VO2max Test Research Articles

The Mediating Effect of Pupils' Physical Fitness on the Relationship Between Family Socioeconomic Status and Academic Achievement in a Danish School Cohort.

Family socioeconomic status influences pupils' academic achievements, and studies have established positive associations between physical fitness and academic achievements. However, whether physical fitness mediates the relationship remains unknown. We investigated if pupils' physical fitness mediates the pathway between family socioeconomic status and academic achievement using causal inference-based mediation analysis. This study included 527 girls and 552 boys between 13 and 15years of age from the Danish municipality of Aalborg. Physical fitness was measured through VO2max tests in 2010 and demographic data were obtained from nationwide registers. Family socioeconomic status was classified into four levels ranging from 1 to 4, where level 1 represents the lowest and level 4 the highest based on either family income or education. Controlling for sex, ethnicity, age, and parents' cohabitation status, all total effects display higher academic achievement with increased family socioeconomic status. Splitting the effects, the direct effects reveal the existence of other pathways not involving physical fitness. The indirect effects established physical fitness as a mediator showing that pupils from family socioeconomic status levels one, three, and four changes grade by - 0.13 [95% confidence interval (CI) - 0.26, - 0.01], 0.07 (95% CI 0.00, 0.14), and 0.24 (95% CI 0.14, 0.34), respectively, compared to socioeconomic status level two. The corresponding proportions mediated are 18% (95% CI 1, 57), 6% (95 CI 0, 13), and 12% (95% CI 7, 18) when family socioeconomic status is based on education. Classifying family socioeconomic status on income, pupils from family socioeconomic status levels one, three, and four show grade changes of - 0.07 (95% CI - 0.16, 0.02), 0.22 (95% CI 0.13, 0.32), and 0.26 (95% CI 0.15, 0.37), respectively, compared to socioeconomic status level two. The corresponding proportions mediated are 12% (95% CI - 6, 41), 30% (95% CI 16, 54), and 20% (95% CI 12, 32). In conclusion, pupils' physical fitness partially mediated the pathway between family socioeconomic status and academic achievement.

Assessing Aerobic Fitness Level in Relation to Affective and Behavioral Functioning in Emerging Adult Cannabis Users.

Cannabis use is common amongst emerging adults and increasingly linked to negative mood and neurocognitive performance. Aerobic fitness, however, may be positively linked. Therefore we assess the potential moderating influence of aerobic fitness on affective and behavioral functioning associated with cannabis. After 3-weeks of abstinence, 83 16-26 year-olds (38 cannabis, 45 controls) completed self-report inventories (BDI-II, STAI-state, FrSBe, BIS/BAS), an objective emotion functioning measure (PennCNP), and VO2 max testing. Multiple regressions assessed symptoms from past year cannabis use, VO2 max, and cannabis*VO2, controlling for alcohol, cotinine, gender, and BMI. Past year cannabis use was associated with increased depressive symptoms (p=.04), BIS/BAS component (p=.002), and emotion recognition (p=.045). Results suggest a robust association between past year cannabis use and depressive symptoms and behavioral and affective functioning. Aerobic fitness, however, did not moderate these relationships. Efforts should be made to inform the public of concerns regarding the potential negative impact of cannabis on mood.

Trajectories of cardio-metabolic health in successful aging.

Maximal oxygen uptake (V̇O2max ) and muscle mass decrease with age. The loss of cardiorespiratory fitness and muscle strength is accelerated with physical inactivity and has well-documented consequences for morbidity and all-cause mortality. Participation in exercise training programs will improve one or more of the cardio-metabolic risk factors, but the long-term effects of such programs are questionable. Here, we re-examined 25 old (72±4years.) men and women who considered him/herself as "success-full agers" and were participants in a 3-month alpine skiing training program 6years earlier. The program focused on healthy aging and included health questionnaires, measurement of lipids and glycemic parameters in blood and a VO2max test. Thirteen and 12 subjects were in the intervention (IG) and the control group (CG), respectively. In response to the training program, subjects improved their cardio-metabolic risk factors. However, after 6years all positive effects had disappeared. Approximately 80% of the subjects had total cholesterol and LDL cholesterol above and HDL cholesterol below the recommended values, but these subjects remained the most metabolically deteriorated, including an increase in fasting glucose concentrations. We conclude that people seem to follow their individual trajectory in terms of cardio-metabolic risk factors, and participation in a relatively short lasting exercise training program with emphasis on healthy aging does not change that. Long-lasting change in lifestyle probably requires a continued attentional focus, goal setting, and feedback.

