Habitual Nocturnal Sleep, Napping Behavior, and Recovery Following Training and Competition in Elite Water Polo: Sex-Related Effects.

PURPOSE: To examine nocturnal sleep patterns, napping behaviors, and subjective wellness responses of elite water polo players within an in-season week and to identify whether sleeping patterns differ between men and women. METHODS: Sleep characteristics of 10 male and 17 female professional water polo players were objectively assessed during 1 week of the in-season period, including 5 training days, 1 match day, and 1 day of rest. Internal load (rating of perceived exertion × duration of training or match) was assessed 30 minutes posttraining or postmatch, and the total quality of recovery was recorded every morning. A series of multilevel models were used to analyze the data. RESULTS: Time in bed and wake-up time were earlier on both training (P < .001) and rest days (P < .001) than on the day of the match. Internal workload did not predict any of the players' sleeping patterns. Midday naps predicted less time in bed (P = .03) and likely less sleep time (P = .08). The total quality of recovery was predicted only by the total sleep time (P < .01). Women exhibited higher sleep efficiency (P < .001), less waking after sleep onset (P = .01), and a lower number of awakenings (P = .02) than men. CONCLUSIONS: The current results indicate that the nocturnal sleep patterns of elite water polo players are not associated with internal load and that women display better nocturnal sleep quality compared with men. As long naps interfere with nocturnal sleep, and total nocturnal sleep time predicts total quality of recovery, we suggest that athletes follow hygiene sleep strategies to facilitate adequate nocturnal sleep and next-day recovery.

In-Season Training Load Variation - Heart Rate Recovery, Perceived Recovery Status, and Performance in Elite Male Water Polo Players: A Pilot Study.

BACKGROUND: Increased training and competition demands of the in-season period may disturb athlete fatigue and recovery balance. The aim of this study was to describe the training load distribution applied in a competitive period and the training adaptations and fatigue/recovery status of elite water polo players. HYPOTHESIS: Effective workload management during tapering (TAP) would restore player recovery and enhance performance. STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4. METHODS: Training load, perceived recovery, maximal speed in 100- and 200-meter swim, heart rate (HR) during submaximal swimming (HRsubmax) and HR recovery (HRR) were assessed in 7 outfield water polo players a week before starting a normal training microcycle (NM), after NM, and after congested (CON) and TAP training blocks in the lead-up to the Final Eight of the European Champions League. RESULTS: Training load was higher in NM compared with CON and TAP by 28.9 ± 2.6% and 42.8 ± 2.1% (P < 0.01, d = 11.54, and d = 13.45, respectively) and higher in CON than TAP by 19.4 ± 4.2% (P < 0.01, d = 3.78). Perceived recovery was lower in CON compared with NM and TAP (P < 0.01, d = 1.26 and d = 3.11, respectively) but not different between NM and TAP (P = 0.13, d = 0.62). Both 100- and 200-meter swim performance was improved in TAP compared with baseline (P < 0.01, d = 1.34 and d = 1.12, respectively). No differences were detected among other training blocks. HRsubmax and most HRR were similar among the training periods. CONCLUSION: Effective management of training load at TAP can restore recovery and improve swimming performance without affecting HR responses. CLINICAL RELEVANCE: Despite lower workloads, CON training impairs perceived recovery without affecting performance; however, a short-term training load reduction after a CON fixture restores recovery and improves performance.

Physiological Responses and Swimming-Performance Changes Induced by Altering the Sequence of Training Sets.

PURPOSE: Interval-training sets may be applied in a different sequence within a swimming training session. The aim of this study was to investigate the effect of different set sequences on performance and physiological responses in a training session. METHODS: Twelve highly trained male swimmers performed 4 sessions in randomized order. Each session included a different combination of 2 training sets: set A-set C, set C-set A, set B-set C, or set C-set B. Set A consisted of 8 × 200 m at speed corresponding to lactate threshold (30-s recovery), set B included 8 × 100 m at maximum aerobic speed (30-s recovery), and set C included 4 × 50-m all-out swimming (2-min recovery). Performance and physiological responses (lactate concentration, pH, base excess, bicarbonate, heart rate, and heart-rate variability) were measured. RESULTS: Performance in each set was similar between sessions irrespective of set sequence. Blood lactate, heart rate, and acid-base responses during set C were similar in all sessions, but blood lactate was higher in sets A and B during C-A and C-B sessions (P = .01). The overall blood lactate and acid-base response was higher in C-A and C-B sessions compared with A-C and B-C sessions, respectively (P = .01). Heart-rate variability in each set, separately as well as the overall session effect, did not differ and was thus independent to the set sequence applied. CONCLUSIONS: Training sessions including all-out swimming as a first set increase the magnitude of metabolic responses to the subsequent aerobic-dominated training set.

