Effect of differences in post-exercise lactate accumulation in athletes’ haemodynamics

2006 ◽  
Vol 31 (4) ◽  
pp. 423-431 ◽  
Author(s):  
Antonio Crisafulli ◽  
Filippo Tocco ◽  
Gianluigi Pittau ◽  
Luigi Lorrai ◽  
Cristina Porru ◽  
...  

To verify the relationship between exercise intensity and post-exercise haemodynamics, we studied haemodynamic and lactate responses during 10 min following 3 bicycle tests. Two tests were performed for 3 min at 70% and 130% of the workload corresponding to anaerobic threshold (70% Wat and 130% Wat tests), and 1 was performed until exhaustion at 150% of the maximum workload achieved during a previous incremental test (150% Wmax test). During the recovery period after the 150% Wmax test we observed the highest increases in blood lactate with respect to the baseline: at the 9th minute of recovery lactate concentration increased by +9.3 ± 2.7, +6.4 ± 3.1, and +1.1 ± 0.9 mmol·L–1 in the 150% Wmax (p > 0.05 with respect to the other protocol sessions), 130% Wat, and 70% Wat tests, respectively. We also observed greater reductions in cardiac pre-load and systemic vascular resistance in the 150% Wmax test than in the 130% Wat and 70% Wat tests. However, the cardiac output response successfully faced the increased vasodilatation occurring during 150% Wmax test so that changes in mean blood pressure were similar in the 3 test conditions. This study shows that exercises that yielded different lactate concentrations also led to greater vasodilatation. Nevertheless, mechanisms controlling the cardiovascular apparatus successfully prevented a drop in blood pressure in spite of the cardiovascular stress.

1974 ◽  
Vol 47 (3) ◽  
pp. 249-257 ◽  
Author(s):  
D. F. Marcus ◽  
H. F. Edelhauser ◽  
M. G. Maksud ◽  
R. L. Wiley

1. Normal subjects performed fatiguing static hand-grip contraction at tensions of 20% and 55% of their maximum voluntary contraction (MVC). Intraocular pressure (IOP) was measured by applanation tonometry before, during and after the isometric exercise. Forearm blood samples were taken from the antecubital vein in both the exercised and non-exercised arm before and 2 min post-exercise for measurement of plasma lactate, osmolality, Pv,o2, Pv,co2 and pH. 2. During hand grip the heart rate and blood pressure increased significantly, whereas the IOP remained unchanged from control in both the 20% and 55% MVC experiments. 3. In the recovery period heart rate and blood pressure returned to control values within 3 min and the IOP decreased significantly from control in both the 20% and 55% MVC experiments. 4. When an occlusion cuff was inflated on the exercising arm just before release of the 55% MVC grip, the decreased IOP could be delayed until the cuff was released. 5. Post-exercise blood samples showed elevated lactate concentrations and Pv,o2 and decreased pH in the exercised arm; however, the values remained unchanged in the non-exercised arm. The decreased IOP after exercise may be related to an increased blood lactate concentration.


1994 ◽  
Vol 72 (01) ◽  
pp. 058-064 ◽  
Author(s):  
Goya Wannamethee ◽  
A Gerald Shaper

SummaryThe relationship between haematocrit and cardiovascular risk factors, particularly blood pressure and blood lipids, has been examined in detail in a large prospective study of 7735 middle-aged men drawn from general practices in 24 British towns. The analyses are restricted to the 5494 men free of any evidence of ischaemic heart disease at screening.Smoking, body mass index, physical activity, alcohol intake and lung function (FEV1) were factors strongly associated with haematocrit levels independent of each other. Age showed a significant but small independent association with haematocrit. Non-manual workers had slightly higher haematocrit levels than manual workers; this difference increased considerably and became significant after adjustment for the other risk factors. Diabetics showed significantly lower levels of haematocrit than non-diabetics. In the univariate analysis, haematocrit was significantly associated with total serum protein (r = 0*18), cholesterol (r = 0.16), triglyceride (r = 0.15), diastolic blood pressure (r = 0.17) and heart rate (r = 0.14); all at p <0.0001. A weaker but significant association was seen with systolic blood pressure (r = 0.09, p <0.001). These relationships remained significant even after adjustment for age, smoking, body mass index, physical activity, alcohol intake, lung function, presence of diabetes, social class and for each of the other biological variables; the relationship with systolic blood pressure was considerably weakened. No association was seen with blood glucose and HDL-cholesterol. This study has shown significant associations between several lifestyle characteristics and the haematocrit and supports the findings of a significant relationship between the haematocrit and blood lipids and blood pressure. It emphasises the role of the haematocrit in assessing the risk of ischaemic heart disease and stroke in individuals, and the need to take haematocrit levels into account in determining the importance of other cardiovascular risk factors.


