Changes In Aerobic Capacity Research Articles

Improved functional oral intake and exercise training attenuate decline in aerobic capacity following chemoradiotherapy in patients with esophageal cancer.

To investigate the impact of chemoradiotherapy on the physical fitness of patients with oesophageal cancer, and the clinical factors influencing it. A total of 67 participants successfully completed the study, with 18 of them engaging in supervised, in-hospital aerobic training at moderate intensity for a minimum of 20 sessions. Cardiopulmonary exercise testing, hand grip strength, body composition assessed via bioelectrical impedance analysis, patient-generated subjective global assessment, albumin, and the Functional Oral Intake Scale (FOIS) were evaluated before chemoradiotherapy and 6-8 weeks after its completion. Among the participants, cardiopulmonary fitness, hand grip strength, and phase angle of BC-BIA declined during chemoradiotherapy. Before and after chemoradiotherapy, V̇O2peak was 19.6 ± 4.4 and 17.4 ± 3.9 mL/min/kg respectively. The improvement in FOIS during chemoradiotherapy showed a positive correlation with changes in aerobic capacity. Additionally, exercise training was associated with attenuating the decline in aerobic capacity. Physical fitness deteriorated in patients with oesophageal cancer following chemoradiotherapy. Improvement in dysphagia helps maintain aerobic capacity. Additionally, exercise training has the potential to mitigate the decline. This discovery can serve as a reference for enhancing holistic care for patients with oesophageal cancer.

Effect of 6-Week Sprint Training on Long-Distance Running Performance in Highly Trained Runners.

Long-distance running performance has been reported to be associated with sprint performance in highly trained distance runners. Therefore, we hypothesized that sprint training could enhance distance running and sprint performance in long-distance runners. This study examined the effect of 6-week sprint training on long-distance running and sprint performance in highly trained distance runners. Nineteen college runners were divided into control (n = 8) and training (n = 11) groups. Participants in the training group performed 12 sprint training sessions in 6weeks, while those in the control group performed 12 distance training sessions. Before and after the interventions, maximal oxygen uptake (V˙O2max), O2 cost during submaximal running (290m·min-1 and 310m·min-1 of running velocity), and time to exhaustion (starting at 290m·min-1 and increased 10m·min-1 every minute) were assessed on a treadmill. Additionally, the 100-m and 400-m sprinting times and 3000-m running time were determined on an all-weather track. In the control group, no measurements significantly changed after the intervention. In the training group, the time to exhaustion, 100-m and 400-m sprinting times, and 3000-m running time improved significantly, while V˙O2max and O2 cost did not change. These results showed that 6-week sprint training improved both sprint and long-distance running performance in highly trained distance runners without a change in aerobic capacity. Improvement in the time to exhaustion without a change in V˙O2max suggests that the enhancement of long-distance running performance could be attributable to improved anaerobic capacity.

Biseasonal Changes in Aerobic Capacity and Sports Performance in Highly Trained Mountain Bike Cyclists Applying Elements of the Polarized Training Programme

Abstract Introduction. This study assessed maximal oxygen uptake (VO2max), power output and sports performance in mountain bike cyclists applying elements of the polarized training programme (POL) Material and Methods. Seven cyclists participated in the study. Immediately before the 2-year experiment (T1), and five times during the experiment (T2, T3, T4, T5, T6), incremental and verification tests were performed to assess VO2max, peak aerobic power (Ppeak) and power at the second ventilatory threshold (PVT2). During the experiment, sports performance in mountain bike cyclists at National Championships, European Championships, World Championships, and World Cup were analyzed. The cyclists performed POL for seven months in each year of the experiment. POL included sprint interval training, high-intensity interval training, and low-intensity endurance training. Results. In the group of cyclists VO2max [l∙min−1] increased in T6 (4.14 ± 1.13) compared to T1 (3.74 ± 0.95), Ppeak [W] increased in T4, T5 and T6 (353 ± 78.45; 350.14 ± 87.96; 360.23 ± 93.83; respectively) compared to T1 (324.14 ± 90.24), and PVT2 [W] increased in T3, T4, T5 and T6 (265.57 ± 80.66; 267.29 ± 63.74; 266.43 ± 69.29; 276.71 ± 78.99; respectively) compared to T1 (229.29 ± 62.91). Cyclists’ sports performance improved during the experiment, and one of them won bronze medal at the World Championships. Conclusions. During the biseasonal experiment using elements of the polarized training programme, improvements in VO2max, Ppeak and PVT2 were observed in cyclists, which was accompanied by better sports performance in cycling races.

