Decline In VO2max Research Articles

The role of muscle disuse in muscular and cardiovascular fitness: A systematic review and meta-regression.

We aimed to assess the effects of muscle disuse on muscle strength (MS), muscle mass (MM) and cardiovascular fitness. Databases were scrutinized to identify human studies assessing the effects of muscle disuse on both (1) MM and (2) maximal oxygen uptake (VO2max) and/or MS. Random-effects meta-analysis and meta-regression with initial physical fitness and length of the protocol as a priori determined moderators were performed. We quantitatively analyzed 51 different studies, and the level of significance was set at p<0.05. Data from the participants in 14 studies showed a decline in both VO2max (SMD: -0.93; 95% CI: -1.27 to -0.58) and MM (SMD: -0.34; 95% CI: -0.57 to -0.10). Data from 47 studies showed a decline in strength (-0.88; 95% CI: -1.04 to -0.73) and mass (SMD: -0.47; 95% CI: -0.58 to -0.36). MS loss was twice as high as MM loss, but differences existed between anatomical regions. Notably, meta-regression analysis revealed that initial MS was inversely associated with MS decline. VO2max and MS decline to a higher extent than MM during muscle disuse. We reported a more profound strength loss in subjects with high muscular strength. This is physiologically relevant for athletes because their required muscular strength can profoundly decline during a period of muscle disuse. It should however be noted that a period of muscle disuse can have devastating consequences in old subjects with low muscular strength.

Association Between Ferritin Levels and Altitude-Dependent Cardiorespiratory Fitness in Mountain Guides.

Pühringer, Reinhard, Martina Muckenthaler, and Martin Burtscher. Association between ferritin levels and altitude-dependent cardiorespiratory fitness in mountain guides. High Alt Med Biol. 24:139-143, 2023. Background: Higher ferritin levels may be associated with lower cardiorespiratory fitness (CRF; i.e., maximal oxygen uptake, VO2max) and may represent early markers of cardiovascular risk but may also support high-altitude acclimatization. To evaluate these potential associations, data recordings from a large sample of male mountain guides have been analyzed. Methods: A total of 154 data sets (including anthropometric data, VO2max, blood lipids, hemoglobin, ferritin, and transferrin levels) of regularly physically active and well-acclimatized mountain guides were available for analyses. Participants performed equal incremental cycle ergometer tests to exhaustion at low (600 m) and (∼1 week later) at moderate altitude (2,000 m). Results: Ferritin levels were positively correlated with levels of hemoglobin (r = 0.29, p < 0.01), total cholesterol (r = 0.18, p < 0.05), triglycerides (r = 0.23, p < 0.01), and low-density lipoprotein (r = 0.22, p < 0.01), and negatively with high-density lipoprotein levels (r = -0.16, p < 0.05) and also with baseline (taken at low altitude) VO2max values (r = -0.19, p < 0.05). In contrast, higher ferritin levels were associated with less VO2max decline from low-to-moderate altitude (r = 0.26, p < 0.01). Conclusion: Higher ferritin levels in male mountain guides are weakly associated with lower CRF and higher prevalence of cardiovascular risk factors but with slightly less reduction in VO2max when acutely exposed to moderate altitude. The clinical relevance of these observations needs further investigation.

Increased maximal oxygen uptake after sprint-interval training is mediated by central haemodynamic factors as determined by right heart catheterization.

There is a lack of knowledge regarding the contribution of central and peripheral factors to the increases in VO2max following sprint-interval training (SIT). This study investigated the importance of maximal cardiac output (Qmax ) in relation to VO2max improvements following SIT and the relative importance of the hypervolemic response on Qmax and VO2max . We also investigated whether systemic O2 extraction increased with SIT as has been previously suggested. Healthy men and women (n=9) performed 6weeks of SIT. State-of-the-art measurements: right heart catheterization, carbon monoxide rebreathing and respiratory gas exchange analysis were used to assess Qmax , arterial O2 content (ca O2 ), mixed venous O2 content (cv O2 ), blood volume (BV) and VO2max before and after the intervention. In order to assess the relative contribution of the hypervolemic response to the increases in VO2max , BV was re-established to pre-training levels by phlebotomy. Following the intervention, VO2max , BV and Qmax increased by 11% (P < 0.001), 5.4% (P=0.013) and 8.8% (P=0.004), respectively. cv O2 decreased by 12.4% (P=0.011) and systemic O2 extraction increased by 4.0% (P=0.009) during the same period, both variables were unaffected by phlebotomy (P=0.589 and P=0.548, respectively). After phlebotomy, VO2max and Qmax reverted back to pre-intervention values (P=0.064 and P=0.838, respectively) and were significantly lower compared with post-intervention (P=0.016 and P=0.018, respectively). The decline in VO2max after phlebotomy was linear to the amount of blood removed (P=0.007, R=-0.82). The causal relationship between BV, Qmax and VO2max shows that the hypervolemic response is a key mediator of the increases in VO2max following SIT. KEY POINTS: Sprint-interval training (SIT) is an exercise model involving supramaximal bouts of exercise interspersed with periods of rest known for its efficiency in improving maximal oxygen uptake (VO2max ). In contrast to the commonly accepted view where central haemodynamic adaptations are considered to be the key mediators of increases in VO2max there have been propositions highlighting peripheral adaptations as the main mediators in the context of SIT-induced changes in VO2max . By combining right heart catheterization, carbon monoxide rebreathing and phlebotomy, this study shows that increases in maximal cardiac output due to the expansion of the total blood volume is a major explanatory factor for the improvement in VO2max following SIT, with a smaller contribution from improved systemic oxygen extraction. The present work not only clarifies a controversy in the field by using state-of-the-art methods, but also encourages future research to investigate regulatory mechanisms that could explain how SIT can lead to improvements in VO2max and maximal cardiac output similar to those that have previously been reported for traditional endurance exercise.