Effects of Training Sets Sequence on Swimming Performance, Training Load and Physiological Responses.

The study examined the effect of set sequence on performance and physiological responses in a training session and in each set separately. Twelve male swimmers performed four sessions in a randomized order, including a combination of two training sets: (i) set A-set C, (ii) set C-set A, (iii) set B-set C, (iv) set C-set B. Set A consisted of 8 × 200 m at a speed corresponding to lactate threshold (30 s recovery), set B included 8 × 100 m at the maximal aerobic speed (30 s recovery), set C included 8 × 50 m sprints at 95% of the maximum 50 m speed (30 s recovery). Speed, blood lactate, pH, base excess, bicarbonate and heart rate variability (HRV) were measured. Speed in each set was similar between sessions irrespective of set sequence (p > 0.05). Physiological responses during sets A and C were similar in all sessions (p > 0.05). In set B, when applied after set C, the metabolic response increased, and HRV decreased (p < 0.05). Overall, session biochemical disturbance was higher when set C was applied before sets A and B (p < 0.05). The magnitude of metabolic and HRV responses in a set conducted at maximal aerobic speed, but not at lactate threshold intensity, is increased when applied after sprint intervals.

Dry-Land Force-Velocity, Power-Velocity, and Swimming-Specific Force Relation to Single and Repeated Sprint Swimming Performance.

The aim of this study was to identify the relationship between dry-land and in-water strength with performance and kinematic variables in short-distance, middle-distance, and repeated sprint swimming. Fifteen competitive swimmers applied a bench press exercise to measure maximum strength (MS), maximum power (P), strength corresponding to P (F@P), maximum velocity (MV), and velocity corresponding to P (V@P) using F-V and P-V relationships. On a following day, swimmers performed a 10 s tethered swimming sprint (TF), and impulse was measured (IMP). On three separate days, swimmers performed (i) 50 and 100 m, (ii) 200 and 400 m, and (iii) 4 × 50 m front crawl sprint tests. Performance time (T), arm stroke rate (SR), arm stroke length (SL), and arm stroke index (SI) were calculated in all tests. Performance in short- and middle-distance tests and in 4 × 50 m training sets were related to dry-land MS, P, TF, and IMP (r = 0.51-0.83; p < 0.05). MS, P, and TF were related to SR in 50 m and SI in 50 and 100 m (r = 0.55-0.71; p < 0.05). A combination of dry-land P and in-water TF variables explains 80% of the 50 m performance time variation. Bench press power and tethered swimming force correlate with performance in short- and middle-distance tests and repeated sprint swimming.

Intensified Olympic Preparation: Sleep and Training-Related Hormonal and Immune Responses in Water Polo.

PURPOSE: To investigate whether sleeping activity, hormonal responses, and wellness are altered in elite water polo players during their preparation toward the Tokyo Olympics. METHODS: Eight elite-level water polo players participated in 3 consecutive training phases: (1) before the commencement of a residential-based conditioning camp (PRE-CAMP; 3 d), (2) residential-based conditioning camp (5 d), and (3) a congested period of training and competition (POST-CAMP; 8 d). Nocturnal sleep was monitored for 14 consecutive days in PRE-CAMP (2 d), CAMP (5 d), and POST-CAMP (7 d). Postawakening salivary cortisol, immunoglobulin-A, and subjective wellness were measured during PRE-CAMP, CAMP, and POST-CAMP, and internal training/match load (ITL) was calculated daily. The averaged values for dependent variables were compared among training phases and analyzed using linear mixed models. RESULTS: At CAMP compared with PRE-CAMP, ITL was higher (P < .01), and sleep onset and offset were earlier (P < .01). At this period, sleep interruptions and salivary cortisol were higher (P < .01, d = 1.6, d = 1.9, respectively), and subjective wellness was worsened (P < .01, d = 1.3). At POST-CAMP, the reduction of workload was followed by increased sleep efficiency, reduced sleep interruptions, and moderately affected salivary cortisol, yet overall wellness remained unaltered. In POST-CAMP, 2 of the players demonstrated severe symptoms of illness. CONCLUSIONS: At the highest level of the sport and prior to the Olympics, large increments in workload during a training camp induced meaningful sleep interruptions and salivary cortisol increases, both of which were reversed at POST-CAMP. We suggest that the increased workload alongside the inadequate recovery affects sleep patterns and may increase the risk of infection.

