VO2max Research Articles

The effects of circuit training versus high-intensity interval training on the endurance of volleyball athletes: a randomized controlled trial

Despite its intermittent nature, volleyball places significance on a high aerobic capacity, particularly evident in multiset games that demand sustained high-performance levels. Various training approaches exist to enhance the endurance of volleyball athletes. Thus, the fundamental aim of this research is to examine the contrasting effects of utilizing high-intensity interval training (HIIT) and circuit training methods to enhance volleyball athletes' endurance. The study used an Experimental group that partook in a HIIT training regime, and a Contrast group that undertook a Circuit training program. Thirty male volleyball players aged between 17 and 22 years (M=19.14; SD±1.61) were purposefully selected for the study and split into Contrast and Experimental groups of 15 each. At the beginning and end of the intervention programs both groups underwent physiological assessments for Maximum Oxygen Consumption (VO2max), Heart Rate Recovery (HRR), Peak Inspiratory Flow (PIF), Peak Expiratory Flow (PEF), and Force Vital Capacity (FVC). As result a meaningful Time x Group interaction for the VO2max, HRR, PIF, PEF and FVC was observed. This represents a significant improvement in the treatment group (p < 0.001). No material change was observed in the comparison group. Findings revealed that the HIIT training approach outperformed the circuit training method in enhancing volleyball athletes' endurance. Consequently, it is should be beneficial for volleyball players to incorporate HIIT into their standard training regimens. Keywords: VO2max; physiology; sport; exercise; aerobic capacity.

High- and low-carb diet and fasting state modify alternative maximal accumulated oxygen deficit.

This investigation aimed to assess if alternative method to estimate the maximal accumulated oxygen deficit (MAODalt) can detect changes in energy system contribution in different substrate availabilities. Following a graded exercise test to determine maximal oxygen uptake intensity (iVO2max), 26 recreational runners performed a time to exhaustion effort (TTE) as baseline at 110% iVO2max. The same TTE was performed in fasting state, then, a muscle glycogen depletion protocol was executed. Subsequently, participants received low-carbohydrate diet and beverage containing high (H-CHO, 10.8±2.1g·kg-1), moderate (M-CHO, 5.6±1.1g·kg-1), or zero (Z-CHO, 0.24±0.05g·kg-1) carbohydrate. Another TTE was performed 24h later. Each energy system contribution was assessed. Generalized linear mixed models were used for statistical analysis (p<0.05). H-CHO increased relative anaerobic capacity (slope effect [baseline-intervention]x[H-CHO-M-CHO]) due to the relative lactic contribution maintenance (slope effect [baseline-intervention]x[H-CHO-Z-CHO] or [H-CHO-M-CHO]) and increase in relative alactic contribution (6.3±3.5kJ·min-1). The aerobic contribution was lower (-8.7±4.0kJ·min-1), decreasing performance (-34±16s) for H-CHO. M-CHO and Z-CHO maintained anaerobic capacity due to increase in alactic contribution (slope effect [fasting-intervention]x[M-CHO-H-CHO]; and Z-CHO was 7.3±3.4kJ·min-1 higher than baseline). Fasting increased relative alactic (2.9±1.7kJ·min-1) but decreased aerobic contribution (-3.3±2.3kJ·min-1), impairing performance (-17±12s). In conclusion, MAODalt can detect changes in energy system supply in different nutritional states. Therefore, participant's nutritional state must be considered prior to conducting the test.

