Search Results (338)

Background: Intermittent Hypoxic–Hyperoxic Training (IHHT) induces physiological adaptations. While its efficacy in athletic performance remains debated, IHHT improves health markers in pathological and geriatric populations. This Exploratory Pilot Study aimed to explore the safety and feasibility of two IHHT protocols through preliminary responses. Methods: Twelve healthy volunteers completed a 4-week intervention (two sessions/week, 45 min/session) combining IHHT simultaneously during low-intensity exercise. The study compared a Training Group (TG: 30 min hypoxia, 7.5 min normoxia, 7.5 min hyperoxia) with a Conditioning Group (CG: 15 min hypoxia, 22.5 min normoxia, 7.5 min hyperoxia). Outcomes assessed included cardiorespiratory parameters, Acute Mountain Sickness symptoms, Perceived Exertion, a comprehensive biochemical panel, systemic inflammation, oxidative stress, and renal status. Results: Both protocols were well-tolerated. The TG exhibited significantly greater oxygen desaturation than the CG (p = 0.048). Moreover, the CG demonstrated a significantly attenuated increase in Interleukin-6 (p = 0.021) compared to the TG. Additionally, preliminary variations highlighted an interesting reduction in lipid parameters (TC, LDL, and Apo A1/B ratios) in both groups, although these did not reach statistical significance after FDR correction. Conclusions: While both protocols proved feasible and safe, a more balanced hyperoxic-to-hypoxic exposure (CG) showed better acute physiological tolerability, attenuating cardiovascular strain and mitigating systemic pro-inflammatory responses compared to the unbalanced exposure (TG). Finally, the preliminary variations observed in lipid parameters provide a rationale that warrants further controlled investigations. Full article

Background: Performing and maintaining high-altitude cardiopulmonary resuscitation (CPR) could pose a significant physical challenge for rescuers. The objective of this study is to analyse the effects of reducing the oxygen fraction at altitudes of 3000 m and 5000 m above sea level (asl), with and without conditioning to hypoxia, on the quality of resuscitation performed in adults. Methods: An analytical before–after study in which 56 students with a Degree in Nursing between 18 and 30 years old perform 10 min of resuscitation on a mannequin at different altitudes (670, 3000 and 5000 m asl) will be carried out. Subsequently completing an intermittent hypoxia conditioning programme, the participants will perform the resuscitation manoeuvres at previously referenced altitudes. Sociodemographics, CPR quality, self-perception CPR, adequate anthropometric data, physical condition, blood tests, oxygenation in muscular tissue, biceps, brachii and erector spinae, subjective perception of effort, anxiety levels and quality of resuscitation will be measured in all participants at different altitudes. Discussion: Although CPR is a submaximal effort manoeuvre, it is subject to being performed by anyone without motor disabilities. Our study will also provide evidence as to whether this characteristic continues to hold true in a hostile environment such as medium and high altitudes. Our study aims to demonstrate that the improvement in physical performance and recovery capacity induced by intermittent hypoxia conditioning programmes increases the quality of CPR in prolonged cardiac arrests and in adverse conditions, such as at high altitudes. The proposed study will contribute as a novelty to the estimation of the influence of high altitudes and conditioning on performing basic CPR manoeuvres. If the hypothesis turns out to be true, recommendations about the practice of moderate-intensity physical exercise could be incorporated into the CPR guidelines as one of the important aspects in the training of rescuers to conduct CPR. Full article