Comparison of Cardiorespiratory Fitness Prediction Models in Young Adults Running head: Comparison of VO2 max Prediction Models

to compare the predictive accuracy of regression models for a non-consecutive day VO2 max/Wingate testing protocol and a same day testing protocol. Participants (N=23) completed a treadmill GXT and Wingate cycle test. Participants (n=12) completed testing on non-consecutive days (NON) and (n=11) the same day (SAME). VO2 max (L/min) and peak power (PP) were collected. Linear regression analysis of NON revealed R2=0.808 and prediction equation Ŷ=1.499+0.004X and SAME showed R2=0.861 and prediction equation Ŷ=1.407+0.003X. NON standard error of estimate (SEE) and standard error of estimate percent (SEE %) were 0.62 L/min and 15.23%, respectively. SAME SEE and SEE% were 0.34 L/min and 10.98%, respectively. These results indicate PP obtained the same day of VO2max testing is a better predictor of cardiorespiratory fitness. Similarly, the SAME model is more accurate according to SEE and SEE%. This may be due to diminished effects of training adaptations that could occur 2-7 days between testing sessions during the NON testing protocol in healthy, active young adults.

Exercise-induced improvements in glucose effectiveness areblunted by a high glycemic diet in adults with prediabetes.

Glucose effectiveness (GE) refers to the ability of glucose to influence its own metabolism through insulin-independent mechanisms. Diminished GE is a predictor of progression to type 2 diabetes. Exercise training improves GE, however, little is known about how dietary interventions, such as manipulating the glycemic index of diets, interact with exercise-induced improvements in GE in at-risk populations. We enrolled 33 adults with obesity and pre-diabetes (17 males, 65.7±4.3 years, 34.9±4.2kgm-2) into a 12-week exercise training program (1 hday-1 and 5 dayweek-1 at ~85% of maximum heart rate) while being randomized to concurrently receive either a low (EX-LOG: 40±0.3au) or high (EX-HIG: 80±0.6au) glycemic index diet. A 75-g oral-glucose-tolerance test (OGTT) was performed before and after the intervention and GE was calculated using the Nagasaka equation. Insulin resistance was estimated using a hyperinsulinemic-euglycemic clamp and cardiorespiratory fitness using a VO2max test. Both EX-LOG and EX-HIG groups had similar improvements in weight (8.6 ± 5.1kg, P < 0.001), VO2max (6 ± 3.5mLkg-1min-1, P < 0.001) and clamp-measured peripheral insulin resistance (1.7 ± 0.9mgkg-1min-1, P < 0.001), relative to baseline data. GE in EX-LOG and EX-HIG was similar at baseline (1.9 ± 0.38 vs. 1.85 ± 0.3mgdL-1min-1, respectively; P > 0.05) and increased by ~ 20% post-intervention in the EX-LOG arm (∆GE: 0.07-0.57mgdL-1min-1, P < 0.05). Plasma free fatty acid (FFA) concentrations also decreased only in the EX-LOG arm (∆FFA: 0.13 ± 0.23mmolL-1, P<0.05). Our data suggest that a high glycemic index diet may suppress exercise-induced enhancement of GE, and this may be mediated through plasma FFAs.

Increased Rate of Heat Storage, and No Performance Benefits, With Caffeine Ingestion Before a 10-km Run in Hot, Humid Conditions.

Although the effect of caffeine in thermoneutral or cool environmental conditions has generally shown performance benefits, its efficacy in hot, humid conditions is not as well known. The purpose of this study was to further examine the effect of caffeine ingestion on endurance running performance in the heat. Ten trained endurance runners (6 males; mean [SD] age = 26 [9]y, height = 176.7 [5.1]cm, and mass = 72.1 [8.7]kg) came to the lab for 4 visits. The first was a VO2max test to determine cardiorespiratory fitness; the final 3 visits were 10-km runs in an environmental chamber at 30.6°C and 50% relative humidity under different conditions: 3mg·kg-1 body mass (low caffeine dosage), 6mg·kg-1 (moderate caffeine dosage), and a placebo. Repeated-measures analyses of variance were used to determine the effect of condition on the 10-km time, heart rate, core temperature, rating of perceived exertion, and thermal sensation. There was no difference in the 10-km time between the placebo (53.2 [8.0]min), 3-mg·kg-1 (53.4 [8.4]), and 6-mg·kg-1 (52.7 [8.2]) conditions (P = .575, ). There was not a main effect of average heart rate (P = .406, ), rating of perceived exertion (P = .151, ), or thermal sensation (P = .286, ). There was a significant interaction for core temperature (P = .025, ); the moderate-dosage caffeine condition showed a higher rate of rise in core temperature (0.26 [0.08] °C·km-1 vs 0.20 [0.06] and 0.19 [0.10] °C·km-1 in the low-caffeine and placebo conditions, respectively). The results support previous research showing a thermogenic effect of caffeine, as the moderate-dosage condition led to a greater rate of heat storage and no performance benefits.