Study To Determine Aerobic Capacity In Early Adulthood To Identify The Adverse Effect Of Sedentary Lifestyle

Study To Determine Aerobic Capacity In Early Adulthood To Identify The Adverse Effect Of Sedentary Lifestyle

Effectiveness of Circuit and Fartlek Exercises to Increase Aerobic Endurance in Adolescent Futsal Players

Aerobic endurance is an important component in futsal sports games, so it requires an exercise that can increase aerobic endurance. This study aims to evaluate the effectiveness of circuit training with fartlek exercises to increase aerobic endurance futsal players Bina Darma. The research method used was an experiment with the design of the control group pre-test post-test. The study population of 40 Bina Darma futsal players was divided evenly into two groups, namely the circuit training group and the fartlek training group consisting of 20 samples. Each group performed the exercises for 8 weeks with a frequency of 3 times a week. Aerobic endurance measurements were taken before and after the exercise program using the Bleep Test. Analysis Data obtained from VO2 max test will be analyzed using statistical software SPSS 23. Statistical analysis that will be used is an Paired Samples Test to compare the increase in aerobic endurance between circuit training group and fartlek exercise group. The results showed a significant increase in aerobic endurance in all groups after the exercise programme. The results of this study showed that the circuit training group was more significant than the fartlek training group with very high statistical significance (p&amp;lt; .001), showing that the difference between circuit training and fartlek training in improving aerobic endurance was significant. In conclusion, circuit training is a more effective option for improving aerobic endurance in Bina Darma futsal players. Choosing the right type of sport can increase the aerobic endurance of futsal players.

The role of the heart in the evolution of aerobic performance.

Aerobic metabolism underlies vital traits such as locomotion and thermogenesis, and aerobic capacity influences fitness in many animals. The heart is a key determinant of aerobic capacity, but the relative influence of cardiac output versus other steps in the O2 transport pathway remains contentious. In this Commentary, we consider this issue by examining the mechanistic basis for adaptive increases in aerobic capacity (thermogenic V̇O2,max; also called summit metabolism) in deer mice (Peromyscus maniculatus) native to high altitude. Thermogenic V̇O2,max is increased by acclimation to cold hypoxia (simulating high-altitude conditions), and high-altitude populations generally have greater V̇O2,max than their low-altitude counterparts. This plastic and evolved variation in V̇O2,max is associated with corresponding variation in maximal cardiac output, along with variation in other traits across the O2 pathway (e.g. arterial O2 saturation, blood haemoglobin content and O2 affinity, tissue O2 extraction, tissue oxidative capacity). By applying fundamental principles of gas exchange, we show that the relative influence of cardiac output on V̇O2,max depends on the O2 diffusing capacity of thermogenic tissues (skeletal muscles and brown adipose tissues). Functional interactions between cardiac output and blood haemoglobin content determine circulatory O2 delivery and thus affect V̇O2,max, particularly in high-altitude environments where erythropoiesis can increase haematocrit and blood viscosity. There may also be functional linkages between cardiac output and tissue O2 diffusion due to the role of blood flow in determining capillary haematocrit and red blood cell flux. Therefore, the functional interactions between cardiac output and other traits in the O2 pathway underlie the adaptive evolution of aerobic capacities.

Effects of Endurance Training on Antioxidant and Hormonal Status in Peripheral Blood of Young Healthy Men.

(1) Background: Physical activity may cause an imbalance in the major functions of the human body. This study aimed to investigate the effects of endurance running training on the parameters of the antioxidant defense system (SOD, CAT, GPx, GR, GSH), LPO (malondialdehyde, MDA), and stress hormones (A, NA) in young healthy, previously untrained men. (2) Methods: The training program was as follows: 8 weeks of running, three times per week; the duration of a single session was 30-70 min, the intensity was twice a week in the so-called extensive endurance zone, and once a week in the anaerobic threshold zone. Blood samples were collected from the subjects, before and after the running program. (3) Results: The training program resulted in a significant increase in maximal oxygen consumption (p < 0.001). The activities of SOD, GPx, and GR also increased significantly (p < 0.05, p < 0.01, and p < 0.05, respectively), while CAT activity and GSH and MDA concentrations remained unchanged. The concentration of A decreased (p < 0.05), while the NA concentration increased significantly (p < 0.05). SOD, GPx, GR, and NA positively correlated with VO2max (p < 0.05, p < 0.001, p < 0.01, p < 0.05, respectively), while a negative correlation was detected between A and VO2max (p < 0.05). (4) Conclusions: These results indicate that there is no persistent oxidative stress in response to the applied 8-week running program, probably due to exercise-induced protective alterations in the antioxidant defense system. Furthermore, adaptations occurred at the hormonal level, making the organism more ready for a new challenge.