The Effect of Wet Conditions and Surface Combat Swimming on Shooting.

INTRODUCTION: Shooting ability is an important aspect of performance in some sports and is vital during a military operation. Load carriage, clothing, and equipment normally associated with fatigue and reduced field of vision or lack of stability at a specific point are important factors that affect the ability to aim when shooting. Additionally, gun support and equipment appear to differentially affect shooting ability with varying shooting positions. All of the studies examining these factors have taken place on dry land and not in water. However, up to date, no study has examined the effect of wet conditions, especially after surface combat swimming (sCS), on shooting ability in different shooting positions. The purpose of this study was to determine the effect of fatigue, produced by prolonged sCS, on a fighter's shooting ability. In addition, we investigated whether the effect of fatigue and wet conditions differed between the shooting positions. MATERIALS AND METHODS: Forty-five participants performed 10 shots in a shooting simulator while standing (ST) and 10 shots while kneeling (KN). This was performed twice and in three conditions: dry, wet, and after 1,000 m of sCS. RESULTS: Wet conditions did not significantly affect shooting abilities. Surface combat swimming negatively affected shooting ability when both ST and KN. The reduction in the center of gravity (COG) of the shots after sCS was 3.7 ± 2.5% for ST and 3.5 ± 0.8% for KN (P < .01). This was accompanied by the increase in horizontal and vertical movement of the gun after the sCS (P < .01). Kneeling was more stable, as shown by a higher percentage of COG of the shots by 3.3 ± 0.1% (P < .01) and by fewer gun movements in both axes (P < .01). CONCLUSIONS: In conclusion, combat swimming affects shooting ability, both in ST and in KN positions. The KN position provides better stability and improved shooting ability.

Effects of Dryland Training During the COVID-19 Lockdown Period on Swimming Performance.

PURPOSE: To examine the effect of dryland training during an 11-week lockdown period due to COVID-19 on swimming performance. METHODS: Twelve competitive swimmers performed 50- and 300-m maximum-effort tests in their preferred stroke and 200-, 400-, and four 50-m front crawl sprints (4 × 50 m) before and after the lockdown period. Critical speed as an index of aerobic endurance was calculated using (1) 50-, 300-, and (2) 200-, 400-m tests. Blood lactate concentration was measured after the 400- and 4 × 50-m tests. To evaluate strength-related abilities, the dryland tests included handgrip and shoulder isometric strength. Tethered swimming force was measured during a 10-second sprint. During the lockdown period, dryland training was applied, and the session rating of perceived exertion training (sRPE) load was recorded daily. RESULTS: sRPE training load during the lockdown was decreased by 78% (16%), and critical speed was reduced 4.7% to 4.9% compared to prelockdown period (P < .05). Performance time in 200, 300, and 400 m deteriorated 2.6% to 3.9% (P < .05), while it remained unaltered in 4 × 50- and 50-m tests (P > .05). Tethered force increased 9% (10%) (P < .01), but handgrip and shoulder isometric force remained unaltered (P > .05). Blood lactate concentration decreased 19% (21%) after the 400-m test and was unchanged following the 4 × 50-m tests (P > .05). CONCLUSIONS: Performance deterioration in the 200, 300, and 400 m indicates reduced aerobic fitness and impaired technical ability, while strength and repeated-sprint ability were maintained. When a long abstention from swimming training is forced, dryland training may facilitate preservation in short-distance but not middle-distance swimming performance.

Effects of an International Tournament on Heart Rate Variability and Perceived Recovery in Elite Water Polo Players.