Effects of marathon training on maximal aerobic capacity and running economy in experienced marathon runners.

Maximal aerobic capacity (VO2max) and running economy (RE) are markers of running performance. A valid evaluation of RE may occur through allometric scaling of body mass (alloVO2; ml kg-0.66 min-1), energy cost (EC; kcal kg-1 km-1), or percent of VO2max (%VO2max). Little is known about physiological changes that occur in competitive runners over a marathon training cycle. The VDOT score, incorporating VO2max and RE, enables comparison of race performances under different temperature conditions. This study's purpose was to determine whether VO2max and measures of RE change with marathon training, and to evaluate the relationship between these variables and VDOT. Eight runners (age 34±2 years; marathon <3:00 males, <3:30 females; five females) completed treadmill marathon-intensity-effort (MIE) and VO2max tests at 10 and 1-2 weeks pre-marathon. Body composition (%BF) was determined using hydrostatic weighing. Paired t-tests were used to compare pre- and post-training values. The alpha level for significance was set at 0.05. Body fat decreased from 18.7±1.5% to 16.7±1.6%, VO2max increased from 51.6±2.4 to 63.9±1.1 ml kg-1 min-1, and %VO2max during the MIE decreased from 82.1±2.0 to 72.3±3.2% (p < 0.05 for all). VDOT was significantly associated with alloVO2 (r = -0.779, p = 0.039) but not with VO2max (r = 0.071, p = 0.867). Experienced competitive runners may increase VO2max and decrease %BF after a marathon-specific training cycle. The decrease in %VO2max in a MIE is likely due to a higher VO2max, as other measures of RE did not change significantly. In this cohort, alloVO2 was negatively correlated with race performance.

Physiological adaptation following four-weeks of high-intensity functional training

Background/Aim. High-Intensity Functional Training (HIFT) is a popular mixed-modal program that utilizes both resistance and aerobic based exercises. The aim of this study was to examine the physiological effects of the HIFT programing on physically active men (10) and women (10) over a four-week period through the measure of the aerobic capacity, anaerobic capacity, and maximal weight lifted. Methods. The participants first completed a maximal oxygen consumption (VO2max) test. After 48-hours of rest, the subjects completed the anaerobic capacity test via the Wingate protocol. Following the Wingate test, the subjects performed a 1-repetition maximum test for squat, snatch and clean at the offsite training location. After the pre-measurements were obtained, the subjects entered a four-week the HIFT intervention and returned to the lab for all post-measurements. Results. Significant improvements were observed in male and female: VO2 max (Pre: 46.7 ? 2.6, 33.7 ? 1.7 mL/kg/min; Post: 49.0 ? 3.0, 35.0 ? 1.8 mL/kg/min), Peak Wingate Power (Pre: 1206 ? 106, 708 ? 44 W; Post: 1283 ? 88, 809 ? 38 W) Mean Wingate Power (Pre: 680 ? 46, 704 ? 48 W; Post: 434 ? 15, 458 ? 18 W; p &lt; 0.05), back squat (Pre: 128.8 ? 8.8 kg, 44.1 ? 6.8 kg; Post: 142.7 ? 9.8, 54.3 ? 6.2 kg) clean (Pre: 82.5 ? 6.2, 24.1 ? 3.4 kg; Post: 92.7 ? 5.8, 33.2 ? 3.3 kg) and snatch (Pre: 59.3 ? 4.4, 20.9 ? 1.7 kg; Post: 69.1 ? 5.3, 25.0 ? 2.3 kg; p &lt; 0.05), respectively. No gender influence on interaction was observed over time (p &gt; 0.05). Conclusion. The HIFT demonstrated the rapid physiological improvements in strength, aerobic and the anaerobic capacity following a four-week intervention in the physically active participants.