Influencing Factors and Training Strategies for Boulder and Lead Athletes' Competitive Performance: A Narrative Review

ABSTRACT With the introduction of sport climbing in the Olympics, there have been increased opportunities for refining and enhancing the sport. Improving competitive performance is a crucial objective of national development strategies. This narrative review aims to analyze the influencing factors and training strategies for the competitive performance of boulder and lead athletes, providing a reference for improving their competitive performance. Conditioning for boulder and lead involves physical, psychological, and technical training. The competitive performance of boulder and lead athletes is primarily influenced by upper-limb strength, endurance, aerobic capacity, climbing efficiency, route previewing, and psychological elements like confidence, anxiety, and focus. To improve physical fitness and competitive performance, athletes should prioritize enhancing upper-limb strength and endurance. Athletes can enhance their climbing skills and progress by engaging in various international standard climbing routes with varying levels and styles of difficulty, thereby expanding their repertoire of techniques. In addition, there should be an increased emphasis on providing psychological counseling to athletes before competition. In future research, the differences between varying training methods for athletes of different levels and genders should be further explored, along with investigating training and recovery strategies.

THE LOW SERUM FERRITIN AS AN INDICATOR OF INADEQUATE NUTRITION IN INTERNATIONAL-LEVEL FEMALE SWIMMER

Introduction: Iron deficiency is a common feature in athletes, and optimizing iron levels may become a contributing factor to improved athletic performance. Purpose: This study aimed to evaluate body iron stores and their relationship with sports performance. It also sought correlations between the swimmers’ hematological, hormonal, anthropometric, and functional status and their sports achievements. Methodology: The research involved 19 athletes (11 women and 8 men) from the Bulgarian national swimming team. They were tested for maximal aerobic capacity on a cycle ergometer and had blood samples taken to determine iron status and hematological and hormonal markers. Their swimming achievements (Swimming points) were evaluated as a percentage of the world records in the respective discipline. Results: There were statistically significant differences between the female and male swimmers for Unbound Iron Binding Capacity (UIBC) and ferritin. A higher UIBC in women indicated lower iron levels in them. Among female swimmers, five had ferritin levels below 40 ng/mL. In women, a highly reliable correlation between the Swimming points and ferritin concentration (r = .68) was observed. All male swimmers had ferritin values above 40 ng/mL, and there was no reliable correlation between ferritin concentration and Swimming points, probably because ferritin was in the optimal range and is no longer a significant performance factor. Conclusions: In swimmers, the optimal serum ferritin concentration is probably in the range of 40–90 ng/mL. Many female swimmers have a relative iron deficiency with sub-optimal ferritin values. In competitive female swimmers, low ferritin level is an indicator of both iron deficiency and inadequate diet. It can be expected that an adequate nutritional regime in athletes with low ferritin values will lead both to the replenishment of iron stores and to an increase in muscle mass and, ultimately, to an improvement in sports performance.

Impact of sodium-glucose cotransporter-2 inhibitor use on peak VO2 in advanced heart failure patients.