The effects of telerehabilitation in adults with complex biventricular congenital heart conditions: protocol for a multi-centre, randomised controlled trial—CH-FIT

BackgroundAccumulated evidence suggests that exercise training exerts beneficial effects on people with congenital heart conditions. These findings are predominantly derived from small, single-centre exercise trials conducted in outpatient rehabilitation facilities. In recent years, the delivery of exercise interventions remotely has increased through digital communications technology (telerehabilitation). However, very little research to date has been conducted into the efficacy of telerehabilitation in people with a congenital heart condition.AimsTo evaluate the effects of a telehealth-delivered exercise intervention in people with a history of a surgical biventricular repair due to a congenital heart condition.MethodsOne hundred eligible adolescent (≥ 16 years) and adult participants living with a complex biventricular congenital heart condition will be recruited from four Australian sites and randomised to either (1) a 16-week telehealth-delivered combined (aerobic and resistance) exercise training programme of moderate-to-vigorous intensity or (2) usual care (control group), in a 1:1 allocation, with an 8-month follow-up.Outcomes of interestThe primary outcome will be the change in aerobic capacity expressed as peak oxygen uptake (VO2peak). Secondary outcomes will include changes in vascular function, muscle oxygenation, metabolic profile, body composition and musculoskeletal fitness, neurohormonal activation, neurocognitive function, physical activity levels, dietary and nutritional status, and quality of life. Outcomes will be assessed at baseline, 16 weeks, and 12 months (to determine longer-term maintenance potential).DiscussionIf found to be efficacious, telerehabilitation may be an alternative option for delivering exercise, improving health outcomes, and increasing accessibility to exercise programmes. Efficacy data is required to quantify the clinical significance of this delivery mode of exercise.Trial registrationACTRN12622000050752Trial registration date: 17 January 2022Trial registration URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382635&showOriginal=true&isReview=trueTrial registry name: Australian and New Zealand Clinical Trials Registry

Analysis of Accumulated Workloads and Performance Testing Across a Collegiate Women's Lacrosse Season.

Fields, JB, Kuhlman, NM, Jagim, AR, Dulak-Sigler, C, and Jones, MT. Analysis of accumulated workloads and performance testing across a collegiate women's lacrosse season. J Strength Cond Res 37(11): 2213-2221, 2023-Monitoring accumulated workloads, acute:chronic workload ratios (ACWR), and training monotony (TM) are practical methods for monitoring athlete physical stress. Performance testing provides useful information about the changing nature of physical abilities. Therefore, the purpose was to examine differences in accumulated workloads based on session type, explore seasonal trends in ACWR and TM, and assess changes in performance assessments in collegiate women's lacrosse athletes. Athletes, who were identified as starters ( n = 12), wore positional monitoring technology during training sessions ( n = 61) and games ( n = 17) and completed preseason and postseason assessments of speed, agility, power (jump tests), strength, aerobic capacity, and body composition. Separate 1-way analyses of variance were used to determine differences in accumulated workloads for session type and differences in performance assessments from preseason to postseason ( p < 0.05). When compared with games, practice sessions elicited greater ( p < 0.001) accumulated total distance, player load, repeated high-intensity efforts, accelerations, change of direction, explosive efforts, high-speed efforts ( p = 0.002), and high-speed distance ( p = 0.002). Throughout the season, ACWR and TM ranged from 0.16 to 1.40 AU and 0.68-1.69 AU, respectively. The 40-yd sprint ( p < 0.001) and pro-agility ( p < 0.001) improved from preseason to postseason, whereas no changes in aerobic capacity, lower-body power, or strength were observed ( p > 0.05). The monitoring of accumulated loads, ACWR and TM, and performance tests revealed novel information about the seasonal demands of collegiate women's lacrosse. Women lacrosse players are able to improve speed and agility throughout the season, while maintaining strength, power, and endurance, with minimal reductions in fat-free mass.