Author(s):  
Gabriel Kolesny Tricot ◽  
Fabiula Isoton Isoton Novelli ◽  
Lucieli Teresa Cambri

AbstractThis study aimed to assess whether obesity and/or maximal exercise can change 24 h cardiac autonomic modulation and blood pressure in young men. Thirty-nine men (n: 20; 21.9±1.8 kg·m−2, and n: 19; 32.9±2.4 kg·m−2) were randomly assigned to perform a control (non-exercise) and an experimental day exercise (after maximal incremental test). Cardiac autonomic modulation was evaluated through frequency domain heart rate variability (HRV). Obesity did not impair the ambulatory HRV (p>0.05), however higher diastolic blood pressure during asleep time (p=0.02; group main effect) was observed. The 24 h and awake heart rate was higher on the experimental day (p<0.05; day main effect), regardless of obesity. Hypotension on the experimental day, compared to control day, was observed (p<0.05). Obesity indicators were significantly correlated with heart rate during asleep time (Rho=0.34 to 0.36) and with ambulatory blood pressure(r/Rho=0.32 to 0.53). Furthermore, the HRV threshold workload was significantly correlated with ambulatory heart rate (r/Rho=− 0.38 to−0.52). Finally, ambulatory HRV in obese young men was preserved; however, diastolic blood pressure was increased during asleep time. Maximal exercise caused heart rate increase and 24h hypotension, with decreased cardiac autonomic modulation in the first hour, regardless of obesity.


1980 ◽  
Vol 66 (1) ◽  
pp. 45-49
Author(s):  
D. J. Smith

AbstractSixteen young, healthy volunteers were exposed to eight thermally severe environments, each subject being exposed to four different climates. Four climates had a radiant heat component; globe temperature some 10°C above dry bulb. In the other four climates, the globe temperature was close to the dry bulb. Measurements of endurance time in the different climates were made, as were changes in deep body temperature and heart rate. The relationship between the wet bulb globe thermometer index (WBGT) and stay times in the non-radiant climates agreed well with that of previous workers. Further, the WBGT index appeared adequate, in the situation under study, in terms of its ability to quantify climatic severity, thermal and cardiovascular stress and hence endurance in climates with a high radiant heat component.


Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 860 ◽  
Author(s):  
Marcos Hortelano ◽  
Richard Reilly ◽  
Francisco Castells ◽  
Raquel Cervigón

Orthostatic intolerance syndrome occurs when the autonomic nervous system is incapacitated and fails to respond to the demands associated with the upright position. Assessing this syndrome among the elderly population is important in order to prevent falls. However, this problem is still challenging. The goal of this work was to determine the relationship between orthostatic intolerance (OI) and the cardiovascular response to exercise from the analysis of heart rate and blood pressure. More specifically, the behavior of these cardiovascular variables was evaluated in terms of refined composite multiscale fuzzy entropy (RCMFE), measured at different scales. The dataset was composed by 65 older subjects, 44.6% (n = 29) were OI symptomatic and 55.4% (n = 36) were not. Insignificant differences were found in age and gender between symptomatic and asymptomatic OI participants. When heart rate was evaluated, higher differences between groups were observed during the recovery period immediately after exercise. With respect to the blood pressure and other hemodynamic parameters, most significant results were obtained in the post-exercise stage. In any case, the symptomatic OI group exhibited higher irregularity in the measured parameters, as higher RCMFE levels in all time scales were obtained. This information could be very helpful for a better understanding of cardiovascular instability, as well as to recognize risk factors for falls and impairment of functional status.


1977 ◽  
Vol 69 (1) ◽  
pp. 173-185
Author(s):  
C. M. Wood ◽  
B. R. McMahon ◽  
D. G. McDonald

Exhausting activity results in a marked and immediate drop in blood pH which gradually returns to normal over the following 6h. The acidosis is caused largely by elevated Pco2 levels, which vary inversely with pH. Blood lactate concentration increases slowly, reaching a maximum at 2--4h post-exercise, and contributes significantly to the acidosis only late in the recovery period. The slow time course of lactic acid release into the blood permits temporal separation of the peak metabolic acidosis from the peak respiratory acidosis. Evidence is presented that a metabolic acid other than lactic also makes a modest contribution to the pH depression during the recovery period.


Author(s):  
Fletcher Kovich

Background: While investigating the real-time impedance at acupuncture points (acupoints), it was found that regular sinusoidal waves were present that corresponded to the pulsing of certain organs, such as respiration and duodenal waves, the stomach&rsquo;s slow waves, and also the heart&rsquo;s beating.Methods: This study investigated such respiration waves at lung-related acupoints to clarify their relation to the respiration pacesetter mechanism. The impedance at key acupoints was monitored in real time while the patients&rsquo; breathing slowed after exercise.Results: In all 7 patients studied, the respiration and heart-beat waves matched the rates in the corresponding organs at rest, and did not vary markedly due to exercise. In 3 of the 7 patients, their post-exercise respiration rate exactly matched that of their duodenal waves, but then dropped, stepwise, back to their usual respiration rate. In the other 4 patients, their post-exercise respiration rate did not reach that of their duodenal waves, so this pattern was not triggered.Conclusion: The results suggested that as well as the brainstem respiration pacesetter, there was also a separate &ldquo;pace signal&rdquo; present which remained constant and seemed to define the respiration rate when at rest. It is currently unknown what mechanism causes the respiration rate to increase due to exercise. But these results suggest that the brainstem pacesetter is sometimes guided by the duodenal pace signal instead of the lung pace signal, which may explain how the pacesetter is able to jump to a higher rate, even though its chemoreceptor inputs may be unchanged.


