Publications — Aquatics Lab

Jin, R., Chen, C., Finlay, M.J., Cuenca-Fernández, F., Zhong, Y., Gao, D., & Wu, Z. (2026). The effects of high-intensity interval training on competitive swimmers: A systematic review and meta-analysis Journal of Science and Medicine in Sport.https://doi.org/10.1016/j.jsams.2026.02.015

OBJECTIVES This systematic review and meta-analysis evaluated the effects of high-intensity interval training (HIIT) on physiological adaptations and performance in competitive swimmers.

METHODS Following PRISMA guidelines, five databases were searched from inception to July 2025. Eligible studies included randomized controlled trials and intervention studies examining HIIT in competitive swimmers. Methodological quality was assessed using PEDro scale. Random-effects meta-analyses calculated standardized mean differences (SMDs) with 95% confidence intervals.

RESULTS Eleven intervention studies comprising 237 competitive swimmers (mean age 15.4 ± 2.5 years) were included. HIIT significantly improved VO2max (SMD = 0.86, 95% CI: 0.52-1.20, p < 0.001, I2 = 0%) and swimming performance (SMD = 0.52, 95% CI: 0.36-0.68, p < 0.001). Sprint events showed greatest improvements (1.8%). Polarized training produced superior VO2max gains (8.8%) compared to traditional sprint interval training (6.6%) and threshold training (4.7%). Interventions ≥8 weeks yielded larger effects (SMD = 0.78) than shorter protocols (<8 weeks) (SMD = 0.42). Ultra-short race-pace training maintained 98.5% of target velocity with 24% lower lactate and 14% lower perceived exertion compared to traditional methods.

CONCLUSIONS HIIT produces consistent improvements in aerobic capacity and swimming performance in competitive swimmers. For sprint events (50-100 m), ultra-short race-pace training is recommended; for middle-distance (200-400 m), polarized training; for distance events (≥800 m), preliminary evidence suggests that pyramidal approaches may be beneficial, though further research is needed. Minimum 8-week interventions are required for meaningful adaptations.

Oliveira, J.P., Marinho, D.A., Sampaio, T., Barbosa, T.M., Silva, A.J., Arellano, R., & Morais, J.E. (2026). Lap stability, stroke kinematics, and turn performance in female 200 m short-course finals at the 2019 LEN European Championships Journal of Sports Analytics, 12.https://doi.org/10.1177/22150218251413358

The aim of this study was to analyse lap performance stability, stroke kinematic variables in the clean swimming phase and turn performance in the finals of the four 200 m short course (SCM) events (freestyle, backstroke, breaststroke, and butterfly). The sample included thirty-two elite female swimmers who competed in the 200 m finals at the 2019 LEN European Short Course Championships in Glasgow. Lap times, stroke kinematics, and turns were analysed using two approaches: (i) official lap time comparison (50 m), and; (ii) comparison of consecutive segments (25 m). Based on the official lap time comparison, performance significantly decreased over time (p < 0.001) with strong effect sizes in all strokes (η 2 between 0.89 and 0.96). Pairwise comparisons between consecutive 25 m segments were not significant. Turn time increased in all four strokes with strong effect sizes (p < 0.001; η 2 between 0.71 and 0.84). The start contributed ∼6% and turns ∼52% of the total race time. These findings highlight that traditional pacing analysis based on official splits may lead to misleading interpretations of performance in SCM events. Analysing 25 m segments provides a more accurate representation of race dynamics and contributes to a clearer understanding of pacing stability in short-course swimming.

Papadimitriou, K., Ruiz-Navarro, J.J., Cuenca-Fernandez, F., & Margaritelis, N.V. (2026). Training intensity distribution for sprinter swimmers: suggestions for swimming coaches and scientists European Journal of Applied Physiology, 126(2), 619-628.https://doi.org/10.1007/s00421-025-06064-x

