Maximal aerobic exercise in pregnant women: heart rate, O2 consumption, CO2 production, and ventilation

1991 ◽  
Vol 70 (3) ◽  
pp. 1016-1023 ◽  
Author(s):  
F. K. Lotgering ◽  
M. B. van Doorn ◽  
P. C. Struijk ◽  
J. Pool ◽  
H. C. Wallenburg

This study was to determine whether pregnancy affects maximal aerobic power. We measured heart rate, O2 uptake (VO2), CO2 production (VCO2), and ventilation at rest and during bicycle (BE) and treadmill exercise (TE) tests with rapidly increasing exercise intensities at 16, 25, and 35 wk gestation and 7 wk after delivery. Maximal heart rate was slightly lower throughout pregnancy compared with the nonpregnant state during both BE [174 +/- 2 vs. 178 +/- 2 (SE) beats/min] and TE (178 +/- 2 vs. 183 +/- 2 beats/min). Maximal VO2 was unaffected by pregnancy during BE and TE (2.20 +/- 0.08, 2.16 +/- 0.08, 2.15 +/- 0.08, and 2.19 +/- 0.08 l/min for BE and 2.45 +/- 0.08, 2.38 +/- 0.09, 2.33 +/- 0.09, and 2.39 +/- 0.08 l/min for TE at 16, 25, and 35 wk gestation and 7 wk postpartum, respectively). As a result of increased VO2 at rest, the amount of O2 available for exercise (exercise minus rest) tended to decrease with advancing gestation, reaching statistical significance only during TE at 35 wk gestation (1.99 +/- 0.08 l/min vs. 2.10 +/- 0.08 l/min postpartum). Power showed a positive linear correlation with O2 availability during BE as well as TE, and the relationship was unaffected by pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

1983 ◽  
Vol 54 (1) ◽  
pp. 113-117 ◽  
Author(s):  
M. N. Sawka ◽  
M. E. Foley ◽  
N. A. Pimental ◽  
M. M. Toner ◽  
K. B. Pandolf

The purpose of this investigation was to evaluate four protocols for their effectiveness in eliciting maximal aerobic power (peak VO2) during arm-crank exercise. Comparisons were made 1) between a continuous (CON) and an intermittent (INT) protocol (both employed a crank rate of 50 rpm) and 2) among the CON protocols employing crank rates of 30, 50, or 70 rpm. For the first group of experiments no significant (P greater than 0.05) differences were found between the CON and INT protocols for peak VO2, maximal pulmonary ventilation (VEmax), maximal heart rate (HRmax), or maximal blood lactate (LAmax) responses. For the second group of experiments, the CON-50 was compared with the CON-30 and CON-70 protocols. In comparison to the CON-50, significantly higher peak VO2 (+10%) and VEmax (+14%) responses were elicited by the CON-70 protocol, whereas significantly lower peak VO2 (-11%), VEmax (-23%), HRmax (-8%), and LAmax (-29%) responses were elicited by the CON-30 protocol. Of the arm-crank protocols examined the combination of a continuous design and a crank rate of 70 rpm provided the most effective protocol to elicit peak VO2 values.


1989 ◽  
Vol 66 (1) ◽  
pp. 336-341 ◽  
Author(s):  
S. P. Sady ◽  
M. W. Carpenter ◽  
P. D. Thompson ◽  
M. A. Sady ◽  
B. Haydon ◽  
...  

Our purpose was to determine if pregnancy alters the cardiovascular response to exercise. Thirty-nine women [29 +/- 4 (SD) yr], performed submaximal and maximal exercise cycle ergometry during pregnancy (antepartum, AP, 26 +/- 3 wk of gestation) and postpartum (PP, 8 +/- 2 wk). Neither maximal O2 uptake (VO2max) nor maximal heart rate (HR) was different AP and PP (VO2 = 1.91 +/- 0.32 and 1.83 +/- 0.31 l/min; HR = 182 +/- 8 and 184 +/- 7 beats/min, P greater than 0.05 for both). Cardiac output (Q, acetylene rebreathing technique) averaged 2.2 to 2.8 l/min higher AP (P less than 0.01) at rest and at each exercise work load. Increases in both HR and stroke volume (SV) contributed to the elevated Q at the lower exercise work loads, whereas an increased SV was primarily responsible for the higher Q at higher levels. The slope of the Q vs. VO2 relationship was not different AP and PP (6.15 +/- 1.32 and 6.18 +/- 1.34 l/min Q/l/min VO2, P greater than 0.05). In contrast, the arteriovenous O2 difference (a-vO2 difference) was lower at each exercise work load AP, suggesting that the higher Q AP was distributed to nonexercising vascular beds. We conclude that Q is greater and a-vO2 difference is less at all levels of exercise in pregnant subjects than in the same women postpartum but that the coupling of the increase in Q to the increase in systemic O2 demand (VO2) is not different.(ABSTRACT TRUNCATED AT 250 WORDS)