Remote ischemic preconditioning enhances aerobic performance by accelerating regional oxygenation and improving cardiac function during acute hypobaric hypoxia exposure.

Remote ischemic preconditioning (RIPC) may improve exercise performance. However, the influence of RIPC on aerobic performance and underlying physiological mechanisms during hypobaric hypoxia (HH) exposure remains relatively uncertain. Here, we systematically evaluated the potential performance benefits and underlying mechanisms of RIPC during HH exposure. Seventy-nine healthy participants were randomly assigned to receive sham intervention or RIPC (4 × 5 min occlusion 180 mm Hg/reperfusion 0 mm Hg, bilaterally on the upper arms) for 8 consecutive days in phases 1 (24 participants) and phase 2 (55 participants). In the phases 1, we measured the change in maximal oxygen uptake capacity (VO2max) and muscle oxygenation (SmO2) on the leg during a graded exercise test. We also measured regional cerebral oxygenation (rSO2) on the forehead. These measures and physiological variables, such as cardiovascular hemodynamic parameters and heart rate variability index, were used to evaluate the intervention effect of RIPC on the changes in bodily functions caused by HH exposure. In the phase 2, plasma protein mass spectrometry was then performed after RIPC intervention, and the results were further evaluated using ELISA tests to assess possible mechanisms. The results suggested that RIPC intervention improved VO2max (11.29%) and accelerated both the maximum (18.13%) and minimum (53%) values of SmO2 and rSO2 (6.88%) compared to sham intervention in hypobaric hypoxia exposure. Cardiovascular hemodynamic parameters (SV, SVRI, PPV% and SpMet%) and the heart rate variability index (Mean RR, Mean HR, RMSSD, pNN50, Lfnu, Hfnu, SD1, SD2/SD1, ApEn, SampEn, DFA1and DFA2) were evaluated. Protein sequence analysis showed 42 unregulated and six downregulated proteins in the plasma of the RIPC group compared to the sham group after HH exposure. Three proteins, thymosin β4 (Tβ4), heat shock protein-70 (HSP70), and heat shock protein-90 (HSP90), were significantly altered in the plasma of the RIPC group before and after HH exposure. Our data demonstrated that in acute HH exposure, RIPC mitigates the decline in VO2max and regional oxygenation, as well as physiological variables, such as cardiovascular hemodynamic parameters and the heart rate variability index, by influencing plasma Tβ4, HSP70, and HSP90. These data suggest that RIPC may be beneficial for acute HH exposure.

The Impact of Training on the Loss of Cardiorespiratory Fitness in Aging Masters Endurance Athletes.

Elite masters endurance athletes are considered models of optimal healthy aging due to the maintenance of high cardiorespiratory fitness (CRF) until old age. Whereas a drop in VO2max in masters athletes has been broadly investigated, the modifying impact of training still remains a matter of debate. Longitudinal observations in masters endurance athletes demonstrated VO2max declines between −5% and −46% per decade that were closely related to changes in training volume. Here, using regression analyses, we show that 54% and 39% of the variance in observed VO2max decline in male and female athletes, respectively is explained by changes in training volume. An almost linear VO2max decrease was observed in studies on young and older athletes, as well as non-athletes, starting a few days after training cessation, with a decline of as much as −20% after 12 weeks. Besides a decline in stroke volume and cardiac output, training cessation was accompanied by considerable reductions in citrate synthase and succinate dehydrogenase activity (reduction in mitochondrial content and oxidative capacity). This reduction could largely be rescued within similar time periods of training (re)uptake. It is evident that training reduction or cessation leads to a considerably accelerated VO2max drop, as compared to the gradual aging-related VO2max decline, which can rapidly nullify many of the benefits of preceding long-term training efforts.

Impact of an individualized counseling program on weight loss and quality of life in breast cancer survivors.