The inclusion of the 50 m butterfly, backstroke, and breaststroke events in the 2028 Olympic Games is likely to influence training methodologies and performance trajectories, considering that in competitive swimming, coaches already implement different training approaches for sprinter swimmers. This study examines whether elite sprint specialists, particularly those specializing in 50 m events, should prioritize high-intensity interval training (HIIT) over the traditionally dominant overdistance training models. The discussion aims to inform coaches and researchers about evolving approaches to sprint training and guide future research on intensity distribution in sprint swimming. There is a clear distinction in energy system demands between sprint events: the 50 m event has an aerobic contribution of approximately 20%, while in the 100 m event, the aerobic contribution can rise to around 40-50%. Despite the high anaerobic demands of the 50 m, many coaches continue to implement a Polarized Training Intensity Distribution (TID), characterized by a significant proportion of aerobic training. Based on recent developments in sprint swimming and some aspects of current literature support for the potential benefits of a greater emphasis on HIIT, assisted sprints, and overspeed training, along with earlier and more targeted specialization for sprinters, and an increased emphasis on dryland strength and conditioning. Nevertheless, further studies are needed to examine the efficacy of different TID approaches, particularly for elite athletes specializing exclusively in the 50 m distance.

Xu, K., Blazevich, A.J., Boullosa, D., Ramirez-Campillo, R., Yin, M., Zhong, Y., Tian, Y., Finlay, M., Byrne, P.J., Cuenca-Fernández, F., & Wang, R. (2026). Response to Comment on “Optimizing Post-Activation Performance Enhancement in Athletic Tasks: A Systematic Review with Meta-Analysis for Prescription Variables and Research Methods” Sports Medicine, 56(1), 293-294.https://doi.org/10.1007/s40279-025-02319-x

Abstract not publicly available · consult publisher.

Born, D., Lorentzen, J., Ruiz-Navarro, J.J., Stöggl, T., Romann, M., & Björklund, G. (2025). Focus on One Swimming Stroke or Compete in Multiple: How Much Specialization Is Needed to Become a World-Class Female Swimmer? Journal of Functional Morphology and Kinesiology, 10(1), 64.https://doi.org/10.3390/jfmk10010064

Objectives: To investigate performance development and variety in swimming strokes of female swimmers from early junior to elite age. Methods: A total of 194,788 race times of female 200 m swimmers representing 77 nations were ranked at peak performance age and clustered into world-class finalists (>850 swimming points), international-class (750–850), national-class (650–750) and regional-class swimmers (550–650). Annual best times for each swimming stroke were retrospectively extracted throughout adolescence from 13 years of age. Longitudinal performance development and differences between the swimmers’ main and their secondary swimming strokes were analyzed using linear mixed model. Results: World-class freestyle swimmers show significantly (p ≤ 0.042) higher swimming points across all age categories compared to international-, national- and regional-class swimmers. Linear mixed model analysis indicates a significant performance progression for international- and national-class freestyle swimmers up to the 19–20-year-old category (p ≤ 0.038), but an earlier plateau was observed for regional-class swimmers (p = 0.714). Comparing main and secondary swimming strokes, freestyle swimmers show the highest degree of specialization. For breaststroke and individual medleys, specialization increases with increasing performance level and the closer an athlete is to elite age. World-class butterfly and backstroke finalists show the lowest specializations in terms of the smallest number of significant differences compared to performances in their secondary swimming strokes. Conclusions: Higher ranked swimmers show a greater degree of specialization. As different specialization patterns are evident for the various swimming strokes, decision makers and talent specialists should align development guidelines accordingly and base them on the most advantageous combinations of swimming strokes.

Ruiz-Navarro, J.J., Boullosa, D., Gil-Calvo, M., & Born, D. (2025). Editorial: Developing sprinters: how can we swim, cycle, and run faster? Frontiers in Sports and Active Living, 7.https://doi.org/10.3389/fspor.2025.1734106

Swimming, cycling, and track and field are among the most watched sports in Olympic 20Games. Despite the complex interaction of aerobic and anaerobic energy supply, sprint 21 performances in these three sports heavily rely on rapid energy production from the 22 anaerobic metabolism. Although event durations and intensities may be similar between 23 sports, training regimens of swimmers, cyclists and track and field athletes differ 24 considerably and provide the opportunity for cross-disciplinary learning. Therefore, this 25 research topic aimed to gather insights on the determinants of sprint performances across 26 these sports to develop faster athletes.

