scholarly journals Ingestion of a Moderately High Caffeine Dose Before Exercise Increases Postexercise Energy Expenditure

Author(s):  
Valentín E. Fernández-Elías ◽  
Juan Del Coso ◽  
Nassim Hamouti ◽  
Juan F. Ortega ◽  
Gloria Muñoz ◽  
...  

Caffeine is an ergogenic aid widely used before and during prolonged exercise. Due to its prolonged biological half-life caffeine effects could remain after exercise. We aimed to investigate the metabolic, respiratory, and cardiovascular postexercise responses to preexercise graded caffeine ingestion. Twelve aerobically trained subjects (mean VO2max = 54 ± 7 ml · min−1 · kg−1) cycled for 60-min at 75% VO2max after ingesting placebo (0 mg of caffeine per kg of body weight) or 0.5, 1.5, 3.0 and 4.5 mg · kg−1 on five occasions. During the 3 hr postexercise, heart rate, blood pressure, glucose, lactate, and fatty acids were analyzed. None of these variables were statistically affected by preexercise caffeine ingestion between 0.5 and 4.5 mg · kg−1. However, ingestion of 4.5 mg · kg−1 of caffeine raised postexercise energy expenditure 15% above placebo (233 ± 58 vs. 202 ± 49 kcal/3 hr; p < .05). Ventilation and tidal volume were elevated after the 4.5 mg·kg−1 caffeine dose above placebo (9.2 ± 2.5 L · min−1 and 0.67 ± 0.29 L · breath−1 vs. 7.8 ± 1.5 L · min−1 and 0.56 ± 0.20 L · breath−1, respectively; p < .05). Ventilation correlated with tidal volume (r = .45; p < .05) and energy expenditure (r = .72; p < .05). In summary, preexercise ingestion of ergogenic caffeine doses do not alter postexercise cardiovascular responses. However, ingestion of 4.5 mg · kg−1 of caffeine raises 3-hr postexercise energy expenditure (i.e., 31 kcal) likely through increased energy cost of ventilation.


1977 ◽  
Vol 42 (2) ◽  
pp. 166-173 ◽  
Author(s):  
J. LeBlanc ◽  
M. Boulay ◽  
S. Dulac ◽  
M. Jobin ◽  
A. Labrie ◽  
...  

Forty young male adults, aged 18–30 yr, with maximal oxygen intake (VO2 max) varying between 35 and 76 ml-kg-1-min-1 were studied. The fasting subjects were perfused for 15 min with saline and thereafter for 30 min with norepinephrine (0.1 mug/kg per min). Blood variables were determined at the end of slaine perfusion, at 15 and 30 min during norepinephrine perfusion and 15 min after the end of NE perfusion. Trained subjects are characterized by lower basal plasma glucose and insulin concentration. NE perfusion produced a larger increase in plasma glucose in the trained subjects. Levels of insulin in the postperfusion period were smaller in the trained group. Serum free fatty acids (FFA) and glycerol increased less in the trained subjects during NE perfusion and this difference persisted in the post-perfusion period. During NE perfusion, blood lactate increased only in the nontrained subjects. Initial heart rate and blood pressure were lower in trained subjects but, during NE perfusion, elevated levels of blood pressure and decreased levels of heart rate were comparable in both groups. Because of similarities in responses to exercise and to NE in trained subjects, the results of the present study suggest a possible role for NE in exercise training.



2021 ◽  
Vol 11 (15) ◽  
pp. 6687
Author(s):  
Muhammad Adeel ◽  
Chien-Hung Lai ◽  
Chun-Wei Wu ◽  
Jiunn-Horng Kang ◽  
Jian-Chiun Liou ◽  
...  

Energy expenditure during weight training exercises produces great fitness and health benefits for humans, but few studies have investigated energy expenditure directly during weight training. Therefore, in this study, we aimed to determine energy costs during three training sessions consisting of three different exercises. Ten participants were randomly allocated into two groups: an untrained (n = 5, with no weight training experience) and a trained group (n = 5, with some weight training experience). Each participant completed three training sessions on separate days. While wearing a mask for indirect calorimetric measurements, each participant participated in training sessions conducted with three dumbbell exercises: the bent-over row, deadlift, and lunge. Metabolic equivalents (METs), energy expenditure (EE), respiratory exchange ratio (RER), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and rate of perceived exertion (RPE) were measured. The total energy cost was calculated from the oxygen consumption (VO2) during each exercise. Our results showed that the METs of a single training session were 3.3 for the untrained group and 3.4 for the trained group, while the sum of the EE was 683–688 and 779–840 kcal, respectively. The physiological parameters, such as heart rate (p = 0.001 *) for the lunge and rate of perceived exertion (p = 0.005 *) for the bent-over row, changed significantly in both groups. It was concluded that the exercise protocol of this study involved a moderate intensity of 2.4–3.9 METs. The energy cost of each training exercise was between 179 and 291 kcal.



