VO2max Research Articles

Mitochondrial function in skeletal muscle contributes to reproductive endothermy in tegu lizards (Salvator merianae).

In cyclic climate variations, including seasonal changes, many animals regulate their energy demands to overcome critical transitory moments, restricting their high-demand activities to phases of resource abundance, enabling rapid growth and reproduction. Tegu lizards (Salvator merianae) are ectotherms with a robust annual cycle, being active during summer, hibernating during winter, and presenting a remarkable endothermy during reproduction in spring. Here, we evaluated whether changes in mitochondrial respiratory physiology in skeletal muscle could serve as a mechanism for the increased thermogenesis observed during the tegu's reproductive endothermy. We performed high-resolution respirometry and calorimetry in permeabilized red and white muscle fibers, sampled during summer (activity) and spring (high activity and reproduction), in association with citrate synthase measurements. During spring, the muscle fibers exhibited increased oxidative phosphorylation. They also enhanced uncoupled respiration and heat production via adenine nucleotide translocase (ANT), but not via uncoupling proteins (UCP). Citrate synthase activity was higher during the spring, suggesting greater mitochondrial density compared to the summer. These findings were consistent across both sexes and muscle types (red and white). The current results highlight potential cellular thermogenic mechanisms in an ectothermic reptile that contribute to transient endothermy. Our study indicates that the unique feature of transitioning to endothermy through nonshivering thermogenesis during the reproductive phase may be facilitated by higher mitochondrial density, function, and uncoupling within the skeletal muscle. This knowledge contributes significant elements to the broader picture of models for the evolution of endothermy, particularly in relation to the enhancement of aerobic capacity.

Italian Canyoning Guides: Physiological Profile and Cardiometabolic Demand during Rope Activities

Canyoning activities require physical effort, highlighting the importance of maintaining a proper physical fitness. Canyoning guides emerge as key figures, not only to ensure safety during the experience but also to handle unforeseen situations promptly. This study aims to assess the physiological profile of canyoning guides and the cardiorespiratory demands experienced during rope activities by means of oxygen uptake and heart rate measurements. Seventeen canyoning guides (42.6 y ± 10.78; BMI of 24.0 kg/m2 ± 2.95) carried out coordinative and conditional tests. The participants showed good values in strength tests (27.3 cm ± 5.97 and 23.3 rep ± 8.06 in SJ and PUp tests, respectively), while the flexibility of males and females was below and well above the average, respectively. A noteworthy result was observed in the reaction test, in which a better performance was recorded with the non-dominant hand (168.1 ms vs. 202.0 ms). All subjects exhibited a low aerobic capacity by means of an RD test (10.6 ua ± 6.62). During rope activities and emergency/support simulations, metabolic and cardiovascular data indicated that a moderate/high effort was exerted, confirmed by an oxidative stress analysis. In conclusion, this study demonstrated how canyoning guides face significant physical requirements, but their physiological profile regarding aerobic power was not appropriate. Therefore, these findings could offer valuable insights into the development of specific training to ensure an appropriate aerobic fitness to perform canyoning safely.

The Response of the Amputee Athlete Heart to Chronic Core Exercise: A Study on Hematological and Biochemical Parameters, and N-Terminal Pro Brain Natriuretic Peptide

Background and Objectives: mortality and morbidity due to cardiovascular causes are frequently experienced in amputees. Research on the effects of chronic exercise on biomarkers and cardiac damage indicators in these individuals is limited. The aim of this study was to investigate the effects of a core training program on brain natriuretic-related peptide, as well as hematological and biochemical parameters in amputee soccer players. Materials and Methods: The participants were randomly allocated to the following two groups: a core exercise group (CEG) and a control group (CG). While the CG continued routine soccer training, the CEG group was included in a core exercise program different from this group. During the study, routine hemogram parameters of the participants, various biochemical markers, and the concentration of brain natriuretic-related peptide (NT-pro-BNP) were analyzed. Results: after the training period, notable improvements in various hematological parameters were observed in both groups. In the CEG, there were significant enhancements in red blood cell count (RBC), hematocrit (HCT), mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH) values. Similarly, the CG also showed substantial improvements in RBC, HCT, mean corpuscular volume (MCV), MCHC, MCH, red cell distribution width-standard deviation (RDW-SD), platelet-to-lymphocyte ratio (PLCR), mean platelet volume (MPV), and platelet distribution width (PDW). Moreover, in the CEG, serum triglycerides (TG) and maximal oxygen uptake (MaxVO2) exhibited significant increases. Conversely, TG levels decreased in the CG, while high-density lipoprotein (HDL), low-density lipoprotein (LDL), and MaxVO2 levels demonstrated substantial elevations. Notably, the N-terminal pro-brain natriuretic peptide (BNP) levels did not undergo significant changes in either the CEG or the CG following the core exercise program (p > 0.05). However, in the CEG, a meaningful positive correlation was observed between NT-pro-BNP and creatine kinase (CK) levels before and after the core exercise program. Conclusions: the findings emphasized the potential benefits of core training in enhancing specific physiological aspects, such as erythrocyte-related parameters and lipid metabolism, as well as aerobic capacity. Furthermore, the observed correlation between NT-pro-BNP and CK levels in the CEG provides intriguing insights into the unique physiological adaptations of amputee athletes.

