Maximal Graded Exercise Test Research Articles

Acute physiological and perceptual responses to moderate intensity cycling with different levels of blood flow restriction.

The aim of this study was to compare: i) the physiological and perceptual responses of low-load exercise [(moderate intensity exercise (MI)] with different levels of blood flow restriction (BFR), and ii) MI with BFR on the bike with high intensity (HI) exercise without BFR. The protocol involved large muscle mass exercise at different levels of BFR, and this differentiates our study from others. Twenty-one moderately trained males (age: 24.6 ± 2.4 years; VO2peak: 47.2 ± 7.0 ml.kg-1.min-1, mean ± sd) performed one maximal graded exercise test and seven 5-min constant-load cycling bouts. Six bouts were at MI [40% peak power (Ppeak), 60%VO2peak], one without BFR and five with different levels of BFR (40%, 50%, 60%, 70%, 80% of estimated arterial occlusion pressure). The HI bout (70%Ppeak, 90%VO2peak) was without BFR. Oxygen uptake (VO2), heart rate (HR), blood lactate (BLa), rate of perceived exertion (RPE), and tissue oxygen saturation (TSI) were recorded. Regardless of pressure, HR, BLa and RPE during MI-BFR were higher compared to MI (p < 0.05, ES: moderate to very large), and TSI reduction was greater in MI-BFR than MI (p < 0.05, ES: moderate to large). The responses of VO2, HR, BLa, RPE and TSI induced by the different levels of BFR in MI-BFR were similar. Regardless of pressure, the responses of VO2, HR, BLa and RPE induced by MI-BFR were lower than HI (p < 0.05), except for TSI. TSI change was similar between MI-BFR and HI. It appears that BFR equal to 40% of arterial occlusion pressure is sufficient to reduce TSI when exercising with a large muscle mass.

Prediction of VO2max based on a 3-kilometer running test for water sports athletes.

No studies have reported the 3-kilometer running test (3KRT) intending to predict VO2max for water sports athletes. Therefore, the purpose of this study was to develop a new model to predict the maximal aerobic capacity (VO2max) for water sports athletes based on 3KRT. One hundred and two water sports athletes completed two sessions of experiments consisting of a maximal graded exercise test (GXT) and a 3KRT. Multiple linear regression was applied to predict VO2max value based on the performance and physiological responses of 3KRT, along with participants' anthropometric and demographic variables. The predicted residual error sum of square (PRESS) and error terms (constant error and total error) were calculated to further evaluate the predictive accuracy. Two significant prediction models based on elapsed exercise time (T3KRT), post-exercise heart rate (PHR3KRT), body mass, and gender were proposed. One model including PHR3KRT was identified (VO2max=120.77-0.028×T3KRT [second]-0.11×PHR3KRT [bpm]-0.334×body mass [kg]+8.70×gender [1: male, 0: female]), with an adjusted R2 of 0.723. Another model excluding PHR3KRT was also identified (VO2max=103.65-0.034×T3KRT [second]-0.317×Body mass [kg] + 7.89×gender [1: male, 0: female]), with an adjusted R2 of 0.713. Both models were further validated by the result of PRESS statistics. This endurance 3-kilometer running test accurately predicted VO2max value for water sports athletes (rowers, canoeists, and kayakers), and the model excluding PHR3KRT would be easier to use.

Effects of Curcumin and Fenugreek Soluble Fiber on the Physical Working Capacity at the Fatigue Threshold, Peak Oxygen Consumption, and Time to Exhaustion

Herrick, LP, Goh, J, Menke, W, Campbell, MS, Fleenor, BS, Abel, MG, and Bergstrom, HC. Effects of curcumin and fenugreek soluble fiber on the physical working capacity at the fatigue threshold, peak oxygen consumption, and time to exhaustion. J Strength Cond Res 34(12): 3346-3355, 2020-The purpose of this study was to examine the effects of curcumin in combination with fenugreek soluble fiber (CUR + FEN) or fenugreek soluble fiber alone (FEN) on the neuromuscular fatigue threshold (PWCFT), peak oxygen consumption (V˙o2peak), and time to exhaustion (Tlim) on a graded exercise test (GXT), in untrained subjects. The PWCFT estimates the highest power output that can be maintained without evidence of neuromuscular fatigue. Forty-seven untrained, college-aged subjects were randomly assigned to one of 3 supplementation groups; placebo (PLA, n = 15), CUR + FEN (500 mg·d, n = 18), or FEN (300 mg·d, n = 14). The subjects completed a maximal GXT on a cycle ergometer to determine the PWCFT, V˙o2peak, and Tlim before (PRE) and after (POST) 28 days of daily supplementation. Surface electromyographic signals were recorded from a bipolar electrode arrangement on the vastus lateralis of the right leg during each test. Separate one-way analysis of covariances were used to determine if there were between-group differences for adjusted POST-PWCFT, POST-V˙o2peak, and POST-Tlim values, covaried for the respective PRE-test scores. The adjusted POST-PWCFT for the CUR + FEN group (mean ± SD: 196 ± 58 W) was greater (p = 0.016) than the PLA group (168 ± 49 W) but the FEN group (185 ± 32 W) was not different from the CUR + FEN or PLA groups (p > 0.05). There were no differences for adjusted POST-V˙o2peak (p = 0.612) or POST-Tlim (p = 0.508) among the groups. These findings suggested curcumin combined with fenugreek soluble fiber might delay neuromuscular fatigue.

