Piero Ruggeri

In taekwondo combat, agility is essential for rapid movement and maintaining match pace, as well as for executing unilateral technical actions swiftly in multidirectional planes. Furthermore, it is also required to dodge and block opponents’ repeated attacks and to handle clinch situations and close-quarters combat effectively. This brief review aims to present the sport-specific tests available in the current literature for change of direction (COD) assessments in taekwondo, summarizing and analyzing the development and validation process of each test. This narrative review was conducted in accordance with the SANRA checklist. A literature search of PubMed/MEDLINE, Google Scholar and Scopus was performed for research articles from September 2017 to February 2026. The inclusion criteria were studies focusing on taekwondo athletes of any competitive level, age category, and nationality; evaluating COD through sport-specific testing; reporting at least one aspect of the validity, reliability, or sensitivity of the test; or providing a practical application of the test protocol. A total of 113 records were identified across databases. After deduplication, screening, and full-text assessment, 26 articles focused on the specific assessment of COD in taekwondo using three currently available tests (i.e., the Taekwondo-Specific Agility Test, the Taekwondo-Specific Aerobic–Anaerobic-Agility test, and the Taekwondo-Specific Change-of-Direction Speed Test) were included in the results. These tests incorporate greater sport-specificity and may provide greater ecological relevance than general tests, as they mimic the typical movements and technical actions of the match. However, the distinct methodological and measurement characteristics of each test must be considered in practical use. Future research should explore further aspects of validity (such as face, convergent and predictive validity), as well as clarify the reliability (i.e., test–retest and/or intra-/inter-rater) and sensitivity of these tests and develop classification tables. Practitioners can use the available tests to monitor the acute and chronic effects of training protocols on sport-specific COD performance, to monitor the relationship between the latter and other fundamental fitness components, or to classify athletes.

Panascì, M, Rago, V, Ferrando, V, Castagna, C, Ruggeri, P, and Faelli, E. Weekly External Load in Italian Women's Football Players: Influence of Playing Time. J Strength Cond Res XX(X): 000–000, 2026—This study compared external load distribution during the first round of the season between starters (ST) and nonstarters (NS) in Italian professional women's football players. Subjects were 18 players (age: 24.3 ± 3.9 years; height: 167 ± 4.2 cm; body mass: 60.4 ± 5.4 kg) from the same team. External load was measured using global positioning system technology. Variables included total distance (TD), high-speed running distance (19.8–25.2 km·h ⁻¹ ), sprint distance (>25.2 km·h ⁻¹ ), and the number of accelerations (ACC; >3.0 m·s ⁻² ) and decelerations (DEC; <−3.0 m·s ⁻² ). Nine players were classified as ST, defined as those who played at least 60 minutes in 3 consecutive matches during this phase of the season, whereas the remaining 9 players were classified as NS. Results revealed that NS had significantly higher values of TD ( p = 0.001), high-speed running ( p = 0.002), ACC ( p < 0.001), and DEC ( p < 0.001) on MD+2 compared with ST. In addition, NS exhibited significantly greater values of TD ( p = 0.003), ACC ( p = 0.035), and DEC ( p = 0.006) on MD−4 compared with ST. No significant differences were observed between groups on MD−3, MD−2, and MD−1. These findings suggest that NS experienced higher external training loads on MD−4 and MD+2, possibly reflecting compensatory training loads because of limited or no match participation.

This single−group observational study investigated, in female football players, the associations between internal training load (ITL) metrics and changes in sprint endurance and aerobic fitness following a 4−week off−season training program combining small−sided games (SSGs) and repeated−sprint training (RST). Fifteen adolescent female football players (age: 14.9 ± 1.6 years) completed two SSG and two RST sessions per week, for a total of 16 sessions. Sprint endurance was assessed by the 30−s all−out test (30−s test), while aerobic fitness was evaluated using the Yo−Yo Intermittent Recovery Test Level 1 (YYIR1), both administered pre− and post−intervention. ITL was quantified using heart rate−derived measures, including time spent at ≥ 90% of peak heart rate (T ≥ 90%HRpeak), training impulse (TRIMP), and session rating of perceived exertion training load (sRPE−TL). Significant changes were observed in both sprint endurance (30−s test: p = 0.004, d = 1.88) and aerobic fitness (YYIR1: p < 0.001, d = 1.21). Weekly TRIMP and T ≥ 90%HRpeak showed significant increases throughout the intervention period (p < 0.01), whereas sRPE−TL remained relatively stable. Correlation analyses revealed significant associations (p ≤ 0.008) between ITL metrics and performance changes: sRPE−TL was correlated with changes in the YYIR1 (ρ = 0.94), TRIMP with the 30−s test (ρ = 0.66), and T ≥ 90%HRpeak with the 30−s test (r = 0.87) and YYIR1 (r = 0.67). These findings suggest that, in adolescent female football players, ITL metrics, particularly T ≥ 90%HRpeak, are associated with changes in sprint endurance and aerobic fitness during a short−term, HIIT off−season program. Moreover, sRPE−TL and TRIMP may provide practical indicators for monitoring individual training responses in short off−season periods. However, our findings should be interpreted with caution due to the absence of a control group.