ABSTRACT: Botonis, PG, Smilios, I, Platanou, TI, and Toubekis, AG. Effects of an international tournament on heart rate variability and perceived recovery in elite water polo players. J Strength Cond Res 36(8): 2313-2317, 2022-The purpose of the study was to evaluate the effects of an international tournament participation in vagal-related heart rate variability and perceived recovery among elite water polo players. Nine elite water polo players participated in an intensified training week (pretournament) and then traveled abroad to take part in an international tournament including 3 high-competitive matches during a 4-day period. Internal workload was measured after training or competition. Morning, postwakening natural logarithm of the root mean square of successive differences (lnRMSSD) and measures of perceived recovery were obtained pretournament and daily during the tournament. Logarithm of the root mean square of successive differences was also measured 30 minutes after the completion of each match of the tournament. Logarithm of the root mean square of successive differences was suppressed after the first match ( p = 0.03, d = -0.75), compared with the first morning of the tournament, rebounded the following morning ( p = 0.03, d = 0.87), and remained unaltered until the third match. In the last morning of the tournament, LnRMSSD was higher compared with the first postmatch measurement ( p = 0.002, d = 1.57) and tended to be higher than pretournament ( p = 0.09, d = 0.81). Perceived recovery and internal workloads were lower in the tournament days compared with pretournament ( p < 0.001, d = 2.0 and p < 0.001, d = 14.0, respectively). In conclusion, heart rate variability may stabilize and progressively increase by the end of a tournament, as compared with a pretournament training period, reflecting an enhanced parasympathetic reactivation may be due to the reduced training load. By contrast, perceived recovery was suppressed indicating that other factors may also influence the overall recovery of the players.

Muscle Oxygenation, Heart Rate, and Blood Lactate Concentration During Submaximal and Maximal Interval Swimming.

This study aimed to determine the relationship between three testing procedures during different intensity interval efforts in swimming. Twelve national-level swimmers of both genders executed, on different occasions and after a standardized warm-up, a swimming protocol consisting of either a submaximal (Submax: 8 efforts of 50 m) or a maximal interval (Max: 4 efforts of 15 m), followed by two series of four maximal 25 m efforts. Near-infrared spectroscopy in terms of muscle oxygen saturation (SmO2), heart rate (HR), and blood lactate concentration (BLa) were analyzed at three testing points: after the Submax or the Max protocol (TP1), after the 1st 4 × 25-m (TP2), and after the 2nd maximal 4 × 25-m set (TP3). BLa and HR showed significant changes during all testing points in both protocols (P ≤ 0.01; ES range: 0.45-1.40). SmO2 was different only between TP1 and TP3 in both protocols (P ≤ 0.05-0.01; ES range: 0.36-1.20). A large correlation during the Max protocol between SmO2 and HR (r: 0.931; P ≤ 0.01), and also between SmO2 and BLa was obtained at TP1 (r: 0.722; P ≤ 0.05). A range of moderate-to-large correlations was revealed for SmO2/HR, and BLa/HR for TP2 and TP3 after both protocols (r range: 0.595-0.728; P ≤ 0.05) were executed. SmO2 is a novel parameter that can be used when aiming for a comprehensive evaluation of competitive swimmers' acute responses to sprint interval swimming, in conjunction with HR and BLa.

The impact of daytime napping on athletic performance - A narrative review.

Mid-day napping has been recommended as a countermeasure against sleep debt and an effective method for recovery, regardless of nocturnal sleep duration. Herein, we summarize the available evidence regarding the influence of napping on exercise and cognitive performance as well as the effects of napping on athletes' perceptual responses prior to or during exercise. The existing studies investigating the influence of napping on athletic performance have revealed equivocal results. Prevailing findings indicate that following a normal sleep night or after a night of sleep loss, a mid-day nap may enhance or restore several exercise and cognitive performance aspects, while concomitantly provide benefits on athletes' perceptual responses. Most, but not all, findings suggest that compared to short-term naps (20-30 min), long-term ones (>35-90 min) appear to provide superior benefits to the athletes. The underlying mechanisms behind athletic performance enhancement following a night of normal sleep or the restoration after a night of sleep loss are not clear yet. However, the absence of benefits or even the deterioration of performance following napping in some studies is likely the result of sleep inertia. The present review sheds light on the predisposing factors that influence the post-nap outcome, such as nocturnal sleep time, mid-day nap duration and the time elapsed between the end of napping and the subsequent testing, discusses practical solutions and stimulates further research on this area.

Supercompensation in Elite Water Polo: Heart Rate Variability and Perceived Recovery.

We examined the association of heart rate variability assessed with the logarithm of the root mean square of successive differences (LnRMSSD) and perceived recovery status of nine elite water polo players with the fluctuations of the internal training load (ITL). ITL, post-wakening LnRMSSD, and measures of perceived recovery were obtained across one regeneration week, during two mesocycles of intensified preseason training (PR1, PR2) and during two mesocycles of in-season training (IN1, IN2). ITL at PR1 and PR2 was increased by 60-70% compared to regeneration week (p<0.01) and was reduced by 30% at IN1 and IN2 compared to PR1 and PR2 (p<0.01). Weekly averaged LnRMSSD (LnRMSSD mean ) was higher in IN2 compared to regeneration week and PR2 (p<0.01 and p<0.05, respectively). Perceived recovery was higher at IN1 and IN2 compared to PR2 (p=0.01 and p<0.001, respectively). ITL correlated with LnRMSSD in the preseason (r=-0.26, p=0.03). Nonetheless, similar association was not apparent during the in-season period (r=0.02, p=0.88). Cardiac autonomic perturbations may not occur when an increment of internal training load is less than 60-70%. However, the reduction of training load in season by 30% improves both LnRMSSD mean and perceived recovery status, implying that training periodization may lead players in supercompensation.