Advanced heart failure (HF) is an epidemic that affects multiple organ systems with high morbidity and mortality rates despite optimal medical therapy (OMT) and remains the leading cause of hospitalizations in type 2 diabetes-related cardiovascular disease. The addition of sodium-glucose co-transporter inhibitors (SGLT2i) in treating these patients has seen improved mortality and hospital admission rates. As such, we felt it was important to investigate whether the use of SGLT2i improved functional capacity in patients with HF when compared to OMT by evaluating maximum oxygen consumption (peak VO2) using cardiopulmonary exercise testing (CPET). We found 94 heart failure patients between August 2020 and August 2021 who underwent CPET before and after treatment at Mayo Clinic in Florida. 50 patients received OMT and 44 received OMT and SGLT2i therapy. CPET results before and after were compared for each group. The baseline ejection fraction was not significantly different between groups, with the OMT group at 38% and the SGLT2i group at 33%, p = 0.10. OMT patients were found to have a significantly lower hemoglobin A1c of 5.7 (5.4-6.1) compared to those with SGLT2i therapy of 6.4 (5.8-7.1), p = 0.01. The baseline peak VO2 was 17.3 ml/kg/min (13.3-21.6) in the OMT group and 17.3 ml/kg/min (14.4-18.9) in the SGLT2i group, p = 0.18, not significantly different. The interesting finding is that the follow-up peak VO2 at one year for the OMT group was 17 ml/kg/min (13.3-21.6), which was not significantly different from the SGLT2i group peak VO2 of 17 ml/kg/min (14.6-19.6), p = 0.19. Our study is the first to compare before and after peak VO2 values of the OMT+SGLT2i group to the patient's own baseline and we found no significant improvement. Our single-center data shows no improvement in functional capacity after the addition of SGLT2i therapy to OMT in patients with advanced heart failure. Improved hospitalization and symptoms may be attributed to other numerous effects of SGLT2i such as volume management.

Association of cardiovascular health with anthropometric markers, cardiorespiratory fitness and quality of life of university workers

Objective: To evaluate cardiovascular health (CVH) in university workers at a higher education institution in relation to other health-related factors. Methods: Cross-sectional study consisting of 121 workers. CVH was assessed by seven measures [food consumption, physical activity level (PAL), smoking, total cholesterol, blood glucose, systemic blood pressure (BP), and body mass index (BMI)]. The independent variables waist circumference (WC), waist-hip ratio (WHR), HDL-c, LDL-c, triglycerides, maximal oxygen consumption (VO2max), workload, and health related quality of life (HRQoL) were assessed. Results: Overall, 25% of the sample had poor CVH. The ideal CVH group had lower WC (p&lt;0.001) and WHR (p&lt;0.001), and higher VO2max (p=0.041). The physical component score was higher in the groups with intermediate (p=0.036) and ideal (p=0.002) CVH. Daily workload was higher in the poor CVH group (p=0.05). CVH score was directly related to VO2max (p=0.001) and physical component (p=0.020), and inversely related to WC (p&lt;0.001), WHR (p&lt;0.001), LDL-c (p&lt;0.001), and triglycerides (p&lt; 0.001). Conclusion: Implementation of educational practices, and promotion of physical activity, adequate dietary intake, and other lifestyle habits can help to improve CVH and the physical component of HRQoL.

Factors and level of physical performance of schoolchildren aged 13–14 years

There is an insufficiency of data on the characteristics of physical performance of schoolchildren in the critical period of ontogenesis associated with pubertal development.The aim of the study. To determine the factors and level of physical performance of schoolchildren aged 13–14 years, taking into account pubertal development.Methodology. The study involved healthy male adolescents aged 13–14 years (n = 165). Five stages of puberty were determined. To diagnose the level of physical performance, a complex of functional and ergometric tests and a battery of motor tests were used. The structure of performance was determined based on the factor analysis.Results and discussion. We determined the factors characterizing physical performance: aerobic capacity; absolute aerobic power; anaerobic alactic performance; anaerobic glycolytic performance; relative aerobic power. The identified factors are associated with zones of relative power. It has been established that during puberty, changes in indicators combined into different factors occur non-linearly and non-simultaneously. The results of the study show that subjects of the same age with stages II, III and IV of puberty differ in the level of key bioenergetic performance criteria. Transition to higher stages of puberty is accompanied with progressive dynamics of most indicators associated with factors of anaerobic performance, while indicators of aerobic power and capacity change in different directions, showing in some cases a tendency to temporarily decrease.Conclusion. It is advisable to use the results of the study when organizing various types of monitoring the functional state and regulation of aerobic and anaerobic physical activity in adolescents aged 13–14 years at different stages of puberty. The obtained materials can serve as a scientific basis for improving the physical education system in order to increase the functional capabilities of children’s bodies during the critical period of ontogenesis associated with pubertal development

The effect of probiotics and casein supplementation on aerobic capacity parameters of male soccer players.