Objective: The effects of fatigue on swimming propulsion are unclear. This study examined upper-limb propulsive force and bilateral coordination during constant-speed front crawl performed until exhaustion. Methods: Twelve competitive swimmers completed a visually paced front-crawl trial performed at a constant speed (95% of maximal speed) until volitional exhaustion. Upper-limb propulsion (pressure-derived) was quantified using wearable differential-pressure mini-paddles synchronized with high-speed video. Propulsive force and impulse were analyzed at ten standardized time points (10–100% of test duration), distinguishing the early (entry–catch–pull) phase and the push phase of the stroke cycle. Results: Total overall propulsive impulse (time-integral of propulsive force) and mean propulsive force decreased significantly as early as 30–40% of test duration, with the largest reductions occurring during the push phase. Interestingly, push-phase impulse declined earlier in the non-dominant left arm (from 20% of test duration) compared to the dominant right arm (from 40%), whereas force generated during the early phase did not change. Peak propulsive force decreased at later stages, while intra-cycle timing indices (peak timing and force centroid) and inter-limb asymmetry remained unchanged. Stroke frequency increased from mid-test onward and was strongly negatively associated with stroke efficiency (r = −0.79). Stroke efficiency correlated positively with push-phase impulse and peak force. Conclusions: During constant-speed front crawl performed to exhaustion, propulsion progressively declines, primarily through reduced force and impulse during the push phase rather than changes in the early (entry–catch–pull) phase or temporal and asymmetry-related variables. Increased stroke frequency initially compensates for declining propulsion but ultimately fails to maintain the imposed swimming velocity.

Background: This study aimed, in U11 male football players, (i) to investigate the effects of an 8-week running-based HIIT or SSGs program on aerobic fitness, neuromuscular performance and internal load, and (ii) to compare training-induced changes in performance variables between training modalities. Methods: Sixteen U11 football players were randomly assigned to either the SSGs group (4 vs. 4 format, 5 × 3 min with 1 min of rest between bouts) or the HIIT group (5 × 3 min of 15 s running at 100% peak velocity (Vpeak) alternating with 15 s of recovery, and 1 min of rest between sets). The intervention period lasted 8 weeks. Aerobic fitness (Yo-Yo Intermittent Recovery Level 1 Children’s Test, YYIR1C), sprint time performance (10 m and 20 m sprints tests) and change-of-direction (COD) ability (Arrowhead Agility Test) were assessed before and after the intervention. Heart rate (HR) and rating of perceived exertion (RPE) were assessed as indices of internal load. Results: Both SSGs and running-based HIIT produced comparable improvements in YYIR1C distance, Vpeak (p < 0.05), with no significant change in the between-group difference. Neuromuscular gains occurred only after SSGs (p < 0.05), with similar 10 m sprint improvements between groups but superior 20 m gains for SSGs (p < 0.01). COD ability improved in both groups (p < 0.05), with broader enhancements following SSGs (p < 0.05). Finally, running-based HIIT elicited greater HRpeak and higher RPE than SSGs (p < 0.05) across most intervention weeks. Conclusions: In U11 male football players, both SSGs and running-based HIIT effectively improved aerobic fitness and COD performance. However, SSGs may offer additional benefits for sprint development with lower perceived psychological stress.

Sarcopenia is a progressive, age-related loss of skeletal muscle mass, strength, and function, strongly associated with frailty, disability, and chronic disease. Its pathogenesis involves chronic low-grade inflammation, hormonal imbalance, and impaired anabolic signaling, making biomarkers essential for diagnosis, prognosis, and intervention monitoring. This review systematically analyzes randomized controlled trials (RCTs) evaluating the impact of physical exercise on biomarkers relevant to sarcopenia. Exercise modulates both pro-inflammatory markers (e.g., IL-6, TNF-α, CRP) and anti-inflammatory cytokines (e.g., IL-10, IL-15), while also affecting growth factors like IGF-1, myostatin, and follistatin. These changes support muscle anabolism, reduce catabolic signaling, and improve physical performance. In addition, we highlight a growing class of emerging exerkines, including irisin, apelin, beta-aminoisobutyric acid (BAIBA), decorin, brain-derived neurotrophic factor (BDNF), and meteorin-like factor (Metrnl). These molecules exhibit promising roles in mitochondrial health, lipid metabolism, muscle regeneration, and immune modulation, key processes in combating inflamm-aging and sarcopenic decline. Despite encouraging findings, biomarker responses remain heterogeneous across studies, limiting translational application. The integration of biomarker profiling with exercise prescription holds the potential to personalize interventions and guide precision medicine approaches in sarcopenia management. Future large-scale, standardized trials are needed to validate these biomarkers and optimize exercise protocols for aging populations.