2008 ◽  
Vol 294 (3) ◽  
pp. R730-R737 ◽  
Author(s):  
Clive M. Brown ◽  
Abdul G. Dulloo ◽  
Gayathri Yepuri ◽  
Jean-Pierre Montani

Overconsumption of fructose, particularly in the form of soft drinks, is increasingly recognized as a public health concern. The acute cardiovascular responses to ingesting fructose have not, however, been well-studied in humans. In this randomized crossover study, we compared cardiovascular autonomic regulation after ingesting water and drinks containing either glucose or fructose in 15 healthy volunteers (aged 21–33 yr). The total volume of each drink was 500 ml, and the sugar content 60 g. For 30 min before and 2 h after each drink, we recorded beat-to-beat heart rate, arterial blood pressure, and cardiac output. Energy expenditure was determined on a minute-by-minute basis. Ingesting the fructose drink significantly increased blood pressure, heart rate, and cardiac output but not total peripheral resistance. Glucose ingestion resulted in a significantly greater increase in cardiac output than fructose but no change in blood pressure and a concomitant decrease in total peripheral resistance. Ingesting glucose and fructose, but not water, significantly increased blood pressure variability and decreased cardiovagal baroreflex sensitivity. Energy expenditure increased by a similar amount after glucose and fructose ingestion, but fructose elicited a significantly greater increase in respiratory quotient. These results show that ingestion of glucose and fructose drinks is characterized by specific hemodynamic responses. In particular, fructose ingestion elicits an increase in blood pressure that is probably mediated by an increase in cardiac output without compensatory peripheral vasodilatation.



Author(s):  
Ewan Thomas ◽  
Marianna Bellafiore ◽  
Ambra Gentile ◽  
Antonio Paoli ◽  
Antonio Palma ◽  
...  

AbstractThe aim of this study will be to review the current body of literature to understand the effects of stretching on the responses of the cardiovascular system. A literature search was performed using the following databases: Scopus, NLM Pubmed and ScienceDirect. Studies regarding the effects of stretching on responses of the cardiovascular system were investigated. Outcomes regarded heart rate(HR), blood pressure, pulse wave velocity (PWV of which baPWV for brachial-ankle and cfPWV for carotid-femoral waveforms), heart rate variability and endothelial vascular function. Subsequently, the effects of each outcome were quantitatively synthetized using meta-analytic synthesis with random-effect models. A total of 16 studies were considered eligible and included in the quantitative synthesis. Groups were also stratified according to cross-sectional or longitudinal stretching interventions. Quality assessment through the NHLBI tools observed a “fair-to-good” quality of the studies. The meta-analytic synthesis showed a significant effect of d=0.38 concerning HR, d=2.04 regarding baPWV and d=0.46 for cfPWV. Stretching significantly reduces arterial stiffness and HR. The qualitative description of the studies was also supported by the meta-analytic synthesis. No adverse effects were reported, after stretching, in patients affected by cardiovascular disease on blood pressure. There is a lack of studies regarding vascular adaptations to stretching.



1963 ◽  
Vol 18 (5) ◽  
pp. 987-990 ◽  
Author(s):  
Shanker Rao

Reports of cardiovascular responses to head-stand posture are lacking in literature. The results of the various responses, respectively, to the supine, erect, and head-stand posture, are as follows: heart rate/min 67, 84, and 69; brachial arterial pressure mm Hg 92, 90, and 108; posterior tibial arterial pressure mm Hg 98, 196, and 10; finger blood flow ml/100 ml min 4.5, 4.4, and 5.2; toe blood flow ml/100 ml min 7.1, 8.1, and 3.4; forehead skin temperature C 34.4, 34.0 and 34.3; dorsum foot skin temperature C 28.6, 28.2, and 28.2. It is inferred that the high-pressure-capacity vessels between the heart level and posterior tibial artery have little nervous control. The high-pressure baroreceptors take active part in postural adjustments of circulation. The blood pressure equating mechanism is not as efficient when vital tissues are pooled with blood as when blood supply to them is reduced. man; heart rate; blood flow; skin temperature Submitted on January 3, 1963



2016 ◽  
Vol 29 (3) ◽  
pp. 543-552
Author(s):  
João Douglas Alves ◽  
Jorge Luiz de Brito Gomes ◽  
Caio Victor Coutinho de Oliveira ◽  
José Victor de Miranda Henriques Alves ◽  
Fabiana Ranielle de Siqueira Nogueira ◽  
...  