In the realm of sports science, nutrition is a well-established pillar for athletes' training, performance, and post-workout recovery. However, the role of gut microbiota, often overlooked, is a novel and intriguing aspect that can significantly impact athletic performance. With this in mind, our study ventures into uncharted territory, investigating the effect of probiotic and casein supplementation on the aerobic capacity of male soccer players. A double-blinded and placebo-controlled study was conducted with 44 male soccer players (Age: 22.81 ± 2.76 yr, Height: 177.90 ± 6.75 cm, Weight: 67.42 ± 8.44 kg). The participants were subjected to the Bruce test in the beginning; then, they were randomly divided into four groups, each consisting of 11 people: probiotics (PRO), casein (CAS), probiotics with casein (PRO+CAS), and placebo (PLA). PRO group was given one probiotic capsule (containing strains of Lactiplantibacillus plantarum BP06, Lacticaseibacillus casei BP07, Lactobacillus acidophilus BA05, Lactobacillus delbrueckii BD08 bulgaricus, Bifidobacterium infantis BI04, Bifidobacterium longum BL03, Bifidobacterium breve BB02 and Streptococcus salivarius thermophilus BT01, with a total dose of 4.5 × 1011 CFU) during dinner, while the CAS group consumed 20 grams of casein powder 45 minutes before bed. The PRO+CAS group was given one probiotic capsule during dinner and 20 grams of casein powder 45 minutes before bed. The participants in the PLA group were given one red capsule (containing 5 grams of starch) during dinner. All participants were instructed to take the supplements only on training days, three times a week for four weeks. The maximal oxygen consumption (VO2max), Ventilatory Threshold (VT), Time-to-exhaustion (TTE), Respiratory Compensation Point (RCP), Isocapnic area Time (Time-IC), Isocapnic area oxygen consumption (VO2-IC), and Hypocapnic Hyperventilation area Time (Time-HHV), after the Bruce test were Measured. All data were analyzed using SPSS Windows software, mixed repeated measure ANOVA, and Bonferroni post hoc test at p < 0.05 level. The current study's findings illustrated that, after the intervention, TTE (p = 0.01) and RCP (p = 0.01) were significantly improved in PRO+CAS compared to the PLA group. No significant difference was observed between PRO and PLA (p = 0.52), PRO and CAS (p = 0.999), PRO and PRO+CAS (p = 0.9), CAS and PLA (p = 0.65), CAS and PRO+CAS (p = 0.73) in TTE. In addition, no significant difference was observed between PRO and CAS (p = 0.999), PRO and PLA (p = 0.40), PRO and PRO+CAS (p = 0.999), CAS and PLA (p = 0.263), CAS and PRO+CAS (p = 0.999) in RCP. Time-HHV was significantly higher in PRO+CAS (p = 0.000) and CAS (p = 0.047) compared to the PLA group. However, no significant difference was observed in the Time-HHV between PRO and CAS (p = 0.999), PRO and PRO+CAS (p = 0.25), PRO and PLA (p = 0.12), and CAS and PRO+CAS (p = 0.57). Additionally, all the groups had no significant differences in VO2max, VT1, VO2-IC and Time-IC. The findings showed that consuming probiotics and casein could relatively improve the aerobic capacity of male soccer players. Nevertheless, simultaneous consumption of probiotics and casein had a more pronounced effect on aerobic capacity indicators, especially TTE and Time-HHV.