Impaired Cardiorespiratory Fitness of Elite Athletes after Asymptomatic or Mild SARS-CoV-2 Infection

Background and Objectives: The aim of the study was to evaluate the health status of professional athletes after recovering from COVID-19 and the impact that SARS-CoV-2 had on their overall cardiorespiratory fitness, which was done by conducting cardiopulmonary exercise testing (CPET). Materials and Methods: A total of twenty-seven professional basketball players (Euroleague Basketball and the ABA League) participated in the study. CPET was performed before (as part of their regular preparticipation exam, during the pre-season period), as well as after SARS-CoV-2 infection (after two weeks of home isolation, during the competitive part of the season). CPET was performed on a treadmill, while cardiovascular, respiratory, and metabolic functions were evaluated by using a breath-by-breath analysis technique (Quark CPET system manufactured by Cosmed, Rome, Italy). Results: Maximal oxygen consumption and aerobic efficiency were significantly reduced after SARS-CoV-2 infection (p = 0.000). An obvious decrease in oxygen pulse was observed during CPET after recovering from COVID-19 (p = 0.001), as was deterioration of ventilatory efficiency. Internal respiration was the most negatively affected. An early transition from aerobic to anaerobic mechanisms of creating energy for work and intensive metabolic fatigue were obvious after SARS-CoV-2 infection. Conclusions: Although it was believed that SARS-CoV-2 only affects the cardiopulmonary status of the elderly population and people with associated comorbidities, it is clear from this research that professional athletes can also be at certain risk. Even though no pathological cardiovascular and respiratory changes were found in athletes after COVID-19, results showed significantly decreased cardiorespiratory fitness, with an emphasis on internal respiration.

Progressive overload in cardiorespiratory exercise training for young and old: Is increasing duration or intensity of exercise more important?

People undertake endurance training to improve their health and cardio-respiratory fitness. Subsequent cardio-respiratory and skeletal muscle aerobic metabolic adaptations are gauged by improvements in maximum or peak oxygen uptake (V̇O2peak) and the blood lactate inflection point or threshold during incremental exercise – (LIP). To further improve physiological capability, subsequent homoeostatic disturbances from exercise should be progressively greater in succeeding exercise sessions. Therefore, exercise duration, frequency or intensity should be progressively increased during a training regimen to ensure adaptation potential is realized. A progressive increase in training workload is termed “progressive overload”. Despite the universal acknowledgment of the importance of progressive overload, it is unclear if systematically progressing altering either exercise intensity or duration (or distance covered) affect cardio-respiratory gains differently in young and older populations. As running faster results in higher heart rates and greater skeletal muscle metabolic stress than running the same distance at a lower speed, in this hypothesis we postulate that progressively increasing exercise run intensity will result in greater mean and higher incidence of V̇O2peak and LIP gains in young adults (<50 years). However, the mechanisms that initiate improvements in cardio-respiratory fitness and skeletal muscle aerobic function may be different in older adults due to the inevitable aging decline in cardio-vascular function and mechanical and morphological properties of muscle–tendon units. In older adults (>60 years) we hypothesize progressively increasing run distance while maintaining the same speed will just be as effective as to progressively increasing speed to improve V̇O2peak and LIP. To test these hypotheses, we propose a study that compares progressively increasing run intensity to a treatment of progressive matched run distance where speed remains constant in young and old adults.

Exercise in newly diagnosed patients with multiple myeloma: A randomized controlled trial of effects on physical function, physical activity, lean body mass, bone mineral density, pain, and quality of life.

Reduced physical function caused by bone destruction, pain, anemia, infections, and weight loss is common in multiple myeloma (MM). Myeloma bone disease challenges physical exercise. Knowledge on the effects and safety of physical exercise in newly diagnosed patients with MM is limited. In a randomized, controlled trial, we studied the effect of a 10-week individualized physical exercise program on physical function, physical activity, lean body mass (LBM), bone mineral density (BMD), quality of life (QoL), and pain in patients newly diagnosed with MM. Lytic bone disease was assessed, and exercise was adjusted accordingly. Primary outcome: knee extension strength. Secondary outcomes: Six-Minute-Walk-Test, 30-s Sit-to-Stand-Test (SST), grip strength, level of physical activity, LBM, BMD, QoL, and pain. Measurements were conducted pre- and post-intervention, and after 6 and 12 months. We included 100 patients, 86 were evaluable; 44 in the intervention group (IG) and 42 in the control group (CG). No statistically significant differences between groups were observed. Knee extension strength declined in the IG (p = .02). SST, aerobic capacity, and global QoL improved in both groups. Pain decreased consistently in the IG regardless of pain outcome. No significant safety concerns of physical exercise in newly diagnosed patients with MM were observed.