Relationship between skills performance and physiological characteristics of Yemeni junior volleyball players

The present study aims to determine the relationship between skills performance and physiological characteristics among Yemeni junior volleyball players. The study sample included 30 junior volleyball players (14-20) years, who played in clubs and schools at Sana’a city, Yemen. The descriptive method used in this study through the conducting skills performance tests and physiological measurements. There is no correlation coefficient between attack and all physiological characteristics. There is no correlation coefficient between forearm pass and physiological characteristics. There is correlation coefficient between repeat pass the ball to the wall and only test of pulse rate at rest, while there is no correlation coefficient between repeat pass the ball to the wall and other physiological characteristics. There is no correlation coefficient between serve and all physiological characteristics. There is correlation coefficient between pass farthest distance and some physiological characteristics, test of pulse rate at rest, and test of Vo2max 30 Sec), but there is no correlation coefficient between pass farthest distance and other physiological characteristics.

Effects of high-intensity interval training while using a breathing-restrictive mask compared to intermittent hypobaric hypoxia

Background: Previous studies of the Elevation Training Mask (ETM) describe comparisons between groups using the ETM and controls for effects on aerobic performance. However, comparisons have not been made to intermittent hypoxic training (IHT). Further, how the ETM impacts exercise economy is unknown. Therefore, we sought to determine the effects of training with the ETM compared to IHT on aerobic performance and cycling economy. Methods: Thirty participants were randomized into an ETM, IHT, or control group (n = 10 each). Pre- and post-testing occurred using a ramp VO2max test on a cycle ergometer allowing submaximal power output (PO) measures of economy. Economy was measured using POs of 100, 125, and 150W. High-intensity cycling interval training (HIIT) occurred 2x/week for 30 min/session for six weeks. Sessions were 20 min of HIIT (30s at 100% peak power output (PPO) of pre VO2max, 90s active recovery at 25W, 10 bouts) with a 5-minute warm-up and cool-down. Repeated measures ANOVA was used for statistical analyses. RESULTS: All participants improved VO2max, PPO, and PO at ventilatory threshold 2 pre- to post-training (p < 0.05). Interactions between groups showed that the RER for the IHT group increased at 100W and 125W, and decreased at RERmax pre- to post-training while the ETM group showed the opposite response (p < 0.05). Conclusion: The ETM and IHT groups performed similarly to the control at maximal and submaximal effort following six weeks of training. The IHT group, but not the ETM group, experienced an increased glycolytic energy shift during submaximal exercise.

Added sugar and dietary fiber consumption are associated with creativity in preadolescent children

ABSTRACT Objectives: Creativity requires the ability to combine existing mental representations in new ways and depends, in part, on the hippocampus. Hippocampal function is, in turn, affected by a number of health factors, including aerobic fitness, excess adiposity, and diet. Specifically, in rodent studies, diets high in saturated fatty acids and sugar – hallmarks of a western diet– have been shown to negatively impact hippocampal function and thereby impair performance on cognitive tasks that require the hippocampus. Yet relatively few studies have examined the relationship between diet and hippocampal-dependent cognition in children. Methods: The current study therefore sought to explore the relationship of several diet quality markers including dietary lipids (saturated fatty acids and omega-3 fatty acids), simple carbohydrates (added sugars), and dietary fiber with creativity in preadolescent children. Participants (N = 57; mean age = 9.1 years) completed the Verbal Form of the Torrance Test of Creative Thinking (TTCT), a standardized test of creativity known to require the hippocampus. Additionally, participants completed a 3-day food intake record with the assistance of a parent, underwent dual energy x-ray absorptiometry (DXA) to assess central adiposity, and VO2max testing to assess aerobic fitness. Results: Added sugar intake was negatively associated, and dietary fiber was positively associated with overall TTCT performance. These relationships were sustained even after controlling for key covariates. Discussion: These findings are among the first to report an association between added sugar consumption and hippocampal-dependent cognition during childhood and, given the key role of the hippocampus in learning and memory, as well as creative thinking, have potential educational and public health implications.

A Randomized Crossover Study Investigating the Running Economy of Highly-Trained Male and Female Distance Runners in Marathon Racing Shoes versus Track Spikes.