Comparison of Yo-Yo Intermittent Recovery Test Level-1 Performance Between Basketball and Field Hockey Players: A Comparative Analysis

Background: The Yo-Yo Intermittent Recovery Test Level-1 (YYIR1) is widely used to evaluate aerobic capacity and recovery in intermittent sports. This study aims to compare YYIR1 performance between basketball and field hockey players to understand sport-specific fitness adaptations and inform training protocols. Methods: A total of 60 male athletes (30 basketball players and 30 field hockey players) from competitive clubs participated in this study. Participants performed the YYIR1 test, which involves repeated 2x20 meter shuttle runs at increasing speeds interspersed with 10-second recovery periods, until exhaustion. Key performance metrics measured were total distance covered and VO2 max, calculated based on the test results. Data were analysed using independent t-tests to compare the performances between the two groups. Results: The basketball players covered a mean distance of 1235 ± 210 meters, while the field hockey players covered 1280 ± 195 meters. The difference in total distance covered between the groups was not statistically significant (p &gt; 0.05). Similarly, VO2 max values were comparable between basketball players (47.8 ± 4.2 mL/kg/min) and field hockey players (48.5 ± 3.9 mL/kg/min), with no significant difference observed (p &gt; 0.05). Conclusion: This study demonstrates that there are no significant differences in YYIR1 performance between basketball and field hockey players, suggesting similar aerobic capacities and recovery abilities across these sports. The findings align with previous research by Mirani and Patil (2021) and Schmitz et al. (2018), indicating the robustness of the YYIR1 test in measuring aerobic endurance irrespective of sport-specific demands. These results highlight the need for tailored training programs that focus on enhancing sport-specific skills rather than general aerobic capacity alone. Keywords: Yo-Yo Intermittent Recovery Test Level-1, basketball, field hockey, VO2Max, sports performance

Endurance training volume cannot entirely substitute for the lack of intensity.

Very low intensity endurance training (LIT) does not seem to improve maximal oxygen uptake. The purpose of the present study was to investigate if very high volume of LIT could compensate the lack of intensity and is LIT affecting differently low and high intensity performances. Recreationally active untrained participants (n = 35; 21 females) cycled either LIT (mean training time 6.7 ± 0.7 h / week at 63% of maximal heart rate, n = 16) or high intensity training (HIT) (1.6 ± 0.2 h /week, n = 19) for 10 weeks. Two categories of variables were measured: Low (first lactate threshold, fat oxidation at low intensity exercise, post-exercise recovery) and high (aerobic capacity, second lactate threshold, sprinting power, maximal stroke volume) intensity performance. Only LIT enhanced pooled low intensity performance (LIT: p = 0.01, ES = 0.49, HIT: p = 0.20, ES = 0.20) and HIT pooled high intensity performance (LIT: p = 0.34, ES = 0.05, HIT: p = 0.007, ES = 0.48). Overall, very low endurance training intensity cannot fully be compensated by high training volume in adaptations to high intensity performance, but it nevertheless improved low intensity performance. Therefore, the intensity threshold for improving low intensity performance is lower than that for improving high intensity performance. Consequently, evaluating the effectiveness of LIT on endurance performance cannot be solely determined by high intensity performance tests.

Effects of β-Alanine Supplementation on Subjects Performing High-Intensity Functional Training.

β-alanine, a non-essential amino acid found in the diet and produced through nucleotide catabolism, is significant for muscle performance due to its role in carnosine synthesis. This study aims to assess the impact of a 4-week β-alanine supplementation on neuromuscular fatigue in individuals engaging in High-Intensity Functional Training (HIFT) and its subsequent effect on sports performance, distinguishing between central fatigue from the CNS and peripheral fatigue from the muscular system. This study (a randomized controlled trial) comprised a total of 27 subjects, who were divided into two groups. Group A (the control group) was administered sucrose powder, while Group B (the experimental group) was given β-alanine powder. The subjects were randomly assigned to either the experimental or control groups. This study lasted four weeks, during which both groups participated in high-intensity interval training (HIFT) on the first day to induce fatigue and work close to their VO2 max. Statistically significant changes were in the sports performance variables, specifically vertical jump and jumping power (p = 0.027). These changes were observed only in the group that had been supplemented with β-alanine. Nevertheless, no alterations were observed in any other variables, including fatigue, metabolic intensity of exercise, or perceived intensity (p > 0.05). A four-week β-alanine intake program demonstrated an improvement in the capacity of subjects, as evidenced by enhanced vertical jump and power performance. Nevertheless, it does result in discernible alterations in performance.