Efficacy of Mulligan joint mobilizations and trunk stabilization exercises versus isometric knee strengthening in the management of knee osteoarthritis: a randomized controlled trial

BackgroundKnee osteoarthritis (KOA) progression is often influenced by biomechanical factors. Biomechanical interventions, such as Trunk stabilization exercise (TSE) and Mulligan joint mobilization (MWM), may offer relief from KOA symptoms and potentially slow disease progression. However, the comparative efficacy of these therapies remains uncertain. This study aimed to compare the efficacy of TSE, Mulligan joint mobilization, and isometric knee strengthening (KSE) on disability, pain severity, and aerobic exercise capacity in patients with KOA.MethodologyA randomized controlled trial (RCT) with three intervention groups was conducted between September 2020 to February 2021. The study enrolled adults aged between 40 and 60 years with a confirmed KOA diagnosis recruited from the physical therapy clinic of the Sindh Institute of Physical Medicine and Rehabilitation, Pakistan. Participants were randomly assigned to receive 24 sessions of either TSE, MWM, or KSE. The knee’s functionality was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS), pain on a visual analogue scale (VAS), and two objective functional tests—the 6-minute walk test (6MWT) and the 11-stair climb test (SCT). These assessments were conducted at baseline, the third week, and the sixth week. Changes in outcome measures were analyzed using a mixed-design ANOVA with Bonferroni post-hoc analysis, with statistical significance set at a p-value < 0.05.ResultOf the 60 participants, 22 (36.7%) were females, and 38 (63.3%) were males. Within-group analysis revealed a significant improvement in all outcome measures at the third week (p < 0.05) and sixth week (p < 0.05). Notably, the TSE group exhibited a greater reduction in mean difference (M.D) in VAS scores than the MWM and KSE groups across various measures in the third week. At rest, during stair ascent, and descent, the TSE group showed significant improvements in VAS scores: MWM (-2.05; -1.94; -1.94), TSE (-2.38; -2.5; -2.5), KSE (-1.05; -0.63; -0.63). Additionally, during sub-maximal exercise capacity assessment, the TSE group showed greater improvement (MWM 12.89; TSE 22.68; KSE 7.89), as well as in Knee Injury and Osteoarthritis Outcome Score for activities of daily living (KOOS-ADL) (MWM 20.84; TSE 28.84; KSE 12.68), and KOOS-pain (MWM 24.84; TSE 27.77; KSE 5.77) at the third-week assessment (p < 0.05). The TSE group demonstrated significant improvements (p < 0.05) across various measures in the sixth week. Specifically, improvements were observed in VAS scores at rest (MWM − 4.15; TSE − 4.42; KSE − 3.78), during stair ascent (MWM − 3.89; TSE − 4.88; KSE − 3.56) and descent (MWM − 3.78; TSE − 4.05; KSE − 2.94). Furthermore, significant improvements were noted in the stair climb test (MWM − 7.05; TSE − 7.16; KSE − 4.21), 6-minute walk test (6MWT) (MWM 22.42; TSE 37.6; KSE 13.84), KOOS-pain (MWM 41.47; TSE 49.11; KSE 28.73), and KOOS-ADL (MWM 40.31; TSE 50.57; KSE 26.05).ConclusionIn this study in patients with KOA, TSE had greater efficacy compared to MWM and KSE in enhancing functional levels, reducing pain, improving sub-maximal exercise capacity, and performance on the stair climb test. Importantly, mean scores between the groups, particularly in the TSE group, reached the minimally important level, particularly in key areas such as pain, functional levels, sub-maximal exercise capacity, and stair climb performance. Clinicians should consider the significant pain reduction, improved functionality, and enhanced exercise capacity demonstrated by TSE, indicating its potential as a valuable therapeutic choice for individuals with KOA.Trial noClinicalTrials.gov = NCT04099017 23/9/2019.

Effect of Heat Acclimatization, Heat Acclimation, and Intermittent Heat Training on Maximal Oxygen Uptake.