1105 Background: Survivors of breast cancer who are obese have a greater than two-fold increase in mortality compared to their counterparts. We assessed the feasibility of an individualized nutrition counseling and exercise program with the goal of helping participants achieve a loss of 10% body weight. Secondary endpoints included impact on multiple metabolic parameters, cardiovascular health, and quality of life. Methods: We present preliminary data from a single-arm pilot trial (NCT04365569) whereby survivors of breast cancer with BMI ≥ 25 kg/m2 participated in a 6-month, individualized counseling program. A registered dietitian (RD) counseled patients based upon recommendations by the American Cancer Society. The intervention included in-person (baseline, months 3 and 6) and telephone visits (months 1, 2, 4, and 5). The nutrition component included weight and body composition measures and blood work, including lipid panel and hemoglobin A1c. Cardiovascular fitness and extrapolated VO2 max were measured using SHAPE study. Quality of life was evaluated using: the Functional Assessment of Cancer Therapy – Breast Cancer (FACT-B), the Brief Pain Inventory (BPI), the Generalized Anxiety Disorder-7 (GAD-7), the Patient Health Questionnaire-9 (PHQ-9), and the NCCN Distress Thermometer. Paired statistics were used to compare changes in these aforementioned outcomes pre-and post-intervention. Results: A total of n=55 female breast cancer survivors (mean age 58.1± 9.13) were enrolled. N=28 completed the trial to date. While 14.3% of participants lost &gt;10% of their baseline weight, 21.4% lost 5-10 % of their weight. Patients had a mean 45.30% drop in body fat composition overall (p&lt;0.001). There was no statistically significant difference in lipids and hemoglobin A1c. In terms of cardiovascular function, a decline in mean VO2 max of -4.71 (SD 4.71, p &lt;0.001) was observed, accompanied by a decline in mean METS of -1.09 (SD 0.84, p &lt;0.001). Higher compliance with the intervention was associated with losing weight (p 0.001). FACT-B scoring revealed improvements in Physical (mean +1.92, SD 3.82), Emotional (mean +1.03, SD 2.71), and Functional well-being (mean +2.70, SD 4.34) (p &lt;0.05). This trial was also associated with lower indicators of depression, as evaluated by PHQ-9 scoring (mean -1.32, SD 3.19, p 0.038). Even in patients with weight gain, improvements in QoL surveys were observed, although not statistically significant, likely due to the small sample size in this subpopulation (n = 7). Conclusions: An individualized counseling program benefits survivors of breast cancer who are overweight by helping them reduce weight and improve their overall quality of life. While no improvements in VO2 max levels were observed, this may be partially explained by a decrease in effort on the part of participants. Further investigation into the utility of extrapolated VO2 max using the SHAPE study is ongoing. Clinical trial information: NCT04365569.

Does Moderate Altitude Affect VO2max in Acclimatized Mountain Guides?

Pühringer, Reinhard, Hannes Gatterer, Martin Berger, Michael Said, Martin Faulhaber, and Martin Burtscher. Does moderate altitude affect VO2max in acclimatized mountain guides? High Alt Med Biol. 23:37-42, 2022. Background: Altitude exposure reduces maximal oxygen uptake (VO2max). Usually, the reduction is not restored with acclimatization (at least at altitudes above 2,500 m) and is more pronounced in highly trained athletes compared to nonathletes. It still remains to be elucidated whether these also apply for well-acclimatized individuals (i.e., mountain guides) acutely exposed to moderate altitude (i.e., 2,000 m). Methods: A total of 128 acclimatized male mountain guides of the Austrian armed forces (42.2 ± 7.0 years, 177.8 ± 5.6 cm, 77.2 ± 7.0 kg) of different fitness levels performed 2 incremental cycle ergometer tests 1 week apart, one at low (600 m) and one at moderate altitude (2,000 m). Oxygen uptake, heart rate (HR), and lactate concentration were measured during the tests. Results: In acclimatized mountain guides, lower baseline VO2max levels were associated with better preservation of VO2max at moderate altitude compared to higher levels. At moderate altitude, physiological responses (HR and blood lactate at 100 W) at a submaximal exercise intensity of 100 W remained unchanged or were even slightly reduced in both groups. Conclusions: Long-term acclimatization to moderate altitude may prevent the VO2max decline at a moderate altitude of 2,000 m particularly in subjects with lower VO2max levels, that is, below the 80th percentile (for age and sex). In people with higher fitness levels, VO2max may still be negatively affected. These results are of practical relevance, for example, for workers, athletes, ski and mountain guides, military staff, or rescue staff who regularly or continuously have to perform at moderate altitude.

