Swimnews: Scientific Articles on Swimming

Current research listing presented by swimclinic.ch

Creatine Supplementation in Endurance and Mixed-Sport Contexts: A Scoping Review of Performance, Recovery, and Body Composition

Wesołowski, I. et al.: Nutrients. 2026 May 24;18(11):1677. doi: 10.3390/nu18111677.
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.

Swimming turns reduce energy demands of the aerobic performance in front crawl

Bosetto, P. et al.: Eur J Appl Physiol. 2026 May;126(5):2491-2500. doi: 10.1007/s00421-025-06084-7. Epub 2025 Dec 6.
Purpose
Performances in short-course (SC, 25 m) are typically faster than in long-course (LC, 50 m), largely due to the greater number of turns, but the specific energetic contribution of turns has not yet been quantified. This study tested the hypothesis that turns reduce the overall energy cost (C) in swimming, providing an energetic advantage in SC over LC.
Methods
Eleven male swimmers completed two randomized sessions in SC and LC pools, each consisting of five 400-m front crawl trials at submaximal intensity (70-86% of race velocity) paced by an underwater light system. Turn and clean swimming velocities were standardized between conditions to isolate the effect of turn number. Oxygen uptake, blood lactate, heart rate, perceived exertion, and stroke frequency were assessed, and metabolic power, total energy expenditure (Etot), and C (Etot/distance) were calculated.
Results
When analyzed at equivalent intensity (e.g. in trials corresponding to the same % of race velocity) mean velocity was higher in SC than LC across all intensities (+ 0.07 ± 0.003 m·s⁻¹, + 5.2%) while kinematic, physiological, and energetic parameters showed no significant differences (p > 0.05). When analyzed at paired (absolute) speeds, C values were about 4% higher il LC than in SC, indicating that swimming in short course is more economical, as hypothesized.
Conclusions
Turns reduce the overall energy cost of 400-m front crawl performance enabling swimmers to sustain higher mean velocities in SC. This highlights the importance of considering pool length when evaluating performance and prescribing training intensities.

Swimming-Related Injuries

Verheul, D.: Clin Sports Med. 2026 Jul;45(3):507-519. doi: 10.1016/j.csm.2025.09.004.
Abstract
Swimming is a popular sport at both domestic and international levels. Over the last 40 to 50 years, there has been an increased focus on swimming injuries and the risk factors associated with them. While the bulk of the work has been done identifying and classifying injuries of the shoulder, given the whole-body nature of the sport, numerous other sites have been reported. Fortunately, the majority of these are overuse in nature, and the need for surgical management remains relatively low.

Impact of an Overload Period on Heart Rate Variability, Sleep Quality, Motivation, and Performance in High-level Swimmers: Use of Explainable Artificial Intelligence (XAI) to Assess Training Load Variations

Carvalho, D. et al.: Sports Med. 2026 May;56(5):1235-1254. doi: 10.1007/s40279-025-02369-1. Epub 2025 Dec 5.
Background
Understanding the impact of training sessions on physiological, psychological, and immunological responses is crucial for adequate training periodization and preventing negative influences on health, training, and performance.
Objectives: To characterize the responses of heart rate variability (HRV), sleep time and quality, motivation, dry-land strength, and swimming performance to an overload period of three consecutive 7-day cycles (cycles 1, 2, and 3) with different training intensity and volume dynamics. Secondly, to test the capability of HRV to assess daily variation in training loads on the basis of explainable artificial intelligence (XAI) models.
Methods
A total of 14 high-level swimmers (4 males and 10 females, aged 17.5 ± 1.5 years) were monitored via an orthostatic test, Hooper index, sleep questionnaires, and rating of perceived exertion (RPE) of each training session. The self-reported and prescribed training loads were compared. At the beginning of each cycle and at the end of cycle 3, swimmers completed anthropometric testing, countermovement jumps, hand-grip strength tests, and a 5 × 200 m incremental protocol.
Results
High-level swimmers accurately perceived their daily training loads. However, differences between the training and RPE loads emerged on weekends, indicating that physiological and psychological loads have different influences and should be considered simultaneously when characterizing training loads. The overload period was characterized by an increase in both training (27%) and RPE (20%) loads without eliciting a negative effect on sleep quantity and quality. During the overload period, supine (F2.18 = 3.448, η2 = 0.28; p = 0.05) and standing (F2.18 = 3.809, η2 = 0.30; p = 0.04) mean heart rate (HR) increased and supine log root mean square of the successive differences (LnRMSSD; F2.18 = 4.379, η2 = 0.33; p = 0.028) and maximal blood lactate (F3.27 = 3.441, η2 = 0.28; p = 0.03) decreased during and after cycle 3 (respectively). Dry-land and swimming performances were maintained, indicating that the autonomic nervous system appears to be more sensitive (XAI models r2 = 0.91 and 0.9) to changes in acute/short-term training load.
Conclusions
HRV indices, particularly supine RMSSD and mean HR, were the most sensitive markers of training load variation, while sleep, strength and power, and swimming performance remained stable. HRV can be employed as a practical tool for monitoring training responses and managing training loads in competitive swimmers.