A toolbox for a structured risk-based prehabilitation program in major surgical oncology.

Prehabilitation is a multimodal concept to improve functional capability prior to surgery, so that the patients' resilience is strengthened to withstand any peri- and postoperative comorbidity. It covers physical activities, nutrition, and psychosocial wellbeing. The literature is heterogeneous in outcomes and definitions. In this scoping review, class 1 and 2 evidence was included to identify seven main aspects of prehabilitation for the treatment pathway: (i) risk assessment, (ii) FITT (frequency, interventions, time, type of exercise) principles of prehabilitation exercise, (iii) outcome measures, (iv) nutrition, (v) patient blood management, (vi) mental wellbeing, and (vii) economic potential. Recommendations include the risk of tumor progression due to delay of surgery. Patients undergoing prehabilitation should perceive risk assessment by structured, quantifiable, and validated tools like Risk Analysis Index, Charlson Comorbidity Index (CCI), American Society of Anesthesiology Score, or Eastern Co-operative Oncology Group scoring. Assessments should be repeated to quantify its effects. The most common types of exercise include breathing exercises and moderate- to high-intensity interval protocols. The program should have a duration of 3-6 weeks with 3-4 exercises per week that take 30-60 min. The 6-Minute Walking Testing is a valid and resource-saving tool to assess changes in aerobic capacity. Long-term assessment should include standardized outcome measurements (overall survival, 90-day survival, Dindo-Clavien/CCI®) to monitor the potential of up to 50% less morbidity. Finally, individual cost-revenue assessment can help assess health economics, confirming the hypothetic saving of $8 for treatment for $1 spent for prehabilitation. These recommendations should serve as a toolbox to generate hypotheses, discussion, and systematic approaches to develop clinical prehabilitation standards.

1065-P: Utilizing a Novel Telemedicine Clinic for Managing Patients with Type 2 Diabetes

Objective: To examine whether a new Diabetes Telemedicine (DT) clinic can lead to improved glycemic control compared to standard of care (SoC). Design: Pilot RCT of patients with type 2 diabetes (T2D) randomized to DT clinic or SoC. DT intervention comprised of continuous glucose monitoring, “connected” insulin pens/caps, telecommunication systems (i.e. video conferencing, online messaging and telephone) and promoting physical activity (PA) by providing brief counseling and exercise physiologist consultation. SoC was managed using point of care glucometer, traditional insulin pens, in-person visits and provider counseling on PA. Primary outcome was change in HbA1c. Secondary outcomes were time in range (TIR) 70-180 mg/dl, time above range (TAR)&amp;gt;180 mg/dl and time below range (TBR)&amp;lt; 70 mg/dl. Patients also completed senior fitness test, assessed by Hedge’s g effect size. Results: A total of 18 patients (17 male) have been recruited, 11 patients were black and 7 white, all non-Hispanic. 14 completed 90 days in the trial. Non statistically significant differences were seen. DT had an 1.6% (mean SE 0.60) HbA1c reduction vs 0.4 (0.69) in SoC [difference -1.2% (0.92), p=0.19]. TIR 70-180 mg/dl increased 8.5% (13.6) (DT) vs 4.4% (15.8) (SoC) [difference +4.1% (20.8), p=0.84]. DT had a decrease in TAR&amp;gt;180 mg/dl of 8.7% (13.7) compared to 4.4% (15.8) in SoC [difference -4.3% (21.0), p=0.85] and TBR&amp;lt;70 mg/dl 0.16% (0.60) (DT) vs 0.13% (0.69) (SoC) [difference of 0.03% (0.92), p=0.97]. DT had improved aerobic capacity (6-minute walk test 402±62 to 418±69m, g=0.53) and strength in the lower- (30-second chair stand 9.0±2.6 to 11.5±2.6 stands, g=0.91) and upper-body (30-second weighted arm curl 17.4±5.3 to 21.0±6.3 curls, g=0.72). SoC had no meaningful changes in aerobic capacity or lower/upper-body strength (g=-0.05 to 0.18). Conclusion: Patients with T2D managed with DT had a non-statistically significant improvement of glucose control and improved physical fitness performance compared to patients in SoC. Disclosure F.Sotomayor: None. I.Spanakis: Research Support; Dexcom, Inc. C.Gothong: None. R.Hernandez: None. G.I.Ash: None. W.H.Scott: None. L.Pinault: None. F.Gomez-peralta: Advisory Panel; Abbott Diabetes, Insulcloud S.L., Speaker's Bureau; A. Menarini Diagnostics, Boehringer Ingelheim and Eli Lilly Alliance, Lilly Diabetes, Novartis, Novo Nordisk. L.G.Singh: None. J.D.Sorkin: None.

