Endurance training regimen based upon arterial blood lactate: Effects on anaerobic threshold

Summary The purpose of this investigation was to assess the effect of endurance training based upon the intensity as determined by the arterial blood lactate concentration (LA). Seven healthy male college students performed endurance training on a Monark bicycle ergometer for 15 min on 3 days/week for 8 weeks, at an intensity corresponding to 4 mmol·l⁻¹ arterial blood LA determined during an incremental exercise test (25 watts increment every minute on a bicycle at 50 rpm). Another six male students served as the control group. To assess the training effect, both an incremental exercise test and a submaximal exercise test were performed before and after the endurance training. In the incremental exercise test, at , anaerobic threshold (AT), and the onset of respiratory compensation for metabolic acidosis (RCMA) were measured. AT was determined as the point at which arterial LA rose above the resting value, and RCMA was determined as the point at which Paco₂ decreased during the incremental exercise test. After training, AT increased significantly (37% increment expressed in ,p<0.05). There was a significant increase (p<0.05) in RCMA (17%) and (14%). This training decreased (4%), (15%), heart rate (10%), respiratory exchange ratio (5%), and LA (23%) significantly (p<0.05) during the submaximal exercise test after training. On the other hand, there were no significant changes in the control group through the period when the training group performed their training. These results showed that the endurance training intensity corresponding to 4 mmol·l₋₁ arterial blood LA was effective for the improvement in AT as well as . It is suggested that the present training regimen could delay the onset of anaerobic glycolysis, thus shifting AT to the higher workload and decreasing LA at a given submaximal exercise after training.     

Anaerobic threshold and maximal steady-state blood lactate in prepubertal boys

Summary To elucidate further the special nature of anaerobic threshold in children, 11 boys, mean age 12.1 years (range 11.4–12.5 years), were investigated during treadmill running. Oxygen uptake, including maximal oxygen uptake (VO_2max), ventilation and the ventilatory anaerobic threshold were determined during incremental exercise, with determination of maximal blood lactate following exercise. Within 2 weeks following this test four runs of 16-min duration were performed at a constant speed, starting with a speed corresponding to about 75% ofVO_2max and increasing it during the next run by 0.5 or 1.0 km·h^–1 according to the blood lactate concentrations in the previous run, in order to determine maximal steady-state blood lactate concentration. Blood lactate was determined at the end of every 4-min period. Anaerobic threshold was calculated from the increase in concentration of blood lactate obtained at the end of the runs at constant speed. The mean maximal steady-state blood lactate concentration was 5.0 mmol · 1^–1 corresponding to 88% of the aerobic power, whereas the mean value of the conventional anaerobic threshold was only 2.6 mmol · 1^–1, which corresponded to 78% of theVO_2max. The correlations between the parameters of anaerobic threshold, ventilatory anaerobic threshold and maximal steady-state blood lactate were only poor. Our results demonstrated that, in the children tested, the point at which a steeper increase in lactate concentrations during progressive work occurred did not correspond to the true anaerobic threshold, i.e. the exercise intensity above which a continuous increase in lactate concentration occurs at a constant exercise intensity.     

Muscle metabolism,blood lactate and oxygen uptake in steady state exercise at aerobic and anaerobic thresholds

Summary Muscle metabolites and blood lactate concentration were studied in five male subjects during five constant-load cycling exercises. The power outputs were below, equal to and above aerobic (AerT) and anaerobic (AnT) threshold as determined during an incremental leg cycling test. At AerT, muscle lactate had increased significantly (p<0.05) from the rest value of 2.31 to 5.56 mmol · kg^–1 wet wt. This was accompanied by a significant reduction in CP by 28% (p<0.05), whereas only a minor change (9%) was observed for ATP. At AnT muscle lactate had further increased and CP decreased although not significantly as compared with values at AerT. At the highest power outputs (> AnT) muscle lactate had increased (p<0.01) and CP decreased (p<0.01) significantly from the values observed at AnT. Furthermore, a significant reduction (p<0.05) in ATP over resting values was recorded. Blood lactate decreased significantly (p<0.01) during the last half of the lowest 5 min exercise, remained unchanged at AerT and increased significantly (p<0.05–0.01) at power outputs AnT. It is concluded that anaerobic muscle metabolism is increased above resting values at AerT: at low power outputs (AerT) this could be related to the transient oxygen deficit during the onset of exercise or the increase in power output. At high power outputs (> AnT) anaerobic energy production is accelerated and it is suggested that AnT represents the upper limit of power output where lactate production and removal may attain equilibrium during constant load exercise.     