Differences in cardiorespiratory responses of young and senior male endurance athletes to maximal graded exercise test.

Within recent years the popularity of sportive activities amongst older people, particularly competitive activities within certain age groups has increased. The purpose of this study was to assess the differences in the cardiorespiratory output at anaerobic threshold and at maximal power, output during an incremental exercise, among senior and young athletes. Ten elderly male subjects [mean (SD) age: 68.45 ± 9.32 years] and eight young male subjects [mean (SD) age: 25.87 ± 5.87 years] performed an incremental exercise test on a treadmill ergometer. No significant differences in body size were evident; however, the differences between the groups for peak power (451.62 ± 49 vs. 172.4 ± 32.2 W), aerobic capacity (57.97 ± 7.5 vs. 40.36 ± 8.6 mL kg-1 min-1), maximal heart rate (190.87 ± 9.2 vs. 158.5 ± 9.1 beats min-1), peak blood lactate (11 ± 1.7 vs. 7.3 ± 1.4 mmol L-1), and % VO2max at ventilatory thresholds (93.18 ± 4.3 vs. 79.29 ± 9.9%) were significantly lower in the senior athletes. The power output at anaerobic threshold was also higher (392 ± 48 vs. 151 ± 23 W) in the young athletes, explaining the significant difference in terms of performance between these groups. We have observed an evident deterioration in some of the cardiovascular parameters; however, the submaximal exercise economy seems to be preserved with aging. Exercise economy (i.e. metabolic cost of sustained submaximal exercise) was not different considerably with age in endurance-trained adults.

HIIT the Road Jack: An Exploratory Study on the Effects of an Acute Bout of Cardiovascular High-Intensity Interval Training on Piano Learning.

Pairing high-intensity interval training (HIIT) with motor skill acquisition may improve learning of some implicit motor sequences (albeit with some variability), but it is unclear if HIIT enhances explicit learning of motor sequences. We asked whether a single bout of HIIT after non-musicians learned to play a piano melody promoted better retention of the melody than low-intensity interval training (LIIT). Further, we investigated whether HIIT facilitated transfer of learning to a new melody. We generated individualized exercise protocols by having participants (n = 25) with little musical training undergo a graded maximal exercise test (GXT) to determine their cardiorespiratory fitness (VO2peak) and maximum power output (Wmax). In a subsequent session, participants practiced a piano melody (skill acquisition) and were randomly assigned to a single bout of HIIT or LIIT. Retention of the piano melody was tested 1 hour, 1 day, and 1 week after skill acquisition. We also evaluated transfer to learning a new melody 1 week after acquisition. Pitch and rhythm accuracy were analyzed with linear mixed-effects modeling. HIIT did not enhance sequence-specific retention of pitch or rhythmic elements of the piano melody, but there was modest evidence that HIIT facilitated transfer to learning a new melody. We tentatively conclude that HIIT enhances explicit, task-general motor consolidation.

Cardiorespiratory fitness diminishes the effects of age on white matter hyperintensity volume.

White matter hyperintensities (WMHs) are among the most commonly observed marker of cerebrovascular disease. Age is a key risk factor for WMH development. Cardiorespiratory fitness (CRF) is associated with increased vessel compliance, but it remains unknown if high CRF affects WMH volume. This study explored the effects of CRF on WMH volume in community-dwelling older adults. We further tested the possibility of an interaction between CRF and age on WMH volume. Participants were 76 adults between the ages of 59 and 77 (mean age = 65.36 years, SD = 3.92) who underwent a maximal graded exercise test and structural brain imaging. Results indicated that age was a predictor of WMH volume (beta = .32, p = .015). However, an age-by-CRF interaction was observed such that higher CRF was associated with lower WMH volume in older participants (beta = -.25, p = .040). Our findings suggest that higher levels of aerobic fitness may protect cerebrovascular health in older adults.