Combined effects of bee pollen supplementation and resistance training on aerobic capacity, muscular performance, antioxidant status, and bone metabolism markers in young men: A randomised controlled trial

Introduction: This study investigated the combined effects of bee pollen and resistance training on aerobic capacity, muscular performance, antioxidant status, and bone metabolism markers among young men. Methods: Forty young men were randomly assigned into four groups: sedentary control (C), bee pollen supplementation (BP), resistance training (RT), and combined bee pollen supplementation and resistance training (BPRT) groups. Bee pollen was consumed by participants in BP and BPRT groups (1500 mg daily for eight weeks). Resistance training was performed thrice per week for eight weeks in RT and BPRT groups. Participants’ anthropometry, aerobic capacity, isokinetic muscular peak torque (strength), and average power were measured. Concentrations of serum total antioxidant status (TAS), serum superoxide dismutase (SOD), serum alkaline phosphatase (ALP), and serum C-terminal telopeptide of type 1 collagen (1CTP) were determined. Results: After eight weeks of intervention, there was a significant decrease in 1CTP in BP group. In RT group, significant increases were observed in both muscular strength and power. In BPRT group, significant increases in both muscular strength and power, and a significant decrease in 1CTP were observed after 8 weeks. There were no significant changes in aerobic capacity, serum TAS, SOD, and ALP in all the study groups. Conclusion: Resistance training using dumbbells and elastic bands seemed to elicit beneficial effects on muscular strength and power, while bee pollen supplementation alone reduced the level of bone resorption marker. In addition, combining bee pollen with resistance training seemed to offer additive benefit in muscular strength and power.

Construct Validity of the Steep Ramp Test for Assessing Cardiorespiratory Fitness in Patients With Breast Cancer and the Effect of Chemotherapy-Related Symptom Burden

ObjectiveTo investigate the construct validity of the Steep Ramp Test (SRT) by longitudinally comparing the correlation between maximum short exercise capacity of the SRT and direct measurements of peak oxygen consumption (Vo2peak) during or shortly after treatment in patients with breast cancer and the potential effect of chemotherapy-induced symptom burden. DesignCross-sectional. SettingMulticenter. ParticipantsWe used data from 2 studies that included women with breast cancer treated with chemotherapy, resulting in 274 observations. A total of 161 patients (N=161) performed the cardiopulmonary exercise test and the SRT in 2 test sessions on different time points around chemotherapy treatment. InterventionsNot applicable. Main Outcome MeasuresFatigue was assessed with the Multidimensional Fatigue Inventory, and nausea and vomiting and pain by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30. The longitudinal correlation between the maximum short exercise capacity and Vo2peak was investigated using a linear mixed model. Interaction terms were added to the model to investigate whether the correlation varied by symptom burden. ResultsWe found a statistically significant moderate correlation between Vo2peak and maximum short exercise capacity (0.61; 95% confidence interval, 0.51-0.70; P<.01) over time. This correlation was slightly attenuated (−0.07; 95% confidence interval, −0.13 to 0.00; P=.04) in patients with chemotherapy-related nausea and vomiting, indicating smaller correlations of Vo2peak with the maximum short exercise capacity with increasing symptom burden. Pain and fatigue did not significantly modify the correlation. ConclusionsThe SRT can only be used as a proxy for changes in aerobic capacity with great caution and with attention for the level of nausea and vomiting.