Automatic detection of maximal oxygen uptake and ventilatory threshold

Maximal oxygen uptake () and ventilatory threshold (VT) are the most common measurements in exercise physiology laboratories for the objective characterization of the physiologic state of metabolic and respiratory systems. Several techniques for their identification were proposed in the literature: the aim of the present study was to review them and assess their performance when applied to experimental data.In the present study, the criteria to detect and VT from respiratory gas-exchange data were analysed and automatic procedures for the identification of these parameters were implemented. These procedures were then applied to experimental data in order to assess the verifiability, repeatability and sensitivity to measurement noise of each proposed method.The results suggest plateau- and RISE-105- as the most reliable automatic procedures for determining , while respiratory exchange ratio-, ventilatory equivalent for O₂- and P_ET,O2-criteria appear to be the most reliable automatic procedures for estimating VT.     

Effect of training on the rating of perceived exertion at the ventilatory threshold

Summary The purpose of this study was to determine the effect of training on the rating of perceived exertion (RPE) at the ventilatory threshold. College students were assigned to either training (n=17) or control (n=10) groups. Trainers completed 18 interval training sessions (five × 5 min cycling at 90–100% ) and 8 continuous training sessions (40 min running or cycling) in 6 weeks. Pre- and post-training, cardiorespiratory, metabolic, and perceptual variables were measured at the ventilatory threshold during graded exercise tests on a cycle ergometer. Ventilatory threshold was that point above which increased abruptly relative to work rate. Post-training means of trained and control subjects were compared using analysis of covariance, with pre-training values as covariates. Following training, the adjusted means for the trained subjects were significantly greater (p<0.05) than for controls for (6%), and for work rate (20%), (23%), and % (13%) at the ventilatory threshold. However, adjusted means for RPE at the ventilatory threshold were not significantly different (2%). Both before and after training, exercise at the ventilatory threshold was perceived as somewhat hard to hard (RPE=13–15) by both groups. The relationship between RPE and % was altered by training, with trained subjects having a lower RPE at a given % . It is concluded that RPE at the ventilatory threshold is not affected by training, despite that after training the ventilatory threshold occurs at a higher work rate and is associated with higher absolute and relative metabolic and cardiorespiratory demands.     

Transient responses in cardiac function below,at, and above anaerobic threshold

Summary Exercise-induced alterations in cardiac function during graded cycling with submaximal and maximal intensities were studied in 13 trained and 13 untrained young men. Stroke volume (SV) and stroke index (SI) at rest and during submaximal and maximal exercise, determined by impedance cardiography, were consistently greater in the trained than in the less fit group. Traning-induced bradycardia was evident in the trained group at rest and during submaximal exercise. Even when SV and SI were compared at the same absolute heart rate and left ventricular ejection time, those for the trained group were markedly greater than those for the untrained. SV for the untrained group was relatively diminished above the work rate corresponding to the anaerobic threshold. The difference in SV during exercise may be attributed to inadequate filling due to the smaller stretch of myocardial fibers in diastole and/or lesser systolic emptying of the left ventricle due to the reduced myocardial contractility in systole of untrained individuals.Data were collected at the Exercise Physiology Laboratory, Osaka City University     

Effects of training upon the maximal oxygen uptake of middle-aged men

Summary An experimental group of 15 middle-aged males participated in a 5-month endurance running program. Significant improvement was observed in maximal oxygen uptake, maximal ventilation, maximal oxygen pulse, and 2-mile run time.A highly trained group of 10 middle-aged males who had been running 2 years or more were compared with the experimental group. The highly trained group was superior in maximal oxygen uptake, maximal ventilation, maximal oxygen pulse, and the 2-mile run time both before and after the 5-month training program of the experimental group. Each of the measures used in this study shows a characteristic age decline after maturity and it appears that these trends are reversible with training.Submitted in partial fulfillment of the requirements for the Ph. D. degree in Physical Education at the University of Illinois under Dr.Th. K. Cureton.     