Maximal oxygen uptake (VO2max) is an important determinant of endurance performance. Heat acclimation/acclimatization (HA/HAz) elicits improvements in endurance performance. Upon heat exposure reduction, intermittent heat training (IHT) may alleviate HA/HAz adaptation decay; however, corresponding VO2max responses are unknown. VO2max is maintained after HAz/HA; IHT mitigates decrements in aerobic power after HAz/HA. Interventional study. Level 3. A total of 27 male endurance runners (mean ± SD; age, 36 ± 12 years; body mass, 73.03 ± 8.97 kg; height, 178.81 ± 6.39 cm) completed VO2max testing at 5 timepoints; baseline, post-HAz, post-HA, and weeks 4 and 8 of IHT (IHT4, IHT8). After baseline testing, participants completed HAz, preceded by 5 days of HA involving exercise to induce hyperthermia for 60 minutes in the heat (ambient temperature, 39.13 ± 1.37°C; relative humidity, 51.08 ± 8.42%). Participants were assigned randomly to 1 of 3 IHT groups: once-weekly, twice-weekly, or no IHT. Differences in VO2max, velocity at VO2max (vVO2), and maximal heart rate (HRmax) at all 5 timepoints were analyzed using repeated-measure analyses of variance with Bonferroni corrections post hoc. No significant VO2max or vVO2 differences were observed between baseline, post-HAz, or post-HA (P = 0.36 and P = 0.09, respectively). No significant group or time effects were identified for VO2max or vVO2 at post-HA, IHT4, and IHT8 (P = 0.67 and P = 0.21, respectively). Significant HRmax differences were observed between baseline and post-HA tests (P < 0.01). No significant group or time HRmax differences shown for post-HA, IHT4, and IHT8 (P = 0.59). VO2max was not reduced among endurance runners after HA/HAz and IHT potentially due to participants' similar aerobic training status and high aerobic fitness levels. HAz/HA and IHT maintain aerobic power in endurance runners, with HAz/HA procuring reductions in HRmax.

Residual polycyclic aromatic hydrocarbons and firefighters' hematological profile

IntroductionFirefighters are exposed to polycyclic aromatic hydrocarbons (PAHs) during fire suppression, but the extent of PAH penetration through turnout gear and its impact on blood cell components remains uncertain. The main objective of this study is to investigate the residual levels of PAHs on turnout gear and skin, and to assess their potential effects on blood cell components in firefighters. We hypothesize that firefighting activities lead to increased PAH exposure, which in turn may induce alterations in blood cell composition. We also hypothesize that differences in PAH exposure and corresponding blood cell changes will be observed between volunteer and career firefighters.MethodsForty-seven firefighters were recruited from 11 fire departments in Oklahoma. PAH levels on gear and skin were measured, and complete blood count (CBC) parameters were analyzed. Parametric and non-parametric tests were used to examine differences in PAH exposures and hematological profiles between volunteer and career firefighters and possible changes over time. Generalized estimating equation (GEE) models were performed to assess the relationships between PAHs and blood cells.ResultsOur analysis revealed significant hematological differences between volunteer and career firefighters, with volunteers exhibiting lower aerobic capacity and higher systemic inflammation. Increased levels of specific PAHs were found on volunteers' gear post-fire.ConclusionOur findings indicate an association between PAH exposure and changes in blood parameters, emphasizing the need for improved decontamination protocols and protective measures, particularly for volunteer firefighters.

Need to revise classification of physical activity intensity in older adults? The use of estimated METs, measured METs and V̇O2Reserve.

Multiples of resting metabolic rate (RMR) are often used to classify physical activity intensity, a concept known as the Metabolic Equivalent of Task (MET). However, the METs metrics may misclassify physical activity intensity in older adults because of age related changes in RMR and maximal aerobic capacity (V̇O2max). This study aimed to 1) compare classifications of activity intensity by estimated (METsestimated) and measured (METsmeasured) METs and 2) compare physical activity classified by absolute (METsmeasured) versus relative intensity (%V̇O2Reserve) in older adults. Ninety-eight adults aged 75-90 years participated in the study. RMR and V̇O2 during sitting, standing, daily activities and 6-minute-walking-test were measured. V̇O2Reserve was defined as the difference between V̇O2max and RMR. Moderate and vigorous intensity was classified as 3 and 6 METs and 40% and 60% of V̇O2Reserve, respectively. Paired t-tests and a confusion matrix were used to investigate aim 1 and 2, respectively. METsmeasured was 24% lower than the standard 1 MET of 3.5ml O2·min-1·kg-1. METsestimated underestimated the intensity during daily and walking activities when compared to METsmeasured. Nevertheless, when comparing METsmeasured to percentages of V̇O2Reserve, a mismatch was shown for moderate intensity in 47-67% of the participants during daily activities, and 21% of the participants during self-selected gait speed. Applying METsestimated for older adults leads to potential underestimation of physical activity intensity, suggesting that current classification metrics should be revised for older adults. V̇O2Reserve is a candidate metric for establishing precise physical activity intensity cut-points for older adults.

The influence of vibratory massage after physical exertion on selected psychological processes