EFFECT OF DIFFERENT INTERVAL SPEED TRAINING ON ATHLETE REACTION

ABSTRACT Introduction: High-intensity Intermittent Training (HIIT) ranked first in the ACSM “2013 Global Training Methodology Survey”. Objective: To explore the influence of different speed training intervals on athlete reaction speed. Methods: Sixteen male bicycle athletes were randomly divided into two groups. The two groups then completed a six-week training routine (NT). The two groups then completed a six-week training routine , started 6 weeks of Sprint Interval Training (SIT) (a total of 12 lessons), with SIT instead of Normal Training (NT) live endurance training, and another training remains unchanged. Results: After 6 weeks of NT, Pmax GXT in the CG and DG groups decreased by 0.7% and 1.7%, respectively,as compared to the pre-training numbers. The difference was not statistically significant (P&gt;0.05). And after 6 weeks of SIT, Pmax GXT increased significantly (P&lt;0.05) in both experimental groupss,with increases of 9.2% and 10.2% for the CG and DG groups, respectively. Conclusions: The results show that intermittent training can effectively improve the aerobic metabolism of short-haul cyclists. As the power bicycle load and the training intensity and volume of the deceleration intermittent training program increase, the more significant the changes in aerobic capacity that can result in adaptability. Level of evidence II; Therapeutic studies - investigation of treatment results.

Flow-induced endothelial mitochondrial remodeling mitigates mitochondrial reactive oxygen species production and promotes mitochondrial DNA integrity in a p53-dependent manner

Tumor suppressor p53 plays a pivotal role in orchestrating mitochondrial remodeling by regulating their content, fusion/fission processes, and intracellular signaling molecules that are associated with mitophagy and apoptosis pathways. In order to determine a molecular mechanism underlying flow-mediated mitochondrial remodeling in endothelial cells, we examined, herein, the role of p53 on mitochondrial adaptations to physiological flow and its relevance to vascular function using endothelial cell-specific p53 deficient mice. We observed no changes in aerobic capacity, basal blood pressure, or endothelial mitochondrial phenotypes in the endothelial p53 mull animals. However, after 7 weeks of voluntary wheel running exercise, blood pressure reduction and endothelial mitochondrial remodeling (biogenesis, elongation, and mtDNA replication) were substantially blunted in endothelial p53 null animals compared to the wild-type, subjected to angiotensin II-induced hypertension. In addition, endothelial mtDNA lesions were significantly reduced following voluntary running exercise in wild-type mice, but not in the endothelial p53 null mice. Moreover, in vitro studies demonstrated that unidirectional laminar flow exposure significantly increased key putative regulators for mitochondrial remodeling and reduced mitochondrial reactive oxygen species generation and mtDNA damage in a p53-dependent manner. Mechanistically, unidirectional laminar flow instigated translocalization of p53 into the mitochondrial matrix where it binds to mitochondrial transcription factor A, TFAM, resulting in improving mtDNA integrity. Taken together, our findings suggest that p53 plays an integral role in mitochondrial remodeling under physiological flow condition and the flow-induced p53-TFAM axis may be a novel molecular intersection for enhancing mitochondrial homeostasis in endothelial cells.

Supervised Cycling Training Improves Erythrocyte Rheology in Individuals With Peripheral Arterial Disease.

Peripheral arterial disease (PAD) results in insufficient flow to lower extremities. Aerobic exercise provides health benefits for individuals with PAD, but basic science behind it is still debated. Twenty-one PAD patients aged about 70 years with female/male as 7/14 were recruited. Among them, 11 were randomized to have supervised cycling training (SCT) and 10 to receive general healthcare (GHC) as controls. SCT participants completed 36 sessions of SCT at the first ventilation threshold within 12 weeks and the controls received GHC for 12 weeks. Ankle-brachial index (ABI), 6-min walk test (6MWT), peak oxygen consumption (O2peak), minute ventilation (E), minute carbon dioxide production (CO2), erythrocyte rheology, including the maximal elongation index (EImax) and shear stress at 50% of maximal elongation (SS1/2), and the Short Form-36 (SF-36) questionnaire for quality of life (QoL) were assessed before and 12 weeks after initial visit. SCT significantly decreased the SS1/2 as well as SS1/2 to EImax ratio (SS1/2/EImax) and increased the erythrocyte osmolality in the hypertonic region as well as the area under EI-osmolality curve. The supervised exercise-induced improvement of erythrocyte deformability could contribute to the increased peripheral tissue O2 delivery and was possibly related with increased O2peak. The physiological benefit was associated with significantly increased ABI, 6-min walking distance, cardiorespiratory fitness, and SF-36 score. However, no significant changes in aerobic capacity and erythrocyte rheological properties were observed after 12-week of GHC. In conclusion, SCT improves aerobic capacity by enhancing erythrocyte membrane deformability and consequently promotes QoL in PAD patients.

