VO2max Criteria Research Articles

DOES AGE, SEX, AND BODY MASS INDEX (BMI) AFFECT THE MAXIMUM CAPACITY FOR OXYGEN CONSUMPTION (VO2MAX) IN UNIVERSITY STUDENTS?

This study explored the connection between age, gender, and body mass index (BMI) and how they influence maximum oxygen consumption (VO2max) among students at Gilgamesh University's College of Physical Education and Sports Sciences in Baghdad. The research involved 27 male and 14 female students aged 19 to 49, randomly selected. Physiological and anthropometric measurements such as height, weight, and BMI were taken using the World Health Organization's (2020) standards for assessing body mass, irrespective of gender differences. VO2max was estimated without fitness tests, based on resting heart rate (HRrest) and maximum heart rate (HRmax). Age-specific norms for peak oxygen consumption (VO2max) in men and women were determined using Cooper's VO2max criteria Heyward (1998). The findings revealed a significant negative correlation between weight gain percentage and VO2max decrease in both genders, with a more pronounced impact on males. The study also highlighted a high prevalence of obesity, poor cardiorespiratory fitness, and an inverse link between BMI and VO2max. Moreover, female students demonstrated higher VO2max compared to male students, possibly due to older and heavier male students in the Evening Study Session compared to both male and female students in the Morning Study Session.

Can linear regression confirm VO2max was attained in middle-aged and older adults?

Evaluate the efficacy of a regression method for identifying a VO2 plateau to confirm the attainment of VO2max compared to a verification trial in middle-aged and older adults. Eleven men and ten women (age 61.0 ± 8.1, VO2max 21.8-50.3ml/kg/min, n = 21) completed an individualized ramp graded exercise test (GXT) on the cycle ergometer, and one hour later, a verification trial at 105% of their maximal work rate (WR) achieved during the GXT. A plateau in VO2 was used to confirm VO2max was attained. VO2 plateau was identified using the difference between the highest VO2 between the two trials and a linear regression analysis of the VO2-WR relationship during the GXT. McNemar's test of marginal homogeneity was used to detect differences in the proportion of paired data of individuals' attainment of VO2max criteria. Of the 21 participants, 15 (71.4%) met the verification criterion while 6 (28.6%) did not, compared to the regression method where 16 (76.2%) achieved the regression criterion while 5 (23.8%) did not. McNemar's test revealed no significant difference between participants' ability to achieve the regression and verification criteria (p = 0.999). The regression method is an effective strategy for confirming VO2max was attained with middle-aged and older adults on a cycle ergometer. This time-efficient regression method is comparable with the verification criterion but does not require a second maximal test, which may be advantageous for those where the verification trial may not be practical.

Aerobic capacity attainment and reasons for cardiopulmonary exercise test termination in people with cancer: a descriptive, retrospective analysis from a single laboratory.

Aerobic exercise prescriptions in clinical populations commonly involve target intensities based on cardiopulmonary exercise tests (CPET). CPETs are often discontinued prior to a patient achieving true maximum oxygen consumption (VO2 max) which can adversely affect exercise dose and efficacy monitoring; however, reasons for early discontinuation are poorly reported. Accordingly, we explored the CPET termination reasons in persons with cancer participating in exercise intervention studies. This study comprised of an exploratory, descriptive analysis of retrospective CPET data (VO2 and anaerobic threshold) and termination reasons in a convenience sample of people with cancer participating in exercise intervention studies in a single laboratory. CPETs were standardized using the modified Bruce treadmill protocol with expired gas collection and analysis using a metabolic cart. VO2 max was considered "met" when participants demonstrated (a) oxygen consumption plateau or (b) two of the following criteria: rating of perceived exertion ≥ 9/10, respiratory exchange ratio ≥ 1.15, and/or heart rate of 95% of age-predicted maximum. The frequency and distribution of reasons for test termination relative to the number of CPET exposures for the participants were reported. Forty-four participants engaged in exercise studies between February 2016 and March 2018 provided data for the analysis. Participants completed up to three CPETs during this period (total of 78 CPETs in the current analysis). Eighty-six percent of all CPETs were terminated prior to achieving VO2 max verification criteria and no tests resulted in an oxygen consumption plateau. For those that did not demonstrate achievement of VO2 max verification criteria, reasons for discontinuation were distributed as follows: equipment discomfort-49%, volitional peak-36%, and physical discomfort-14.9%. For those who met VO2 max criteria, volitional peak was the most common reason for test termination (45.5%), followed by physical discomfort (36.4%), and equipment discomfort (18.2%). In our sample of cancer survivors, VO2 max criteria were infrequently met with equipment discomfort being a primary reason for participant-driven test termination. Protocol and equipment considerations are necessary for interpretation and application of CPET findings in clinical practice.