Running economy represents a complex interplay of physiological and biomechanical factors that are able to adapt chronically through training, or acutely through other interventions such as changes in footwear. The Nike Vaporfly (NVF) shoe was designed for marathon running on the roads and has been shown to improve running economy by ~ 4% compared with other marathon shoes, however, during track racing, distance runners traditionally wear a much lighter shoe with an embedded spike plate around the forefoot. The aim of this study was to determine if, and to what extent, the NVF shoes improve running economy compared with established track spikes (Nike Zoom Matumbo 3 [NZM]) and marathon racing shoes (Adidas Adizero Adios 3 [ADI]). Twenty-four highly-trained runners (12 male, 12 female) ran 4 × 5min trials on a treadmill while wearing each of the four shoe conditions: NVF, NZM, ADI, and the NVF matched in weight to the ADI shoe (NVF +), during three separate visits-visit 1: familiarization; visit 2: 14 and 18km·h-1 for men, 14 and 16km·h-1 for women; visit 3: 16km·h-1 for men, 15km·h-1 for women, plus a maximal rate of oxygen uptake (VO2max) test for both sexes. We measured the rates of oxygen uptake (VO2), carbon dioxide production and biomechanical measures while running at each velocity and shoe condition. The NVF shoe improved running economy by 2.6 ± 1.3% compared with the NZM, 4.2 ± 1.2% compared with ADI, and 2.9 ± 1.3% when matched in weight of the ADI shoe. Among the 24 subjects, the difference in running economy over the four velocities between the NVF and NZM shoes ranged from +0.50 to -5.34%, and -1.72 to -7.15% for NVF versus ADI. Correlations between changes in running economy and changes in biomechanical variables were either trivial or small, but unclear. The NVF enhanced running economy compared with track spikes and marathon shoes, and should be considered a viable shoe option for track and road racing.

Assessment of HRV after maximal exercise in trained postmenopausal women.

Increased parasympathetic tone achieved with endurance training may provide cardioprotection after menopause. To compare heart rate variability (HRV) from rest through maximal exercise and recovery in trained postmenopausal women. Thirty-six postmenopausal women who self-reported training at either moderate (MOD; 3-5.9 METS; 58.9+/-4.4 year) or vigorous (VIG; >6 METS; 59.7+/-5.2 year) intensities participated. HRV was measured for 5 min in the supine position, in the last minute of the VO2max test and after 2 min of active recovery. HRV in MOD and VIG was compared using a factorial ANOVA with repeated measures on time. MOD and VIG responded similarly over the three time periods for root mean square of sequential deviations (rMSSD), and high (HF) and low frequency (LF) power (p>0.05). Maximal exercise lowered rMSSD (3.3+/-0.08 vs. 1.2+/-0.06) and lnLF (4.1+/-0.05 vs. 3.3+/-0.13) and increased lnHF (3.3+/-0.14 vs. 4.0+/-0.10; p<0.01) from resting. However, active recovery restored lnHF (3.3+/-0.11) and lnLF (4.1+/-0.08) from maximal values (p<0.01). Our findings suggest that moderate and vigorous exercise training may enhance HRV recovery following one bout of maximal exercise in older women.

Acute Effects of an Ergometer-Based Dryland Alpine Skiing Specific High Intensity Interval Training.

Introduction: To establish an alpine ski racing (ASR) specific dryland high intensity training protocol (HIT), we set out to analyze cardiorespiratory and metabolic responses of three ASR specific HIT modes using a ski ergometer compared with a running HIT.Methods: Ten healthy international FIS level subjects (18 ± 1 years) performed an incremental running VO2max test, three different ASR specific HIT modes [slalom (SL), giant slalom (GS), and SL/GS mix] and a running HIT with measurements of VO2, heart rate (HR), blood lactate, and rate of perceived exertion (RPE). The HIT protocols included 15 × 1-min intervals with >90% HRmax and 30 s active rest. Furthermore, one elite alpine skier performed an 8-week, 17 session HIT block using the SL/GS mixed mode.Results: Running HIT resulted in greater VO2peak and whole-body RPE compared with the three ASR-specific HIT modes. During all four exercise modes participants were able to reach exercise intensities high enough to be classified as HIT (>90% HRmax and >89% VO2max). Legs RPE was similar between the four HIT modes, while arms RPE was higher for the ski-specific HIT. For all studied parameters, similar results for the three skiing specific HIT modes were observed. The 8-week HIT block was feasible for the athlete and resulted in an 11% increase in VO2max at unchanged peak power output.Conclusion: Across all HIT protocols high cardiorespiratory and metabolic responses were achieved. Therefore, the ASR specific HIT was shown to be feasible, thus could offer new possibilities for endurance training in elite alpine skiers. It is suggested to use the SL/GS mixed mode in terms of movement variety. The reduced VO2 in the ski-specific modifications can be attributed to the concentric and eccentric muscle activity resulting in mechanical hindrance for O2 extraction. The long-term effectiveness of ASR specific HIT in elite alpine skiers needs to be proven in a future study.