The Effect of a Surface Combat Swimming Training Program on Swimming Performance.

In this study the effect of a surface combat swimming (sCS) training program on performance in freestyle swimming and sCS was examined. Forty-five officer cadets were divided into three equivalent groups: a control group (CG), a group that was trained only with a swimsuit and fins (SF), and a group that was trained with combat uniform and equipment (UE). Groups SF and UE followed a 60-min training program with sCS for 4 weeks, 4 times per week. Before and after the training program all groups performed 4×50 and 400-m freestyle swimming, 250-m sCS with a uniform and equipment, 350-m with a swimsuit and fins, and 300-m with a swimsuit. The UE group showed improved performance in 4×50-m (mean±SD 14±9 s) and in 250-m sCS (24±14 s) (p<0.01). Both the SF group and the UE group improved in 300-m sCS, in 350-m sCS and in 400-m freestyle (p<0.05). We conclude that the training adaptations seemed to be specific, not only with regard to the activity performed, but also in terms of the actual conditions of an operation, which also include equipment.

Lactate Threshold Evaluation in Swimmers: The Importance of Age and Method.

The purpose of the study was to define the most appropriate method for the calculation of the speed corresponding to lactate threshold (sLT) in male swimmers. Eight boys and eight adolescents (age: 11.4±0.5 and 15.8±0.8 years) performed 7×200-m swimming front-crawl and after drawing the speed vs. lactate curve, the sLTs were calculated using five methods: i) the intersection of two linear regression lines, ii) visual inspection, iii) D-max, iv) D-max modified, v) intersection of combined linear and exponential regression lines. All methods were compared to the speed corresponding to maximal lactate steady state (sMLSS). Two to four 30-min efforts of continuous swimming at imposed constant pace were used for sMLSS calculation. In both groups, speed of D-max modified was similar to sMLSS (children, 1.061±0.073 vs. sMLSS: 1.071±0.072 m·s-1; p>0.05; effect size: ES=0.15, small; adolescents, 1.318±0.060 vs. sMLSS: 1.284±0.047 m·s-1; p>0.05; ES=0.64, medium). In adolescents, sLT calculated by intersection of two regression lines and by visual inspection presented medium ES (0.22-0.24) and were no different to sMLSS (1.296 ± 0.051, 1.295±0.053 m·s-1, p>0.05). When testing children, D-max modified is the most appropriate method to estimate sMLSS. The intersection of the linear regression lines and visual inspection are suggested for sMLSS determination in adolescents.

Heart rate recovery responses after acute training load changes in top-class water polo players.

The purpose of the study was to investigate the effects of acute training load changes of elite water polo players on heart rate recovery (HRR) responses after a standardized swimming test. Nine water polo players were tested after a two-day light-load and two-day heavy-load training. Preliminarily, critical swimming speed was calculated. Testing comprised of an intermittent 4 × 100-m swimming separated by 10 s of rest with an intensity corresponding to 85% of their maximum speed previously attained during a 100-m swim test followed immediately by assessment of HRR. Internal training load (ITL) was measured using the rating of perceived exertion and the duration of training sessions. The swimming speed corresponded to 1.43 ± 0.06 m·s-1 and 1.45 ± 0.06 m·s-1 after light-load and heavy-load training, respectively (p = 0.06, d = 0.74). ITL was increased in high-load compared to light-load training (p < 0.001, d = 11.54). The difference in HR at end of exercise (HR-end) and after 60 s rest and the difference in mean HR during last min of exercise and HR after 60 s rest were higher in light-load training (p < 0.05, d = 0.85-1.15). The absolute change in ITL was correlated with the respective change in the percentage change of HR-end at 10 s of recovery (%HRR10s) (r = 0.72, p = 0.03). Significant correlation was observed between the percentage change of ITL with the %HRR10s (r = 0.67, p = 0.05). We conclude that HRR tracks acute changes in training load. The lower HRR following high-load training likely indicates a blunted parasympathetic re-activation.