Effect of Treadmill Protocol on Attainment of VO2max Criteria in Collegiate Women Athletes

When performing the same test protocol, athletes from sports of differing metabolic demands may vary in the achievement of physiological criteria that are indicative of attaining maximal oxygen consumption (VO2max). PURPOSE: To examine whether the attainment of VO2max criteria differs in two sports with differing metabolic demands as a result of the graded exercise treadmill test (GXT) protocol used. METHODS: Twenty-nine National Collegiate Athletic Association Division 1 women athletes (basketball (WBB): n=11; lacrosse (WLAX): n=18) completed a continuous GXT to volitional fatigue. Speed increased following each 1-minute stage with a 1% constant grade. VO2peak indicated the highest VO2 value reached during a single test, while VO2max indicated the subject’s functional limit was reached. The criteria to attain VO2max were: VO2 plateau of <0.15 L/min with an increase in the last two workloads; maximum heart rate (HRmax) within 10 bpm of age-predicted heart rate max; respiratory exchange ratio (RER)>1.10; rating of perceived exertion (RPE, 1-10 scale)>8; blood lactate (LAC) collected 5-min post-test >8mmol/L. The attainment > 3 of 5 criteria was required for VO2max. Independent t-tests were used for comparison of values between teams, and chi-squared test was used for comparison of criteria attainment. Alpha level was set at p<0.05. RESULTS: Relative VO2peak values did not differ between teams (WBB: 55.3 ± 8.1; WLAX: 53.8 ± 5.4 mL∙kg-1∙min-1). The percent of athletes that met each of the five criteria were: plateau (WBB: 55%, WLAX: 56%), HRmax (WBB: 27%, WLAX: 39%), RER (WBB: 0%, WLAX: 17%), RPE (WBB: 55%, WLAX: 44%), LAC (WBB: 100%, WLAX: 83%). More WLAX attained VO2peak than VO2max (55% vs. 45%). WBB was evenly distributed between VO2peak (50%) and VO2max (50%). There was no statistical difference between WBB and WLAX in VO2max or the number of athletes from each team who met each individual criterion. Significant differences between teams were observed for LAC (WBB 13.3 ± 1.7, WLAX 10.3 ± 2.3 mmol/L; p=0.001) and RER (WBB 0.96 ± 0.05, WLAX 1.04 ± 0.09; p=0.002). CONCLUSION: These findings suggest physiological responses to a fixed VO2max protocol may vary between sport teams of different metabolic demands. Consideration should be given to such variations when selecting test protocols and interpreting results.

Laboratory determination of maximum oxygen consumption. Do we actually test the maximum values?