Good mental preparation of an athlete plays an important role in achieving optimal sports results. An athlete who enters a competition should not feel fatigue resulting from intense physical exercise. Therefore, new and effective methods are being sought that could help accelerate the process of both physical and mental regeneration. Vibrotherapy is one of them. The aim of the study was to determine the optimal frequency of vibration, its duration and the position in which the subjects were placed during the treatments, in relation to the reduction of subjectively perceived exertion muscle pain, mental discomfort, emotional states and the level of cognitive processes that were disturbed by intense physical activity. Sixteen healthy male volunteers were involved in this study. The participants were assessed for their aerobic and anaerobic capacity. Each of the subjects performed a set of intensive physical exercises and then underwent vibrotherapy treatment. In random order, each of the men tested the effectiveness of eight combinations of frequency, duration, and body position. Psychological tests were conducted for each combination: frequency, duration of treatment, and position during treatment, in four stages: (1) before the start of the experiment (baseline POMS measurements), (2) immediately after the exercise (VAS scale, scale examining psychological discomfort and STROOP test), (3) immediately after the vibration treatment (POMS measurements, VAS scale, scale examining psychological discomfort and STROOP test), (4) 24 h after the vibration treatment (VAS scale examining subjective assessment of perceived pain and psychological discomfort). Based on the results, it was concluded that all the studied variables improved significantly over time (after the vibration treatment and 24 h after training). In addition, a statistically significant interaction measurement × frequency was noted for vigor scale (52HZ favored greater improvement in this state), and a statistically significant interaction was found for measurement × time for the VAS scale (p &amp;lt; 0.05) – the lower pain value was indicated 24 h after the 10-min vibration treatment. The type of frequency used, position, and duration of the treatment did not play a statistically significant role in changing STROOP test results and severity of psychological discomfort (p &amp;gt; 0.05).

Effect of body mass index on exercise capacity following pediatric heart transplantation.

Obesity and impaired exercise tolerance following heart transplantation increase the risk of post-transplant morbidity and mortality. The aim of this study was to evaluate the effect of body mass index on markers of exercise capacity in pediatric heart transplant recipients and compare this effect with a healthy pediatric cohort. A retrospective analysis of cardiopulmonary exercise test data between 2004 and 2022 was performed. All patients exercised on a treadmill using the Bruce protocol. Inclusion criteria included patients aged 6-21 years, history of heart transplantation (transplant cohort) or no cardiac diagnosis (control cohort) at the time of testing, and a maximal effort test. Patients were further stratified within these two cohorts as underweight, normal, overweight, and obese based on body mass index groups. Two-way analyses of variance were performed with diagnosis and body mass index category as the independent variables. A total of 250 exercise tests following heart transplant and 1963 exercise tests of healthy patients were included. Heart transplant patients across all body mass index groups had higher resting heart rate and lower maximal heart rate, heart rate recovery at 1 min, exercise duration, and peak aerobic capacity (VO2peak). Heart transplant patients in the normal and overweight body mass index categories had higher VO2peak and exercise duration when compared to underweight and obese patients. Underweight status and obesity are strongly associated with lower VO2peak and exercise duration in heart transplant patients. Normal and overweight heart transplant patients had the best markers of exercise capacity.

Re-evaluating the Need for Routine Maximal Aerobic Capacity Testing within Fighter Pilots.

INTRODUCTION: There is a current belief in aviation suggesting that aerobic training may reduce G-tolerance due to potential negative impacts on arterial pressure response. Studies indicate that increasing maximal aerobic capacity (<mml:math id="ie1" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂ max) through aerobic training does not hinder G-tolerance. Moreover, sustained centrifuge training programs revealed no instances where excessive aerobic exercise compromised a trainee's ability to complete target profiles. The purpose of this review article is to examine the current research in the hope of establishing the need for routine <mml:math id="ie2" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max testing in air force pilot protocols.METHODS: A systematic search of electronic databases including Google Scholar, PubMed, the Aerospace Medical Association, and Military Medicine was conducted. Keywords related to "human performance," "Air Force fighter pilots," "aerobic function," and "maximal aerobic capacity" were used in various combinations. Articles addressing exercise physiology, G-tolerance, physical training, and fighter pilot maneuvers related to human performance were considered. No primary data collection involving human subjects was conducted; therefore, ethical approval was not required.RESULTS: The <mml:math id="ie3" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max test provides essential information regarding a pilot's ability to handle increased Gz-load. It assists in predicting G-induced loss of consciousness by assessing anti-G straining maneuver performance and heart rate variables during increased G-load.DISCUSSION: <mml:math id="ie4" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max testing guides tailored exercise plans, optimizes cardiovascular health, and disproves the notion that aerobic training hampers G-tolerance. Its inclusion in air force protocols could boost readiness, reduce health risks, and refine training for fighter pilots' safety and performance. This evidence-backed approach supports integrating <mml:math id="ie5" display="inline"><mml:mrow><mml:mover><mml:mtext>V</mml:mtext><mml:mo>˙</mml:mo></mml:mover></mml:mrow></mml:math>o₂-max testing for insights into fitness, risks, and tailored exercise.Zeigler Z, Acevedo AM. Re-evaluating the need for routine maximal aerobic capacity testing within fighter pilots. Aerosp Med Hum Perform. 2024; 95(5):273-277.