Ruiz-Navarro, J.J., & Born, D. (2025). Annual Performance Progression in Swimming Across Competition Levels and Race Distances Journal of Functional Morphology and Kinesiology, 10(3), 297.https://doi.org/10.3390/jfmk10030297

Objective: As performance progression provides an essential indicator for talent selection and development, this study aimed to compare annual swimming performance progression between different competitive levels and to establish benchmarks for long-term athlete development. Methods: Annual best times of swimmers who competed up to the age of 21 years and achieved over 450 World Aquatics points were extracted from the database of European Aquatics. A total of 13,310 male and 7798 female pool swimmers of all race distances were grouped into three performance levels. Results: The results showed a continuous decline in annual performance progression throughout the years across all race distances (all p < 0.001) and in both sexes. There were differences between performance level across the age groups for all race distances in male swimmers, but only for the 100–400 m races in females (p < 0.05). Absolute performance showed significant main effects for level and age over all race distances for both sexes (all p < 0.001). Conclusions: Annual performance progression of swimmers consistently decreases across the competitive lifetime in both sexes, regardless of race distance and performance level. The event-specific benchmarks should be used as a framework to set realistic goals for both sexes and swimmers of different competitive levels, as well as to guide swimmers throughout their careers.

Ruiz-Navarro, J.J., Born, D., Febles-Castro, A., Gay, A., López-Belmonte, Ó., Morales-Ortíz, E., López-Contreras, G., & Arellano, R. (2025). Correction: Exploring the load–velocity profile with sprint swimming performance and sex differences International Journal of Sports Medicine, 46(08), e2-e2.https://doi.org/10.1055/a-2598-0220

Abstract not publicly available · consult publisher.

Santos, C.C., Ruiz-Navarro, J.J., Martinho, D., Ferreira, F.A., Marinho, D.A., & Costa, M.J. (2025). Understanding upper limbs in-water force in young swimmers with Statistical Parametric Mapping analysis Journal of Biomechanics, 189, 112847.https://doi.org/10.1016/j.jbiomech.2025.112847

The present study aimed to compare swimmers' in-water force according to swimming performance tiers within the same age group and compare the dominant and non-dominant upper limbs within the same tier throughout continuous and discrete analyses. Fifty-two young swimmers (girls and boys: 12.13 ± 0.71 years) were split up into two tiers based on the mean speed: Tier-1 (n = 28), low-tier; and Tier-2 (n = 24), top-tier. In-water forces of upper limbs were assessed with a differential pressure system composed of two hand sensors during 25 m front crawl swimming. Force-time curves of the underwater paths and the mean peak force (FPEAK, N) were considered for further analysis using discrete and continuous analyses (Statistical Parametric Mapping, SPM). Results showed that top-tier swimmers applied greater in-water forces in front crawl (∼61 N) when compared to the low-tier (∼51 N). With SPM, differences were found between 64-74 % and ∼60-90 % of the underwater path of the stroke cycle for the dominant and non-dominant upper limb, respectively. Both upper limbs appear to apply a similar in-water force (p > 0.05), regardless of the performance tier. Therefore, swimmers within the same age group differ in the upper limbs applied in-water force during the front crawl. The SPM analysis seems to provide more insights into the applied force during the hand path,as it allows identifying differences according to the underwater phases.

Staunton, C., Ruiz-Navarro, J.J., Edholm, P., & Born, D. (2025). The influence of tactical positioning on performance in world-championship freestyle swimming Frontiers in Sports and Active Living, 7.https://doi.org/10.3389/fspor.2025.1600554