The main aim of the article is to enhance the reader interest to the current state of determination of maximum oxygen consumption. The issue is still current. Scientists are constantly discussing the testing protocol design. We want to provide not only an objective view on concept of the testing protocol, but also we want to have a keen interest in validity criteria of maximum oxygen consumption. In general, VO2 changes ≤ 150 ml/min between two consecutive stages is still considered as the primary criteria. On the other hand, we can also found more strict values VO2 changes ≤ 50–100 ml/min in scientific literature. Besides that, the secondary criteria are often used the respiratory exchange ratio ≥ 1.15 and reached ≥ 90 % age predicted maximum heart rate). Subsequently, recent evidence suggests that using verification phase is a valid tool for scientist (verification phase usually starts until 20 minutes after the completion of the progressive test). This article is not a meta-analysis. The article provides basic information about the fi eld of performance diagnostics. Key aspects of valid VO2max criteria are that they should be objective and specifi c to the subject.

Biological Variability in Maximum Oxygen Uptake at Altitude

Cardiorespiratory fitness, typically determined by maximal oxygen uptake (VO2max), represents the maximal rate of oxygen consumption during exercise testing to volitional fatigue. Previous research (Katch, Sady, & Freedson, 1982) has reported that the biological variability of VO2max at sea-level equates to 5.3%. To our knowledge, the biological variability of VO2max has not been studied at altitude. PURPOSE: The aim of this study was to quantify the biological variability of VO2max at 2,348 meters (a desirable elevation for altitude training) using two different VO2max criteria: the traditional VO2 plateau at VO2max concept and verification procedure. METHODS: Ten physically active men and women (age = 27.1 ± 7.2 yr, height = 176.0 ± 9.4 cm, weight = 75.1 ± 12.2 kg) participated in this study. In week #1 participants performed 2x maximal graded exercise trials (GXT) on the treadmill separated by 1-4 days with the traditional VO2 plateau at VO2max concept applied to confirm VO2max. In week #2 participants completed 2x GXT + verification bout trials on a cycle ergometer separated by 1-4 days with the verification procedure used to confirm attainment of VO2max. Verification bouts were performed 20 min after GXT at a constant exercise workload of 105% peak work rate. Coefficient of variation (CV%) was calculated to quantify biological variability of VO2max for each VO2max criteria. ESULTS: Treadmill VO2max values for trials #1 and #2 were 45.2 6.4 and 46.7 ± 6.9 mL/kg/min, respectively with the biological variability of VO2max equating to 4.3% when using the VO2 plateau at VO2max concept applied to confirm VO2max. Cycle ergometry VO2max values for trials #1 and #2 were 45.3 ± 7.3 and 43.2 ± 7.0 mL/kg/min, respectively with the biological variability of VO2max equating to 2.3% when using the verification procedure to confirm attainment of VO2max. CONCLUSION: In summary, our findings support use of the verification procedure to quantify biological variability of VO2max at altitude. This is particularly relevant to interpretation of studies that have used repeated measurements of VO2max to establish a training effect or when VO2max is used for designing training programs.

Accuracy Of The NHANES Treadmill Test In Estimating Aerobic Fitness In Adolescents

Use of the submaximal treadmill test to evaluate cardiorespiratory fitness in adolescents has been widely accepted. The National Youth Fitness Survey (NYFS) adopted the same protocol as previously used in the National Health and Nutrition Examination Survey (NHANES). Questions have arisen as to the appropriateness of this test in adolescents due to maturation differences. In a recent study of fitness in Hungarian adolescents, the NYFS treadmill protocol was used in combination with VO2 measured test to maximal effort. These data provides an opportunity to test the difference between actual and estimated VO2peak values in a sample of youth ages 11-18 years. PURPOSE: To test gender and age group differences in actual and estimated VO2max to establish if interpretation of the submaximal test is within acceptable accuracy. METHODS: A random sample of 578 adolescents were tested in five laboratories across Hungary. From 482 completed treadmill tests, a total of 288 subjects’ data (males = 153, females = 135) was included in the analyses using standard VO2max criteria. Estimates of VO2max were calculated using HR response to exercise stages and compared actual measures of VO2peak. Repeated measures ANOVA and regression analyses were used to test for interactions and relationships respectively. RESULTS: The mean age for this subjects was 15.3±2.3 years distributed over 8 age groups. The ANOVA indicated a significant (p=0.011) interaction of gender and differences in VO2max measures. For the boys, the estimated mean of 49.8±9.4 was not significantly (p=0.153) different with the actual measure of 50.8±7.7 however the girls’ estimate was significantly (p=0.039) higher at 43.0±8.6 than the actual mean measure of 41.7±8.0 mL/kg/min. No gender specific age group differences were significant. Significant (p<0.001) relationships between VO2max values for the subject population were found however the model explained only 25% of the variance. CONCLUSIONS: It seems the NYFS treadmill protocol for adolescents provide an acceptable group estimate of VO2max. While girls’ group means were significantly different, the residual was less than 2 mL/kg/min, a value within daily variances. Moderate relationship between the two measures might indicate individual differences however age did not seem to affect the differences.