Background/Objectives: Caffeinated chewing gum is a practical, rapidly absorbed ergogenic aid increasingly used in team sports, yet its interaction with different small-sided soccer game (SSG) formats in young male players remains unclear. This study evaluated the effects of acute caffeinated (CAF) chewing gum on psychophysiological responses and kinematic profiles during intermittent (INT) and continuous (CON) 3-a-side SSGs. Methods: Twenty-four young male soccer players (18.4 ± 0.5 years) completed four 3-a-side SSG sessions separated by 48 h in a randomized, double-blind, placebo (PLA)-controlled, crossover design (CAF-INT, PLA-INT, CAF-CON, PLA-CON). Participants chewed 300 mg of CAF or PLA gum for 5 min, with mastication completed 5 min before warm-up session. The heart rates and kinematic profiles were recorded during the SSGs, and the ratings of perceived exertion (RPE), exercise enjoyment scale (EES), and visual analogue scale (VAS) to perceived mental fatigue (MF) were assessed post-game. Results: Compared with the PLA, the CAF increased the heart rate responses (HR), EES, total distance (TD), player load (PL), acceleration (ACC), and distances covered in selected speed zones (from Z0 to Z5), while reducing the RPE and MF. Significant format × supplementation interactions indicated that CAF-induced changes in high-intensity kinematic outcomes (TD, PL, ACC, Z2–Z5) and HR responses (HR_mean, HR_max) were generally greater in INT, whereas CAF-induced increases in low-intensity running distances (Z0 and Z1) and %HR_max were more pronounced in the CON format (all p < 0.05 for the reported effects; ${\eta }_p^2$ = 0.16–0.93 for CAF main effects [large effects]). The EES improvements were more pronounced in the CON format, whereas the MF and RPE reductions were more pronounced in the INT format. Conclusions: CAF chewing gum may be a practical acute strategy for modulating psychophysiological responses and kinematic profiles during SSGs, with the effects depending partly on the game format. Full article

High-intensity intermittent exercise can acutely alter circulating cytokines, but findings are heterogeneous. The aim was to systematically synthesize acute blood cytokine responses after a single high-intensity intermittent exercise session in humans. PubMed, Scopus, and Web of Science Core Collection, plus reference screening. Eligibility criteria included original human studies measuring serum or plasma cytokines pre-exercise and at least one post-exercise time point after high-intensity intermittent exercise. Sampling was mapped to prespecified recovery windows. Risk of bias was assessed using RoB 2 (randomized trials) and the Joanna Briggs Institute quasi-experimental tool. Narrative synthesis was used. From 2077 records, 45 studies were included. Most protocols used cycling or treadmill modalities, and sampling clustered in the immediate and early recovery windows. Interleukin 6 most consistently increased after exercise, whereas tumor necrosis factor alpha, interleukin 10, and other mediators showed mixed or context-dependent changes. Risk of bias was commonly rated as some concerns, with frequent limitations in pre-analytical control and reporting. Across included studies, high-intensity intermittent exercise tended to elicit a short-lived myokine-dominant inflammatory signal, characterized primarily by an increase in circulating interleukin 6, most often detected in the immediate and early recovery windows. Conflicting findings for tumor necrosis factor alpha, interleukin 10, redox-related outcomes, and less frequently measured mediators were best explained by a small set of dominant moderators: post-exercise sampling window, exercise dose/internal load, participant metabolic and training phenotype, and pre-analytical or assay-related heterogeneity. Registration: Open Science Framework (osf.io/wspr6; 17 February 2026). Full article

Rising ambient temperatures and the increasing frequency of training and competition in hot climates have made heat stress a major challenge in football. Under such conditions, players experience greater cardiovascular and thermoregulatory strain, faster glycogen use, higher perceived exertion, and progressive impairment in repeated high-intensity actions and decision-making. These responses have intensified interest in nutritional strategies that might complement heat acclimation, hydration/electrolyte planning, cooling practices, and recovery management. This narrative review critically synthesizes current evidence on nutritional interventions that may be relevant to football performed in the heat, with emphasis on hydration and electrolyte replacement, carbohydrate–protein strategies, taurine, branched-chain amino acids (BCAAs), creatine, menthol, antioxidant- and nitrate-related approaches, and selected multi-ingredient products. Across the available literature, hydration/electrolyte planning and carbohydrate–protein feeding remain the practical foundation, menthol appears most consistently useful for perceptual cooling, creatine seems safe and potentially helpful for repeated-sprint support, and taurine is promising but still supported by relatively few trials. By contrast, evidence for BCAAs, antioxidants, nitrates, and caffeine as stand-alone heat strategies, as well as for many compound supplements, remains inconsistent, context-specific, or too indirect for strong football-specific endorsement. Overall, the evidence base remains heterogeneous in study quality, protocol design, exercise mode, and sport specificity. A substantial proportion of the available data is derived from cycling, endurance, or laboratory heat-exercise models rather than football-specific trials. Accordingly, any practical recommendation should be interpreted cautiously and embedded within broader heat-management strategies. Future work should prioritize ecologically valid randomized controlled trials in football or football-like intermittent protocols, with transparent reporting of dose, timing, perceptual outcomes, and match-relevant performance measures. Full article