Relationship among Aerobic, Lung, and Anaerobic Capacity in Middle-long Distance Athletes

The purpose of our study was investigate the correlation among aerobic, lung, and anaerobic capacity in improving the performance of middle- and long-distance athletes. The participants were divided into a high school group (n = 11) and college and senior group (n = 25). The aerobic capacity was measured using the maximal graded exercise test to measure the maximum oxygen uptake, anaerobic threshold, and running time. The forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured for lung capacity, and the peak power, average power, and fatigue index were measured for anaerobic capacity using the Wingate test. The correlation between the measured variables was analyzed using Spearman’s correlation coefficient and Pearson’s correlation coefficient. The VO2max of the high school group showed a significant correlation with anaerobic threshold (r = 0.791) and running time (r = 0.852). The college and senior group showed a significant correlation with anaerobic threshold (r = 0.502), running time (r = 0.586), and fatigue index (r = -0.451). The total group showed a significant correlation with anaerobic threshold (r = 0.678), running time (r = 0.739), peak power (r = -0.338), and fatigue index (r = -0.337). The lung capacity test variables were not significantly correlated with the aerobic capacity variables in any group. Anaerobic endurance is needed to improve the aerobic ability and performance of middle- and long-distance athletes.

What are the Physiological Benefits of Increased Daily Number of Steps in Middle-Aged Women?

BackgroundPhysical activity plays an important role in the prevention of cardio-metabolic diseases. The present study evaluated the effect of habitual physical activity on body composition, peak oxygen consumption, cardiac and metabolic function. MethodsThis was a retrospective study. Data was collected between February 2014 and November 2015. Thirty-six healthy women (age 50±16 years) were stratified according to daily number of steps into low- (<7500 steps/day, n=17) or high-active group (>12500 steps/day, n=19). All participants underwent body composition assessment, oral glucose tolerance test and non-invasive gas-exchange and haemodynamic (bioreactance) measurements at rest and in response to maximal graded cardiopulmonary exercise test. ResultsThe high active group averaged 16280±3205 steps/day and the low active group averaged 6285±943 steps/day (difference p=0.00). High-active women (vs. low active) demonstrated significantly lower body weight (62.1±12.3 vs. 71.2±9.1 kg, p=0.02), body fat (27.2±9.1 vs 37.7±6.4 %, p=0.00), but increased lean body mass (72.8±9.1 vs. 62.3±6.4 %, p=0.00). Peak oxygen consumption was significantly higher in high- versus low active women (2.0±0.5 vs. 1.5±0.2 l/min, p=0.00). There were no significant differences between the groups in fasting- and 2-hour glucose levels (4.9±0.6 vs. 4.8±0.5, p=0.45 and 4.8±1.3 vs. 5.5±1.4 mmol/L, p=0.16) haemodynamic measures of cardiac function including cardiac power output, cardiac output, stroke volume and arterial blood pressure at rest and in response to exercise stress test (p>0.05). ConclusionsIncreased levels of habitual physical activity improve body composition and peak oxygen consumption but appears to have limited effect cardio-metabolic function in middle-aged women.

Acute Physiological Responses To Low-intensity Exercise With Different Levels Of Blood Flow Restriction

PURPOSE: External pressure is a key factor in blood flow restriction (BFR) training. Previous studies have used a limited range of occlusion pressures to compare the acute physiological and perceptual responses during leg exercise. The aim of this study was twofold: i) to compare the physiological and perceptual responses of low-intensity exercise (LI) with different levels of BFR, and ii) to compare LI with BFR on the bike with high-intensity (HI) exercise without BFR. METHODS: Twenty-one healthy, moderately-trained male (age: 24.6±2.4 yrs; VO2peak: 47.2±7.0 ml/kg/min, mean±sd) volunteered to perform one maximal graded exercise test on the bike and seven 5-min constant intensity exercise bouts on separate days and in a counterbalanced order. Six bouts were at 40% peak power (Ppeak; LI); one without BFR and five with different levels of BFR (40%, 50%, 60%, 70%, 80% of arterial occlusion pressure, LI-BFR40/50/60/70/80). Finally, they performed one HI bout (70% Ppeak) without BFR. Oxygen uptake (VO2), heart rate (HR), blood lactate (BLa), rating of perceived exertion (RPE), and tissue oxygen saturation (TSI) with near-infrared spectroscopy were recorded. RESULTS: Regardless of pressure, HR, BLa and RPE during LI-BFR were higher compared to LI (p<0.05), and TSI reduction was greater in LI-BFR (LI-BFR40/50/60/70/80: -10.6±3.1%, -10.2±4.0%, -10.1±5.1%, -10.0±4.2%, -11.3±4.9%, respectively) than LI (-6.0±4.2%, p<0.05).The responses of VO2, HR, BLa, RPE and TSI induced by the different levels of BFR applied in LI-BFR were similar. Regardless of pressure, the responses of VO2, HR, BLa and RPE induced by LI-BFR was lower than HI (p<0.05), except for TSI. TSI change was similar between LI-BFR40/50/60/70/80 and HI (LI-BFR40/50/60/70/80 range: -10.0±4.2% to -11.3±4.9%, HI: -11.5±4.5%). CONCLUSION: It appears that BFR equal to 40% of arterial occlusion pressure is sufficient to reduce TSI. This BFR level seems to stress the physiological mechanisms adequately and there is no need for higher external pressure application. This level of BFR can also produce local hypoxia similar to that during HI. Therefore, low-intensity exercise with BFR could be an alternative exercise mode for individuals who are unable to perform high-intensity exercise.