The Separate And Combined Effects Of Acute Simulated Altitude And High Ambient Temperature On Cycling Time Trial Performance

Simulated altitude and high ambient temperature independently compromise endurance performance, although there is limited evidence on the combined exposure to both stressors. In addition, the effect of corresponding underlying key mechanisms has yet to be quantified. PURPOSE: To investigate the separate and combined effects of acute simulated altitude and high ambient temperature on time trial (TT) performance, VO2max, the ventilatory threshold (VT) and gross efficiency (GE). METHODS: Ten trained male cyclists performed 4 maximal incremental exercise tests (GXT) and GE-tests, both at sea-level (0 m; 20.93% O2) and simulated altitude (2000 m; 16.3% O2) in high environmental temperature (36.00 ± 1.4°C, 42.58 ± 0.8% RH) and temperate conditions (16.00 ± 0.32°C, 40.20 ± 1.2% RH). The GXT included 3 min at 100 W, followed by 25 W·min-1 until volitional fatigue. GE was determined at 50% of the power attained at VO2max in relative conditions, prior to and following 4000m TT performances. RESULTS: Although average PO was significantly reduced during TT performance at simulated altitude (31 ± 18 W, p<.001, n2p=.795) and high ambient temperature (9 ± 16 W, p=.007, n2p=.570), no significant interaction was found (p=.137). At simulated altitude, VO2max (3.77 ± 2.1 ml·kg-1·min-1, p<.001, n2p=.925), VT (3.39 ± 2.9 ml·kg-1·min-1, p<.001, n2p=.795) and GE (0.72 ± 0.97%, p=.021, n2p=0.555) were significantly reduced compared to sea level. However, VO2max (3.33 ± 3.1 ml·kg-1·min-1, p=.005, n2p=.608) and VT (2.05 ± 3.1 ml·kg-1·min-1, p=.021, n2p=.462) were significantly increased at high ambient temperature, although no effect on GE (p=0.240) was found. CONCLUSION: The reduction in TT performance at acute simulated altitude is associated with a decline in VO2max, VT and GE, likely because a lower SpO2. VO2max and VT are significantly higher at acute high ambient temperature, likely because the metabolic cost of physiological heat stress increases relative exercise intensity at similar absolute PO. GE was unaffected by acute high ambient temperature, likely because heat exposure during the GE-test was too short to increase Tcore. VO2max, VT and GE were not compromised during combined exposure, which corresponds with the absence of a significant interaction effect in endurance performance.

A Focused Review on the Maximal Exercise Responses in Hypo- and Normobaric Hypoxia: Divergent Oxygen Uptake and Ventilation Responses.

The literature suggests that acute hypobaric (HH) and normobaric (NH) hypoxia exposure elicits different physiological responses. Only limited information is available on whether maximal cardiorespiratory exercise test outcomes, performed on either the treadmill or the cycle ergometer, are affected differently by NH and HH. A focused literature review was performed to identify relevant studies reporting cardiorespiratory responses in well-trained male athletes (individuals with a maximal oxygen uptake, VO2max > 50 mL/min/kg at sea level) to cycling or treadmill running in simulated acute HH or NH. Twenty-one studies were selected. The exercise tests in these studies were performed in HH (n = 90) or NH (n = 151) conditions, on a bicycle ergometer (n = 178) or on a treadmill (n = 63). Altitudes (simulated and terrestrial) varied between 2182 and 5400 m. Analyses (based on weighted group means) revealed that the decline in VO2max per 1000 m gain in altitude was more pronounced in acute NH vs. HH (−7.0 ± 1.4% vs. −5.6 ± 0.9%). Maximal minute ventilation (VEmax) increased in acute HH but decreased in NH with increasing simulated altitude (+1.9 ± 0.9% vs. −1.4 ± 1.8% per 1000 m gain in altitude). Treadmill running in HH caused larger decreases in arterial oxygen saturation and heart rate than ergometer cycling in acute HH, which was not the case in NH. These results indicate distinct differences between maximal cardiorespiratory responses to cycling and treadmill running in acute NH or HH. Such differences should be considered when interpreting exercise test results and/or monitoring athletic training.

Reference values for aerobic capacity estimated by cardiopulmonary exercise test on a cycle ergometer in a healthy Greek population

ObjectiveAerobic capacity (AC) is inversely associated with a high risk of cardiovascular morbidity and mortality as well as all-cause mortality. Cardiopulmonary exercise testing (CPET) represents the gold standard for assessing exercise capacity based on maximum oxygen uptake (VO2max). The purpose of our study was to provide for the first time CPET-derived normative reference values in a Greek cohort of apparently healthy men and women on a cycle ergometer to evaluate their AC, and to compare our results with similar studies from other countries. MethodsA cohort of 194 apparently healthy subjects (118 males and 76 females, age range, 15-69 years) was submitted to CPET using a cycle ergometer. Mean ± SD values for several exercise parameters, VO2max included, were determined. We compared our results with existing data derived from USA and North Europe cohorts. ResultsMale subjects achieved significantly higher levels of relative and absolute VO2max (p < 0.001) across all ages compared to female subjects. A decline in relative and absolute VO2max among older participants was observed in both sexes. Greek subjects had lower AC than the North Europe cohort and almost similar to the USA cohort. ConclusionWe provide the first reference data for AC in apparently healthy Greek subjects based on CPET using cycle ergometer. Our findings will allow for more accurate interpretation of CPET in several groups of healthy subjects or patients with CV diseases. The differences found between our reference values and those reported from the USA and northern European countries, underscore the need for individual countries to develop their own AC reference values.