Swimmer’s Shoulder: An Update on Pathogenesis, Risk Factors, Clinical Assessment, and Management

Edenfield, K.M. et al.: Curr Phys Med Rehabil Rep 13, 35 (2025). https://doi.org/10.1007/s40141-025-00506-5
Purpose of Review
Shoulder pain is the most common cause of pain in competitive swimmers. This review will cover the current available literature on the pathogenesis, assessment, management, and gaps in knowledge of swimmer’s shoulder; and provide insight into the practical clinical evaluation, treatment, and future directions from a multi-disciplinary group of authors with extensive clinical experience treating swimmers.
Recent Findings
Good thoracic mobility and extension is vitally important in the scapula’s success maintaining dynamic stability of the glenohumeral joint in swimmers. Both the front squat and overhead squat are good functional movement assessments for shoulder mobility and stability. Three evidence-based risk factors for shoulder pain in swimmers have been identified by experts and supported with evidence in the literature: low posterior shoulder strength-endurance, inconsistent training load, and poor stroke technique. Additionally, twenty-two other risk factors have been proposed by swimming experts, though these have not been investigated adequately in the literature.
Summary
Overdevelopment of the anterior shoulder muscles combined with tightness in the pectoralis minor and posterior shoulder capsule, imbalanced scapular stabilizers, and decreased thoracic mobility can lead to fatigue, dysfunctional swim stroke, and shoulder pain. Evaluation should focus on known risk factors and utilize functional movements. Treatment should be interdisciplinary and include relative rest, anti-inflammatories, stretches of the posterior capsule and pectoralis minor, and a progressive exercise program of shoulder and scapular strengthening.

Swimming is superior to running in inducing physiological cardiac hypertrophy and enhancing myocardial performance

Yoshizaki, A. et al.: Sci Rep 16, 6592 (2026). https://doi.org/10.1038/s41598-026-36818-2
Abstract
Aerobic exercise training (AET) can induce cardiac hypertrophy, but the specific adaptive response for different types of AET remains unclear. We evaluated nonsingular cardiac remodeling in rats through running (RT) and swimming (ST) training at approximately 75% of VO₂max. Male Wistar rats (8–10 weeks old; ~ 250 g) were divided into untrained (UT), RT, and ST groups. The RT and ST were performed five days a week, once daily for 60 min for eight weeks. Cardiopulmonary fitness was assessed by measuring maximal oxygen consumption and swimming time to exhaustion. Echocardiography evaluated left ventricular parameters, while myocardial mechanics were assessed through the papillary muscle. Histology and Western blotting were performed to evaluate cardiomyocyte size and proteins modulating phosphoinositide 3-kinase (PI3K110α)/AKT1 signaling. Real-time PCR was used to assess the expression of genes and microRNAs involved in myocardial hypertrophy. Both AET protocols enhanced cardiopulmonary capacity, but only the ST group showed increased myocardial mass, cardiomyocyte growth, and LV cavity size, along with greater tension and papillary muscle shortening velocity. A more pronounced alteration in gene expression pattern for proteins modulating PI3K110α/AKT1 signaling was found in the ST group than in the RT group. A similar difference was also found for microRNA 1, 21, 27a, 124, and 144 expressions. ST is more effective than RT in inducing cardiac hypertrophy and enhancing contractility, linked to the PTEN-AKT-S6K1 pathway and increased expressions of microRNAs 1, 21, 27a, 124, and 144. Thus, ST is superior to RT for inducing physiological cardiac hypertrophy.

Mail to the editor