PurposeThis study examined tactical positioning and pacing in short-distance (100 m), middle-distance (200 m, 400 m) and long-distance (800 m, 1,500 m) freestyle events, focusing on the influence of race distance, competition round (HEAT vs. FINAL), and sex.MethodsRace data from multiple World Championships (2013–2023) were analyzed. Spearman's rank correlations (ρ) were calculated to examine rank stability across race distances, competition rounds, and sex. Additionally, lane distributions of Top3 finishers were analyzed to assess the impact of lane position on race outcomes.ResultsRank correlations increased progressively from the first to the final lap across all race distances (p < 0.05). Long-distance events exhibited earlier rank stabilization, with correlations reaching ρ ≥ 0.90 by 50% race completion, whereas middle-distance events showed greater positional variability throughout. Rank correlations were lower in FINALS than in HEATS (p < 0.05), indicating greater positional shifts in high-stakes races. No significant sex-based differences were observed (p > 0.05). Central lanes (4 and 5) were associated with the highest Top3 finish rates, while outer lanes (0, 1, 8, and 9) had the lowest, particularly in long-distance events.ConclusionFinals foster more dynamic race strategies, with increased positional changes. Rank stability was achieved at a relatively earlier proportion of the race in long-distance events compared to middle-distance events. By the final lap, rank stability converged across all distances, suggesting that race order was largely set before the last lap, emphasizing early tactical positioning over late-race surges. These findings offer insights into optimizing race tactics and pacing in elite swimming.

Staunton, C.A., Ruiz-Navarro, J.J., & Born, D. (2025). Stroke rate–stroke length dynamics in elite freestyle swimming: application of kernel density estimation Frontiers in Sports and Active Living, 7.https://doi.org/10.3389/fspor.2025.1656633

ObjectivesTo analyse stroke rate (SR) and stroke length (SL) combinations among elite swimmers to better understand stroke strategies across all race distances of freestyle events.DesignWe analysed SR and SL data from 324 male and female swimmers competing in all individual freestyle events (50 m to 1,500 m) at the 2019 European Short-Course Championships using video-based kinematic analysis.MethodsTwo-dimensional kernel density estimation (2D KDE) was applied to visualise SR–SL combinations. Spearman correlations quantified relationships between stroke parameters and speed by sex and race distance.ResultsIn the 50 m sprint, SL showed the strongest positive correlation with speed (men: ρ = 0.57; women: ρ = 0.50), while SR correlations were trivial. As race distance increased, SR correlations with speed strengthened, reaching moderate levels in long-distance events (men's 1,500 m: ρ = 0.37; women's 800 m: ρ = 0.45), whereas SL correlations weakened. The 2D KDE heatmaps revealed an inverse SR–SL relationship, with medallists often employing stroke strategies distinct from finalists and the broader field. Gold medallists in sprint events favoured above-average SR without compromising SL, while in middle- and long-distance races, a shift toward higher SR and reduced SL was observed, particularly among women.ConclusionsThese findings highlight the complexity and individuality of stroke mechanics at elite levels and suggest that superior conditioning and technique enable medallists to sustain elevated SR without compromising SL. The application of 2D KDE provides a novel, intuitive method to capture nuanced biomechanical strategies, offering valuable insights for coaching and performance optimisation.

Xu, K., Blazevich, A.J., Boullosa, D., Ramirez-Campillo, R., Yin, M., Zhong, Y., & et al. (2025). Optimizing Post-activation Performance Enhancement in Athletic Tasks: A Systematic Review with Meta-analysis for Prescription Variables and Research Methods Sports Medicine, 55(4), 977-1008.https://doi.org/10.1007/s40279-024-02170-6