Effect of off-season iron supplementation on aerobic capacity of female handball player: a randomized, double-blinded, placebo-controlled study

BackgroundIron supplementation, especially in female athletes, is one of the influential factors in aerobic capacity, and its deficiency can lead to significant problems related to reduced aerobic capacity. This study aimed to investigate the effect of three weeks of iron supplementation on the aerobic capacity of female handball players. MethodsIn this randomized, double-blinded, and placebo control trial, fourteen elite handball players (age: 21.6 ± 5.68 years; height: 169.5 ± 4.9 cm; weight: 62.2 ± 9.25 kg; BMI: 21.5 ± 2.9 kg/m2) randomly divided into two supplement groups (receiving a 100 mg/day of poly-maltose tri hydroxide iron complex in the form of tablets) and the placebo group (receiving a tablet containing 100 mg/day starch which is the same color and shape as iron tablets). The supplementation protocol was performed for three weeks during the off-season. Maximal oxygen consumption (VO2max), amounts of carbon dioxide at the first ventilatory threshold (VT1 CO2), amounts of carbon dioxide at the second ventilatory threshold (VT2 CO2), Time to exhaustion (TTE), pulmonary ventilation (VE), ventilatory equivalents for oxygen (EQO2), amounts of oxygen at the first ventilatory threshold (VT1 O2), amounts of oxygen at the second ventilatory threshold (VT2 O2), Time to reach first ventilatory threshold (Time VT1), end-tidal partial pressure of oxygen at the first ventilatory threshold (PETO2 VT1), end-tidal partial pressure of carbon dioxide at the first ventilatory threshold (PETCO2 VT1) and ventilatory equivalents for carbon dioxide (EQCO2) were measured using the Bruce test and gas analyzer in two pre-test and post-test stages. ResultThere were significant improvements in VT1 O2, Time VT1, and PETCO2 VT1 and a significant decrease in PETO2 VT1 (P<0.05). Also, no significant changes were found in VO2max, VT1 CO2, VT2 CO2, VT2 O2, TTE, VE, EQO2, and EQCO2 after three weeks of iron supplementation (P>0.05). ConclusionThe study found that three weeks of off-season iron supplementation positively impacted female handball players' aerobic capacity; however, it did not significantly improve their VO2max.

EXERCISE INTERVENTIONS ON THE ACUTE MEDICAL WARD: A SYSTEMATIC REVIEW AND META-ANALYSIS

INTRODUCTION &amp; AIMS An acute hospital stay is associated with high proportions of sedentary time, and bed rest, with low physical activity participation for the stay duration. Exercise prescription on the acute inpatient medical ward can prevent decline, or at least maintain, physical outcomes in the adult population. The purpose of this systematic review with meta-analyses was to evaluate the effectiveness of exercise intervention on the acute inpatient medical ward on physical outcomes of muscle strength, aerobic capacity and balance in adults, compared with usual care. METHODS Medline, CINAHL and EMBASE were searched from inception to 20th April 2023. Randomised controlled trials in English, which reported muscle strength, aerobic capacity or balance outcomes for adults who received an exercise intervention on an acute medical ward were included. Studies were excluded if they did not have a control group receiving usual care. Study quality was assessed using the PEDro and TESTEX scales. The GRADE rating assessed quality of evidence to evaluate certainty of effect. Where studies with continuous data used different measures of assessment, and reported post-test outcomes, standardised mean differences with a random effects model was used. For studies with continuous data that used different measures of assessment, and reported change from baseline scores, a weighted mean difference with a random effects model was used. Significance was set at p&amp;lt;0.05. RESULTS Twelve studies were included, with 1,273 unique participants, which compared exercise intervention with usual care. Low quality evidence demonstrated a significant difference between groups for aerobic capacity (p=0.02) and maximum isometric strength (p=0.001). A meta-analysis of balance outcomes could not be performed. CONCLUSION Exercise prescribed during an acute medical ward stay may improve participants’ aerobic capacity and maximum isometric strength.

Let's get physical: Aerobic capacity, muscle strength, and muscle endurance after pediatric heart transplantation.

Pediatric heart (HTx) and kidney transplant (KTx) recipients may have lower physical fitness than healthy children. This study sought to quantify fitness levels in transplant recipients, investigate associations to clinical factors and quality of life, and identify whether a quick, simple wall-sit test is feasible as a surrogate for overall fitness for longitudinal assessment. Aerobic capacity (6-min walk test, 6MWT), normalized muscle strength, muscle endurance, physical activity questionnaire (PAQ), and quality of life (PedsQL™) were prospectively assessed in transplanted children and matched healthy controls. Twenty-two HTx were compared to 20 controls and 6 KTx. 6MWT %predicted was shorter in HTx (87.2 [69.9-118.6] %) than controls (99.9 [80.4-120] %), but similar to KTx (90.3 [78.6-115] %). Muscle strength was lower in HTx deltoids (6.15 [4.35-11.3] kg/m2) and KTx quadriceps (9.27 [8.65-19.1] kg/m2) versus controls. Similarly, muscle endurance was lower in HTx push-ups (28.6 [0-250] %predicted), KTx push-ups (8.35 [0-150] %predicted), HTx curl-ups (115 [0-450] %predicted), and KTx wall-sit time (18.5 [10.0-54.0] s) than controls. In contrast to HTx with only 9%, all KTx were receiving steroid therapy. The wall-sit test significantly correlated with other fitness parameters (normalized quadriceps strength R = .31, #push-ups R = .39, and #curl-ups R = .43) and PedsQL™ (R = .36). Compared to controls, pediatric HTx and KTx have similarly lower aerobic capacity, but different deficits in muscle strength, likely related to steroid therapy in KTx. The convenient wall-sit test correlates with fitness and reported quality of life, and thus could be a useful easy routine for longitudinal assessment.