Validation Of A Wrist-mounted Heart Rate Monitor During Maximal Graded Exercise Testing

The electrocardiogram (ECG) serves as the gold standard of heart rate (HR) monitoring but is rarely used outside of a clinical environment. Newly developed wearable technology is more usable outside of a clinical setting, but has not been validated against this gold standard. PURPOSE: The purpose of this study is to determine the validity of a wrist-mounted photoplethysmography (PPM) device used for measuring HR during incremental treadmill exercise using ECG as the criterion HR measurement. METHODS: Twenty-two subjects (13 men, 9 women; 35.8 ± 6.3 yr, 14.6 ± 7.5 % body fat, VO2max: 55.5 ± 0.49 ml·kg-1·min-1) performed a Bruce treadmill protocol graded exercise test. HR was recorded at rest and at the end of each minute with the Mio Alpha PPM device and ECG simultaneously. HR was compared between methods across the entire testing session (rest and exercise values) and separately for each exercise test stage using paired-samples t-tests and the Bonferroni correction. Validity coefficients were determined using the Pearson correlation. RESULTS: HR across the entire intensity range (rest to maximal exercise) exhibited a significant correlation between methods (r = 0.97, p < 0.001) and was similar between ECG and Mio after the Bonferroni correction was applied, requiring p < 0.008 (overall mean HR: ECG = 124 ± 39 b·min-1, Mio = 123 ± 37 b·min-1, t359 = -2.504, p = 0.013). Significant correlations were observed at rest and each exercise test stage, with r values ranging from 0.67 to 0.96 (all p < 0.001). HR was similar between methods at rest and each exercise test stage except for stage 4 (ECG = 168 ± 13 b·min-1, Mio = 164 ± 14 b·min-1, p = 0.004). CONCLUSIONS: Correlational analyses indicated a strong agreement between HR methods overall, as well as individually at rest and during each exercise test stage. However, mean comparisons observed a significant difference between methods at stage 4 and mean differences between methods became larger as intensity increased. From a practical standpoint, the mean difference between methods did not exceed 3 b·min-1 except for stage 5. Therefore, a PPM device seems valid for HR monitoring during low-to-moderate-intensity but not high-intensity treadmill exercise.

Relationships Between Resting Heart Rate Variability, Maximal Heart Rate, And VO2peak Among Active-duty Firefighters

Heart rate variability (HRV) is a non-invasive marker of autonomic nervous system (ANS) function based on the beat to beat variation in heart rate measured by the duration of the R-R interval. Clinically, lower resting HRV has been linked to greater risk for cardiovascular disease and higher HRV is thought to be cardioprotective and reflective of a greater fitness. Firefighters represent a unique population where sudden cardiac death is a high risk of the job that demands the ability to perform high intensity tasks. Resting HRV may provide insight into the contributions of the ANS to maximal capacity of a firefighter. PURPOSE: To examine the relationships between resting HRV and heart rate and aerobic capacity (VO2peak) during a maximal treadmill test. METHODS: 37 male career active-duty firefighters (mean ± SD, 39.1 ± 8.9 yrs; 178.8 ± 5.4 cm; 87.9 ± 11.2 kg) participated in this study. All participants completed a 5-minute resting HRV sample followed by a maximal graded exercise test on a treadmill using a modified version of the submaximal Wellness Fitness Initiative test for firefighters. Heart rate and oxygen consumption were monitored throughout the test and maximal HR (MHR) at cessation of the test and VO2peak were recorded for each participant. HRV was determined by measuring the time intervals between R-waves and reflected as the mean RR for the 5-minute resting sample. Bivariate Pearson correlations determined the relationship between resting RR, MHR, and VO2peak. An alpha of 0.05 determined statistical significance. RESULTS: Resting RR (864.8 ± 134.0 ms) had a moderate and significant relationship with VO2peak (44.6 ± 7.1 ml/kg/min; r = 0.458, P = 0.004) and MHR (181.5 ± 10.7 bpm; r = -0.360, P = 0.029), but VO2peak was not related to MHR (r = 0.308, P = 0.064). CONCLUSION: Higher resting RR was associated with greater VO2peak, but lower MHR. The positive relationship between RR and VO2peak is consistent with prior research suggesting that a higher resting HRV is related to higher fitness. The inverse relationship between HRV and MHR suggests that greater parasympathetic nervous system control at rest (i.e., higher RR) may extend into maximal exercise tasks. Thus, for a firefighter, the benefit of a more favorable resting HRV may not only be cardioproective, but also influence the relative intensity of a maximal task.