Effects Of A Self-selected Pace On Vo2max During A Running Test To Volitional Exhaustion

PURPOSE: The purpose of this study was to evaluate the effects of a self-selected pace during an incremental running test to volitional exhaustion on the attainment of VO2max values. METHODS: Thirteen aerobically-trained females (22.4 ± 1.66 years, 1.63 ± .05 m, 57.3 ± 10.2 kg) with prior experience in VO2max testing and RPE volunteered to participate in the current study. Each subject completed a ramp protocol (TVO2) whereby the speed of the treadmill was increased by 1 km/hr every minute until volitional fatigue and a self-paced protocol (EVO2) whereby each subject was able to self-select the treadmill speed to correspond to predetermined RPE values that were increased during 5 x 2-min stages. The treadmill gradient was set at 1% for each protocol and the subjects completed each protocol in a randomized order. The variables of VO2max, running velocity at fatigue, time to exhaustion, and thermal sensation during each protocol were compared using paired t-tests with alpha ≤0.05. RESULTS: There was no significant difference in VO2max (43.18 vs 43.33 ml/kg/min, p=.790) and running velocity at fatigue (14.9 vs 14.7 km/hr, p=.530) between the two protocols, while time to exhaustion was significantly longer during TVO2 (671.5 vs 592.7 s, p=.003). Additionally, there was no significant difference in perceived heat between the protocols (3.9 vs 3.8, p=.387). Based on the VO2max criteria selected, 7 of the 13 subjects achieved VO2max in each protocol. CONCLUSION: Although VO2max values were not significantly different between the protocols, subjects predominately exercised at a lower intensity and for a shorter (finite) duration of time during EVO2. These findings may be accredited to the closed-loop design that enabled subjects to develop a pacing strategy for optimal performance. This has implications for future studies whereby similar VO2max values can be found using an experimental design that better resembles conditions encountered outside the laboratory.

Metabolic rate, cardiac response, and aerobic capacity in fibromyalgia: a case–control study

Objectives: Several studies report reduced aerobic capacity in patients with fibromyalgia (FM). The purpose of our study was to investigate whether a reduction in aerobic capacity in these patients is accompanied by alterations in metabolic rate and heart rate (HR) response.Method: Twelve women with FM and 12 healthy controls (HCs) matched on sex and age, and with similar leisure time physical activity, participated in the study. All subjects performed an incremental submaximal cycle ergometer test to anaerobic threshold [AT; i.e. blood lactate concentration (bLa) ≥ 4 mmol/L], followed by a stepwise test to exhaustion to estimate maximal oxygen consumption (VO2max).Results: Oxygen consumption and workload were lower among patients than HCs both at AT and at termination of the VO2max test (p < 0.011 for all comparisons). Two patients (18%) and nine HCs (75%) reached VO2max criteria. The relationship between metabolic rate and workload did not differ between groups at exercise below AT. At exercise above AT, the metabolic rate increased disproportionally to workload in the patients. Although the patients had a higher anaerobic contribution to the total metabolic rate at the end of the submaximal test, the anaerobic contribution at the end of the maximal test did not differ between groups. HR responses were largely similar between groups.Conclusions: The current study indicates that patients with FM have similar metabolic and cardiovascular responses to submaximal exercise as HCs. However, these patients have reduced ability to reach VO2max and a possible deficit in the metabolic system when exercising above the AT.

