High-intensity endurance training in 20- to 30- and 60- to 70-yr-old healthy men

1990 ◽  
Vol 69 (5) ◽  
pp. 1792-1798 ◽  
Author(s):  
L. Makrides ◽  
G. J. Heigenhauser ◽  
N. L. Jones
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Endurance Training ◽  
High Intensity ◽  
Cycle Ergometer ◽  
Short Term ◽  
Vascular Conductance ◽  
Isokinetic Test ◽  
Ergometer Exercise ◽  
Young Subjects

Factors contributing to maximal incremental and short-term exercise capacity were measured before and after 12 wk of high-intensity endurance training in 12 old (60-70 yr) and 10 young (20-30 yr) sedentary healthy males. Peak O2 uptake in incremental cycle ergometer exercise increased from 1.60 +/- 0.073 to 2.21 +/- 0.073 (SE) l/min (38% increase) in the old subjects and from 2.54 +/- 0.141 to 3.26 +/- 0.181 l/min (29%) in the young subjects. Peak cardiac output, estimated by extrapolation from a series of submaximal measurements by the CO2 rebreathing method, increased by 30% (from 12.7 to 16.5 l/min) in the old subjects, associated with a 6% increase (from 126 to 135 ml/l) in arteriovenous O2 difference; in the young subjects there were equal 14% increases in both variables (18.0 to 20.5 l/min and 140 to 159 ml/l, respectively). Submaximal mean arterial pressure and cardiac output were lower posttraining in the old subjects; total vascular conductance and cardiac stroke volume increased. Although peak power at the start of a short-term maximal isokinetic test did not change, total work accomplished in 30 s at a pedaling frequency of 110 revolutions/min increased in both groups, from 11.2 to 12.6 kJ and from 15.7 to 16.9 kJ in the old and young, respectively; fatigue during the 30-s test was less, and postexercise plasma lactate concentrations were lower. In older subjects, increases in aerobic power after high-intensity endurance training are at least as large as in younger subjects and are associated with increases in vascular conductance, maximal cardiac output, and stroke volume.

Central and peripheral adaptations of the gas transport system to one-leg training

1981 ◽  
Vol 59 (11) ◽  
pp. 1146-1154 ◽  
Author(s):  
S. G. Thomas ◽  
D. A. Cunningham ◽  
M. J. Plyley ◽  
D. R. Boughner ◽  
R. A. Cook
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Endurance Training ◽  
Maximal Oxygen Uptake ◽  
Enzyme Activities ◽  
Cardiovascular Responses ◽  
Cycle Ergometer ◽  
Left Ventricular ◽  
Enzyme Analysis ◽  
Ergometer Exercise

The role of central and peripheral adaptations in the response to endurance training was examined. Changes in cardiac structure and function, oxygen extraction, and muscle enzyme activities following one-leg training were studied.Eleven subjects (eight females, three males) trained on a cycle ergometer 4 weeks with one leg (leg 1), then 4 weeks with the second leg (leg 2). Cardiovascular responses to exercise with both legs and each leg separately were evaluated at entry (T1), after 4 weeks of training (T2), and after a second 4 weeks of training (T3). Peak oxygen uptake ([Formula: see text] peak) during exercise with leg 1 (T1 to T2 increased 19.8% (P < 0.05) and during exercise with leg 2 (T2 to T3 increased 16.9% (P < 0.05). Maximal oxygen uptake with both legs increased 7.9% from T1 to T2 and 9.4% from T2 to T3 (P < 0.05). During exercise at 60% of [Formula: see text] peak, cardiac output [Formula: see text] was increased significantly only when the trained leg was exercised. [Formula: see text] increased 12.2% for leg 1 between T1 and T2 and 13.0% for leg 2 between T2 and T3 (P < 0.05). M-mode echocardiographic assessment of left ventricular internal diameter at diastole and peak velocity of circumferential fibre shortening at rest or during supine cycle ergometer exercise at T1 and T3 revealed no training induced changes in cardiac dimensions or function. Enzyme analysis of muscle biopsy samples from the vastus lateralis (At T1, T2, T3) revealed no consistent pattern of change in aerobic (malate dehydrogenase and 3-hydroxyacyl-CoA dehydrogenase) or anaerobic (phosphofructokinase, lactate dehydroginase, and creatine kinase) enzyme activities. Increases in cardiac output and maximal oxygen uptake which result from short duration endurance training can be achieved, therefore, without measurable central cardiac adaptation. The absence of echocardio-graphically determined changes in cardiac dimensions and contractility and the absence of an increase in cardiac output during exercise with the nontrained leg following training of the contralateral limb support this conclusion.