The Relation Between Cardiorespiratory Fitness And Cerebral Blood Flow Regulation

Contradictory relationships have been reported between cardiorespiratory fitness levels and cerebral blood flow regulation. Some studies report an inverse relationship between cardiorespiratory fitness and cerebrovascular reactivity to carbon dioxide (CO2), and an inverse relationship between cardiorespiratory fitness and dynamic cerebral autoregulation. Other studies have found a positive relationship. PURPOSE: The purpose of this study was to assess the relation between objectively measured cardiorespiratory fitness and cerebrovascular reactivity to CO2 and to dynamic cerebral autoregulation. METHODS: Twenty-three healthy, normotensive adults (13M/10F; age: 26±4 yrs; BMI: 24±5 kg/m2; BP: 105±9/58±6 mmHg, mean±SD) participated in this study. Mean VO2 max was 40.0±9.7 ml/kg/min (range, 17.9-62.3 ml/kg/min). Each participant completed a maximal graded exercise test on a treadmill until volitional fatigue. Heart rate was measured using a heart rate monitor (Polar H7, Polar, USA). Oxygen consumption and CO2 production were measured and averaged in 15-second intervals using indirect calorimetry via an automated open circuit system (Parvo Medics, Sandy, UT) throughout the exercise test. Transcranial Doppler of the right middle cerebral artery was measured. We measured cerebrovascular reactivity to two minutes of hypercapnia (via 8% CO2, 21% oxygen, balance nitrogen). We assessed dynamic cerebral autoregulation during eight minutes of supine rest. The relation between cerebral blood flow regulation and cardiorespiratory fitness were analyzed using Pearson’s correlations. RESULTS: Cerebrovascular reactivity to hypercapnia was not significantly correlated with cardiorespiratory fitness (r=0.35, P=0.10). There was no correlation with cardiorespiratory fitness in very low frequency gain (r=-0.22, P=0.92) or phase (r=-0.03, P=0.87). There was no correlation with cardiorespiratory fitness and low frequency gain (r=0.3, P=0.13). Interestingly, low frequency phase was inversely correlated with cardiorespiratory fitness (r=-0.4, P=0.04). CONCLUSION: These preliminary data suggest that cardiorespiratory fitness may not impact cerebrovascular reactivity to hypercapnia. However, a relation may exist between cardiorespiratory fitness and dynamic cerebral autoregulation.

Comparison Of Interval Exercise And Continuous Exercise On Excess Post-exercise Oxygen Consumption: Matched For Duration