PO-249 Does High Serum MG53 Level Associates with Better Cardiorespiratory Function?

Objective To investigate the association between the endogenous human serum MG53 level and cardio-respiratory function in response to graded exercise test (GXT).&#x0D; Methods Sixteen healthy male volunteers (23.1±2.9yrs, 169.5±6.0cm in height, 63.2±5.9kg in weight, 12.2±3.1% in %FAT, 53.2±5.4ml/min/kg in VO2max) fully acknowledged and signed informed consent and participated in this study. Fasting blood samples were drawn before each VO2max test, serum MG53 was measured by ELISA kits (LifeSpan, USA). Two VO2max tests were performed on each of these sixteen participants with cycle ergometer, and they had a 7 weeks regular physical training (all individuals performed a same routine summer camp exercise training) between the two tests. Difference between groups was determined by UNIANOVA and the correlation coefficient (r) between the cardiorespiratory parameters and serum MG53 value was determined by pearson test.&#x0D; Results Results were divided into 3 groups according to serum MG53 levels, they are Low serum MG53 (n=5, 0.60±0.45 ng/ml) group (L), Medium serum MG53 (n=6, 2.08±0.75 ng/ml) group (M) and High serum MG53 (n=4, 4.23±1.80 ng/ml) group (H). There is no significant difference between M and L when comparing end tidal gas component. However, we found M had higher red blood cell count (RBC) than L (4.98±0.22 vs 4.65±0.31 *1012/L, p&lt;0.01), higher hemoglobin (Hb) than L (155.3±7.6 vs 141. 5±8.1 g/L, p&lt;0.01), and higher hematocrit (HCT) than L (46.6±2.1 vs 43.1±2.6 %, p&lt;0.01). Moreover, we found that H had higher ventilation threshold (VT) than L (47.5±6.5 vs 38.6±3.9 ml/min/kg, p&lt;0.01) and M (47.5±6.5 vs 42.5±2.8 ml/min/kg, p&lt;0.05). Similarly, we found H had higher VO2max than L (59.6±4.7 vs 51.6±6.7 ml/min/kg, p&lt;0.05), higher workload at VT than L (13.2±3.7 vs 11.1±1.7 Watts, p&lt;0.05), higher RBC than L (5.20±0.18 vs 4.65±0.31 *1012/L, p&lt;0.01), higher Hb than L (158.8±4.2 vs 141. 5±8.1 g/L, p&lt;0.01), and higher HCT than L (47.4±1.5 vs 43.1±2.6 %, p&lt;0.01 ). Correlation analysis demonstrated that VO2max(r=0.43, p&lt;0.05), workload at VT (r=0.41, p&lt;0.05), RBC (r=0.53, p&lt;0.01), Hb (r=0.57, p&lt;0.01) and HCT (r=0.47, p&lt;0.01) are positively correlated with Serum MG53.&#x0D; Conclusions It suggested that human serum MG53 level might be positively correlated with cardiorespiratory parameters that have been tested (e.g. VO2max, workload at VT, RBC, HCT and Hb).&#x0D;

PO-181 The Comparative Study on the Maximum Oxygen Uptake Test of 10- Month Old Wistar Rats

Objective The maximum oxygen uptake (VO2max) is an ideal index to objectively evaluate the cardiopulmonary function, as well as the basic to define exercise intensity. In the field of sports science, laboratory animals are often used to explore the effect and mechanism of exercise intervention. Therefore, it is very important to design optimal VO2max test protocol and to ensure the accuracy of VO2max according to the characteristics of the experimental animal itself. In this study, Wistar rats were selected, and various VO2max test protocols were designed and analyzed to screen out the optimal VO2max test protocol for the 10-month old wistar rats.&#x0D; Methods 20 SPF Wistar rats (male, 10 month old) were tested for maximal oxygen uptake by a four channel metabolic monitoring system and running treadmill. Five different test protocols were executed. Each rat completed five test protocols in random order with 3 days’ interval. The exercise performance (coordination degree, exhaustion state), oxygen uptake platform, finish time, VO2max and RER value were recorded during the test of each program, and the performance and test data were compared.&#x0D; Results 1) 12 rats completed all 5 test protocols of VO2max. The induction ratio of VO2max of P1 was only 58%, and P2 and P4 were 75%. While, the induction rate of P3 and P5 were both 83%. 2) For the Bedford improvement protocol (P1), due to the intense increased exercise load, the rats showed more intense stress, the less coordination degree, injured even death, and lower induction rate of VO2max. 3) The VO2max and RER values induced by the P5 are significantly higher than that of P1 (p&lt;0.05). The finish time of P3 is significantly higher than that of P1 (p&lt;0.01) and P5 (p&lt;0.05).&#x0D; Conclusions For the VO2max test for middle aged rats, with the suitable speed of the running treadmill, the change of gradient should be as the main way of increasing load, or increasing the gradient of the slope firstly, which can obtained optimal VO2max, meanwhile reduce the stress response and the risk of injury and serious damage.