Background/Objectives: Although creatine monohydrate is widely recognized as an effective ergogenic aid in strength and power sports, its role in endurance and mixed-sport disciplines remains less clearly established. This scoping review aimed to map the current evidence regarding the effects of creatine supplementation on performance, recovery-related outcomes, and body composition in endurance and mixed-sport contexts. Methods: A scoping review of randomized controlled trials published between 1996 and 2025 was conducted. Eligible studies evaluated creatine supplementation in endurance and mixed-sport contexts, including both sport-specific and broader exercise populations when the exercise protocol, testing model, or outcomes were relevant to endurance or mixed-sport performance, recovery, or body composition. A total of 38 studies met the inclusion criteria. Outcomes were categorized into exercise performance, biochemical markers related to recovery and exercise stress, and body composition parameters. Results: Creatine supplementation was most often associated with reported favorable changes in repeated-sprint performance and high-intensity power output, particularly during intermittent, sprint-based, or power-endurance tasks. Several studies reported favorable changes in sprint performance, peak power, or total work output relative to placebo or baseline values in cycling, swimming, rowing, and canoeing/kayaking protocols, although findings were not uniform across studies and not all favorable within-group changes were placebo-superior. Some studies also reported favorable changes in end-phase sprint capacity during prolonged exercise. Findings related to recovery were less consistent. Selected studies reported reductions in inflammatory markers, including C-reactive protein (CRP) and tumor necrosis factor α (TNF-α), whereas markers of muscle damage showed mixed responses. Most supplementation protocols involved a 5–7-day loading phase of 20 g/day, occasionally followed by a maintenance dose of 2–5 g/day. Small increases in total body mass were commonly observed, while evidence regarding fat-free mass and aerobic outcomes remained limited or inconsistent. Conclusions: Current evidence suggests that creatine supplementation may be most relevant in selected endurance and mixed-sport contexts involving repeated high-intensity efforts, sprint finishes, or power-endurance demands, rather than for endurance performance broadly. In contrast, evidence for recovery-related biochemical responses, body composition changes, and aerobic adaptations remains equivocal. Further well-controlled, sport- or context-specific, and field-based studies are needed to better clarify the role of creatine in endurance and mixed-sport exercise. Full article

This study examined whether acute exercise performed within individualized physiological intensity zones affects multidimensional soccer shooting performance. Twenty male collegiate soccer players completed a Yo-Yo Intermittent Recovery Test Level 1 with portable gas analysis to determine the ventilatory threshold (VT) and respiratory compensation point (RCP). Three individualized zones were defined: Low (<VT), Moderate (VT–RCP), and High (>RCP). In a randomized design, players completed three 3 min shuttle-running bouts, each followed immediately by the 356 Soccer Shooting Test. Ball velocity (BV), shooting accuracy (SA), and shooting quality (SQ) were analyzed using repeated-measures ANOVA. Exercise condition significantly affected SA (p = 0.013) and SQ (p = 0.007), but not BV (p = 0.216). Bonferroni-adjusted comparisons showed that SA and SQ were lower in High than in Low, whereas no pairwise BV comparison reached significance. A sensitivity analysis using all ten recorded attempts rather than the original best-seven scoring approach showed an overall condition effect for BV without a significant pairwise comparison, retained overall effects for SA and SQ, and showed that the Low–High contrast remained robust only for SQ. Baseline comparisons were not significant. These findings indicate condition-specific shooting responses, with the clearest evidence for lower SQ after High compared with Low, supportive evidence for lower SA, and no significant primary condition effect for BV. Full article