Interrelationship Between Sex, Age, Blood Volume, and Vo2max.

BACKGROUND: Circulating blood volume (BV) and maximal oxygen uptake (Vo2max) are physiological characteristics important for optimal human performance in aerospace and military operational environments. We tested the hypothesis that BV and Vo2max are lower in older people independent of sex.METHODS: To accomplish this, a "data mining" effort of an historic database generated from NASA and U.S. Air Force experiments was conducted. BV, red cell volume, plasma volume, hematocrit, and Vo2max were measured in 84 healthy individuals (24 women, 60 men) across an age range of 23 to 65 yr to assess the interrelationship between sex, age, BV, and Vo2max. Subjects were classified in age groups by < 40 yr and ≥ 40 yr; these groups identified women as pre- vs. postmenopausal.RESULTS: Consistent with our hypothesis, comparisons revealed that men had higher BV, red cell volume, hematocrit, and Vo2max than women when standardized for body mass. Against expectations, BV was not different in older compared with younger men and women. Vo2max was not different in older compared with younger women, while Vo2max was lower in older men.CONCLUSION: We conclude that physiological mechanisms other than BV associated with aging appear to be responsible for a decline in Vo2max of our older men. Furthermore, factors other than menopause may also influence the control of BV in the women. Our results provide evidence that aging may not compromise men or women in scenarios where BV can affect performance in aerospace and military environments.Koons NJ, Suresh MR, Schlotman TE, Convertino VA. Interrelationship between sex, age, blood volume, and Vo2max. Aerosp Med Hum Perform. 2019; 90(4):362-368.

Interrelationship between sex, age, blood volume and VO2max

BackgroundCirculating blood volume (BV) and maximal oxygen uptake (VO2max) are physiological characteristics important for optimal human performance in aerospace and military operational environments. Addressing the interrelationships between BV, VO2max, sex, and age together is relevant to identifying those individuals with greatest risk of poor outcomes from hemorrhage, as well as assessing the levels of performance competence of individuals deployed in operational environments. In the present investigation, we report and compare for the first time BV and VO2max in a cohort of males and females together to test the hypothesis that BV and VO2max is lower in older people independent of sex.MethodsTo accomplish this, a ‘data mining’ effort of an historic database generated from NASA and U.S. Air Force experiments was conducted. BV, red cell volume, plasma volume, hematocrit, and VO2max were measured in 94 healthy individuals (28 females, 66 males) across an age range of 23 to 65 years to assess the interrelationship between sex, age, BV, and VO2max. Subjects were classified in age groups by &lt; 40 years and ≥ 40 years; these groups identified females as pre‐ vs. post‐menopausal.ResultsConsistent with our hypothesis, comparisons revealed that males had higher (p &lt; 0.01) BV, red cell volume, hematocrit, and VO2max than females when standardized for body size. Against expectations, BV was not different in older compared with younger males and females. VO2max was not different in older compared with younger females, while VO2max was lower in older males (p &lt; 0.01).ConclusionWe conclude that physiological mechanisms other than BV associated with aging appear to be responsible for a decline in VO2max of our older male subjects. Furthermore, factors other than menopause may also influence the control of BV in the female population. Our results provide evidence that aging may not compromise males or females in scenarios where BV can affect performance in aerospace and military environments.Support or Funding InformationThis research was supported in part by appointment of Ms. Koons to the Postgraduate Research Fellowship Program at the US Army Institute of Surgical Research administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the US Department of Energy and USAMRMC. Study funding was provided by a grant from the US Army Combat Casualty Care Research Program (D‐009‐2014‐USAISR).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Abstract GS5-02: Cardiovascular function and the effect of exercise training during adjuvant breast cancer treatment. Results from The EBBA-II trial