PO-014 The effects of HIIT on ROS-AMPK- PGC-1α pathway in skeletal muscle and VO2max of ageing Wistar rats.

Objective To observe the 16 weeks of HIIT intervention on SOD,ROS and its related factors AMPK and oxidation capacity PGC-1α expression and the influence of the VO2max and its change rule in the process of the natural aging rats, To explore the correlation between the expression of ROS, AMPK and PGC-1αand the change of VO2max; Furthermore, it provides a theoretical basis for HIIT to delay the reduction of aerobic capacity in skeletal muscle ageing.&#x0D; Methods 58 male wistar rats(age：32 weeks) were selected and randomly divided into quiet group (C) and HIIT intervention group (H). All rats were fed in the barrier environment. Each group of rats entered the animal laboratory for a week of adaptive feeding and exercise. VO2max was tested and observed every two weeks in each group. Rats of group C don't exercise, group H at a rate of 50%, 70% and 90% VO2max corresponding alternation of 50 min/day, 5 days/week, for 16 weeks of exercise intervention, and according to the VO2max test results the exercise intensity. Both groups of rats in the intervention of 8 weeks, 16 weeks after the end of the 24 hours of materials, stripping rats soleus, SOD and content of ROS was tested by multifunctional enzyme mark, using western blot test the expression of AMPK and PGC-1α. VO2max, SOD, ROS test results and AMPK, PGC-1α, and relative expression data were analyzed using SPSS for one way ANOVA.&#x0D; Results The cardiopulmonary endurance of rats in group C and group H showed a decreasing trend in group C and group H during HIIT intervention, but the decrease trend in group H was slower than that in group C. 2. During 16 weeks aging , SOD expression of group C in the process of rendering first rise after falling, and expressed in 8 weeks SOD content was significantly lower than base value (P &lt; 0.05), 16 weeks group C SOD levels higher than the base state. After 16 weeks of intervention, the expression of SOD in group H was relatively flat in the first 8 weeks, and the trend was in 8-16 weeks, and was significantly lower than 8 weeks in 16 weeks (P &lt; 0.05). 3.The ROS content was significantly higher than basic state in 8 weeks and 16 weeks in the intervention process (P&lt;0.05), and the ROS content was significantly higher than 8 weeks (P&lt;0.05) at 16 weeks. The ROS content of group C and group H was significantly higher than that in the group at 8 weeks (P &lt; 0.05). 4.The AMPK content in group C was significantly lower than that of the basic value (P&lt;0.05), and the AMPK content in group H was significantly higher than that in group C (P&lt;0.05). 5.After the intervention of 16 weeks, the content of PGC-1α in group C and group H showed a decrease trend and significantly lower than the basic value (P&lt;0.05), but the content of group H was significantly higher than that of group C (P&lt;0.05). 6.The changes of AMPK, PGC-1α and cardiopulmonary endurance were the same in all groups during the intervention.&#x0D; Conclusions 1.16 weeks of HIIT can effectively delay the decrease of SOD content in the aging rats, thus inhibiting the accumulation of ROS in the body. 2.16 weeks of HIIT intervention can effectively delay the expression of VO2max and AMPK and PGC-1α in aging rats. 3.16 weeks HIIT may delay the decrease of AMPK-PGC1 protein expression by inhibiting the accumulation of skeletal muscle ROS in the aging rats, thus inhibiting the decrease of VO2max.