Background/Objectives: Regular physical exercise is strongly recommended for individuals with type 1 diabetes mellitus (T1DM) because of its beneficial effects on cardiovascular fitness, insulin sensitivity, metabolic control, and overall health. Nevertheless, participation in physical activity remains limited, largely due to the fear of exercise-induced hypoglycemia and glycemic instability. Glycemic responses to exercise in T1DM are influenced by the interaction between exercise modality, circulating insulin levels, nutritional status, and diabetes technologies. Continuous aerobic exercise, resistance training, high-intensity interval exercise, and mixed intermittent activities elicit distinct metabolic and hormonal responses, resulting in heterogeneous glycemic trajectories. This narrative review aimed to provide a clinically oriented synthesis of the physiological mechanisms underlying exercise-related glycemic fluctuations in T1DM and to discuss integrated insulin- and carbohydrate-based strategies to support safer participation in physical activity in the context of modern diabetes technologies. Methods: A structured narrative review was conducted using PubMed/MEDLINE, Scopus, and complementary searches in Google Scholar to identify experimental studies, observational studies, systematic reviews, consensus statements, and clinical guidelines focused on exercise-related glycemic responses in individuals with T1DM. Only articles published in English were considered. Evidence was selected and synthesized according to relevance to exercise modality, insulin therapy strategies, carbohydrate management, and diabetes technologies, including continuous glucose monitoring, continuous subcutaneous insulin infusion, and automated insulin delivery systems. The final narrative synthesis was based on 44 selected studies, reviews, consensus statements, and guidance documents considered most relevant to the objectives of this narrative review. Results: Available evidence indicates that continuous moderate-intensity aerobic exercise is most consistently associated with progressive glucose declines and increased risk of hypoglycemia, particularly when performed in the presence of elevated insulin on board. In contrast, resistance exercise and short-duration high-intensity or anaerobic exercise more frequently induce stable glycemia or transient hyperglycemia through adrenergic stimulation and increased hepatic glucose output. Mixed and intermittent exercise modalities often produce more variable responses depending on exercise sequencing, nutritional status, and insulin exposure. Across studies, integrated adjustment of basal and prandial insulin doses together with individualized carbohydrate supplementation emerged as the most effective strategy to reduce exercise-related glycemic instability. Continuous glucose monitoring and insulin pump technologies improved glucose trend awareness and management flexibility; however, physical exercise remains a challenging condition for current automated insulin delivery algorithms and still requires active user-driven decision-making. Conclusions: Exercise management in T1DM should be based on an individualized interpretation of exercise modality, glucose trends, insulin exposure, and nutritional context rather than on fixed glucose thresholds alone. Combining anticipatory insulin adjustments, tailored carbohydrate strategies, and appropriate use of diabetes technologies may substantially reduce glycemic variability and improve confidence toward physical activity participation. Structured education and individualized clinical guidance remain essential to translate physiological knowledge into effective real-world exercise management. Full article

Background/Objectives: Intermittent fasting (IF) has gained increasing attention as a nutritional strategy to improve metabolic health, body composition, and disease-related outcomes. However, its effects are often interpreted as broadly uniform, despite growing evidence that biological sex may modulate fasting responses. This narrative review examines sex-specific differences in the physiological, endocrine, clinical, and psychosocial effects of IF in women and men. Methods: We conducted a narrative synthesis of human and preclinical evidence addressing IF protocols, mechanisms, benefits, adverse effects, and sex-related differences. Particular attention was given to substrate metabolism, hormonal regulation, neuroendocrine sensitivity, energy availability, exercise performance, chronic disease management, aging-related outcomes, and psychological or behavioral responses. Results: The available literature suggests that women and men share several beneficial responses to IF, including improvements in body composition and cardiometabolic markers, but may differ in the magnitude, tolerability, and mechanistic basis of these effects. Women appear to show greater sensitivity of reproductive and neuroendocrine function to energetic stress, particularly under conditions of low energy availability, high exercise load, or reproductive vulnerability. In contrast, men may exhibit preserved functional outcomes despite measurable endocrine adaptations, including changes in testosterone dynamics. Across both sexes, responses vary according to fasting protocol, nutritional adequacy, baseline metabolic status, life stage, and clinical context. Conclusions: Current evidence supports a sex-informed and context-specific interpretation of IF rather than universally applicable fasting prescriptions. Direct sex-comparative studies remain scarce, and many conclusions are inferred from parallel male and female studies. Future research should integrate sex as a core biological variable in precision nutrition and fasting-based interventions. Full article