PURPOSE: Compare the excess post-exercise oxygen consumption (EPOC) after duration-matched bouts of high-intensity (HIIT) and sprint interval (SIT) exercise to moderate-intensity continuous (MCT) exercise. METHODS: Recreationally active men (n=7; 22±3 yrs; 180.4±4.7 cm; 77.8±9.3; 13.4±3.4 %BF; 44.7±2.6 ml·kg-1·min-1) completed a maximal graded exercise test (VO2max) and three exercise trials (HIIT, SIT, and MCT) in a randomized, counterbalanced fashion on a cycle ergometer. HIIT consisted of 15 × 90-sec bouts at 85% VO2max and 90-sec active recovery periods. SIT consisted of 15 × 20-sec bouts at 130% maximum wattage and 160-sec active recovery periods. MCT was continuous bout at 65% VO2max. Each trial lasted 53 min, including a 5-min warm-up and a 3-min cool-down. Oxygen consumption (VO2; ml·kg-1·min-1) was measured after bouts 1 (B1), 5 (B5), 10 (B10), 15 (B15), and cool-down (CD) which corresponded with min 0-3, 12-15, 27-30, and 42-45 of MCT, respectively. VO2 was also measured for 30 min prior to exercise (PRE) and during 1 h of recovery. EPOC (L of O2) was measured by the area under the curve with respect to increase (AUCi) from PRE VO2 during the first 20 min of recovery. Trial effects were assed via one-way analyses of variance. RESULTS: VO2 was lower in SIT compared to MCT after B1 (p = 0.002; 17.6 ± 4.6 ml·kg-1·min-1; 24.2 ± 1.8 ml·kg-1·min-1, respectively), B5 (p = 0.007; 21.8 ± 4.8 ml·kg-1·min-1, 29.1 ± 3.4 ml·kg-1·min-1, respectively), B10 (p < 0.001; 21.8 ± 2.6 ml·kg-1·min-1, 30.0 ± 2.5 ml·kg-1·min-1, respectively) and B15 (p < 0.001; 21.8 ± 2.6 ml·kg-1·min-1, 29.3 ± 3.3 ml·kg-1·min-1, respectively). SIT was also lower than HIIT at B5 (27.5 ± 3.4 ml·kg-1·min-1; p = 0.021), B10 (28.2 ± 2.9 ml·kg-1·min-1; p < 0.001) and B15 (28.8 ± 3.7 ml·kg-1·min-1; p = 0.001), while MCT was higher than HIIT at B10. After CD, VO2 was higher in MCT (19.0 ± 2.9 ml·kg-1·min-1) compared to SIT (16.4 ± 2.6 ml·kg-1·min-1; p = 0.015) and HIIT (15.5 ± 2.0 ml·kg-1·min-1; p = 0.007). EPOC was lower following SIT (5.5 ± 1.1 L) compared to MCT (7.4 ± 1.6 L; p = 0.005) and HIIT (6.7 ± 0.8 L; p = 0.006). CONCLUSION: EPOC was similar following both HIIT and MCT, but not SIT, when matched for duration. Of note, despite identical duration, the MCT protocol involved more total work when compared to both HIIT and SIT.

A Comparison Of Tnfr1 And Tnfr2 Expression On Monocyte Subsets Following Continuous And Interval Exercise

PURPOSE: To examine the tumor necrosis factor receptor (TNFR) 1 and 2 response on monocyte subsets to interval and continuous aerobic exercise. METHODS: Six men (22.5±3.9 yrs; 180.8±5.0 cm; 80.5±6.6 kg; 11.8±4.3 %BF; 44.2±2.4 ml·kg-1·min-1) completed three cycling protocols: moderate continuous (MCT), sprint-interval (SIT), and high-intensity-interval (HIIT), in a randomized order. Visit 1 consisted of a maximal graded exercise test (VO2max) on a cycle ergometer. HIIT consisted of 15 90-sec bouts at 85% VO2max and 90-sec active recovery periods. SIT consisted of 15 20-sec bouts at 130% max wattage and 160-sec active recovery periods. MCT was a continuous bout at 65% VO2max. Each trial duration was 53 min, including a 5-min warm-up and a 3-min recovery. Blood was collected before (PRE), immediately (IP), 30 minutes (30M), 2 hours (2H), 6 hours (6H) and 24 hours (24H) post-exercise. Changes in surface expression, as measured by median fluorescent intensity (MFI) of TNFR 1 and 2 on monocyte subsets (classical: CD14++CD16−; intermediate: CD14++CD16+; and non-classical: CD14+CD16++) were analyzed via flow cytometry. Changes in TNFR1 and 2 expression were determined using a mixed model regression with fixed effects on time and condition. RESULTS: Analysis indicated a time effect for TNFR1 expression on classical (F=4.450, p=0.001) and intermediate (F=3.517, p=0.006) monocytes. TNFR1 expression on classical monocytes decreased (p < 0.05) from PRE (6637 ± 704 MFI), IP (6538 ± 522 MFI), 30M (6836 ± 661 MFI), and 2H (6600 ± 564 MFI) at 6H (5934 ± 814 MFI) and 24H (6156 ± 516 MFI). TNFR1 expression on intermediate monocytes decreased (p <0.05) from PRE (6391 ± 649 MFI), 30M (6618 ± 655 MFI) and 2H (6418 ± 569 MFI) at 6H (5912 ± 814 MFI) and 24H (5936 ± 443 MFI). A time effect (F= 4.079, p=0.002) was observed for TNFR2 expression on intermediate monocytes, with a decrease (p< 0.05) from PRE (25528 ± 3188 MFI) at 30M (22327 ± 4067 MFI), 2H (21008 ± 5113 MFI), and 6H (20515 ± 5918 MFI). TNFR2 expression on intermediate monocytes recovered by 24H (25483 ± 3189 MFI). CONCLUSION: Changes in TNFR1 and TNFR2 expression were observed across time, with no differences observed between conditions. Therefore, TNFR1 and TNFR2 expression on monocytes may not be dependent on intensity, but more investigation in necessary. Partially supported by the NSCA Foundation

