2 measured at a fixed submaximal workload of 30 W is a surrogate for VO2peak. We studied 42 normotensive African-American female university students, 18–25 years of age. We measured VO2peak, blood pressure, and VO2 at a 30 W exercise workload and computed BMI. We found significant negative correlations between BMI and VO2peak (r=−0.41, P<0.01) and between BMI and VO2 at 30 W (r=−0.53, P<0.001). Compared to VO2peak, VO2 at 30 W increased the significance of the negative correlation with BMI. The heart rate-systolic pressure product at 30 W was positively correlated with BMI (r=0.36, P<0.01) and negatively correlated with VO2peak (r=−0.38, P<0.001). The positive correlation between BMI and the heart rate-systolic pressure product and the greater negative correlation between VO2 and BMI at 30 W of exercise than that at exercise to fatigue suggest that normalized measurements of VO2 at the fixed exercise workload of 30 W could be useful surrogates for measurements of VO2peak.

2018 ◽  
Vol 33 (3) ◽  
pp. 428-438 ◽  
Author(s):  
Marguerite Harvey ◽  
Kathryn L Weston ◽  
William K Gray ◽  
Ailish O’Callaghan ◽  
Lloyd L Oates ◽  
...  

Objectives: To investigate whether people with Parkinson’s disease can exercise at a high-intensity across a 12-week intervention and to assess the impact of the intervention on cardiorespiratory fitness. Design: This is a randomized, controlled, feasibility study with waiting list control. Assessors were blinded to group allocation. Setting: The intervention took place at an exercise centre and assessments at a district general hospital. Subjects: This study included 20 people with idiopathic Parkinson’s disease. Intervention: A total of 36 exercise sessions over 12 weeks, with each session lasting ~45 minutes, were conducted. Main measures: The main measures were maximal heart rates achieved during exercise, recruitment rate, attendance, drop-out, change in peak oxygen consumption, cardiac output, cognitive function and quality of life. The study was considered technically feasible if participants achieved ⩾85% of maximal heart rate during exercise. Results: There were 12 male and 8 female participants; they had a mean age of 68.5 years (standard deviation 6.825). Two participants were of Hoehn and Yahr stage I, 11 stage II and 7 stage III. In all, 17 participants completed the intervention. The median (interquartile range) proportion of repetitions delivered across the intervention which met our high-intensity criterion was 80% (67% to 84%). Mean peak heart rate was 88.8% of maximal. Peak oxygen consumption increased by 2.8 mL kg−1 min−1 in the intervention group and 1.5 mL kg−1 min−1 in the control group after 12 weeks of exercise. We estimate that a fully powered randomized controlled trial would require 30 participants per group. Conclusion: High-intensity interval exercise is feasible in people with Parkinson’s disease. Improvements in cardiorespiratory function are promising.


2000 ◽  
Vol 32 (12) ◽  
pp. 2059-2066 ◽  
Author(s):  
RICHARD R. SUMINSKI ◽  
ROBERT J. ROBERTSON ◽  
FREDRIC L. GOSS ◽  
and SILVA ARSLANIAN

2000 ◽  
Vol 98 (6) ◽  
pp. 643-648 ◽  
Author(s):  
Gerald P. MCCANN ◽  
Helen CAHILL ◽  
Stephen KNIPE ◽  
Douglas F. MUIR ◽  
Paul D. MACINTYRE ◽  
...  

5-Hydroxytryptamine (5-HT; serotonin) has been implicated in the perception of exercise-induced fatigue. Sumatriptan is a selective 5-HT1B/D receptor agonist which does not cross the blood–brain barrier. The aim of the present study was to determine the effect of sumatriptan on exercise capacity. Ten healthy male subjects (mean age 28.4±10.8 years) performed a maximal treadmill exercise test according to the Bruce protocol with expired gas analysis on two occasions. Either 6 mg of sumatriptan or placebo was administered subcutaneously in a randomized, double-blind, placebo-controlled, cross-over design. Exercise time was greater after placebo compared with sumatriptan [914 and 879 s respectively; 95% confidence interval (CI) of difference 12.1 s, 59.1 s; P = 0.008]. There was no significant effect on peak oxygen consumption (placebo, 50.6±6.3 ml·min-1·kg-1; sumatriptan, 51.7±7.6 ml·min-1·kg-1). Sumatriptan administration resulted in decreases in both heart rate (sumatriptan, 188±14 beats/min, placebo, 196±12 beats/min; 95% CI of difference 12.6, 2.6; P = 0.008) and respiratory exchange ratio (sumatriptan, 1.23±0.06; placebo, 1.26±0.07; 95% CI of difference 0.05, 0.01; P = 0.01) at peak exercise. There were no significant differences in blood pressure, heart rate or submaximal oxygen consumption between sumatriptan and placebo treatments at any stage of exercise. Thus sumatriptan reduces maximal exercise capacity in normal males. The failure to demonstrate any haemodynamic or cardiorespiratory effect suggests that sumatriptan enhances perception of fatigue by a peripheral mechanism affecting 5-HT modulation.


