Physiological Responses to Cycling for 60 Minutes at Maximal Lactate Steady State

2000 ◽  
Vol 25 (4) ◽  
pp. 250-261 ◽  
Author(s):  
Claude Lajoie ◽  
Louis Laurencelle ◽  
François Trudeau

Changes in physiological variables during a 60-min continuous test at maximal lactate steady state (MLSS) were studied using highly conditioned cyclists (1 female and 9 males, aged 28.3 ± 8.1 years). To determine power at MLSS, we tested at 8-min increments and interpolated the power corresponding to a blood lactate value of 4 mmol/L. During the subsequent 60-min exercise at MLSS, we observed a sequential increase of physiological parameters, in contrast to stable blood lactate. Heart rate drifted upward from beginning to end of exercise. This became statistically significant after 30 min. From 10-60 min of exercise, a change of + 12.6 ± 3.2 bpm was noted. Significant drift was seen after 30 min for the respiratory exchange ratio, after 40 min for the rate of perceived exertion using the Borg scale, and after 50 min for % [Formula: see text] and minute ventilation. This slow component of [Formula: see text] may be the result of higher recruitment of type II fibers. Key words: Rate of perceived exertion, heart rate, oxygen consumption, blood lactate, cycling

2017 ◽  
Vol 42 (2) ◽  
pp. 142-147 ◽  
Author(s):  
Oliver Faude ◽  
Anne Hecksteden ◽  
Daniel Hammes ◽  
Franck Schumacher ◽  
Eric Besenius ◽  
...  

The maximal lactate steady-state (MLSS) is frequently assessed for prescribing endurance exercise intensity. Knowledge of the intra-individual variability of the MLSS is important for practical application. To date, little is known about the reliability of time-to-exhaustion and physiological responses to exercise at MLSS. Twenty-one healthy men (age, 25.2 (SD 3.3) years; height, 1.83 (0.06) m; body mass, 78.9 (8.9) kg; maximal oxygen uptake, 57.1 (10.7) mL·min−1·kg−1) performed 1 incremental exercise test, and 2 constant-load tests to determine MLSS intensity. Subsequently, 2 open-end constant-load tests (MLSS 1 and 2) at MLSS intensity (3.0 (0.7) W·kg−1, 76% (10%) maximal oxygen uptake) were carried out. During the tests, blood lactate concentrations, heart rate, ratings of perceived exertion (RPE), variables of gas exchange, and core body temperature were determined. Time-to-exhaustion was 50.8 (14.0) and 48.2 (16.7) min in MLSS 1 and 2 (mean change: −2.6 (95% confidence interval: −7.8, 2.6)), respectively. The coefficient of variation (CV) was high for time-to-exhaustion (24.6%) and for mean (4.8 (1.2) mmol·L−1) and end (5.4 (1.7) mmol·L−1) blood lactate concentrations (15.7% and 19.3%). The CV of mean exercise values for all other parameters ranged from 1.4% (core temperature) to 8.3% (ventilation). At termination, the CVs ranged from 0.8% (RPE) to 11.8% (breathing frequency). The low reliability of time-to-exhaustion and blood lactate concentration at MLSS indicates that the precise individual intensity prescription may be challenging. Moreover, the obtained data may serve as reference to allow for the separation of intervention effects from random variation in our sample.


1995 ◽  
Vol 79 (3) ◽  
pp. 781-785 ◽  
Author(s):  
F. Leweke ◽  
K. Bruck ◽  
H. Olschewski

According to the most customary exercise protocols, core temperature (Tc) rises in parallel with workload (WL) and experimental time. Physiological variables, however, may be related to each of these factors. To investigate effects of WL independent of experimental time and body temperature, we employed four moderate WLs in 4-min steps between 35 and 65% peak O2 uptake (VO2 peak) in randomized order. To investigate independent effects of body temperature, the same work protocol was performed both after resting in comfortable ambient temperature [control test (Cont)] and after a double cold exposure [precooling test (Pret)], where Tc and the temperature set point are decreased by approximately 0.6 and 0.3 degrees C, respectively. Eight male subjects (24 +/- 1.9 yr, VO2 peak 4.9 +/- 0.5 l/min) worked on a cycle ergometer in a climatic chamber. Heart rate (HR) and breathing frequency (BF), but not preferred pedal rate (PR), were positively correlated to Tc, the slopes amounting to 17 and 3.75 min-1/degree C for HR and BF, respectively. The regression appeared linear over the whole temperature range, and the regression lines were not shifted by precooling. PR was increased by time, but Pret-Cont differences of PR and Tc were inversely correlated (r = -0.50, P < 0.01). The effects of WL were highly significant on HR, O2 uptake, and rate of perceived exertion but not on BF, PR, and sweat rate. The relation of rate of perceived exertion to HR was shifted by precooling.