Association of Different Genotypes of VEGF Gene with Changes in Aerobic Capacity Following Endurance Training in Obese Women

Objective: Obesity is a chronic disease characterized by an excessive mass of adipose tissue in the body. The present study aimed to investigate the relationship between different genotypes of VEGF gene and changes in aerobic capacity following aerobic exercise in obese women. Materials and Methods: In this study, 23 inactive women aged 34 to 43 years with BMI 30 and 35 were purposefully selected and participated in eight weeks of aerobic exercise including 4 sessions per week and 30 minutes per session with an intensity of 55 to 75% of maximum heart rate. Before and after the training period, aerobic power (VO2max) was measured by the modified Bruce test. Saliva Sample was collected at 12 hours of fasting to measure VEGF genotypes. To compare aerobic capacity between different genotypes, since we had three genotypes GG, CG, and CC, one-way analysis of variance was used. Results: Although the mean amount of aerobic power changes of GG genotype was somewhat higher after eight weeks of aerobic training than the other two genotypes, this difference was not significant. (P-value= 0.663, P-value= 0.873 and P-value= 0.173, respectively). Conclusion: Eight weeks of aerobic training leads to increased aerobic capacity in obese women and increased VEGF plays a role, but there is not seemingly a difference between different VEGF genotypes for these changes. In any case, since this study was conducted for the first time, we need more studies to draw a more accurate conclusion.

Effects of supervised exercise on aerobic capacity and quality of life in patients with chronic liver disease and patients who underwent liver transplantation: a systematic review and meta-analysis.

Chronic liver disease and liver transplantation are risk factors for poor physical health and quality of life. This meta-analysis aimed to examine whether supervised exercise improves the physical health and quality of life in patients with chronic liver disease and liver transplant. Articles were searched in four databases (MEDLINE, Cochrane, Embase, and the Web of Science) from 1 January 1990 to 6 July 2021. Studies that assessed the change in aerobic capacity and quality of life following supervised exercise in patients with chronic liver disease or in those who had undergone liver transplantation were included in this meta-analysis. The two independent reviewers extracted data and the methodological quality of the included studies was assessed by the Cochrane Handbook for Systematic Reviews of Interventions. The extracted data were statistically analyzed using review management software (RevMan 5.3). The meta-analysis included 11 studies, comprising 159 patients. We observed that aerobic capacity measured as VO2 peak and 6-min walking test improved in patients with chronic liver disease and liver transplant after supervised exercise. Among the parameters of Short-form-36 (SF-36) used for measuring the quality of life, only physical functioning improved after supervised exercise. The other parameters of SF-36 including role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health were not significantly improved after supervised exercise. Supervised exercise seems essential for patients with chronic liver disease and liver transplant. It was found to be helpful in enhancing the aerobic capacity and physical function in these patients.

Comparison of Aerobic Capacity Changes as a Result of a Polarized or Block Training Program among Trained Mountain Bike Cyclists.

This study compared the effectiveness of a block training program and a polarized training program in developing aerobic capacity in twenty trained mountain bike cyclists. The cyclists were divided into two groups: the block training program group (BT) and the polarized training program group (PT). The experiment lasted 8 weeks. During the experiment, the BT group alternated between 17-day blocks consisting of dominant low-intensity training (LIT) and 11-day blocks consisting of sprint interval training (SIT), and high-intensity interval training (HIIT), while the PT group performed SIT, HIIT, and LIT simultaneously. Before and after the experiment, the cyclists performed incremental tests during which maximal oxygen uptake (VO2max), maximal aerobic power (Pmax), power achieved at the first ventilatory threshold (PVT1), and at the second ventilatory threshold (PVT2) were measured. VO2max increased in BT group (from 3.75 ± 0.67 to 4.00 ± 0.75 L∙min−1) and PT group (from 3.66 ± 0.73 to 4.20 ± 0.89 L∙min−1). In addition, Pmax, PVT1, and PVT2 increased in both groups to a similar extent. In conclusion, the polarized training program was more effective in developing the VO2max compared to the block program. In terms of developing other parameters characterizing the cyclists’ aerobic capacity, the block and polarized program induced similar results.