Phlebotomy eliminates the maximal cardiac output response to six weeks of exercise training

2014 ◽  
Vol 306 (10) ◽  
pp. R752-R760 ◽  
Author(s):  
Thomas C. Bonne ◽  
Gregory Doucende ◽  
Daniela Flück ◽  
Robert A. Jacobs ◽  
Nikolai B. Nordsborg ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Exercise Training ◽  
Endurance Training ◽  
Blood Volume ◽  
Cycle Ergometer ◽  
Training Period ◽  
Training Intervention ◽  
Functional Changes ◽  
Ergometer Exercise ◽  
Maximal Cardiac Output

With this study we tested the hypothesis that 6 wk of endurance training increases maximal cardiac output (Q̇max) relatively more by elevating blood volume (BV) than by inducing structural and functional changes within the heart. Nine healthy but untrained volunteers (V̇o2max 47 ± 5 ml·min−1·kg−1) underwent supervised training (60 min; 4 times weekly at 65% V̇o2max for 6 wk), and Q̇max was determined by inert gas rebreathing during cycle ergometer exercise before and after the training period. After the training period, blood volume (determined in duplicates by CO rebreathing) was reestablished to pretraining values by phlebotomy and Q̇max was quantified again. Resting echography revealed no structural heart adaptations as a consequence of the training intervention. After the training period, plasma volume (PV), red blood cell volume (RBCV), and BV increased ( P < 0.05) by 147 ± 168 (5 ± 5%), 235 ± 64 (10 ± 3%), and 382 ± 204 ml (7 ± 4%), respectively. V̇o2max was augmented ( P < 0.05) by 10 ± 7% after the training period and decreased ( P < 0.05) by 8 ± 7% with phlebotomy. Concomitantly, Q̇max was increased ( P < 0.05) from 18.9 ± 2.1 to 20.4 ± 2.3 l/min (9 ± 6%) as a consequence of the training intervention, and after normalization of BV by phlebotomy Q̇max returned to pretraining values (18.1 ± 2.5 l/min; 12 ± 5% reversal). Thus the exercise training-induced increase in BV is the main mechanism increasing Q̇max after 6 wk of endurance training in previously untrained subjects.

scholarly journals Exercise intensity regulates cytokine and klotho responses in men

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roeland J. W. Middelbeek ◽  
Piryanka Motiani ◽  
Nina Brandt ◽  
Pasquale Nigro ◽  
Jia Zheng ◽  
...  
Keyword(s):  
Exercise Training ◽  
High Intensity ◽  
Training Programs ◽  
Cycle Ergometer ◽  
Cardiovascular Fitness ◽  
Whole Body ◽  
Moderate Intensity ◽  
Short Term ◽  
Ergometer Exercise ◽  
Intensity Training

Abstract Background Short-term exercise training programs that consist of moderate intensity endurance training or high intensity interval training have become popular choices for healthy lifestyle modifications, with as little as two weeks of training being shown to improve cardiorespiratory fitness and whole-body glucose metabolism. An emerging concept in exercise biology is that exercise stimulates the release of cytokines and other factors into the blood that contribute to the beneficial effects of exercise on metabolism, but whether these factors behave similarly in response to moderate and high intensity short term training is not known. Here, we determined the effects of two short-term exercise training programs on the concentrations of select secreted cytokines and Klotho, a protein involved in anti-aging. Methods Healthy, sedentary men (n = 22) were randomized to moderate intensity training (MIT) or sprint intensity training (SIT) treatment groups. SIT consisted of 6 sessions over 2 weeks of 6 × 30 s all out cycle ergometer sprints with 4 min of recovery between sprints. MIT consisted of 6 sessions over 2 weeks of cycle ergometer exercise at 60% VO2peak, gradually increasing in duration from 40 to 60 min. Blood was taken before the intervention and 48 h after the last training session, and glucose uptake was measured using [18F]FDG‐PET/CT scanning. Cytokines were measured by multiplex and Klotho concentrations by ELISA. Results Both training protocols similarly increased VO2peak and decreased fat percentage and visceral fat (P < 0.05). MIT and SIT training programs both reduced the concentrations of IL-6, Hepatocyte Growth Factor (HGF) and Leptin. Interestingly, MIT, but not SIT increased monocyte chemoattractant protein-1 (MCP-1) concentrations, an exercise-induced cytokine, as well as Klotho concentrations. Conclusion Short-term exercise training at markedly different intensities similarly improves cardiovascular fitness but results in intensity-specific changes in cytokine responses to exercise.