Response of left ventricular diastolic filling to graded exercise relative to the lactate threshold

Summary During incremental exercise, the left ventricular ejection fraction increases up to the intensity of the anaerobic threshold and tends to level off at higher exercise intensities. Since there is a correlation between the response of peak filling rate and ejection fraction to exercise, this study was conducted to determine whether the response of left ventricular diastolic function is similar to the response of systolic function relative to lactate threshold. Twelve healthy men performed two exercise tests on a cycle ergometer. In the first test, lactate threshold and maximal power output were determined. In the second exercise test, gated radionuclide ventriculography was performed at rest, at the lactate threshold intensity, and at peak exercise to measure ejection fraction and peak filling rate. Ejection fraction increased significantly from rest [mean (SD): 62 (5)%] to lactate threshold [76 (7) %] and did not change significantly from lactate threshold to peak exercise [77 (7)%]. Likewise, peak filling rate (normalized for stroke counts) increased from resting [6.1 (0.9)V _s · s^–1] to lactate threshold [9.4 (1.8)V _s · s^–1] and did not change significantly from lactate threshold to peak exercise [9.6 (2.9)V _s · s^–1]. There was no correlation between the change in peak filling rate and the change in ejection fraction from rest to lactate threshold. Thus, during incremental exercise, left ventricular diastolic function responds qualitatively similar to systolic function.     

Comparison of heart rate as a non-invasive determinant of anaerobic threshold with the lactate threshold when cycling

Summary In 9 trained athletes and 4 sedentary subjects the anaerobic threshold was assessed on a cycle ergometer, using the deflection point of heart rate in a protocol in which the workload increased by 10 W every 45 s. The workload at which plasma lactate concentration equalled 4 mmol · l^–1 was assessed under steady state conditions on separate occasions. In addition, in 3 subjects the non-invasive anaerobic threshold and the 4 mmol · l^–1 lactate level under steady state conditions were assessed on a treadmill. On the cycle ergometer 6 subjects demonstrated a deflection point in the heart rate record, whereas the others failed to do so. The workload at which heart rate departed from linearity in the progressive protocol did not coincide with the steady state 4 mmol · l^–1 workload but occurred at a higher workload. On the treadmill no deflection in heart rate was observed. It is concluded that in cyclists a deflection in heart rate does not always occur, and when it does, it does not coincide with the anaerobic threshold determined under steady state conditions.     

Effect of lung resection on blood lactate threshold in lung cancer patients

Summary We studied the effect of a decrease in vital capacity (VC) on the blood lactate threshold detected during exercise in 16 preoperative (PRE) and 10 postoperative (POST) lung cancer patients who had undergone lobectomy or pneumonectomy. The PRE patients were selected on the basis of having normal preoperative pulmonary function. The POST patients were selected on the basis of having normal preoperative pulmonary function and a postoperative VC of less than 80%. The oxygen consumption/body surface area at a 2.2 m.mol·l^–1 arterial lactate concentration ( / BSA at La-2.2) was adopted as the blood lactate threshold. VC/BSA in the POST group significantly correlated with /BSA at La-2.2 (r=0.85, P<0.01), but not in the PRE group. SaO₂ at La-2.2 was 95.4+-1.5% in the PRE group and 95.2+-1.3% in the POST group. SaO₂ at La-2.2 did not correlate with VC/BSA in either group. The hemoglobin concentration (Hb) in the arterial blood correlated significantly with VC/BSA in the POST group (r= 0.65, P< 0.05) but not in the PRE group. These results indicate that /BSA at La-2.2 was restricted by VC in patients with restrictive pulmonary function disorder. Of the three elements of oxygen delivery, Hb was a limiting factor for /BSA at La-2.2 but SaO₂ was not. Cardiac output, which was not measured in our study, was speculated to be another limiting factor for _388-05 at La-2.2     

Psychomotor performance during prolonged exercise above and below the blood lactate threshold

Previous investigations from this laboratory have demonstrated that during graded exercise with exercise intensities increasing every 3 min until exhaustion the multiple choice reaction time (RT) decreased until the intensity exceeded the lactate threshold (LT) by approximately 25%, and then rapidly increased. The aim of this study was to follow up changes in RT during prolonged exercise at constant intensities above and below LT and to relate these changes to changes in venous blood lactate [La⁻]_b, and plasma catecholamine [CA]_pl concentration responses to the exercise. For this purpose eight young soccer players exercised for 20-min on a cycle ergometer at 10% above LT, and nine exercised for 60 min at an intensity 30% below LT. During both tests RT, heart rate (HR), as well as [La⁻]_b, and [CA]_pl were measured. Above LT, RT decreased from the 5th min until the end of exercise, whilst HR, [La⁻]_b, and [CA]_pl increased progressively. Significant inverse correlations were ascertained between RT and plasma adrenaline (r = − 0.651) and noradrenaline concentrations (r = − 0.678). During exercise below LT, RT decreased up to approximately 40 min, then it reached a nadir, and stabilized at this level. This was accompanied by only small changes in [La⁻]_b and [CA]_pl. The present findings would indicate that young athletes are able to maintain for a relatively long time, or even increase, their psychomotor performance during endurance exercise both below and above the LT. Accepted: 23 June 1997     