2014 ◽  
Vol 9 (5) ◽  
pp. 772-776 ◽  
Author(s):  
Naiandra Dittrich ◽  
Ricardo Dantas de Lucas ◽  
Ralph Beneke ◽  
Luiz Guilherme Antonacci Guglielmo

The purpose of this study was to determine and compare the time to exhaustion (TE) and the physiological responses at continuous and intermittent (ratio 5:1) maximal lactate steady state (MLSS) in well-trained runners. Ten athletes (32.7 ± 6.9 y, VO2max 61.7 ± 3.9 mL · kg−1 · min−1) performed an incremental treadmill test, three to five 30-min constant-speed tests to determine the MLSS continuous and intermittent (5 min of running, interspaced by 1 min of passive rest), and 2 randomized TE tests at such intensities. Two-way ANOVA with repeated measures was used to compare the changes in physiological variables during the TE tests and between continuous and intermittent exercise. The intermittent MLSS velocity (MLSSint = 15.26 ± 0.97 km/h) was higher than in the continuous model (MLSScon = 14.53 ± 0.93 km/h), while the TE at MLSScon was longer than MLSSint (68 ± 11 min and 58 ± 15 min, P < .05). Regarding the cardiorespiratory responses, VO2 and respiratory-exchange ratio remained stable during both TE tests while heart rate, ventilation, and rating of perceived exertion presented a significant increase in the last portion of the tests. The results showed a higher tolerance to exercising during MLSScon than during MLSSint in trained runners. Thus, the training volume of an extensive interval session (ratio 5:1) designed at MLSS intensity should take into consideration this higher speed at MLSS and also the lower TE than with continuous exercise.


2011 ◽  
Vol 29A (Special-Issue) ◽  
pp. 59-68 ◽  
Author(s):  
Roxana Brasil ◽  
Ana Barreto ◽  
Leandro Nogueira ◽  
Edil Santos ◽  
Jefferson Novaes ◽  
...  

Comparison of Physiological and Perceptual Responses Between Continuous and Intermittent CyclingThe present study tested the hypothesis that the exercise protocol (continuous vs. intermittent) would affect the physiological response and the perception of effort during aquatic cycling. Each protocol was divided on four stages. Heart rate, arterial blood pressure, blood lactate concentration, central and peripheral rate of perceived exertion were collected in both protocols in aquatic cycling in 10 women (values are mean ± SD): age=32.8 ± 4.8 years; height=1.62 ± 0.05 cm; body mass=61.60 ± 5.19 kg; estimated body fat=27.13 ± 4.92%. Protocols were compared through two way ANOVA with Scheffé's post-hoc test and the test of Mann- Whitney for rate of perceived exertion with α=0.05. No systematic and consistent differences in heart rate, arterial blood pressure, double product and blood lactate concentration were found between protocols. On the other hand, central rate of perceived exertion was significantly higher at stage four during continuous protocol compared with intermittent protocol (p=0.01), while the peripheral rate of perceived exertion presented higher values at stages three (p=0.02) and four (p=0.00) in the continuous protocol when compared to the results found in intermittent protocol. These findings suggest that although the aquatic cycling induces similar physiologic demands in both protocols, the rate of perceived exertion may vary according to the continuous vs. intermittent nature of the exercise.