Abstract Background: Breast cancer survival rates have improved, but cardiovascular disease is a competing cause of death among breast cancer survivors, and treatment-induced cardio-toxicity remains a major concern. The effect of aerobic exercise on cardiovascular function during adjuvant breast cancer treatment is not yet well established. Material &amp; methods: The women participating in the Energy Balance and Breast Cancer Aspect (EBBA)-II trial are aged 18-75 years and diagnosed with stage I-II breast cancer. VO2max was assessed at three separate times, prior to surgery and at 6 and 12 months after, using a maximum exercise test on a treadmill (modified Balke protocol).The patients were randomized after surgery to a control group (n=188, usual care) or an intervention group (n=187) stratified by menopausal status. The 12 months exercise intervention program started 2-3 weeks after surgery and the patients received a detailed training program based on their own VO2max at baseline. They met for training sessions in groups of 10-12 women for 60 minutes twice a week during a 12 month period, and were in addition asked to perform at least 120 minutes of exercise at home (a total of 240 minutes of exercise weekly).Analyses were done on an intention-to-treat basis (NCT02240836). Preliminary results: Breast cancer patients (n=375) with a mean age at diagnosis of 55.2 years (27.0-75.0 years) had a mean body mass index (BMI) of 25.1kg/m2, a mean VO2max before surgery of 31.5 ml•min−1•kg−1, and 57 % of the patients underwent chemotherapy (paclitaxel, epirubicin/cyclophosphamide based adjuvant chemotherapy). Comparing the intervention group to the control group, the intervention group had a decrease in VO2max of 2.7% after 6 months, but they improved their VO2max by 2.3 % at 12 months compared to before surgery (p=0.001). Breast cancer patients in the control group had a 10 % reduction in VO2max 6 months after surgery (p&amp;lt;0.001), and a 3.8% decrease in VO2max was observed at 12 months compared to before surgery (p&amp;lt;0.001). Among patients in the control group who received chemotherapy, a decline in VO2max by 5.3 ml•min−1•kg−1 (16.2%) (p&amp;lt;0.001) at 6 months was observed. This reduction in VO2max at 6 months was most pronounced in patients who received paclitaxel alone, or paclitaxel in combination with epirubicin/cyclophosphamide (6.1 ml•min−1•kg−1, 18.7% decrease). In comparison, patients in the intervention group who received chemotherapy had a decline of 2.4 ml•min−1•kg−1 (7.6%) in VO2max at 6 and after 12 months VO2max was equal to before surgery. Differences in VO2max at 6 and after 12 month between groups were in favor of the intervention group (p&amp;lt;0.05). Conclusion: Our findings strongly support that tailored exercise training during adjuvant breast cancer treatment may counteract a decline in cardiovascular function, and in particular among those receiving chemotherapy. Our study supports incorporation of supervised clinical exercise programs into breast cancer treatment guidelines. Final results of the trial at SABCS 2018 (the trial closes October 15, 2018) total included N=539 (NCT02240836) Citation Format: Thune I, Husøy A, Frydenberg H, Flote VG, Fjeldheim F, Bertheussen GF, Lundgren S, Lømo J, Wist EA, McTiernan A, Schlichting E. Cardiovascular function and the effect of exercise training during adjuvant breast cancer treatment. Results from The EBBA-II trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS5-02.

OR-003 Time-sequential Changes of Myocardial AMPK and PGC-1α Expression during Detraining between High-intensity Interval Training and Moderate-intensity Continuous Training on Wistar Rats

Objective Without appropriate training stimulus, the athlete experiences a loss of the physiological adaptations brought about by exercise. In most of highly trained athletes, short of training induces a rapid decline in VO2max, but it remains above control values. However, there is no specific information for normal people about the effects of detraining during certain period aerobic training. Therefore, the purpose of this study was to examine the effects of detraining between high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on myocardial AMPK and PGC-1α expression characterization time-sequential changes in Wistar rats, as well as the changing characteristics between AMPK and PGC-1α expression characterization and cardiacrespiratory fitness (CRF). Moreover, the potential mechanism for exercise arrangement was also investigated.&#x0D; Methods In this study, 27 four-month-old male Wistar rats were randomly divided into the sedentary control group (C), MICT group (M) and HIIT group (H).Animals in the training groups ran on a treadmill 5 days/week during 6 weeks. HIIT group (70%-90%-50%VO2max) and MICT (50%VO2max) group was ran for 50min exercise every training day. All the rats free to gather the food and drinking water. All rats were measured the VO2max after a week adaptive training and then the M group and H group began to exercise intervention. After 6 weeks of training, rats were randomly selected from each group at the 24h, the 3rd day, the 7th day and the 10th day. The Maximal oxygen uptake test was carried out before the samples were taken, and the abdominal aortic blood, myocardium and other tissues were collected after anesthesia. The expression characterization of AMPK and PGC-1α was tested by Western blotting analysis. All statistical analyses were performed using SPSS 17.0 and GraphPad Prism 5.01 for Windows. Data was presented as mean and standard deviation（SD), unless otherwise stated. The two-way ANOVA (intervention × time) with repeated measures were used to analyze differences of HIIT and MICT with time-sequential. One-way ANOVA was used to compare the difference between time-sequential among the groups for each variable. The relationship between variables was assessed using the Pearson correlation coefficient. The expression characterization of the detraining effect was also assessed using Cohen’s d effect sizes (ES) and thresholds (&lt;0.5=small; 0.5~0.79=moderate;≥0.8=large). The level of significance was set at P&lt;0.05 and the confidence intervals at 95%.&#x0D; Results VO2max showed a gradual downward trend in both H and M groups throughout the 10 days detraining periods. Detraining in the 10th day, training cessation resulted in the VO2max of H and M group were significantly lower than detraining 24h. (P&lt;0.05). Detraining in 3rd day, myocardial AMPK and PGC-1α increased in H group, it was significantly higher than the C group (P&lt;0.05), but there is no differences in the other detraining days(P&gt;0.05). Furthermore, detraining in the 7th day myocardial PGC-1α decreased in H group, this value was significantly lower than detraining 24h (P&lt;0.05). Detraining in 7th day, myocardial AMPK and PGC-1α started decreasing, but it was not significant than C group or other detraining days (P&gt;0.05).&#x0D; Conclusions (1)The present data suggest that 6 weeks HIIT and MICT can increase the expression of myocardial AMPK and PGC-1α, the VO2max training effects disappeared after 10 days detraining. (2)Detraining during the 3rd day and the 7th day was the critical time point for retraining, endurance training intervention should be arranging among these days. (3)The VO2max time-sequential changes was partially consistent with AMPK and PGC-1α expression characterization, but AMPK and PGC-1α expression characterization was more sensitive than VO2max.