Background: Sleep hygiene protocols (SHPs) have been shown to improve sleep and stress regulation; however, the role of cortisol in shaping downstream physiological and performance adaptations remains unclear. This study primarily examined the effects of a short-term SHP on sleep duration and salivary cortisol responses across resting, pre-exercise, and post-exercise states in female collegiate soccer players and, secondarily, whether cortisol statistically mediated selected aerobic and anaerobic performance outcomes. Methods: Fourteen players (22.1 ± 3.3 y; 157.8 ± 6.0 cm; 53.5 ± 3.9 kg) completed a randomised, counterbalanced crossover study comparing habitual sleep (no sleep hygiene protocol; nSHP) with a comprehensive SHP incorporating environmental, behavioural, and educational strategies. Salivary cortisol was sampled one hour post-waking and 30 min pre- and 15 min post-exercise during standardised testing sessions. Performance outcomes included vertical jump, sprint performance (40 m and repeated sprints [RAST]), and the Yo-Yo Intermittent Recovery Test Level 1. Linear mixed-effects models assessed cortisol responses, and mediation analyses explored cortisol–performance relationships. Results: After SHP, perceived (7.87 h vs. 6.5 h; p = 0.002, ESg = 1.0) and calculated sleep duration (8.5 h vs. 6.9 h; p = 0.004, ESg = 0.95) increased significantly. Cortisol was markedly lower following SHP at selected timepoints, including before RAST (−43.05%, p = 0.006, ESg = 0.84), with additional timepoint-specific, condition-dependent differences post-anaerobic and post-aerobic exercise (Δ = 7.37 and 5.98 nmol·L⁻¹, respectively; p < 0.001). Vertical jump height demonstrated significant total (9.92 cm, p = 0.002) and direct effects (7.72 cm, p = 0.034), and peak repeated-sprint performance showed a significant direct effect (p = 0.026). Cortisol did not significantly mediate any performance outcomes (ACME p > 0.05). Conclusions: Short-term sleep hygiene is associated with increased sleep duration, timepoint-specific modulation of cortisol responses, and selected anaerobic performance benefits; however, these effects were not explained by measured cortisol responses and are unlikely to be sustained without ongoing reinforcement or support, particularly in athletic populations. Full article

Background: Acute alcohol consumption may interfere with the dynamics between internal and external load during exercise, potentially attenuating cardiovascular responses. Objective: This study investigated the association between distance covered during a running test and mean heart rate, while examining the moderating role of the rating of perceived exertion (RPE) under conditions with and without acute alcohol ingestion. Methods: This crossover experimental study included 12 physically active male university students (23.7 ± 3.7 years). Participants completed two intermittent running sessions (control and alcohol conditions), separated by ≥48 h. In the alcohol condition, participants consumed 0.4 g of ethanol/kg of body mass. Heart rate was continuously monitored using a Polar RCX5 monitor, and total distance covered and RPE (Borg 6–20 scale) were assessed immediately after test completion. Analyses included paired comparisons, Pearson correlations, and linear regression models with interaction terms. Results: No significant associations between variables were observed in the control condition. With alcohol consumption, distance covered was positively associated with mean heart rate, and RPE significantly moderated this relationship. Conclusions: Acute alcohol ingestion may modify the interaction between external load, perceived exertion, and cardiovascular response during running. These results highlight the importance of integrated monitoring of internal and external load, especially in contexts involving recent alcohol consumption. Full article