Physiological insight into the evolution of complex phenotypes: aerobic performance and the O2 transport pathway of vertebrates.

Evolutionary physiology strives to understand how the function and integration of physiological systems influence the way in which organisms evolve. Studies of the O2 transport pathway - the integrated physiological system that transports O2 from the environment to mitochondria - are well suited to this endeavour. We consider the mechanistic underpinnings across the O2 pathway for the evolution of aerobic capacity, focusing on studies of artificial selection and naturally selected divergence among wild populations of mammals and fish. We show that evolved changes in aerobic capacity do not require concerted changes across the O2 pathway and can arise quickly from changes in one or a subset of pathway steps. Population divergence in aerobic capacity can be associated with the evolution of plasticity in response to environmental variation or activity. In some cases, initial evolutionary divergence of aerobic capacity arose exclusively from increased capacities for O2 diffusion and/or utilization in active O2-consuming tissues (muscle), which may often constitute first steps in adaptation. However, continued selection leading to greater divergence in aerobic capacity is often associated with increased capacities for circulatory and pulmonary O2 transport. Increases in tissue O2 diffusing capacity may augment the adaptive benefit of increasing circulatory O2 transport owing to their interactive influence on tissue O2 extraction. Theoretical modelling of the O2 pathway suggests that O2 pathway steps with a disproportionately large influence over aerobic capacity have been more likely to evolve, but more work is needed to appreciate the extent to which such physiological principles can predict evolutionary outcomes.

Criterion Validity and Responsiveness of the Steep Ramp Test to Evaluate Aerobic Capacity in Survivors of Cancer Participating in a Supervised Exercise Rehabilitation Program

ObjectiveTo evaluate the criterion validity and responsiveness of the steep ramp test (SRT) compared with the cardiopulmonary exercise test (CPET) in evaluating aerobic capacity in survivors of cancer participating in a rehabilitation program. DesignA prospective cohort study in which survivors of cancer performed an SRT and CPET before (T=0) and after (T=1) a 10-week exercise rehabilitation program. Peak work rate achieved during the SRT (SRT-WRpeak) was compared with peak oxygen consumption measured during the CPET (CPET-Vo2peak), which is the criterion standard for aerobic capacity. Correlation coefficients were calculated between SRT-WRpeak and CPET-Vo2peak at T=0 to examine criterion validity and between changes in SRT-WRpeak and CPET-Vo2peak from T=0 to T=1 to determine responsiveness. Receiver operating characteristic analysis was performed to examine the ability of the SRT to detect a true improvement (6%) in CPET-Vo2peak. SettingUniversity medical center. ParticipantsSurvivors of cancer (N=106). InterventionsExercise rehabilitation. Main Outcome MeasuresCorrelation coefficients between CPET-Vo2peak and SRT-WRpeak and between changes in CPET-Vo2peak and SRT-WRpeak. ResultsAn r of 0.86 (N=106) was found for the relation between SRT-WRpeak and CPET-Vo2peak at T=0. An r of 0.51 was observed for the relation between changes in SRT-WRpeak and CPET-Vo2peak (n=59). Receiver operating characteristic analysis showed an area under the curve of 0.74 for the SRT to detect a true improvement in CPET-Vo2peak, with an optimal cutoff value of +0.26 W/kg (sensitivity 70.7%, specificity 66.7%). ConclusionsBecause SRT-WRpeak and CPET-Vo2peak were strongly correlated, the SRT seems a valid tool to estimate aerobic capacity in survivors of cancer. The responsiveness to measure changes in aerobic capacity appears moderate. Nevertheless, the SRT seems able to detect improvement in aerobic capacity, with a cutoff value of 0.26 W/kg.

The Effect of High-Intensity Interval Training Periods on Morning Serum Testosterone and Cortisol Levels and Physical Fitness in Men Aged 35-40 Years.