2014 ◽  
Vol 39 (3) ◽  
pp. 345-350 ◽  
Author(s):  
Sebastian Buitrago ◽  
Nicolas Wirtz ◽  
Ulrich Flenker ◽  
Heinz Kleinöder

The present study aimed to investigate the relationship between the mechanical load during resistance exercise and the elicited physiological responses. Ten resistance-trained healthy male subjects performed 1 set of resistance exercise each at 55%, 70%, and 85% of 1 repetition maximum for as many repetitions as possible and in 4 training modes: 4-1-4-1 (4 s concentric, 1 s isometric, 4 s eccentric, and 1 s isometric successive actions), 2-1-2-1, 1-1-1-1, and explosive (maximum velocity concentric). Mean concentric power and total concentric work were determined. Oxygen uptake (V̇O2) was measured during exercise and for 30 min post exercise. Total volume of consumed oxygen (O2 consumed) and excess post-exercise oxygen consumption (EPOC) were calculated. Maximum blood lactate concentration (LAmax) was also determined. V̇O2 exhibited a linear dependency on mean concentric power. Mean concentric power did not have a detectable effect on EPOC and LAmax. An augmentation of total concentric work resulted in significant linear increase of O2 consumed and EPOC. Total concentric work caused a significant increase in LAmax. In general, a higher mechanical load induced a larger physiological response. An increase in mean concentric power elicited higher aerobic energy turnover rates. However, a higher extent of total concentric work augments total energy cost covered by oxidative and (or) glycolytic pathways.


2015 ◽  
Vol 45 (1) ◽  
pp. 217-224 ◽  
Author(s):  
José Luiz Dantas ◽  
Christian Doria

Abstract Incremental tests on a treadmill are used to evaluate endurance athletes; however, no criterion exists to determine the intensity at which to start the test, potentially causing the loss of the first lactate threshold. This study aimed to determine the ideal speed for runners to start incremental treadmill tests. The study consisted of 94 runners who self-reported the average speed from their last competitive race (10-42.195 km) and performed an incremental test on a treadmill. The speeds used during the first three test stages were normalised in percentages of average competition speed and blood lactate concentration was analysed at the end of each stage. The relationship between speed in each stage and blood lactate concentration was analysed. In the first stage, at an intensity corresponding to 70% of the reported average race speed, only one volunteer had blood lactate concentration equal to 2 mmol·L-1, and in the third stage (90% of the average race speed) the majority of the volunteers had blood lactate concentration ≥2 mmol·L-1. Our results demonstrated that 70% of the average speed from the subject’s last competitive race - from 10 to 42.195 km - was the best option for obtaining blood lactate concentration <2 mmol·L-1 in the first stage, however, 80% of the average speed in marathons may be a possibility. Evaluators can use 70% of the average speed in competitive races as a strategy to ensure that the aerobic threshold intensity is not achieved during the first stage of incremental treadmill tests.


Hypertension ◽  
2021 ◽  
Vol 78 (5) ◽  
pp. 1502-1510
Author(s):  
Stephen P. Juraschek ◽  
Anthony M. Ishak ◽  
Kenneth J. Mukamal ◽  
Julia M. Wood ◽  
Timothy S. Anderson ◽  
...  

Guidelines recommend 1 to 2 minutes between repeated, automated office-based blood pressure (AOBP) measures, which is a barrier to broader adoption. Patients from a single hypertension center underwent a 3-day evaluation that included a 24-hour ambulatory blood pressure (BP) monitor (ABPM) and one of two nonrandomized, unattended AOBP protocols. Half of the patients underwent 3 AOBP measurements separated by 30 seconds, and the other half underwent 3 BP measurements separated by 60 seconds. All measurements were compared with the average awake-time BP from ABPM and the first AOBP measurement. We used linear regression to assess whether the 30-second protocol was associated with individual or average AOBP measurements or awake-time ABPM and used an interaction term to determine whether interval modified the relationship between AOBP measurements (individual and mean) with awake-time ABPM. Among 102 patients (mean age, 59.2±16.2 years; 64% women; 24% Black), the average awake-time BP was 132.5±15.6/77.7±12.2 mm Hg among those who underwent the 60-second protocol and 128.6±13.6/76.5±12.5 mm Hg for the 30-second protocol. Mean systolic/diastolic BP was lower with the second and third AOBP measurement by −0.5/−1.7 mm Hg and −1.0/−2.3 mm Hg for the 60-second protocol versus −0.8/−2.0 mm Hg and −0.7/−2.7 mm Hg for the 30-second protocol; protocol did not significantly modify these differences. Differences between AOBP measurements (first, second, or third) and awake-time ABPM were nearly identical across protocols. In conclusion, a 30-second interval between AOBP measurements was as accurate and reliable as a 60-second interval. These findings support shorter time intervals between BP measurements, which would make AOBP more feasible in clinical practice.


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