THE EFFECT OF DRY AND HUMID HEAT ACCLIMATION ON PERFORMANCE IN EACH ENVIRONMENT

BACKGROUND Athletes adopt heat acclimation (HA) to partly restore heat-mediated decrements in performance. However, the influence of environmental characteristics during HA on performance in dry and humid conditions is unclear. Therefore, this study aimed to compare dry and humid HA on performance in each environment. METHODS In a counterbalanced crossover study, ten trained male cyclists (age 43 ± 9 y; body mass 80.8 ± 7.3 kg; maximal oxygen uptake; 59 ± 7 mL.kg-1.min-1) completed a 30-min time-trial in hot-dry (TT-DRY; 42°C, 25% RH) and warm-humid (TT-HUM; 33°C, 80% RH) conditions before and after 8 days of controlled heart rate (HR) HA in either dry (DRY-HA) or humid conditions (HUM-HA). A Bayesian multi-level model was used to determine posterior means, 90% credible intervals, and probability of direction (%). RESULTS The improvement in power output during TT-HUM was similar following DRY-HA (13 W [3, 22]; 99%) and HUMID-HA (11 W [3, 19]; 98%). In TT-DRY, the improvement in power output was 12 W ([1, 22]; 97%) higher following DRY-HA (19 W [10, 28]; &amp;gt;99%) compared to HUM-HA (7 W [-2, 17]; 91%). During TT-HUM, mean rectal temperature changed following HUM-HA (0.03°C [-0.11, 0.17]; 63%) and DRY-HA (-0.14°C [-0.29, 0.02]; 92%), with a difference of 0.16°C ([-0.36, 0.03]; 92%). During TT-DRY, the difference was -0.20°C ([-0.40, 0.01]; 94%) between HUM-HA (-0.22°C [-0.38, -0.06]; 98%) and DRY-HA (-0.03°C [-0.19, 0.13]; 63%). Mean HR during TT-DRY (3 beats·min-1 [-2, 8]; 85%) and TT-HUM (-4 beats·min-1 [-10, 2]; 85%) was similar following DRY-HA and HUM-HA. CONCLUSIONS DRY-HA further improved mean power output during TT-DRY compared to HUM-HA. However, HUM-HA tended to lower rectal temperature more than DRY-HA during TT-DRY. HA condition did not influence HR during either TT. Our data indicate that performance is further improved in hot-dry conditions when acclimating to the same environment.

ACUTE EFFECT OF INTERVAL TRAINING SET STRUCTURE ON PHYSIOLOGICAL AND PERCEPTUAL RESPONSES TO EXERCISE

INTRODUCTION &amp; AIMS A novel method for prescribing maximal aerobic speed (MAS) interval sessions involves the use of rest redistribution (RR). This approach could reduce perceived exertion and fatigue, preventing a decline in performance. This study aimed to compare acute physiological and perceptual responses between traditional (TS) and RR MAS interval training in endurance athletes. METHODS Twenty-five endurance runners (19 males, 6 females; age=31.9±8.5 y; maximal oxygen consumption (V̇O2max)=54.6±5.7 ml·kg·min-1; height=1.77±0.10 m; body-mass=74.0±13.0 kg) who ran &amp;gt;5 hours/week participated. Participants completed two MAS interval sessions equal in duration (18 min total, 360 s exercise, TS=660 s rest/RR=680 s rest) in a randomised order; TS: 3 sets x 6 repetitions (1 rep=20 s running:20 s rest) at 110% MAS and RR: 18 sets x 1 repetition (20 s running:40 s rest) at 110% MAS. During both sessions V̇O2 and heart rate (HR) were measured after each repetition, and blood lactate (HLa-) measured pre-exercise and after repetitions 6, 12 and 18. Rating of perceived exertion (RPE) was measured after repetitions 6, 12, and 18, and overall session RPE 10 minutes post-session. RESULTS Linear mixed effects models showed that TS led to a faster increase in V̇O2 (β=.16, p=.04) and HLa- (β=.09, p&amp;lt;.01), with consistently higher HR than RR (β=5.35, p&amp;lt;.01). Additionally, RPE (β=1.35, p&amp;lt;.01) and session RPE were lower in RR than TS (β=1.13, p&amp;lt;.01). CONCLUSION Results indicate that when session time is similar, TS (1:1 work-to-rest ratio), produces a greater physiological stimulus with higher V̇O2, HR and HLa-. Conversely, RR (1:2 work-to-rest ratio) resulted in lower perceived exertion and metabolic stress. This makes RR an appropriate choice for training periods with lower physiological stress or during periods of fatigue management. The reduced physiological demands in RR can facilitate a more controlled and sustainable training experience while still providing valuable training benefits.