2018 ◽  
Vol 13 (1) ◽  
pp. 112-114 ◽  
Author(s):  
Carlo Capelli

Purpose: To analyze best 1-h unaccompanied performances of master athletes in ages ranging from 35 to 105 y to estimate the decay of maximal aerobic power (MAP) across the spectrum of age. Methods: MAP at the various ages was estimated by computing the metabolic power () maintained to cover the distances during best 1-h unaccompanied performances established by master athletes of different classes of age and by assuming that they were able to maintain an equal to 88% of their MAP during 1 h of exhaustive exercise. Results: MAP started monotonically decreasing at 47 y of age. Thereafter, it showed an average rate of decrease of ∼14% for the decades up to 105 y of age, similar to other classes of master athletes. Conclusions: The results confirm, by extending the analysis to centennial subjects, that MAP seems to start declining from the middle of the 5th decade of age, with an average percentage decay that is faster than that traditionally reported, even when one maintains a very active lifestyle. The proposed approach may be applied to other types of human locomotion for which the relationship between speed and is known.


1985 ◽  
Vol 58 (3) ◽  
pp. 763-769 ◽  
Author(s):  
J. M. Pequignot ◽  
R. Favier ◽  
D. Desplanches ◽  
L. Peyrin ◽  
R. Flandrois

To investigate the relationship between dopamine (DA) released into the bloodstream and sympathoadrenal activity, levels of free DA, norepinephrine (NE), and epinephrine (E) in plasma were recorded in four dogs subjected to three tests: treadmill exercise at two work levels [55 and 75% maximal O2 uptake; 15 min], normobaric hypoxia (12% O2; 1 h), combined exercise and hypoxia. Normoxic exercise induced slight nonsignificant decreases in the arterial partial pressure of O2 (PaO2), increases in NE [median values and ranges during submaximal work vs. rest: 1086 (457–1,637) vs. 360 (221–646) pg/ml; P less than 0.01] and E [277 (151–461) vs. 166 (95–257) pg/ml; P less than 0.05], but it failed to alter the DA level. Hypoxia elicited large decreases in PaO2 [hypoxia vs. normoxia: 42.8 (40.3–50.0) vs. 97.6 (83.2–117.6) Torr; P less than 0.01], increases in DA [230 (105–352) vs. 150 (85–229) pg/ml; P less than 0.01] and NE [383 (219–1,165) vs. 358 (210–784) pg/ml; P less than 0.05], but it failed to alter the E level. Combined exercise and hypoxia further increased NE levels but did not alter the DA response to hypoxia alone. The data indicate that free DA in plasma may vary independently of the sympathoadrenal activity.


1986 ◽  
Vol 61 (3) ◽  
pp. 1203-1209 ◽  
Author(s):  
B. J. Legge ◽  
E. W. Banister

Relationships among O2 uptake (VO2), heart rate, and work rate during constant-load submaximal cycle ergometry and ramp-forced exercise to exhaustion have been studied in core groups of trained (n = 15) and untrained (n = 10), 20- to 29-yr-old males. A signal aim was to improve on the accuracy of the 1954 Astrand-Ryhming (A-R) nomogram predicting maximum aerobic power from heart rate elevation at submaximum work rates. A new nomogram has been developed based on a linear relationship, established in experimental groups, between VO2 and delta HR, the latter being defined as the elevation of exercise heart rate above that reached during zero-load pedaling at 90 rpm. The delta HR variable used in a nomogram linking it and submaximum VO2 (either derived by calculation from the concomitant steady-state work rate or measured directly from respiratory gas analysis) successfully differentiated maximum aerobic power of trained from untrained subjects in core groups whose different abilities could not otherwise be distinguished by the A-R nomogram itself. In a validation group of trained (n = 5), untrained (n = 5), and moderately trained (n = 4) 20- to 29-yr-old males, the correlation measured between VO2max values and those predicted from the new nomogram was significantly better (r = 0.98) (P less than 0.05) than predictions made from the A-R nomogram (r = 0.80).