BACKGROUND: Post-activation performance enhancement (PAPE) has demonstrated efficacy in acutely improving athletic performance. However, its distinction from general warm-up (GW) effects remains ambiguous, and experimental designs adopted in most PAPE studies exhibit important limitations. OBJECTIVES: The aims of this work are to (i) examine the effects of research methodology on PAPE outcomes, (ii) explore PAPE outcomes in relation to comparison methods, performance measures, GW comprehensiveness, recovery duration, participants' characteristics, conditioning activity (CA) parameters, and (iii) make recommendations for future PAPE experimental designs on the basis of the results of the meta-analysis. METHODS: Four databases were searched for peer-reviewed English-language literature. Risk of bias was assessed using a modified Cochrane Collaboration's tool and PEDro scale. PAPE groups were compared with control groups, pre-conditioning activity (pre-CA) performances were compared with post-conditioning activity (post-CA) performances throughout a verification test in PAPE groups, and control groups were compared before and after the "rest" period using a three-level meta-analysis. Further analyses, including subgroup analysis and both linear and nonlinear meta-regression methods, were used to explore the effect of different moderating factors on PAPE magnitude. A subgroup analysis of GW comprehensiveness was conducted using four classification methods. One method classified GW as non-comprehensive (stretching or jogging only), partially comprehensive (stretching, jogging, and low-intensity self-weighted dynamic exercises), and comprehensive (adding maximal or near-maximal intensity CAs to a partially comprehensive GW). The other three classifications were adjusted according to the type and number of GW exercises. Certainty of evidence was assessed using the GRADE approach. RESULTS: The final analysis included 62 PAPE studies (1039 participants, male: n = 857, female: n = 182) with a high risk of bias and low certainty of pooled evidence. A trivial PAPE effect was observed from pre- to post-CA (effect size [ES] = 0.12, 95% CI [0.06 to 0.19], prediction intervals [PI] = - 0.29 to 0.54); a small PAPE effect was observed when compared with a control group (ES = 0.30, 95% CI [0.20 to 0.40], PI [- 0.38 to 0.97]). The slightly greater effect against control resulted from a small decrease in performance in control groups (ES = - 0.08, 95% CI [- 0.13 to - 0.03], PI [- 0.30 to 0.14]), but there was no relationship with between PAPE recovery time (beta = - 0.005, p = 0.149). Subgroup analyses showed that PAPE magnitude was greater for non-comprehensive GWs (ES = 0.16) than comprehensive (ES = 0.01) and partially comprehensive GWs (ES = 0.11). In contrast, the control group showed a decline in performance after comprehensive GW (ES = - 0.20). An inverted U-shaped PAPE was noted as a function of recovery time. In some cases, PAPE appeared to manifest at < 1 min post CA. Additionally, participants with longer training experience (ES = 0.36) and higher training levels (ES = 0.38) had larger PAPE magnitudes. PAPE effect was higher in females (ES = 0.51) than males (ES = 0.32) and mixed groups (ES = 0.16) but did not reach a significant difference (p > 0.05). Plyometric exercise (ES = 0.42) induced greater PAPE amplitude than traditional resistance exercise (ES = 0.23), maximal isometric voluntary contraction (ES = 0.31) and other CA types (ES = 0.24). CONCLUSIONS: Although the overall pooled results for both PAPE pre- versus post-CA and PAPE versus control group comparisons showed significant improvement, the wider and past-zero prediction intervals indicate that future studies are still likely to produce negative results. The comprehensiveness of the GW, the time between GW and the pre-CA test, participant sex, training level, training experience, type of CA, number of CA sets, and recovery time after CA all influence the PAPE magnitude. The PAPE magnitude was trivial after comprehensive GW, but it was greater in studies with a control group (i.e., no CA) because performance decreased over the control period, inflating the PAPE effect. Finally, two theoretical models of PAPE experimental design and suggestions for methodological issues are subsequently presented. Future studies can build on this to further explore the effects of PAPE. PROTOCOL REGISTRATION: The original protocol was prospectively registered (osf.io/v7sbt) with the Open Science Framework.

Barbosa, T.M., Barbosa, A.C., Simbaña Escobar, D., Mullen, G.J., Cossor, J.M., Hodierne, R., Arellano, R., & Mason, B.R. (2023). The role of the biomechanics analyst in swimming training and competition analysis Sports Biomechanics, 22(12), 1734-1751.https://doi.org/10.1080/14763141.2021.1960417

ABSTRACT Swimming analysts aid coaches and athletes in the decision-making by providing evidence-based recommendations. The aim of this narrative review was to report the best practices of swimming analysts that have been supporting high-performance athletes. It also aims to share how swimming analysts can translate applied research into practice. The role of the swimming analyst, as part of a holistic team supporting high-performance athletes, has been expanding and is needed to be distinguished from the job scope of a swimming researcher. As testing can be time-consuming, analysts must decide what to test and when to conduct the evaluation sessions. Swimming analysts engage in the modelling and forecast of the performance, that in short- and mid-term can help set races target-times, and in the long-term provide insights on talent and career development. Races can be analysed by manual, semi-automatic or fully automatic video analysis with single or multi-cameras set-ups. The qualitative and quantitative analyses of the swim strokes, start, turns, and finish are also part of the analyst job scope and associated with race performance goals. Land-based training is another task that can be assigned to analysts and aims to enhance the performance, prevent musculoskeletal injuries and monitor its risk factors.