Effect of practical hyperoxic high-intensity interval training on exercise performance

This study investigated the effect of a practical hyperoxic high-intensity interval training (HIIT) on aerobic and anaerobic exercise capacity. Sixteen male athletes were randomized into 2 groups: normoxic HIIT (NHIIT, n = 8) group or hyperoxic HIIT (HHIIT, n = 8) group and trained for 3 weeks (2 days/week) on a cycle ergometer (2-min intervals, with 2-min rest between intervals) at maximal workload, which was obtained during a maximal graded exercise test under normoxia. All training sessions were performed until exhaustion. Participants performed maximal graded exercise, submaximal exercise, and 90-s maximal exercise tests before and after the training period. Maximal oxygen uptake (P < 0.01) increased significantly in both groups. Blood lactate curve during submaximal exercise improved significantly only in the HHIIT group (P < 0.01). Mean power output during maximal exercise increased significantly only in the HHIIT group (P = 0.02). This study demonstrated that a practical hyperoxic HHIIT might be effective for improving aerobic capacity and anaerobic performance.

Assessing Maximal Oxygen Uptake: Creating Personalized Incremental Exercise Protocols Simply and Quickly

ABSTRACT Measuring cardiorespiratory fitness (CF) is important for researchers, clinicians, and exercise practitioners to assess an individual's CF. One method of assessing CF is accomplished by measuring the maximal oxygen uptake during a personalized maximal graded exercise test (GXT). Tailoring a GXT protocol to a specific subject can be troublesome and time-consuming. In this article, simple and ready-to-use spreadsheets allowing the creation of individualized walking, running, and cycling GXT protocols are presented and explained. The procedures within the spreadsheets are based on the latest validated protocols, and the spreadsheets represent a time-saving, practical, and useful tool.

Examination of Curcumin and Fenugreek Soluble Fiber Supplementation on Submaximal and Maximal Aerobic Performance Indices.

This study examined the effects of curcumin and fenugreek soluble fiber supplementation on the ventilatory threshold (VT) and peak oxygen consumption (O2 peak). Methods: Forty-five untrained men and women were randomly assigned to one of three supplementation groups: placebo (PLA, n = 13), 500 mg·day−1 CurQfen® (CUR, n = 14), or 300 mg·day−1 fenugreek soluble fiber (FEN, n = 18). Participants completed a maximal graded exercise test on a cycle ergometer to determine the VT and O2 peak before (PRE) and after (POST) 28 days of daily supplementation. Separate, one-way analyses of covariance (ANCOVAs) were used to examine the between-group differences for adjusted POST VT and O2 peak values, covaried for the respective PRE-test values. Results: The adjusted POST VT O2 values for the CUR (mean ± SD = 1.593 ± 0.157 L·min−1) and FEN (1.597 ± 0.157 L·min−1) groups were greater than (p = 0.039 and p = 0.025, respectively) the PLA (1.465 ± 0.155 L·min−1) group, but the FEN and CUR groups were not different (p = 0.943). There were no differences in the adjusted O2 peak values (F = 0.613, p = 0.547) among groups. Conclusion: These findings indicated that fenugreek soluble fiber was responsible for the improvements in the submaximal performance index for both CUR and FEN groups.

0139 Associations of Actigraphic Sleep Parameters with Maximal Oxygen Consumption and Resting Metabolism in Well-Functioning Older Adults