The underwater environment: cardiopulmonary, thermal, and energetic demands

2009 ◽  
Vol 106 (1) ◽  
pp. 276-283 ◽  
Author(s):  
D. R. Pendergast ◽  
C. E. G. Lundgren
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Time Dependent ◽  
Breath Holding ◽  
Peripheral Blood Flow ◽  
Short Term ◽  
Underwater Environment ◽  
Maximal Cardiac Output

Water covers over 75% of the earth, has a wide variety of depths and temperatures, and holds a great deal of the earth's resources. The challenges of the underwater environment are underappreciated and more short term compared with those of space travel. Immersion in water alters the cardio-endocrine-renal axis as there is an immediate translocation of blood to the heart and a slower autotransfusion of fluid from the cells to the vascular compartment. Both of these changes result in an increase in stroke volume and cardiac output. The stretch of the atrium and transient increase in blood pressure cause both endocrine and autonomic changes, which in the short term return plasma volume to control levels and decrease total peripheral resistance and thus regulate blood pressure. The reduced sympathetic nerve activity has effects on arteriolar resistance, resulting in hyperperfusion of some tissues, which for specific tissues is time dependent. The increased central blood volume results in increased pulmonary artery pressure and a decline in vital capacity. The effect of increased hydrostatic pressure due to the depth of submersion does not affect stroke volume; however, a bradycardia results in decreased cardiac output, which is further reduced during breath holding. Hydrostatic compression, however, leads to elastic loading of the chest wall and negative pressure breathing. The depth-dependent increased work of breathing leads to augmented respiratory muscle blood flow. The blood flow is increased to all lung zones with some improvement in the ventilation-perfusion relationship. The cardiac-renal responses are time dependent; however, the increased stroke volume and cardiac output are, during head-out immersion, sustained for at least hours. Changes in water temperature do not affect resting cardiac output; however, maximal cardiac output is reduced, as is peripheral blood flow, which results in reduced maximal exercise performance. In the cold, maximal cardiac output is reduced and skin and muscle are vasoconstricted, resulting in a further reduction in exercise capacity.

Leg crossing with muscle tensing, a physical counter-manoeuvre to prevent syncope, enhances leg blood flow

2007 ◽  
Vol 112 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Jan T. Groothuis ◽  
Nynke van Dijk ◽  
Walter ter Woerds ◽  
Wouter Wieling ◽  
Maria T. E. Hopman
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Orthostatic Intolerance ◽  
Peripheral Resistance ◽  
Haemodynamic Effects ◽  
Vascular Conductance ◽  
Leg Blood Flow ◽  
Head Up Tilt

In patients with orthostatic intolerance, the mechanisms to maintain BP (blood pressure) fail. A physical counter-manoeuvre to postpone or even prevent orthostatic intolerance in these patients is leg crossing combined with muscle tensing. Although the central haemodynamic effects of physical counter-manoeuvres are well documented, not much is known about the peripheral haemodynamic events. Therefore the purpose of the present study was to examine the peripheral haemodynamic effects of leg crossing combined with muscle tensing during 70° head-up tilt. Healthy subjects (n=13) were monitored for 10 min in the supine position followed by 10 min in 70° head-up tilt and, finally, for 2 min of leg crossing with muscle tensing in 70° head-up tilt. MAP (mean arterial BP), heart rate, stroke volume, cardiac output and total peripheral resistance were measured continuously by Portapres. Leg blood flow was measured using Doppler ultrasound. Leg vascular conductance was calculated as leg blood flow/MAP. A significant increase in MAP (13 mmHg), stroke volume (27%) and cardiac output (18%), a significant decrease in heart rate (−5 beats/min) and no change in total peripheral resistance during the physical counter-manoeuvre were observed when compared with baseline 70° head-up tilt. A significant increase in leg blood flow (325 ml/min) and leg vascular conductance (2.9 arbitrary units) were seen during the physical counter-manoeuvre when compared with baseline 70° head-up tilt. In conclusion, the present study indicates that the physical counter-manoeuvre of leg crossing combined with muscle tensing clearly enhances leg blood flow and, at the same time, elevates MAP.

scholarly journals Training improves the response in glucose flux to exercise in postmenopausal women