2014 ◽  
Vol 8 (2) ◽  
pp. 29-35
Author(s):  
Tomáš Vencúrik

The study compares intensity of game load among individual players’ positions and between first and second half. Ten female basketball players in senior category participated in this study. Four intensity zones were determined based on maximal heart rate (HRmax). Telemetric device Suunto Team Pack was used for monitoring the heart rate (HR) during the games. The mean HR during the games reached 88.1±3.9% of HRmax of total time. When we compared players’ positions in individual intensity zones we did not record statistical (p>0.05) nor practical significance and neither in % of HRmax (87.4±3.6 vs. 87.8±4.6 vs. 88.8±3.5; point guard vs. forward vs. center). Moreover, when we compared the 1st and the 2nd half in individual zones and in % of HRmax (87.7±4.1 vs. 88.5±3.7) we also did not record any statistical significance (p>0.05) and effect size coefficient shows small effect. Players spent 76.3% of total time with HR grater than 85% of HRmax. The results indicate high physiological demands on female basketball players during the games without taking into consideration the player’s position. This information can be useful for planning and managing training process as well as for comparison with training load. In similar future research we recommend to also evaluate the time-motion analysis besides the internal response and thus a more detailed look at the examined subject in question may be reached.


2021 ◽  
Vol 11 ◽  
Author(s):  
Hadi Nobari ◽  
Ana Filipa Silva ◽  
Filipe Manuel Clemente ◽  
Marefat Siahkouhian ◽  
Miguel Ángel García-Gordillo ◽  
...  

The purposes of this study were (i) to analyze the variations in maximal oxygen consumption (VO2max), maximal heart rate (HRmax), heart rate at rest, acceleration, maximal speed, agility, anaerobic sprint test (RAST) of peak power (RPP), RAST of minimum power, RAST of average power (RAP), and RAST of fatigue index (RFI) during the competitive season, using maturation status and accumulated training load as covariates, and (ii) to describe the differences between responders and non-responders in relation to baseline levels. Twenty-three elite players from the same team competing in the national under-16 competitions were evaluated for 20 weeks in period 1 (before league), middle (mid league), and period 2 (after league). The VO2max (p = 0.009), maximal speed (p = 0.001), RPP (p < 0.001), RAP (p < 0.001), and RFI (p < 0.001) significantly changed across the assessment periods. Interestingly, using accumulated training load and maturation status as covariates revealed no statistical significance (p > 0.05). When analyzing responders and non-responders, only HRmax (between periods 1 and 2) showed no differences between the groups. As a conclusion, it can be seen that accumulated training load and maturation status play an important role in the differences observed across the season. Thus, coaches should consider the importance of these two factors to carefully interpret fitness changes in their players and possibly adjust training decisions according to the maturation level of the players.


Author(s):  
José-Antonio Salas-Montoro ◽  
Manuel Mateo March ◽  
Cristóbal Sánchez-Muñoz ◽  
Mikel Zabala

The use of near-infrared spectroscopy could be an interesting alternative to other invasive or expensive methods to estimate the second lactate threshold. Our objective was to compare the intensities of the muscle oxygen saturation breakpoint obtained with the Humon Hex and the second lactate threshold in elite cyclists. Ninety cyclists performed a maximal graded exercise test. Blood capillary lactate was obtained at the end of steps and muscle oxygenation was continuously monitored. There were no differences (p>0.05) between muscle oxygen oxygenation breakpoint and second lactate threshold neither in power nor in heart rate, nor when these values were relativized as a percentage of maximal aerobic power or maximum heart rate. There were also no differences when men and women were studied separately. Both methods showed a highly correlation in power (r=0.914), percentage of maximal aerobic power (r=0.752), heart rate (r=0.955), and percentage of maximum heart rate (r=0.903). Bland-Altman resulted in a mean difference of 0.05±0.27 W·kg–1, 0.91±4.93%, 0.63±3.25 bpm, and 0.32±1.69% for power, percentage of maximal aerobic power, heart rate and percentage of maximum heart rate respectively. These findings suggest that Humon may be a non-invasive and low-cost alternative to estimate the second lactate threshold intensity in elite cyclists.


1990 ◽  
Vol 60 (4) ◽  
pp. 282-287 ◽  
Author(s):  
J. Rutenfranz ◽  
M. Máček ◽  
K. Lange Andersen ◽  
R. D. Bell ◽  
J. Vávra ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document