Abstract Introduction Both poor sleep and poor cardiorespiratory fitness are common in older age and associated with negative health outcomes. Additionally, among older adults, higher resting metabolic rate (RMR) has been associated with increased morbidity and mortality risk. To evaluate whether, and in what ways, sleep may affect these relationships, we investigated the association of actigraphic sleep indices with cardiorespiratory fitness and RMR in older adults. Methods We studied 393 community-dwelling participants in the Baltimore Longitudinal Study of Aging (mean age 73.5±10.3 years, 52% women) who completed 6.7±0.9 nights of wrist actigraphy, RMR testing, and a maximal graded exercise test. Primary predictors included mean actigraphic total sleep time (TST, minutes), sleep efficiency (SE, %), wake after sleep onset (WASO, minutes), and average wake bout length (WBL, minutes). Cardiorespiratory fitness, as measured by maximal oxygen consumption (V O2MAX; ml/kg/min), and RMR (kcal/day) were the primary outcomes. Results After adjustment for age, sex, race, body mass index, comorbidity index, and depressive symptoms, longer WBL was associated with lower V O2MAX (β=-0.12, 95% confidence interval (CI)=-0.20, -0.04), greater WASO was associated with lower V O2MAX (β=-0.09, 95% CI=-0.17, -0.01), and greater SE was associated with higher V O2MAX (β=0.12, 95% CI=0.03, 0.20). In addition, longer TST was associated with lower RMR (β=-0.10, 95% CI=-0.19, -0.01) and longer WBL was linked to higher RMR (β=0.12, 95% CI=0.04, 0.21). Conclusion In well-functioning older adults, indices of greater wakefulness after sleep onset are linked with poorer cardiorespiratory fitness and higher resting metabolism, while longer and more efficient sleep are associated with better fitness and lower resting metabolic rate. Our findings suggest that sleep disturbance may be linked to disrupted energy homeostasis, evidenced by excessive energy expenditure at rest and inefficient energy utilization in response to maximal demands. Prospective analyses are necessary to determine the nature of these associations. Support This study was supported in part by National Institute on Aging (NIA) grants R01AG050507 and T32-AG027668, the NIA Intramural Research Program (IRP), and Research and Development Contract HHSN-260-2004-00012C.

Associations of cardiorespiratory fitness, physical activity, and BMI with arterial health in middle-aged men and women.

We investigated the associations of cardiorespiratory fitness (CRF), physical activity (PA) with regard to aerobic and resistance training, and body mass index (BMI) with pulse wave velocity (PWV) and augmentation index (AIx) in middle‐aged adults with at least one cardiovascular risk factor. A total of 84 (46 men and 38 women) participated in the study. Cardiorespiratory fitness was measured using a maximal graded exercise test on a cycle ergometer and was defined as maximal power output (Wmax) normalized for body weight‐0.35. Participation in aerobic and resistance training was assessed by a detailed questionnaire and BMI was calculated as weight (kg)/[height (m2)]. Pulse wave velocity and AIx were measured using an applanation tonometry before (pre), immediately after (post), and after 10 min (post10) of maximal exercise test. Cardiorespiratory fitness, PA, or BMI was not associated with PWV or AIx. Pulse wave velocity decreased significantly from pre to post10 among those in the highest third of CRF (mean difference=−0.793 m/s, 95% CI = −1.494 to −0.091, p = .023) and in normal weight participants (p = .084 for time*group interaction mean difference=−0.781 m/s, 95% CI = −1.496 to −0.066, p = .029), but not among those in the other thirds of CRF or overweight or obese participants. Participants who had regular resistance training had continuously higher AIx from pre to post10 than those who had no regular resistance training (mean difference = −1.98, 95% CI = −4.02 to 0.069, p = .058). In conclusion, exercise may decrease PWV and AIx. Our results suggest that positive arterial responses to exercise could be slightly improved in fit and normal weight individuals.

Impact of Active Recovery and Whole-Body Electromyostimulation on Blood-Flow and Blood Lactate Removal in Healthy People.

This study aimed to determine whether an active recovery with added whole-body electromyostimulation (WB-EMS) can increase blood flow and lead to blood lactate removal after intense exercise. Thirty-five healthy individuals (23.1 ± 4.6 years) were randomly assigned to: (a) an experimental group using active recovery together with the WB-EMS (n = 18) or (b) a control group using the same active recovery protocol with the suit with no-stimulation (CON, n = 17). Participants performed a maximal graded exercise test followed by an active recovery protocol (walking at 40% of their maximum aerobic velocity). During the recovery, participants in WB-EMS and CON received continuous stimulation at 7 Hz or no stimulation, respectively. Heart rate, blood lactate concentrations, pain/discomfort, and hemodynamic measurements were recorded before and after the test, and repeated immediately after and at min 30 and 60. The between-group analysis showed a substantially greater Peak blood velocity (−0.27 [−0.68; 0.14]) in WB-EMS compared to CON. The pain/discomfort levels were also lower in WB-EMS compared with CON (0.66 [−0.12; 1.45]). Non-significant differences in participants’ blood lactate were observed in WB-EMS compared with CON both immediately; at 30and 60 min. Our findings suggest that increased local blood flow induced by WB-EMS may have contributed to greater lactate removal from active muscles and blood lactate clearance. WB-EMS may be an effective means of increasing muscle blood flow after a maximal graded exercise test and could result in improved recovery.