2009 ◽  
Vol 107 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Zinta A. Zarins ◽  
Matthew L. Johnson ◽  
Nastaran Faghihnia ◽  
Michael A. Horning ◽  
Gareth A. Wallis ◽  
...  
Keyword(s):  
Endurance Training ◽  
Postmenopausal Women ◽  
Power Output ◽  
Insulin Response ◽  
Cycle Ergometer ◽  
Peak Oxygen Consumption ◽  
Whole Body ◽  
Younger Women ◽  
Glucose Flux ◽  
Ergometer Exercise

We examined the effects of endurance training on parameters of glucose flux during rest and exercise in postmenopausal women. Ten sedentary, but healthy women (55 ± 1 yr) completed 12 wk of endurance exercise training on a cycle ergometer [5 days/wk, 1 h/day, 65% peak oxygen consumption (V̇o2peak)]. Flux rates were determined by primed continuous infusion of [6,6-2H]glucose (D2-glucose) during 90 min of rest and 60 min of cycle ergometer exercise during one pretraining exercise trial [65% V̇o2peak (PRE)] and two posttraining exercise trials [the power output that elicited 65% pretraining V̇o2peak (ABT) and 65% posttraining V̇o2peak (RLT)]. Training increased V̇o2peak by 16.3 ± 3.9% ( P < 0.05). Epinephrine and glucagon were lower during ABT and lactate was lower during ABT and RLT ( P < 0.05), but the apparent insulin response was unchanged. Whole body glucose rate of appearance decreased posttraining during exercise at a given power output (4.58 ± 0.39 mg·kg−1·min−1 during ABT compared with 5.21 ± 0.48 mg·kg−1·min−1 PRE, P < 0.05), but not at the same relative workload (5.85 ± 0.36 mg·kg−1·min−1). Training resulted in a 35% increase in glucose MCR during exercise at the same relative intensity (7.16 ± 0.42 ml·kg−1·min−1 during RLT compared with 5.28 ± 0.42 ml·kg−1·min−1 PRE, P < 0.05). Changes in parameters of glucose kinetics during exercise were accomplished without changes in dietary composition, body weight, or body composition. We conclude that despite changes in the hormonal milieu that occur at menopause, endurance training results in a similar magnitude in training-induced alterations of glucose flux as seen previously in younger women.

Cardiovascular responses to treadmill and cycle ergometer exercise in children and adults

1997 ◽  
Vol 83 (3) ◽  
pp. 948-957 ◽  
Author(s):  
Kenneth R. Turley ◽  
Jack H. Wilmore
Keyword(s):  
Stroke Volume ◽  
Peripheral Resistance ◽  
Cardiovascular Responses ◽  
Cycle Ergometer ◽  
Left Ventricular ◽  
Absolute Amount ◽  
Exercise Tests ◽  
Exercise Modality ◽  
Cycle Ergometer Exercise ◽  
Ergometer Exercise

Turley, Kenneth R., and Jack H. Wilmore. Cardiovascular responses to treadmill and cycle ergometer exercise in children and adults. J. Appl. Physiol. 83(3): 948–957, 1997.—This study was conducted to determine whether submaximal cardiovascular responses at a given rate of work are different in children and adults, and, if different, what mechanisms are involved and whether the differences are exercise-modality dependent. A total of 24 children, 7 to 9 yr old, and 24 adults, 18 to 26 yr old (12 males and 12 females in each group), participated in both submaximal and maximal exercise tests on both the treadmill and cycle ergometer. With the use of regression analysis, it was determined that cardiac output (Q˙) was significantly lower ( P ≤ 0.05) at a given O2 consumption level (V˙o 2, l/min) in boys vs. men and in girls vs. women on both the treadmill and cycle ergometer. The lower Q˙ in the children was compensated for by a significantly higher ( P ≤ 0.05) arterial-mixed venous O2difference to achieve the same or similarV˙o 2. Furthermore, heart rate and total peripheral resistance were higher and stroke volume was lower in the children vs. in the adult groups on both exercise modalities. Stroke volume at a given rate of work was closely related to left ventricular mass, with correlation coefficients ranging from r = 0.89–0.92 and r = 0.88–0.93 in the males and females, respectively. It was concluded that submaximal cardiovascular responses are different in children and adults and that these differences are related to smaller hearts and a smaller absolute amount of muscle doing a given rate of work in the children. The differences were not exercise-modality dependent.

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