Achievement of V[Combining Dot Above]O2max Criteria During a Continuous Graded Exercise Test and a Verification Stage Performed by College Athletes

The purpose of this study was to determine the incidence of meeting specific VO2max criteria and to test the effectiveness of a VO2max verification stage in college athletes. Thirty-five subjects completed a continuous graded exercise test (GXT) to volitional exhaustion. The frequency of achieving various respiratory exchange ratio (RER) and age-predicted maximum heart rate (HRmax) criteria and a VO2 plateau within 2 and 2.2 ml·kg(-1)·min(-1) (<2SD of the expected increase in VO2) were measured and tested against expected frequencies. After 10 minutes of active recovery, 10 subjects who did not demonstrate a plateau completed a verification stage performed at supramaximal intensity. From the GXT, the number of subjects meeting VO2max plateau was 5 (≤2 ml·kg(-1)·min(-1)) and 7 (≤2.2 ml·kg(-1)·min(-1)), RER criteria 34 (≥1.05), 32 (≥1.10), and 24 (≥1.15), HRmax criteria, 35 (<85%), 29 (<10 b·min(-1)) and 9 (HRmax). The VO2max and HRmax did not differ between GXT and the verification stage (53.6 ± 5.6 vs. 55.5 ± 5.6 ml·kg(-1)·min(-1) and 187 ± 7 vs. 187 ± 6 b·min(-1)); however, the RER was lower during the verification stage (1.15 ± 0.06 vs. 1.07 ± 0.07, p = 0.004). Six subjects achieved a similar VO2 (within 2.2 ml·kg(-1)·min(-1)), whereas 4 achieved a higher VO2 compared with the GXT. These data demonstrate that a continuous GXT limits the college athlete's ability to achieve VO2max plateau and certain RER and HR criteria. The use of a verification stage increases the frequency of VO2max achievement and may be an effective method to improve the accuracy of VO2max measurements in college athletes.

VO2max May Not be Reached During Constant-Load Exercise to Exhaustion Above Critical Power

Critical power (CP) is an aerobic parameter that theoretically represents a power output that can be maintained indefinitely, and is operationally defined as the power asymptote of the hyperbolic relationship between power and time to exhaustion during severe exercise. Whether VO2max is reached during exercise at all intensities >CP is uncertain. PURPOSE: To determine whether VO2 reaches a true maximum during "submaximal" fatigue-inducing constant-load exercise bouts above CP. METHODS: 9 males (age = 24.6 ± 3.6 yr.; ht = 182.8 ± 6.9 cm; wt = 77.8 ± 12.1 kg) and 4 females (age = 29.0 ± 7.3 yr.; ht = 170.8 ± 3.2 cm; wt = 61.8 ± 8.2 kg) underwent an incremental VO2max test (IET) on a cycle ergometer, followed by 4 or 5 randomly assigned, constant-load exercise bouts to exhaustion, each on a separate day. Ventilation and gas exchange were measured continuously during all exercise bouts. Critical power for each subject was estimated using a 3-parameter nonlinear regression model. RESULTS: IET VO2max averaged 3.55 + 0.92 l/min (Respiratory exchange ratio = 1.21 + 0.05; max heart rate = 186.4 + 10.3 bpm; 96.1 + 6.3% age-predicted max heart rate). During the 3 most severe constant-load bouts (two of which were 53 to 82 W less than peak work rate attained during IET), peak VO2 at exhaustion (range 3.32 + 0.88 to 3.54 + 0.91 l/min) was not significantly different than IET VO2max (3.55 ± 0.92 l/min). However, only 44% of the subjects achieved peak VO2 values > VO2max during these three bouts. Additionally, peak VO2 (3.14 + 0.78 l/min) during the lowest constant-load exercise bout (11-44 W above CP) was significantly lower than IET VO2max (p < 0.05), with only 1 out of 13 subjects achieving a peak VO2 > VO2max. CONCLUSIONS: These data suggest that for some power outputs above CP, VO2 at the point of exhaustion does not reach a true maximum. The data also suggest that there are "submaximal" power outputs above CP (but lower than that reached during an IET) that elicit a VO2 equal to, or greater than, VO2max attained during an IET. Thus the highest VO2 values measured during a traditional VO2 "max" test (i.e., IET) may not reflect the highest attainable VO2 even though VO2max criteria are met.