Aging entails concurrent declines in physical and cognitive domains, contributing to reduced independence, higher fall risk, and lower quality of life. Understanding how motor performance relates to cognition is crucial for prevention in community-dwelling older adults. This cross-sectional study investigated associations between physical fitness—including strength, endurance, balance, and aerobic capacity—and cognitive outcomes assessed by Trail Making Tests (TMT-A, TMT-B), the Digit Symbol Substitution Test (DSST), and dual-task cost in the Timed Up & Go Test (TUG_DTC). Thirty-four sedentary but cognitively healthy adults aged ≥60 years were evaluated. Quadriceps strength was significantly related to TUG_DTC and executive function (TMT-B), while upper-limb endurance correlated with both attentional and executive measures. Dynamic balance, particularly in posterior directions, was linked to DSST and TMT-B, and 6-min walk test performance was associated with executive functioning and processing speed. TUG_DTC itself showed strong correlations with cognitive outcomes, underscoring its sensitivity to motor–cognitive interference. These findings highlight selective motor–cognitive relationships and suggest that simple, field-based tests may serve as early markers of cognitive vulnerability. Targeting lower-limb strength, balance, and aerobic capacity could represent cost-effective strategies to promote mobility and cognitive resilience in aging populations.

Background: The off-season is often characterized by a significant decrease or even a complete cessation of training. If this reduction is not planned properly, it can result in detraining. Despite numerous studies examining the effects of HIIT in football players, its specific role in mitigating detraining and maintaining aerobic and anaerobic performance during the off-season in adolescent female football players remains underexplored. Therefore, this study evaluated the effects of a 4-week off-season high-intensity training (HIIT) program on aerobic performance level and sprint endurance ability in Under-15 (U-15) female football players. Methods: Fifteen U-15 female football players from a professional club completed an experimental protocol consisting of two HIIT formats: Small-Sided Games (SSGs) and Repeated Sprint Training (RST), each performed twice weekly. Before and after the intervention period, participants performed the Yo-Yo Intermittent Recovery Level 1 (YYIR1) test to gauge aerobic performance and the 30-seconds sprint test to assess sprint endurance. The internal training load was monitored via heart rate (HR) and blood lactate concentration ([La]⁺), while external training load metrics included the total distance (TD), moderate-speed distance (MSD), high-speed distance (HSD), acceleration distance (≥3 m·s⁻²; ACC), and deceleration distance (≤−3 m·s⁻²; DEC). Results: YYIR1 improved by 57% (p = 0.0001; d = 1.12; 95% CI: 121.94–224.71) and the 30-s test performance increased by 13% (p = 0.004; d = 0.91; and 95% CI: 14.46–25.53) following the intervention period. A very large correlation between time spent at 90–95% HRmax and the 30-s test (r = 0.90, p = 0.0001) and YYIR1 (r = 0.81, p = 0.0001) performance was observed. Very large and nearly perfect correlations between DHS and YYIR1 (r = 0.82, p = 0.0001) and the 30-s test performance (r = 0.94, p = 0.0001), respectively, were found. Conclusions: In U-15 female football players, a four-week off-season HIIT program improved both aerobic performance and sprint endurance ability, indicating that a HIIT regime attenuates the off-season detraining, thus supporting a better-conditioned return to play. Coaches may implement 4-week high-intensity off-season programs to enhance aerobic performance and start the pre-season with a satisfactory level of aerobic fitness and sprint endurance.

Background: Aging is associated with reduced joint flexibility and balance, which increases the risk of falls, especially during stair descent where motor control is critical. Stretching has been shown to improve ankle range of motion and gait speed. This study investigated the effects of a 4-week training program combining stretching plus resistance training (RT) with elastic bands on functional capacity and ankle stability during stair descent in older women. Methods: Twenty-four active older women (mean age: 73.1 ± 0.97 years) were randomly assigned to static stretching (SS), dynamic stretching (DS) and control (CG) groups. All participants completed two weekly 60 min sessions consisting of progressive RT preceded by three different warm-ups. The SS and DS groups completed static or dynamic stretching, while the CG walked. Assessments included 30s-Chair Stand (30s-CS), Handgrip Strength (HGS), Time Up and Go (TUG), Chair Sit and Reach (CSR), Rating of Perceived Exertion (RPE), and ankle kinematics during stair descent. Results: All groups improved 30s-CS and TUG (p < 0.05). Only the SS group improved CSR in both legs and the ankle dorsiflexion angle during stair descent at final foot contact (p = 0.002). RPE increased over time across all groups (p < 0.0001); however, the SS and DS groups reported lower exertion than the CG group in first–second weeks (p = 0.0001–0.003). Conclusions: SS prior to progressive RT improved flexibility and ankle kinematics during stair descent, thus reducing the perception of effort particularly during the initial training phase. These findings indicate the effectiveness of SS as a warm-up strategy for increasing ROM and potentially reducing the risk of falls in this population.