The effects of specificity of training on rating of perceived exertion at the lactate threshold

Summary To determine the effects of cycle and run training on rating of perceived exertion at the lactate threshold (LT), college men completed a 40-session training program in 10 weeks (n=6 run training,n=5 cycle training,n=5 controls). Pre-and post-training variables were measured during graded exercise tests on both the bicycle ergometer and treadmill. ANOVA on the pre- and post-training difference scores resulted in similar improvements in for both testing protocols, regardless of training mode. The run training group increased at the LT by 58.5% on the treadmill protocol and by 20.3% on the cycle ergometer. Cycle trainers increased LT only during cycle ergometry (+38.7%). No changes were observed in the control group. No differences for RPE at the LT were found before or after training, or between testing protocols for any group. Perception of exercise intensity at the LT ranged from “very light” to “light”. The relationship between RPE and was altered by the specific mode of training, with trained subjects having a lower RPE at a given (no change in RPE at max.). It was concluded that RPE at the LT was not affected by training, despite the fact that after training the LT occurs at a higher work rate and was associated with higher absolute and relative metabolic and cardiorespiratory demands.     

Specificity effects of run versus cycle training on ventilatory threshold

Summary This study compared the effects of 9 weeks of run (RT) versus cycle (CT) training on ventilatory threshold (Th_v) determined during treadmill (TM) and cycle ergometer (CE) graded exercise testing. Sixteen college age men were assigned to a RT or CT group and performed a TM and a CE test before and after training. Both training groups performed similar training protocols which initially consisted of continuous exercise 4 days·week^–1 at 75–80% maximum heart rate (fc,_max) for 45 min. Training intensity was later increased to 80–85% fc _max and interval training (90–95% fc,_max) was incorporated 2 days·week^–1 into the continuous training. Both groups showed significantly improved maximal oxygen consumption ( O_2max) on both TM and CE tests (P<0.01) with no significant differences between the groups. Significant Th_v increases (P<0.05) were found on TM tests for RT (n=8) and CT (n=8) groups [mean (SD); 443 (438) and 373 (568) ml O₂·min^–1, respectively] with no difference between the groups. Results from the CE tests revealed a significant Th_v increase (P<0.01) for the CT group [566 (663) ml O₂·min^–1] with no change for the RT group. The Th_v improvement noted for the RT group was significantly different (P< 0.05) comparing CE with TM tests but not for the CT group. The results indicate that CT and RT improvement in Th_v for runners is dependent upon mode of training and testing, and there is an apparent dissociation of O_2maxand Th_v specific to training.     

Ventilatory threshold and maximal oxygen uptake in present triathletes.

The aim of this study was to determine the physiological profile of young triathletes who began triathlon competition as their first sport. Twenty-nine male competitive triathletes (23 regionally and nationally ranked triathletes and 6 elite, internationally ranked triathletes) performed two tests, one on a cycle ergometer (CE VO2max) and one on a treadmill (TM VO2max). Results showed (a) no difference between CE VO2max and TM VO2max in the triathletes (69.1 +/- 7.2 vs. 70.2 +/- 6.2 mL x kg(-1) x min(-1), respectively), (b) values of CE VO2max and TM VO2max in elite triathletes (75.9 +/- 5.2 and 78.5 +/- 3.6 mL x kg(-1) x min(-1), respectively) that were comparable to those reported in elite single-sport athletes in these specialities, and (c) although the ventilatory threshold (Th(vent)) was similar in CE and TM, TM Th(vent) was consistently lower for triathletes than TM Th(vent) usually reported for runners.     