Effect of exercise dose on fat oxidation capacity in postmenopausal women

The capacity to oxidize fat may play an important role in health and disease. However, the effect of exercise dose on maximal fat oxidizing capacity remains unexplored. To investigate this relationship, we utilized a sub‐cohort of women (n = 260) from the DREW study (n = 464) who met stringent VO2max criteria before and after 6 months of exercise. Women were randomly assigned to doses of exercise (kcal·kg body weight−1·week−1; KKW) at 50% VO2max; control (CON; n = 54), 4 KKW (n = 82), 8 KKW (n = 62), and 12 KKW (n = 62). Maximal fat oxidation (MFO; g/min) and intensity eliciting MFO (FatMax) were calculated from VO2max data. Overall, our current sub‐cohort had similar improvements in VO2max to those previously published by our group (trend P &lt; 0.001). Mean (±SD) baseline MFO and relative FatMax (%) were 0.20 ± 0.06 g/min and 51.3 ± 6.3%, respectively. Neither MFO (P = 0.93) nor FatMax (%; P = 0.51) increased with training; however, improvements in absolute FatMax (mL·kg−1·min−1) were greater after training at 8KKW (0.7 ± 1.2) and 12KKW (1.0 ± 1.1) compared with CON (0.0 ± 1.4) and 4KKW (0.1 ± 1.1; P &lt; 0.001). In conclusion, exercise at 50% VO2max for 6 months does not significantly improve MFO or relative FatMax. The data suggest that 50% VO2max may not be adequate to improve MFO. Absolute FatMax data indicate that the workload during training must be constantly increased at higher doses of exercise in order to optimize fat oxidation. This research was funded by grant HL66262 from the National Institutes of Health.

Maximal Physiological Responses between Aquatic and Land Exercise in Overweight Women

To investigate the maximal physiological responses between aquatic and land-based graded exercise tests in overweight women. Twenty healthy, overweight (body mass index (BMI) > or = 25 kg.m(-2)), Caucasian women (mean +/- SD; age 48 +/- 7 yr, BMI 30 +/- 4 kg.m(-2)) completed a deep water running (DWR) and treadmill walking (TMW) graded exercise test. Maximal responses during the DWR and TMW graded exercise tests were compared using paired t-tests. Comparisons were made in the incidence of achievement of maximal oxygen consumption (VO2max) criteria between DWR and TMW protocols. Criteria were a plateau in VO2 (change < 2.1 mL.kg.min(-1)), heart rate (HR) equal to or above the age-adjusted maximum, and respiratory exchange ratio (RER) > or = 1.15. Maximal responses for VO2max (22.5 +/- 4.86 vs 27.7 +/- 4.73 mL.kg.min(-1)), HRmax (159 +/- 16 vs 170 +/- 12 bpm), and RER (1.03 +/- 0.06 vs 1.10 +/- 0.06) were significantly lower (P < 0.01) for the DWR test compared with the TMW test, respectively. Achievement of various VO2max criteria was demonstrated more consistently during the TMW test than the DWR test. Maximal physiological responses of overweight women to DWR and TMW are significantly different but are comparable with other populations. As the maximal responses for DWR compared with TMW differ, the use of land-based criteria for VO2max is not recommended for a graded DWR exercise test.