Iron deficiency and aerobic endurance performance in a female club runner

Summary Objective This study aimed to monitor longitudinal changes in performance and aerobic adaptations as well as ferritin (Fer) and additional markers pertaining to iron status in an iron deficient female runner. Methods Over 26 months, a venous blood sample was taken every 3 months, lactate profiling and VO2max tests were conducted every 5–6 months. Running performance was recorded during 5 km timed runs (Parkrun). The intervention consisted of iron supplementation, increases in dietary iron intake and implementing a structured approach to training. Results Fer values increased from 4 to 40 μg.L−1 during the period of investigation. Running times improved from 28:02 (m:s) to 23:15. Hemoglobin increased from 9.8 g.dL−1 to 13.7 g.dL−1. Hematocrit ranged from 31.8 to 37.9%, peaking at 40.4%. Mean corpuscular volume and hemoglobin increased from 70 fl to 89 fl and 21.5 pg to 30.1 pg, respectively. VO2max improved from 47.40 to 55.79 mLO2.kg.min−1. Conclusions Our results demonstrate that iron supplementation, increase in dietary iron intake and structured training induced improvements in: (i) Fer and other markers of iron status, (ii) running performance and (iii) VO2max of an iron deficient female club runner.

Aerobic Capacity Is Not Associated with Most Cognitive Domains in Patients with Multiple Sclerosis-A Cross-Sectional Investigation.

(1) Background: Cognitive impairment is highly prevalent in multiple sclerosis (MS). Staying physically fit may be associated with preservation of cognitive performance in persons with MS (pwMS); (2) Objective: To investigate the association between aerobic capacity and the cognitive domains of information processing, learning and memory, and verbal fluency as well as single and composite z-scores of the Brief Repeatable Battery of Neuropsychological tests (BRBNT) in pwMS; (3) Methods: All subjects first performed the BRBNT and then a maximal oxygen consumption (VO2-max) test on a bicycle ergometer as a measure of aerobic capacity. Simple and multiple (adjusting for age, sex, and education level) regression analyses were performed to evaluate the relationship between aerobic capacity and cognitive performance in different domains. Published international norms were used to compute z-scores for each individual and composite BRBNT score. Furthermore, cognitive impairment was defined as one or more z-scores ≤−1.5 standard deviation (SD) of healthy controls; (4) Results: Eighty-four subjects were included (44.9 ± 9 years, 16.3 ± 2 education years, Expanded Disability Status Scale (EDSS): 2.6 ± 1.4, MS-type (relapsing-remitting, primary progressive, or secondary progressive): 73/6/5, disease duration: 9.9 ± 7 years, VO2-max: 28.4 ± 7.0 mL O2/min/kg). No significant associations between aerobic capacity and cognitive performance in the individual BRBNT tests were found, except that a weak relationship was found between aerobic capacity and the composite processing speed z-score (R2 = 0.06, p = 0.02). The average global BRBNT z-score (−0.2 ± 0.66) was not associated with aerobic capacity. Comparison of the cognitively impaired group (34.5%) with the nonimpaired group (65.5%) showed lower aerobic capacity in the impaired group (25.9 ± 1 vs. 29.7 ± 1 mLO2/min/kg, p = 0.02); (5) Conclusions: Limited support was found for an association between performance in most cognitive domains and aerobic capacity in the present MS group with a third of patients showing signs of cognitive impairments.

Cirrhosis affects maximal oxygen consumption, functional capacity, quality of life in patients with hepatitis C.

The aim is assess, compare, and correlate maximal oxygen consumption (VO2max. ), functional capacity and quality of life in cirrhotic patients with hepatitis C virus (HCV) and in healthy individuals. This case-control study included 36 participants (18 patients with HCV cirrhosis and 18 healthy individuals) matched for sex and age. VO2max was assessed using ergospirometry with an incremental load test on a cycloergometer. Functional capacity was measured by a 6-min walk test (6WT), and quality of life was assessed using the 36-Item Short-Form Health Survey (SF-36). Both the cirrhotic group and the control group had similar results for sex (44.4% male) and age (55.6±8.31 and 55.2±8.85years, respectively). The cirrhotic group scored lower in all domains of the SF-36, on the VO2max test (cirrhotic group 16.2 [11.6-18.6] ml/kg/min; control group 19.9 [16.28-26.9]; p=0.007) and on the 6WT (cirrhotic group 521.5 [476.25-544.75] m; control group 618.0 [570.75-643.75] m; p=0.0001). Correlations were found between the 6WT and the VO2max (r=0.801, p<0.0001) and between the 6WT and quality of life (SF-361-functional capacity domain; r=0.552, p=0.018) only in the cirrhotic group. Patients with cirrhosis due to HCV show changes in VO2max and in functional capacity, which have a significant impact on their quality of life.