Overall and differentiated ratings of perceived exertion at the respiratory compensation threshold: effects of gender and mode

Research on gender differences in ratings of perceived exertion (RPE) has been equivocal with few studies comparing exercise modes and differentiated RPE. The current study examined gender differences in overall and differentiated RPE at the respiratory compensation threshold (RCT) during cycling and treadmill exercise. Each minute during a maximal treadmill and maximal cycling test, men (n=18) and women (n=16) estimated RPE corresponding to overall (RPE-O), legs (RPE-L), and breathing/chest (RPE-C) exertion. A 2 (gender) × 2 (mode) × 3 (RPE-O, RPE-L, RPE-C) repeated measures MANOVA revealed no significant mode × gender or RPE × gender interactions. The exercise mode × RPE interaction approached significance (P=0.055) when cycling [mean (SD) 14.8 (2.9)] and treadmill exercise [12.8 (2.9)] were compared. No main effects for gender [men: 13.7 (2.6), women: 13.4 (2.6)] were detected. Main effects for mode showed RPE to be significantly greater during cycling [14.4 (2.8)] versus treadmill exercise [12.7 (2.9)]. Main effects for differentiated RPE showed RPE-L [13.8 (2.6)] to be significantly greater than RPE-O [13.5 (2.6)] and RPE-C [13.3 (2.6)]. Results suggest that overall and differentiated RPE at the RCT are not significantly different between genders during cycling or treadmill exercise. While RPE-L was statistically greater than RPE-O and RPE-C, the magnitude of the differences makes this result of little practical significance. The marginal interaction suggests greater RPE-L values might be expected at the RCT during cycling versus treadmill exercise. However, results suggest that minimal RPE differences exist between men and women during cycling and treadmill exercise. Electronic Publication     

The validity of anaerobic threshold determination by a Douglas bag method compared with arterial blood lactate concentration

Summary Using an open circuit system (Douglas bag method), measurement of the anaerobic threshold (AT) was performed on ten healthy male college students during an incremental exercise test on a bicycle ergometer in an attempt to determine the validity of this method as compared with arterial blood lactate AT measurement.Blood samples were taken from either the radial or brachial artery through a Teflon catheter (3 ml/each time) every minute until the subject's maximal exercise tolerance was reached. Blood lactate was analyzed by the enzymatic method.Differences in work rate, O₂, % O_{2 max}, _E, HR, and R at AT _LA (AT determined by the increase in blood lactate) and at AT _GE (gas exchange AT based on the non-linear increases in _E, CO₂, and other respiratory parameters), respectively, were all found to be statistically insignificant. There was a significant correlation (r=0.866, p<0.01) between AT _LA and AT _GE when expressed in O₂ values (l/min). There was also a significant correlation between AT _LA and O_{2 max} (r=0.778, p<0.01). These results indicate that the commonly used Douglas bag method could provide a valid non-invasive measure of anaerobic threshold.     

Effects of previous exercise on the ventilatory determination of the aerobic threshold

Summary To study the effects of previous submaximal exercise on the ventilatory determination of the Aerobic Threshold (AeT), 16 men were subjected to three maximal exercise tests (standard test = ST, retest = RT, and test with previous exercise = TPE) on a cycle ergometer. The protocol for the three tests consisted of 3 min pedalling against 25 W, followed by increments of 25 W every minute until volitional fatigue. TPE was preceded by 10 min cycling at a power output corresponding to the AeT as determined in ST, followed by a recovery period pedalling against 25 W until returned to values consistent with the initial response to 25 W. AeT was determined from the gas exchange curves (ventilatory equivalent for O₂, fraction of expired O₂, excess of , ventilation, and respiratory gas exchange ratio) printed every 30 s. The results showed good ST×RT reliability (r=0.89). TPE showed significantly higher AeT values (2.548±0.44 l·min^–1) when compared with ST (2.049±0.33 l·min^–1) and RT (2.083±0.30 l·min^–1). There were no significant differences for the sub-threshold respiratory gas exchange ratios among the trials. The sub-threshold response showed significantly higher values for TPE at power outputs above 50 W. It was concluded that the performance of previous exercise can increase the value for the ventilatory determination of the AeT due to a faster sub-threshold response.Supported by fellowship number 3660/80-3, CAPES, Brazil     

Effects of aerobic endurance training status and specificity on oxygen uptake kinetics during maximal exercise