Applicability of VO2max Criteria in African American and Caucasian Individuals

Applicability of VO2max Criteria in African American and Caucasian Individuals

Influence on aerobic fitness on aortic stiffness in apparently healthy Caucasian and African-American subjects

Background Previous research suggests that arterial stiffness may be significantly higher in African-Americans compared to Caucasians. However, the influence of aerobic fitness on the putative difference in arterial stiffness between these groups has not been previously investigated. Methods Two hundred forty-eight subjects (215 Caucasian, 33 African-American) participated in this study. Within one week following enrollment, subjects underwent body mass index (BMI, kg/m 2) assessment, cardiopulmonary exercise testing and measurement of aortic wave velocity (AWV, m/s) via magnetic resonance imaging. Initially, 33 Caucasian subjects were randomly age (± 4 years) and sex-matched (10 male/23 female) to the African-American subjects. 25 Caucasian subjects were then randomly matched for age (± 4 years), sex (7 male/18 female) and maximal oxygen consumption (VO 2Max ± 7 mlO 2 kg − 1 min − 1 ) to the African-American subjects. Matching based upon VO 2Max criteria was not possible for 8 African-American subjects. Results In the age and sex-matched analysis, Caucasian subjects demonstrated a significantly higher VO 2Max (38.3 ± 9.6 vs. 27.9 ± 8.6 mlO 2 kg − 1 min − 1 , p < 0.001) and lower BMI (24.5 ± 3.2 vs. 29.3 ± 6.2 kg/m 2, p < 0.001) and AWV (5.8 ± 1.7 vs. 6.7 ± 1.5 m/s, p = 0.03). However, when subjects were matched for age, sex and VO 2Max, the differences in both BMI (26.8 ± 5.5 vs. 27.9 ± 5.6 kg/m 2, p = 0.45) and AWV (6.1 ± 1.8 vs. 6.5 ± 1.6 m/s, p = 0.77) were insignificant. Conclusions The results of the present study suggest that previously reported differences in arterial stiffness between Caucasians and African-Americans are at least partially a consequence of a lower level of aerobic fitness in the latter group, a phenomenon that has also been previously demonstrated.

Applicability of VO2max criteria: discontinuous versus continuous protocols.

This study compared the classic discontinuous Taylor et al. (1955) protocol to a continuous version of the same protocol to evaluate maximal physiological responses, and the quantitative values and incidence of achievement of the various maximal oxygen uptake (VO2max) criteria in 10 males (24.1 +/- 2.5 yr). Criteria were a plateau in VO2 (change < 2.1 ml.kg-1.min-1), HR = age adjusted maximal, PER > or = 1.15, and lactate > 8 mmol.l-1. Values for VO2max (56.8 +/- 4.7 vs 55.8 +/- 4.2 ml.kg-1.min-1), ventilation (150.7 +/- 16 vs 149.5 +/- 17.5 l.min-1 BTPS), and HR (186.3 +/- 7.7 beats.min-1 vs 191.7 +/- 6.7 beats.min-1) were similar (P < 0.05) between the discontinuous protocol (DT) and the continuous protocol (CT), respectively. Values for RER (1.28 +/- 0.05 vs 1.22 +/- 0.05) and lactate (14.3 +/- 2.7 vs 11.9 +/- 2.7 mmol.l-1) were greater (P < 0.05) on the DT than the CT. Criteria achievement were the following: 40% (CT) and 10% (DT) for HR; 50% (CT) and 60% (DT) for a VO2 plateau; and, 90% (CT) and 100% (DT) for RER and lactate. It is concluded that a VO2 plateau is not a prerequisite for defining VO2max and is of limited use as the primary objective criterion for evaluating the quality of a graded exercise test. Therefore, the achievement of secondary objective criteria, specifically RER and lactate in combination, increases the likelihood that the highest VO2 value achieved is VO2max.

Maximal oxygen intake as an objective measure of cardio-respiratory performance.

Maximal oxygen intake as an objective measure of cardio-respiratory performance.