Background: Intensive physical activity largely modulates resting concentrations of blood cortisol (C) and testosterone (T) and their molar ratio, which is defined as the anabolic–catabolic index and expressed as T/C × 102. The aim of the study is to evaluate the effect of the author’s high-intensity training program on T, C, T/C × 102, and selected physical fitness indices in men between 35 and 40 years of age. Methods: The experiment was conducted on a group of 30 healthy men, divided into control and experimental groups. The experimental group followed a high-intensity 8-week training program, which included three sessions per week, each of them lasting 1 h and consisting of intensive-interval exercises followed by strength circuit exercises. The controls did not change their previous recreational physical activity. T, C, and T/C × 102 were measured before and after the experiment for all participants. Physical performance was examined using a standardized laboratory exercise test to determine maximal oxygen uptake (VO2max). Results: There were statistically significant increases in T (by 36.7%) and T/C × 102 (by 59%), while C somewhat dropped (by 12%) in the experimental group. No changes in the hormonal indices were found in the control group. After completing the experimental training, there were no statistically significant changes in aerobic capacity, but it improved muscle strength in the men studied. Conclusions: High-intensity interval training, continued over an 8-week period, modulates (significantly and positively) the balance between testosterone and cortisol levels and improves physical capacity in men aged 35–40 years.

Seasonal Changes in 25(OH)D Concentration in Young Soccer Players-Implication for Bone Resorption Markers and Physical Performance.

Searching for potential relations between changes in 25(OH)D concentration and in physical fitness is an interesting scientific topic. Thus, the main purpose of this study was to investigate the changes in serum concentrations of 25(OH)D in young football players in conjunction with indicators determining bone resorption and physical fitness. A total of 35 young soccer players were tested during the autumn competition period. Biochemical analysis of blood, aerobic capacity, running speed and power tests (Wingate test, squat jump, counter movement jump) were carried out at the beginning and at the end of the competition period. Significant decrements in concentration of 25(OH)D from 33.9 ± 5.87 to 23.7 ± 5.58 ng/mL were noted after the analyzed competition period. There were no significant changes in aerobic capacity along the competition period. Significant improvements were observed in 10 m sprint, 30 m sprint (p < 0.001), maximal power (p = 0.011) and total work capacity (p = 0.024). We found that the effect of changes in the players’ physical fitness does not occur in relation to 25 OH(D) concentration but occurs when these changes are analyzed as a function of the duration of the observation period. Changes in physical fitness of soccer players are determined by other factors then 25(OH)D concentration.

Potential effectiveness of a surgeon-delivered exercise prescription and an activity tracker on pre-operative exercise adherence and aerobic capacity of lung cancer patients

ObjectivesPre-operative exercise may improve functional outcomes for lung cancer patients, but barriers associated with cost, resources, and burden make it challenging to deliver pre-operative exercise programs. The goal of this proof-of-concept study was to determine level of moderate-vigorous physical activity (MVPA) and change in aerobic capacity after participation in a home-based pre-operative exercise intervention. Materials and methodsEighteen patients scheduled for surgery for suspected stage I-III lung cancer received an exercise prescription from their surgeon and wore a commercially-available device that tracked their daily MVPA throughout the pre-operative period. Descriptive statistics were used to calculate adherence to the exercise prescription. A one-sample t-test was used to explore change in aerobic capacity from baseline to the day of surgery. ResultsParticipants exhibited a mean of 20.4 (sd = 46.2) minutes of MVPA per day during the pre-operative period. On average, the sample met the goal of 30 min of MVPA on 16.4% of the days during the pre-operative period. The mean distance achieved at baseline for the 6-min walk test was 456.7 m (sd = 72.9), which increased to 471.1 m (sd = 88.4) on the day of surgery. This equates to a mean improvement of 13.8 m (sd = 37.0), but this difference was not statistically different from zero (p = 0.14). Eight of the 17 participants (47%) demonstrated a clinically significant improvement of 14 m or more. ConclusionA surgeon-delivered exercise prescription plus an activity tracker may promote clinically significant improvement in aerobic capacity and MVPA engagement among patients with lung cancer during the pre-operative period, but may need to be augmented with more contact with and support from practitioners over time to maximize benefits. Trial registrationThe study protocol was registered with ClinicalTrials.gov prior to initiating participant recruitment (NCT03162718).