Abstract Introduction: Tai-Chi-Chuan and Yoga have becoming popular practices. However is unclear the cardiovascular effects, and if they present similar behavior to aerobic and resistance sessions. Objective: To evaluate the cardiovascular responses during the session and post-exercise hypotension (PEH) of Tai Chi Chuan (TS) and Yoga (YS) in comparison to aerobic (AS) and resistance (SR) exercises. Methods: Fourteen young women (22.3 ± 2 years) apparently healthy performed four sessions (AS, RS, TS and YS). The heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP) were recorded at resting, during (every 10 minutes) and until 50 minutes of recovery. Results: AS, RS, TS e YS showed significant increase in HR compared to resting.AS at 10, 30 e 50 minutes in relation to RS, TS e YS. The RS in relation to TS and YS at 10, 30 and 50 minutes. No significant difference between TS and YS. SBP was significantly increased in AS, RS, TS e YS at 10, 30 e 50 minutes during the session, in relation to rest. AS was significantly higher at 30 e 50 minutes than RS and higher than TS and YS at 10, 30 e 50 minutes. No significant difference in DBP. For PEH, AS, RS and TS significantly reduced at 10, 30 and 50 minutes. YS reduced at 50 minutes. No significant diastolic PEH. Conclusion: TS and YS showed as safe alternatives of exercising in the normotensive young adult woman, despite having lower values, they promote similar hemodynamic behavior to AS and RS.





1987 ◽  
Vol 62 (3) ◽  
pp. 1186-1191 ◽  
Author(s):  
J. W. Kozelka ◽  
G. W. Christy ◽  
R. D. Wurster

The ascending spinal pathways mediating somatocardiovascular reflexes during exercise were studied in unanesthetized dogs by placing lesions in the lumbar spinal cord. After training to run on a treadmill with hindlimbs only, 20 dogs were anesthetized and instrumented using sterile surgical techniques. To chronically record heart rate and arterial blood pressure, the aorta was cannulated via the omocervical artery. To test the intactness of descending spinal sympathetic pathways, reflex pressor responses to baroreceptor hypotension were produced by bilateral carotid arterial occlusion using pneumatic vessel occluders placed around the common carotid arteries. To generate transient ischemic exercise (120 s), a pneumatic occluder was placed around the left iliac artery. Eight to 10 days after instrumentation, blood pressure and heart rate were monitored at rest and during hindlimb running with and without simultaneous iliac arterial occlusion. The modest pressor response and tachycardia elicited by hindlimb exercise were markedly augmented by simultaneous hindlimb ischemia (i.e., iliac arterial occlusion). Lesion placement in the dorsolateral sulcus area and the dorsolateral funiculus at L2 significantly reduced the blood pressure and heart rate responses to simultaneous exercise occlusion. The cardiovascular responses to nonischemic exercise and bilateral carotid arterial occlusion were not altered by such spinal sections. It is concluded that in the dog the ascending spinal pathways mediating cardiovascular responses to ischemic exercise are located in the lateral funiculus, including the dorsolateral sulcus area and dorsolateral funiculus.



2002 ◽  
Vol 10 (3) ◽  
pp. 199-210 ◽  
Author(s):  
Adamu Alemayehu ◽  
Laura Breen ◽  
Drahomira Krenova ◽  
Morton P. Printz

Evidence exists implying multiple blood pressure quantitative trait loci (QTL) on rat chromosome 2. To examine this possibility, four congenic strains and nine substrains were developed with varying size chromosome segments introgressed from the spontaneously hypertensive rat (SHR/lj) and normotensive Wistar-Kyoto rat (WKY/lj) onto the reciprocal genetic background. Cardiovascular phenotyping was conducted with telemetry over extended periods during standard salt (0.7%) and high-salt (8%) diets. Our results are consistent with at least three independent pressor QTL: transfer of SHR/lj alleles to WKY/lj reveals pressor QTL within D2Rat21-D2Rat27 and D2Mgh10-D2Rat62, whereas transfer of WKY/lj D2Rat161-D2Mit8 to SHR/lj reveals a depressor locus. Our results also suggest a depressor QTL in SHR/lj located within D2Rat161-D2Mgh10. Introgressed WKY/lj segments also reveal a heart rate QTL within D2Rat40-D2Rat50 which abolished salt-induced bradycardia, dependent upon adjoining SHR/lj alleles. This study confirms the presence of multiple blood pressure QTL on chromosome 2. Taken together with our other studies, we conclude that rat chromosome 2 is rich in alleles for cardiovascular and behavioral traits and for coordinated coupling between behavior and cardiovascular responses.



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