Ultra-long-distance running and the liver

Regular exercise attenuates the age associated decline in VO2max, functional impairment in different organs, production of reactive oxygen species (ROS) and the related oxidative damage. Although regular exercise attenuates the age-associated decline in VO2max and deterioration of most of the organs via enhanced mitochondrial function and dynamics the effects are complex and mediated by multi signaling pathways. Exercise training attenuates the age-related loss in cellular housekeeping system, which includes proteasome, Lon protease, autophagy, mitophagy and DNA repair systems which beneficially impacts organ function. Accumulating evidence suggests that exercise lessen the deleterious effects of aging, however it seems unlikely that the systemic effects are mediated through a specific biomarker.

Cardiopulmonary fitness in children with congenital heart diseases versus healthy children: A multicenter cross-sectional study

We aimed to compare the cardiopulmonary fitness of children with congenital heart diseases (CHD) to that of age- and gender-adjusted controls. We also intended to identify clinical characteristics associated with maximum oxygen uptake (VO2 max ) in this population. We included in a cross-sectional multicentre study a total of 798 children (496 CHD and 302 controls) who underwent a complete cardiopulmonary exercise test (CPET). The association of clinical characteristics with VO2 max was studied using a multivariate analysis. The study was approved by the South Mediterranean IV Ethics Committee (2009-A00423-54) and registered on ClinicalTrials.gov ( NCT01202916 ). Informed consent was obtained from all parents. Mean VO2 max in the CHD group and control represented 93 ± 20% and 107 ± 17% of predicted values, respectively. VO2 max was significantly lower in the CHD group, overall (37.8 ± 0.3 vs. 42.6 ± 0.4 mL/kg/min, P < 0.0001) and for each group ( P < 0.05) ( Table 1 ). The mean VO2 max decline per year was significantly higher in CHD than in the controls overall (−0.84 ± 0.10 vs −0.19 ± 0.14 mL/kg/min/year, P < 0.01), for males (−0.72 ± 0.14 vs. 0.11 ± 0.19 mL/kg/min/year, P < 0.01), and for females (−1.00 ± 0.13 vs. −0.55 ± 0.21 mL/kg/min/year, P = 0.05) ( Fig. 1 ). VO2 max was associated with body mass index, ventilatory anaerobic threshold, female gender, restrictive ventilatory disorder, right ventricle systolic hypertension, tricuspid regurgitation, the number of cardiac catheter or surgery procedures, and the presence of a genetic anomaly. This comparative CPET study provided, for the first time, relevant values of VO2 max and their clinical determinants in the largest reported cohort of CHD children compared to a control group. Although the magnitude of the difference was not large, VO2 max among children with CHD was significantly lower than in normal children. We suggest performing CPET in routine follow-up of these patients.

Age Related Decline in VO2max and Lean Body Mass in Masters Athletes

Improving physical performance of athletes is an important goal to success in sports achievements. Aging influences both body composition and results in a decline in maximal oxygen consumption (VO2max). This decline results from several factors, including increased body fat and reduced maximal cardiac output. Sex differences in age-related decline in VO2max and lean body mass (LBM) in Masters Athletes is still not fully understood. PURPOSE: To examine the sex differences in the age-related decline in VO2max and LBM in Masters Athletes. METHODS: A total of 26 master athletes (females: n=14, males: n=12), 26 to 60 years of age, participated in this cross-sectional study. VO2max was determined via Vmax Encore metabolic system. Lean body mass was evaluated by dual energy X-ray absorptiometry (DXA). RESULTS: There were no significant differences in VO2max (40.1+8.7 and 38.2+12.1 mL/kg/minute) (t (24) = 1.29, P=0.208) and age (36.5+5.4 and 41.4+9.1 years) (t (24) = -0.784, P=0.441) between males and females, respectively. Males had a significantly greater LBM than females (t (24) = 5.59, P=0.00) (61.7+9.1 kg and 44.2+6.9, respectively). For males, there was no significant correlation between age and VO2max (r = -0.31, P =0.32), age and LBM (r = -0.23, P=0.47), or VO2max and LBM (r = 0.04, P=0.89). For females, there was a significant negative correlation between age and VO2max (r = -0.603, P=0.02); but no significant correlations were found between age and LBM (r = -0.244, P=0.40) and VO2max and LBM (r = 0.121, P=0.68). There was not a significant age-related decline in VO2max in males and females (r2 = 0.09, r2 = 0.36, respectively) or in LBM (r2 = 0.05, r2 = 0.06, respectively). CONCLUSION: Although there were declines in VO2max in both men and women, these age-related declines were not significant. In addition, age-related declines in LBM were not significant in this sample of Masters Athletes. These represent data from an unfunded research project