The main purpose of this study was to analyze the effects of exercise mode, training status and specificity on the oxygen uptake (O₂) kinetics during maximal exercise performed in treadmill running and cycle ergometry. Seven runners (R), nine cyclists (C), nine triathletes (T) and eleven untrained subjects (U), performed the following tests on different days on a motorized treadmill and on a cycle ergometer: (1) incremental tests in order to determine the maximal oxygen uptake (O_2max) and the intensity associated with the achievement of O_2max (IO_2max); and (2) constant work-rate running and cycling exercises to exhaustion at IO_2max to determine the effective time constant of the O₂ response (O₂). Values for O_2max obtained on the treadmill and cycle ergometer [R=68.8 (6.3) and 62.0 (5.0); C=60.5 (8.0) and 67.6 (7.6); T=64.5 (4.8) and 61.0 (4.1); U=43.5 (7.0) and 36.7 (5.6); respectively] were higher for the group with specific training in the modality. The U group showed the lowest values for O_2max, regardless of exercise mode. Differences in O₂ (seconds) were found only for the U group in relation to the trained groups [R=31.6 (10.5) and 40.9 (13.6); C=28.5 (5.8) and 32.7 (5.7); T=32.5 (5.6) and 40.7 (7.5); U=52.7 (8.5) and 62.2 (15.3); for the treadmill and cycle ergometer, respectively]; no effects of exercise mode were found in any of the groups. It is concluded that O₂ during the exercise performed at IO_2max is dependent on the training status, but not dependent on the exercise mode and specificity of training. Moreover, the transfer of the training effects on O₂ between both exercise modes may be higher compared with O_2max.     

Blood lactate during constant-load exercise at aerobic and anaerobic thresholds

Summary Venous blood lactate concentrations [la_b] were measured every 30 s in five athletes performing prolonged exercise at three constant intensities: the aerobic threshold (Th_aer), the anaerobic threshold (Th_an) and at a work rate (IWR) intermediate between (Th_aer and Th_an. Measurements of oxygen consumption and heart rate (HR) were made every min. Most of the subjects maintained constant intensity exercise for 45 min at Th_aer and IWR, but at Th_an none could exercise for more than 30 min. Relationships between variations in [la_b] and concomitant changes in or HR were not statistically significant. Depending on the exercise intensity (Th_aer, IWR, or Th_an) several different patterns of change in [la_b] have been identified. Subjects did not necessarily show the same pattern at comparable exercise intensities. Averaging [la_b] as a function of relative exercise intensity masked spatial and temporal characteristics of individual curves so that a common pattern could not be discerned at any of the three exercise levels studied. The differences among the subjects are better described on individual [la_b] curves when sampling has been made at time intervals sufficiently small to resolve individual characteristics.     

Maximal oxygen uptake,anaerobic threshold and running economy in women and men with similar performances level in marathons

Sex differences in running economy (gross oxygen cost of running, C_R), maximal oxygen uptake (VO_2max), anaerobic threshold (Th_an), percentage utilization of aerobic power (% VO_2max), and Th_an during running were investigated. There were six men and six women aged 20–30 years with a performance time of 2 h 40 min over the marathon distance. The VO_2max, Th_an, and CR were measured during controlled running on a treadmill at 1° and 3° gradient. From each subject's recorded time of running in the marathon, the average speed (v _M) was calculated and maintained during the treadmill running for 11 min. The VO_{2 max} was inversely related to body mass (m _b), there were no sex differences, and the mean values of the reduced exponent were 0.65 for women and 0.81 for men. These results indicate that for running the unit ml·kg^–0.75·min^–1 is convenient when comparing individuals with different m _b. The VO_2max was about 10% (23 ml·kg^–0.75·min^–1) higher in the men than in the women. The women had on the average 10–12 ml·kg^–0.75·min^–1 lower VO₂ than the men when running at comparable velocities. Disregarding sex, the mean value of C_R was 0.211 (SEM 0.005) ml·kg^–1·m^–1 (resting included), and was independent of treadmill speed. No sex differences in Th_an expressed as % VO_2max or percentage maximal heart rate were found, but Than expressed as VO₂ in ml·kg^–0.75·min^–1 was significantly higher in the men compared to the women. The percentage utilization of f _emax and concentration of blood lactate at v _M was higher for the female runners. The women ran 2 days more each week than the men over the first 4 months during the half year preceding the marathon race. It was concluded that the higher VO_2max and Th_an in the men was compensated for by more running, superior C_R, and a higher exercise intensity during the race in the performance-matched female marathon runners.