Setting sail for Paris 2024: Retrospective analysis of world-class ILCA 7 Olympic sailors' cardiorespiratory fitness (2015-2020).

The aim of this retrospective analysis was to provide a more comprehensive understanding of the cardiorespiratory profile of world-class ILCA-7 sailors (n=3, all males), through a longitudinal evaluation offering real-world data on physiological profile and exercise intensity domains. The cardiopulmonary exercise testing (CPET) was performed by the same researchers using the same equipment during the study. Assessments took place twice a year, aligning with major international competition preparations. Participants trained and competed at the same sailing club in Split, Croatia, under consistent supervision from the same team throughout the study, winning a total of 21 medals at major international competitions. The recorded ranged from 51.7±1.6 to 61.9±3.0mLmin-1kg-1, respectively. Similarly, peak power output varied from 352±10 to 426±34W. The changes in physiological responses at the ventilatory thresholds were proportional to the changes in peak cardiorespiratory fitness capacity. Interestingly, the oxygen pulse measured in 2015 was 25±1mLO2beat-1. Over the subsequent 6 years, the O2 pulse marginally increased and appeared to stabilize at 27±1mLO2beat-1 in 2020, when these athletes were 32±3 years old. This work offers a broader understanding of world-class Olympic sailors' cardiorespiratory fitness, going beyond the standard assessment of peak to incorporate an analysis of ventilatory thresholds. While a direct link between cardiorespiratory fitness and competitive success remains ambiguous, the importance of a well-rounded aerobic capacity for excellence in ILCA-7 sailing class is evident. HIGHLIGHTS: What is the central question of this study? What are the temporal changes in the physiological profiles of three world-class ILCA-7 sailors? What is the main finding and its importance? Data on oxygen pulse adjustments suggest the involvement of compensatory cardiovascular mechanisms, likely associated with the isometric and quasi-isometric contractions inherent in ILCA-7 sailing. This is evidenced by the absence of an age-related increase in oxygen pulse, a phenomenon often observed in endurance athletes throughout their competitive careers.

Impact of probiotic supplementation on exercise endurance among non-elite athletes: a randomized, placebo-controlled, double-blind, clinical trial.

This randomized, placebo-controlled, double-blind, parallel trial investigated whether generally healthy adult, non-elite runners would have a greater time-to-exhaustion during submaximal treadmill running with probiotic versus placebo supplementation. It was hypothesized that the probiotic would impact training progression by reducing gastrointestinal (GI) and cold/flu symptoms. Participants who typically ran ≥24 km/week, ran or cross-trained 3-5 days per week, and had a maximal oxygen intake (VO2 max) in the 60-85th percentile were enrolled. VO2 max was used to establish individualized workload settings (85% of VO2 max) for the submaximal endurance tests at baseline and following 6 weeks of supplementation with a probiotic (Lactobacillus helveticus Lafti L10, 5x109 CFU/capsule/day) or placebo. Participants self-reported GI and cold/flu symptoms and physical activity via daily and weekly questionnaires. Outcomes were tested using a linear model to determine if mean response values adjusted for baseline differed between groups. Twenty-eight participants (n=14/group), aged 255 years (meanSD) with a body mass index of 233 kg/m2, completed the study. At the final visit the probiotic group had a lower time-to-exhaustion versus the placebo group (P=0.01) due to an increase in time-to-exhaustion with the placebo (1344±188 to 1565±219 seconds, P=0.01) with no change with the probiotic (1655±230 to 1547±215 seconds, P=0.23). During the intervention, the probiotic group completed fewer aerobic training sessions per week (P=0.02) and trained at a lower intensity (P=0.007) versus the placebo group. Few GI and cold/flu symptoms were reported with no differences between groups. Time-to-exhaustion increased in the placebo group, possibly due to differences in training habits.

Cardiorespiratory fitness associates negatively with arterial stiffness in a cohort of industrial workers followed up for 4 years.