The Age-related Decline In Vo2max

The Age-related Decline In Vo2max

Replacement of daily load attenuates but does not prevent changes to the musculoskeletal system during bed rest

The dose-response effects of exercise in reduced gravity on musculoskeletal health have not been well documented. It is not known whether or not individualized exercise prescriptions can be effective in preventing the substantial loss in bone mineral density and muscle function that have been observed in space flight and in bed rest. In this study, typical daily loads to the lower extremities were quantified in free-living subjects who were then randomly assigned to control or exercise groups. Subjects were confined to 6-degree head-down bed rest for 84days. The exercise group performed individually prescribed 1g loaded locomotor exercise to replace their free-living daily load. Eleven subjects (5 exercise, 6 control) completed the protocol. Volumetric bone mineral density results from quantitative computed tomography demonstrated that control subjects lost significant amounts of bone in the intertrochanteric and total hip regions (p<0.0125), whereas the exercise group showed no significant change from baseline in any region (p>0.0125). Pre-and post-bed rest muscle volumes were calculated from analysis of magnetic resonance imaging data. The exercise group retained a larger percentage of their total quadriceps and gastrocnemius muscle volume (−7.2%±5.9, −13.8%±6.1, respectively) than their control counterparts (−23.3%±5.9, −33.0±8.2, respectively; p<0.01). Both groups significantly lost strength in several measured activities (p<0.05). The declines in peak torque during repeated exertions of knee flexion and knee extension were significantly less in the exercise group than in the control group (p<0.05) but work done was not significantly different between groups (p>0.05). The decline in VO2max was 17%±18 in exercising subjects (p<0.05) and 31%±13 in control subjects (p=0.003; difference between groups was not significant p=0.26). Changes in blood and urine measures showed trends but no significant differences between groups (p>0.05). In summary, the decline in a number of important measures of musculoskeletal and cardiovascular health was attenuated but not eliminated by a subject-specific program of locomotor exercise designed to replace daily load accumulated during free living. We conclude that single daily bouts of exposure to locomotor exercise can play a role in a countermeasures program during bed rest, and perhaps space flight, but are not sufficient in their own right to ensure musculoskeletal or cardiovascular health.

Eight-Week Training Cessation Suppresses Physiological Stress but Rapidly Impairs Health Metabolic Profiles and Aerobic Capacity in Elite Taekwondo Athletes.

Changes in an athlete’s physiological and health metabolic profiles after detraining have not been studied in elite Taekwondo (TKD) athletes. To enable a better understanding of these physiological changes to training cessation, this study examined the effects of 8-weeks detraining on the aerobic capacity, body composition, inflammatory status and health metabolic profile in elite TKD athletes. Sixteen elite TKD athletes (age: 21.0 ± 0.8 yrs, BMI: 22.4 ± 3.9 kg/m2; Mean ± SD; 11 males and 5 females) participated in this study. Physical activity level assessment using computerized physical activity logs was performed during the competitive preparation season (i.e. one-week before national competition) and at two week intervals throughout the detraining period. Participant aerobic capacity, body fat, and blood biomarkers were measured before and after detraining, and the blood biomarker analyses included leukocyte subpopulations, blood glucose, insulin, dehydroepiandrosterone-sulfate (DHEA-S), and cortisol. Eight-week detraining increased DHEA-S/cortisol ratio (+57.3%, p = 0.004), increased insulin/cortisol ratio (+59.9%, p = 0.004), reduced aerobic power (–2.43%, p = 0.043), increased body fat accumulation (body fat%: +21.3%, p < 0.001), decreased muscle mass (muscle mass%: –4.04%, p < 0.001), and elevated HOMA-IR (the biomarker of systemic insulin resistance; +34.2%, p = 0.006). The neutrophil-to-lymphocyte ratio (NLR), a systemic inflammatory index, increased by 48.2% (p = 0.005). The change in aerobic capacity was correlated with the increased fat mass (r = –0.429, p = 0.049) but not with muscle loss. An increase in the NLR was correlated to the changes in HOMA-IR (r = 0.44, p = 0.044) and aerobic capacity (r = –0.439, p = 0.045). We demonstrate that 8-week detraining suppresses physiological stress but rapidly results in declines in athletic performance and health metabolic profiles, including reduced aerobic capacity, increased body fat, muscle loss, insulin resistance development and elevated systemic inflammatory status in these young elite TKD athletes. The inflammation state was positively associated with insulin resistance development, fat mass, WHR (the index for central fat accumulation), and the decline in VO2max.