Background: Blood flow restriction (BFR) resistance exercise has emerged as a training methodology capable of inducing muscular adaptations comparable to traditional high-load training despite substantially lower mechanical loads. While low-load BFR protocols (20–50% 1RM) are well-established, emerging evidence supports applications across the full loading spectrum, including moderate-to-high loads (>50–90% 1RM), contralateral training effects, and proximal–distal adaptations. In this second installment of the Blood Flow Restriction in Athletic Populations series, we review current evidence on BFR resistance exercise in athletic populations, with emphasis on morphological, neuromuscular, and functional adaptations across diverse application contexts. Methods: A narrative review of research examining BFR resistance exercise in trained and athletic populations was conducted via a PubMed/MEDLINE search. Search terms: (“blood flow restriction” OR “BFR” OR “occlusion training” OR “KAATSU”) AND (“resistance training” OR “resistance exercise” OR “strength training”) AND (“athletes” OR “athletic” OR “trained” OR “elite” OR “sport”) AND (“cross-education” OR “contralateral” OR “cross transfer” OR “proximal” OR “distal”). Studies investigating low-load (20–50% 1RM) and moderate-to-high load (>50% 1RM) protocols, contralateral cross-education effects, and proximal–distal adaptations were evaluated. Primary outcomes included muscle hypertrophy, strength, power, and sport-specific performance measures. Results: Low-load BFR resistance exercise has been shown to produce significant improvements in muscle hypertrophy and strength gains over 4–12 week interventions compared to low-load control conditions. Moderate-to-high load BFR enhanced barbell velocity and power output, particularly at loads > 80% 1RM with intermittent inflation protocols. Contralateral and cross-transfer effects of BFR training demonstrate variable efficacy across muscle groups, with the most consistent evidence supporting cross-transfer enhancement of training adaptations when BFR is applied to one body region while exercising another. Proximal BFR application induced adaptations in both proximal and distal musculature, suggesting systemic mechanisms beyond local vascular restriction. Conclusions: BFR resistance exercise represents a versatile training modality producing meaningful morphological and neuromuscular adaptations across the loading spectrum. Contralateral and proximal–distal effects expand practical applications for injury rehabilitation and targeted adaptation. These findings support BFR integration within periodized training programs when mechanical load management is prioritized. Full article

In this study, we employed forced convective cooling under the fan-cooling garment (FC condition) and conductive cooling under the neck cooling device (NC condition) in a hot environment during intermittent exercise to compare their effects on thermophysiological and subjective responses. Cooling was examined under two conditions: continuous application throughout both exercise and rest periods (Experiment 1) and application solely during rest periods (Experiment 2). As different participant groups were utilized for each experiment, the effects of cooling timing were interpreted in an exploratory manner. No differences were observed between conditions at baseline. In the FC condition, whole-body heat dissipation (HF_mean) significantly increased (p < 0.05), particularly during the recovery phase, and was associated with significant suppression of mean skin temperature rise (p < 0.05) and enhanced thermal comfort. Conversely, although localized heat dissipation at the neck (HF_neck) significantly increased under the NC condition, its effects on whole-body heat dissipation and mean skin temperature were limited. No consistent differences were observed between cooling conditions in axillary temperature or heart rate responses. These results suggest that forced convective cooling, which facilitates ventilation within clothing, and localized conductive cooling exhibit distinct thermal response characteristics. This study provides fundamental comparative data under controlled conditions, contributing to the understanding of the response characteristics of wearable cooling devices. Full article