The Influence of the Coaches' Demographics on Young Swimmers' Performance and Technical Determinants.

The purpose of this study was to understand the relationship between the coaches' demographics (academic degree and/or coaching level and/or coaching experience) and young swimmers' performance and technical ability. The sample was composed by 151 young swimmers (75 boys and 76 girls: 13.02 ± 1.19 years old, 49.97 ± 8.77 kg of body mass, 1.60 ± 0.08 m of height, 1.66 ± 0.09 m of arm span), from seven different clubs. Seven coaches (one per club) were responsible for the training monitoring. Performance and a set of biomechanical variables related to swim technique and efficiency were assessed. The swimmers' performance was enhanced according to the increase in the coaches' academic degree (1: 75.51 ± 10.02 s; 2: 74.55 ± 9.56 s; 3: 73.62 ± 7.64 s), coaching level (1: 76.79 ± 11.27 s; 2: 75.06 ± 9.31 s; 3: 73.65 ± 8.43 s), and training experience (≤5-y training experience: 75.44 ± 9.57 s; >5-y training experience: 74.60 ± 9.54 s). Hierarchical linear modeling retained all coaches' demographics characteristics as main predictors (being the academic degree the highest: estimate = -1.51, 95% confidence interval = -0.94 to -2.08, p = 0.014). Hence, it seems that an increase in the demographics of the coaches appears to provide them with a training perspective more directed to the efficiency of swimming. This also led to a higher performance enhancement.

Verifying Physiological and Biomechanical Parameters during Continuous Swimming at Speed Corresponding to Lactate Threshold.

The purpose of this study was to verify the physiological responses and biomechanical parameters measured during 30 min of continuous swimming (T30) at intensity corresponding to lactate threshold previously calculated by an intermittent progressively increasing speed test (7 × 200 m). Fourteen competitive swimmers (18.0 (2.5) years, 67.5 (8.8) kg, 174.5 (7.7) cm) performed a 7 × 200 m front crawl test. Blood lactate concentration (BL) and oxygen uptake (VO2) were determined after each 200 m repetition, while heart rate (HR), arm-stroke rate (SR), and arm-stroke length (SL) were measured during each 200 m repetition. Using the speed vs. lactate concentration curve, the speed at lactate threshold (sLT) and parameters corresponding to sLT were calculated (BL-sLT, VO2-sLT, HR-sLT, SR-sLT, and SL-sLT). In the following day, a T30 corresponding to sLT was performed and BL-T30, VΟ2-T30, HR-T30, SR-T30, and SL-T30 were measured after the 10th and 30th minute, and average values were used for comparison. VO2-sLT was no different compared to VO2-T30 (p > 0.05). BL-T30, HR-T30, and SR-T30 were higher, while SL-T30 was lower compared to BL-sLT, HR-sLT, SR-sLT, and SL-sLT (p < 0.05). Continuous swimming at speed corresponding to lactate threshold may not show the same physiological and biomechanical responses as those calculated by a progressively increasing speed test of 7 × 200 m.

Validating Physiological and Biomechanical Parameters during Intermittent Swimming at Speed Corresponding to Lactate Concentration of 4 mmol·L-1.

BACKGROUND: Physiological and biomechanical parameters obtained during testing need validation in a training setting. The purpose of this study was to compare parameters calculated by a 5 × 200-m test with those measured during an intermittent swimming training set performed at constant speed corresponding to blood lactate concentration of 4 mmol∙L-1 (V4). METHODS: Twelve competitive swimmers performed a 5 × 200-m progressively increasing speed front crawl test. Blood lactate concentration (BL) was measured after each 200 m and V4 was calculated by interpolation. Heart rate (HR), rating of perceived exertion (RPE), stroke rate (SR) and stroke length (SL) were determined during each 200 m. Subsequently, BL, HR, SR and SL corresponding to V4 were calculated. A week later, swimmers performed a 5 × 400-m training set at constant speed corresponding to V4 and BL-5×400, HR-5×400, RPE-5×400, SR-5×400, SL-5×400 were measured. RESULTS: BL-5×400 and RPE-5×400 were similar (p > 0.05), while HR-5×400 and SR-5×400 were increased and SL-5×400 was decreased compared to values calculated by the 5 × 200-m test (p < 0.05). CONCLUSION: An intermittent progressively increasing speed swimming test provides physiological information with large interindividual variability. It seems that swimmers adjust their biomechanical parameters to maintain constant speed in an aerobic endurance training set of 5 × 400-m at intensity corresponding to 4 mmol∙L-1.