1983 ◽  
Vol 244 (2) ◽  
pp. H206-H214 ◽  
Author(s):  
H. Suga ◽  
R. Hisano ◽  
S. Hirata ◽  
T. Hayashi ◽  
O. Yamada ◽  
...  

Left ventricular (LV) systolic pressure-volume area (PVA), a new measure of total mechanical energy for the contraction, linearly correlates with its oxygen consumption per beat (VO2) regardless of contraction mode in a canine heart with stable chronotropism and inotropism. PVA is the area in the pressure-volume (PV) diagram circumscribed by the end-systolic and end-diastolic PV relation curves and the systolic segment of the PV loop and has dimensions of energy. We investigated whether primary changes in heart rate would affect the VO2-PVA relation. In the excised cross-circulated canine heart with left ventricular load controlled with a servo pump, we changed heart rate by pacing to compare the VO2-PVA relations at low [124 +/- 17 (SD) min-1] and high (193 +/- 23) heart rates. In 15 left ventricles, VO2 (ml O2 X beat-1 X 100 g LV-1) was (1.75 +/- 0.57) X 10(-5) PVA (mmHg X ml X beat-1 X 100 g LV-1) + 0.031 +/- 0.011 (ml O2 X beat-1 X 100 g LV-1). The VO2-PVA relation was virtually independent of heart rate in individual hearts. We conclude that the load-independent VO2-PVA relationship is not affected by chronotropism in a given canine left ventricle.


2016 ◽  
Vol 41 (3) ◽  
pp. 255-265 ◽  
Author(s):  
Angela S. Alberga ◽  
Denis Prud’homme ◽  
Ronald J. Sigal ◽  
Gary S. Goldfield ◽  
Stasia Hadjiyannakis ◽  
...  

The purpose of this study was to examine the effects of aerobic, resistance, and combined exercise training on cardiorespiratory and musculoskeletal fitness in postpubertal adolescents with obesity. After a 4-week supervised moderate-intensity exercise run-in, 304 adolescents aged 14–18 years with body mass index ≥85th percentile were randomized to 4 groups for 22 weeks of aerobic training, resistance training, combined training, or a nonexercising control. All participants received dietary counselling with a maximum daily energy deficit of 250 kcal. Cardiorespiratory fitness (peak oxygen consumption) was measured by indirect calorimetry using a graded treadmill exercise test. Musculoskeletal fitness was measured using the 2003 Canadian Physical Activity Fitness and Lifestyle Appraisal tests (hand grip, push-ups, partial curl-ups, sit and reach, and vertical jump). Muscular strength was assessed using an 8-repetition maximum test on the bench press, seated row, and leg press machines. A greater increase in peak oxygen consumption in the aerobic exercise group (30.6 ± 0.6 to 33.4 ± 0.7 mLO2/kg/min) was measured relative to the control group (30.6 ± 0.5 to 30.9 ± 0.7 mLO2/kg/min) (p = 0.002). Similarly, the number of partial curl-ups increased in the aerobic group (19 ± 1 to 23 ± 1) while no differences were measured in the control group (19 ± 1 to 20 ± 1) (p = 0.015). Increases in muscular strength and number of push-ups were greatest in the resistance group versus the control and combined groups versus the aerobic group (p < 0.05). In conclusion, aerobic training had the strongest effect on cardiorespiratory fitness, while resistance and combined training improved both muscular strength and endurance more than control and aerobic training alone, respectively, in adolescents with obesity.


Author(s):  
Thomas Möller ◽  
Vibeke Klungerbo ◽  
Simone Diab ◽  
Henrik Holmstrøm ◽  
Elisabeth Edvardsen ◽  
...  

AbstractThe role of dysfunction of the single ventricle in Fontan failure is incompletely understood. We aimed to evaluate hemodynamic responses to preload increase in Fontan circulation, to determine whether circulatory limitations in different locations identified by experimental preload increase are associated with cardiorespiratory fitness (CRF), and to assess the impact of left versus right ventricular morphology. In 38 consecutive patients (median age = 16.6 years, 16 females), heart catheterization was supplemented with a rapid 5-mL/kg body weight volume expansion. Central venous pressure (CVP), ventricular end-diastolic pressure (VEDP), and peak systolic pressure were averaged for 15‒30 s, 45‒120 s, and 4‒6 min (steady state), respectively. CRF was assessed by peak oxygen consumption (VO2peak) and ventilatory threshold (VT). Median CVP increased from 13 mmHg at baseline to 14.5 mmHg (p < 0.001) at steady state. CVP increased by more than 20% in eight patients. Median VEDP increased from 10 mmHg at baseline to 11.5 mmHg (p < 0.001). Ten patients had elevated VEDP at steady state, and in 21, VEDP increased more than 20%. The transpulmonary pressure difference (CVP‒VEDP) and CVP were consistently higher in patients with right ventricular morphology across repeated measurements. CVP at any stage was associated with VO2peak and VT. VEDP after volume expansion was associated with VT. Preload challenge demonstrates the limitations beyond baseline measurements. Elevation of both CVP and VEDP are associated with impaired CRF. Transpulmonary flow limitation was more pronounced in right ventricular morphology. Ventricular dysfunction may contribute to functional impairment after Fontan operation in young adulthood.ClinicalTrials.govidentifier NCT02378857


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