Objective: This study aimed to investigate the acute effects of intermittent high-intensity badminton court exercise on cardiac autonomic modulation in male non-elite badminton players. Methods: This study employed a single-arm, repeated-measures experimental design, recruiting 25 healthy male collegiate badminton players. Participants completed five sets of high-intensity intermittent court tests until exhaustion, followed by calculation of stress index (SI), time-domain (RMSSD and SDNN), and frequency-domain (LF, HF, and LF/HF ratio) parameters at rest using a certified heart rate variability (HRV) analyzer. Repeated-measures ANOVA and effect size (partial η² and Hedges’ g) were used to assess changes and recovery trends of HRV parameters across time points: pre-test, immediate, 15 min, 24 h, and 48 h post-exercise. Results: (1) Stress index: The overall temporal trend showed statistical significance (p < 0.001, partial η² = 0.236, large effect size). Compared to pre-test, immediate and 15 min post-exercise increases were 8.24 (95% CI: 0.63–15.85) and 9.84 (95% CI: 3.07–16.61) respectively, with Hedges’ g values of 0.77 and 0.99 (p < 0.001, large effect sizes). Values returned to pre-test levels at 24 and 48 h with no significant differences (p > 0.05). (2) Time-domain parameters: The overall temporal trend was statistically significant (p < 0.001, partial η² = 0.553 for RMSSD and 0.586 for SDNN, both large effect sizes). Immediate post-exercise decreases in RMSSD and SDNN were 35.44 (95% CI: 21.95, 48.93) and 48.44 (95% CI: 32.49, 64.38) respectively, with Hedges’ g values of 2.31 and 2.78 (p < 0.001, large effect sizes). At 15 min, decreases were 31.64 (17.85, 45.42) and 41.48 (26.23, 56.72) respectively, with Hedges’ g values of 1.99 and 2.25 (p < 0.001, large effect sizes). Values returned to pre-test levels at 24 and 48 h with no significant differences (p > 0.05). (3) Frequency-domain parameters: Compared to pre-test, differences in LF, HF, and LF/HF were not statistically significant at any time point (all p > 0.05). Conclusions: Following high-intensity exercise leading to peripheral fatigue, cardiac autonomic function demonstrates a “suppression–recovery” dynamic pattern: cardiac stress levels increase significantly within 15 min post-exercise, with decreased overall HRV regulatory capacity and strong inhibition of parasympathetic activity; HRV status may return to baseline levels after 24 h. However, the frequency-domain indices of HRV showed no significant changes in response to the acute effects of high-intensity exercise. Full article

Backround and Objectives: Basketball performance is shaped by repeated high-intensity actions interspersed with brief recovery. Conventional continuous or strictly incremental testing may not fully capture short active-recovery dynamics relevant to stop-and-go sports. Material and Methods: This study applied a VT₂-referenced progressive–intermittent treadmill protocol and focused on 60-s active-recovery kinetics to describe effort tolerance in an applied basketball setting. Basketball players from Mureș County completed anthropometry (24 h pre-test, fasted) and a single laboratory visit. Pre-test training and diet were standardized for 48 h (submaximal training; predominantly carbohydrate intake). CPET was performed in 3-min stages (6.5 km·h⁻¹ start; +0.7 km·h⁻¹ per stage) and stopped at RER = 1.00 and/or blood lactate = 4.0 mmol·L⁻¹ (operational VT2). After 3 min active recovery, participants completed six 60-s high-speed bouts separated by 60-s active recovery intervals (AR1–AR6), with intensities prescribed at 120–180% of VT2-derived speed, followed by an 8-min active recovery. For each AR interval, linear regression over 0–60 s yielded slopes for VO₂, VO₂/HR, VCO₂, V̇E, VE/VO₂, VE/VCO₂, and PetCO₂. Results: VT₁ was determined at 2.29 m·s⁻¹ (VO₂ 32 mL·min⁻¹·kg⁻¹) and VT2 at 3.07 m·s⁻¹ (VO₂ 42 mL·min⁻¹·kg⁻¹). Maximal intermittent speed was 5.33 m·s⁻¹ (VO₂ 45.5 mL·min⁻¹·kg⁻¹; RER 1.06; PetCO₂ 38 mmHg). VO₂ differed across successive bouts (p = 0.0001), while PetCO₂ showed a small downward drift across repetitions. Peak indices (max speed, VE/VCO₂max, PetCO₂max, VEmax) were associated with phase-specific recovery slopes across early, mid, and late recovery periods (false discovery rate–adjusted correlations). Lactate decreased over 8 min, but lactate change rates were not associated with peak indices. Conclusions: The VT₂-referenced progressive–intermittent protocol appears feasible in basketball players and provides phase-dependent recovery information that complements conventional peak CPET outcomes, with potential relevance for applied team settings. Full article