COMPARING THE EFFECTS OF AROMATASE INHIBITORS AND SELECTIVE OESTROGEN RECEPTOR MODULATORS ON BODY COMPOSITION, EXERCISE TOLERANCE AND MARKERS OF CARDIOVASCULAR RISK IN FEMALES WITH BREAST CANCER

INTRODUCTION Adjuvant endocrine therapy (AET) blocks the action of estrogens and is commonly prescribed in hormone receptor-positive breast cancer. Given the putative cardioprotective role of estrogens in females, AET may exacerbate the negative metabolic side-effects of anthracycline chemotherapy. This study examined the early effects of combined anthracycline chemotherapy and AET on body composition, exercise tolerance and markers of cardiovascular risk in a cohort of females with breast cancer. METHODS This was a secondary analysis of the BReast cancer EXercise InTervention (BREXIT) Trial. Females with breast cancer (n=105, aged 51 ± 8 years, BMI 27.4 ± 5.1, mean ± SD) scheduled for anthracycline chemotherapy participated in this study. Aerobic exercise capacity, body composition, physical function, and blood pressure were measured before anthracycline treatment and after 4- and 12-months follow-up. Linear mixed models assessed whether aromatase inhibitors (AI) or selective estrogen receptor modulators (SERMS) affected exercise tolerance, body composition and markers of cardiovascular risk compared to non-endocrine breast cancer treatments. RESULTS Twelve months of anthracycline treatment combined with AI or SERMs decreased total body lean mass by 1.4 kg (2%; interaction p=0.01) and 1kg (1%; interaction p=0.16) respectively, when compared to non-endocrine therapies. There were trends for AET to decrease total fat (-1.5%, interaction p=0.05) and android fat (-2.3%, interaction p=0.07) mass compared to non-endocrine therapy after 12 months. AIs significantly increased both systolic (5.8mmHg, interaction p=0.05) and diastolic (4.0mmHg, interaction p=0.05) blood pressure after 12 months of treatment compared to SERMs or non-endocrine therapies. There was no effect of either AET or SERMS on VO2peak, leg press or seated row 1RM, 30 second sit to stand or handgrip strength. DISCUSSION AND CONCLUSION Short-term treatment with adjuvant endocrine therapies may accelerate muscle loss and increase blood pressure compared to non-endocrine therapies. However, these changes were not associated with worsening of physical function.

ENHANCING FUNCTIONAL CAPACITY AND QUALITY OF LIFE WITH ECCENTRIC CYCLING TRAINING IN HEART FAILURE PATIENTS: A RANDOMIZED CONTROLLED TRIAL

INTRODUCTION Exercise training is recommended for comprehensive management of patients with heart failure and reduced ejection fraction (HFrEF). However, limited exercise capacity prevents many patients from gaining optimal training benefit. Given eccentric cycling is well tolerated in HFrEF, and enables greater power output, we hypothesized that eccentric cycling training would result in superior functional outcomes than concentric cycling training when the interventions were matched for heart rate (HR). METHODS Forty-five participants (9♀, 57±13 y; BMI 27±5 kg/m2) with HFrEF (ejection fraction 33±10%, New York Heart Association class II) were randomized in a 1:1 superiority clinical trial to either eccentric cycling training (ET, n = 25) or concentric cycling training (CT, n = 20). Each intervention involved 2-weeks of familiarization and 12-weeks of training at matched relative intensity (40-80% of HR reserve), twice weekly. Primary outcome was peak oxygen consumption (V̇O2peak), secondary outcomes included 6-minute walk, functional lower extremity strength and health-related quality of life (Minnesota Living with Heart Failure, MLHF). RESULTS Repeated measures ANOVA revealed significant interaction effects for 6-min walk (ET 476±77 to 547±80 m vs CT 485±106 to 516±113 m, P=0.015), 30s sit-to-stand (ET 12±3 to 16±3 repetitions vs CT 13±4 to 14±3 repetitions, P=0.002), and timed up-and-go (ET 7.2±1.2 to 6.2±1.1 s vs CT 7.6±1.5 to 7.3±1.9 s, P=0.019). There were significant time effects for V̇O2peak (ET: 17.7±4.8 to 19.1±5.2 ml/kg/min and CT 17.4±6.0 to 19.8±6.0 ml/kg/min, P&amp;lt;0.001), and MLWHF (ET 31±24 to 23±16 and CT 32±19 to 27±16, P=0.003). CONCLUSION When matched for heart rate to control cardiovascular burden, ET demonstrated superior effect in functional capacity, and similar benefits in aerobic capacity (V̇O2peak) and health-related quality of life, when compared to CT. ET is a novel and efficacious approach for clinical benefit in highly compromised HFrEF patients, who represent a challenge in terms of exercise prescription.