2016 ◽  
Vol 22 ◽  
pp. 20 ◽  
Author(s):  
Veronika Myran Wee ◽  
Erna Von Heimburg ◽  
Roland Van den Tillaar

The aim of this study was to compare perceptual and physiological variables between running on three different modalities — an indoor athletics track, a motorized treadmill, and a non-motorized curved treadmill — for 1000 m at three different velocities. Ten male athletes (age 24±3 years, body mass 69.8±6.91 kg, height 1.80±0.06 m, VO2peak 69.0±6.70 ml/kg/ min) conducted three 1000 m laps at increasing velocity on three different running modalities. The athletes had a 3-minute recovery between each lap, where the rate of perceived exertion (RPE) was registered and the blood lactate concentration and heart rate were measured. Oxygen uptake was measured using a portable metabolic analyser. The physiological (oxygen uptake, heart rate, and blood lactate concentration) and perceptual (RPE) variables were higher when running on a non-motorized curved treadmill compared with running on the track or a motorized treadmill. No differences were found between running on a motorized treadmill and the track except for the RPE, which was lower when running on the track compared with the motorized treadmill. Running on a non-motorized curved treadmill at three different velocities results in a higher oxygen uptake (37%) and heart rate (22%) and is subjectively much harder than running on a track or a motorized treadmill at the same velocities. The difference is around 4 km/h when comparing the physiological and perceptual responses. Thus, when performing training sessions on a non-motorized curved treadmill, subjects should subtract 4 km/h from their regular pace on a track or motorized treadmill to get the same response considering oxygen uptake, heart rate, RPE and blood lactate concentration.


Author(s):  
Claudio Perret ◽  
Kathrin Hartmann

AbstractThe heart rate-based lactate minimum test is a highly reproducible exercise test. However, the relation between lactate minimum determined by this test and maximal lactate steady state in running and cycling is still unclear. Twelve endurance-trained men performed this test in running and cycling. Exercise intensity at maximal lactate steady state was determined by performing several constant heart rate endurance tests for both exercise modes. Heart rate, power output, lactate concentration, oxygen uptake and rating of perceived exertion at lactate minimum, maximal lactate steady state and maximal performance were analysed. All parameters were significantly higher at maximal lactate steady state compared to lactate minimum for running and cycling. Significant correlations (p<0.05) between maximal lactate steady state and lactate minimum data were found. Peak heart rate and peak oxygen uptake were significantly higher for running versus cycling. Nevertheless, the exercise mode had no influence on relative (in percentage of maximal values) heart rate at lactate minimum (p=0.099) in contrast to relative power output (p=0.002). In conclusion, all measured parameters at lactate minimum were significantly lower but highly correlated with values at maximal lactate steady state in running and cycling, which allows to roughly estimate exercise intensity at maximal lactate steady state with one single exercise test.


2019 ◽  
Vol 9 (2) ◽  
pp. 150
Author(s):  
Rami Hammad ◽  
Amro Abu Baker ◽  
Julika Schatte ◽  
Adnan Alqaraan ◽  
Ahmad Almulla ◽  
...  

The aim of this study was to determine the effects of different musical rhythms on taekwondo athletes. The variance in athletes&rsquo; anaerobic abilities performed under slow and fast musical rhythms was tested in the study presented. Previous studies have demonstrated how music may cause physiological responses before, during, or after different types of exercises. The aim of this study was to identify the effect of music played in two different rhythms (slow 80 b/m, and fast 200 b/m) during anaerobic exercises by measuring four specific physiological variables: heart rate (HR), blood pressure (BP), blood lactate (BL), and rate of perceived exertion (RPE). Additionally, the peak power of each athlete was assessed. Ten black-belt taekwondo male athletes (average age 20.38&plusmn;1.51) performed for 30 seconds at their maximum anaerobic power on a Monarch Ergonomic that was connected to the Wingate test. The RPE indicated significant differences with a probability value of 0.014 when measured two minutes after the testing. Measurements of heart rate, blood lactate, and diastolic blood pressure after exposure to slow and fast rhythms did not show significant differences. While it has been shown in previous research that the human body tends to synchronize with rhythmic elements of music, this only holds true for exposure to specific rhythms after a longer period of time. The study conducted was based on exposure to different rhythms for only 30 seconds, which may be why these variables did not differ significantly. Yet, results for systolic blood pressure proved significantly different for fast and slow musical rhythms with a probability value of 0.0004.&nbsp;


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