Previously we have found increased carotid-to-femoral pulse wave velocity (cfPWV) among shift workers compared to day workers in industry, and a decline in maximal oxygen uptake (V̇O2max) in all 86 workers. Utilizing all available measurements in 2018, 2021 and 2022, this study investigated associations between V̇O2max and measures of arterial stiffness. Using a mixed model approach, we analysed the cross-sectional association between all V̇O2max (outcome) and measures of arterial stiffness (covariates). We observed a significant association between V̇O2max and cfPWV of -1.59 (95%CI -3.03, -0.16), augmentation pressure (AP) and augmentation index (Aix) of -0.32 (95%CI -0.58, -0.06) and -0.12 (95%CI -0.23, -0.005), respectively. We found a significant negative association between cardiorespiratory fitness and measures of arterial stiffness. The former and present results pose challenges for shift workers' future macro and microvascular health.

Impact of a 12-wk physical conditioning program on the aerobic capacity of aviation cadets.

Flight cadets need to have good physical fitness to cope with the challenges of flying missions. The continuous development of science and technology has led to the constant upgrading of fighter jets and the improvement of their performance, which has resulted in new and higher requirements for the physical fitness of flight personnel. The traditional physical training mode, method, and assessment have been used for many years and do not meet current fitness needs. To investigate the impact of a 12-wk comprehensive anti-G fitness training program on the aerobic capacity of aviation cadets and to evaluate its effectiveness. Fifty-five cadets were randomly assigned to control and experimental groups using a randomized, single-blind design. The control group maintained their existing training regimen, while the experimental group participated in a 12-wk comprehensive training intervention. The training program comprised strength training twice per week, high-intensity interval training three times per week, and supplemental nutritional and psychological support. Maximal oxygen uptake (VO2max), lower limb strength, and hemoglobin levels were measured at baseline, at 6 wk and 12 wk post-intervention. Repeated measures analysis of variance revealed significant differences of both VO2max and relative VO2 in both groups across time points (P < 0.05). However, no significant time-group interaction was observed (P > 0.05). Paired t-tests comparing baseline and 12-wk results showed that VO2max and relative VO2 were significantly higher in the experimental group than the control group (P < 0.05). This suggests that the training program effectively enhanced the aerobic capacity of the experimental group. Key indicators of aerobic capacity, bilateral lower limb strength and hemoglobin levels, were also significantly different over time and between groups (P < 0.05). No significant differences were noted in heart-rate metrics (P > 0.05). A 12-wk comprehensive anti-G fitness training program significantly improved the aerobic capacity of aviation cadets, thereby enhancing their overall capacity and laying a physiological foundation for enduring high-G flights.

Prehabilitation Consultation on Self-Care and Physical Exercise in Patients Diagnosed with Abdominopelvic Cancer: Protocol of the Study.

Introduction: Prehabilitation in the field of oncology has been defined as "the process in the continuum of care that occurs between diagnosis and the start of treatment involving physical and psychological measures that determine the patient's baseline functional status." To determine the effectiveness of a Prehabilitation consultation on self-care and targeted physical exercise for patients diagnosed with abdominopelvic cancer. An observational study that will evaluate the pre-post efficacy of an ad-hoc designed Prehabilitation intervention. The study population consists of patients diagnosed with colon or gynecological cancer with a surgical indication as part of their therapeutic plan from the General Surgery Services. It is configured around four key interventions: (a) health education and self-care, (b) specific nutritional counseling, (c) initial psychological assessment, and (d) directed physical exercise intervention. Health education, self-care interventions, and physical exercise will be carried out weekly from diagnosis to the scheduled surgery day. Aspects such as self-care capacity or agency, perioperative anxiety, aerobic capacity, strength and flexibility, postoperative complications, and recovery time to adjuvant treatment will be measured using tools such as Appraisal of self-care agency scale (ASA), State Trait Anxiety Inventory (STAI), walking test, sit and Reach, Hand Grip or Squad Jump. Utilizing validated tools for analyzing selected variables will contribute to refining and expanding care guidelines, ultimately enhancing support for both patients and their caregivers.