Acute effects of dryland muscular endurance and maximum strength training on sprint swimming performance in young swimmers.

The study examined acute effects of dryland muscular endurance (ME) and maximum strength (MS) sessions on performance, physiological, and biomechanical variables during a subsequent sprint swimming session. Twenty-seven swimmers (16.5 ± 2.6 yrs) completed three experimental conditions including: i) ME, 55% of 1-repetition maximum, ii) MS, 90% of 1-repetition maximum, and iii) control (CON, no dry-land). Twenty minutes following ME, MS and CON sessions swimmers performed a 10-s tethered swimming sprint, four by 50-m (4 × 50-m), and a 100-m front crawl sprints. Performance time, blood lactate, heart rate (HR), stroke rate (SR), stroke length (SL), stroke index (SI), and stroke efficiency (ηF) were measured during 4 × 50-m and 100-m. Hand grip strength (HG), and shoulder muscles isometric strength (ISO) were measured after each session. Mean 4 × 50-m time increased in ME compared to CON by 1.7 ± 2.7% (p = 0.01), while 100-m time was similar among conditions (p > 0.05). ISO was lower after dry-land training in all conditions (p = 0.01). Tethered force, HG, HR, SR, SL, SI, and ηF were no different between conditions (p > 0.05). Dryland ME session decrease swimming performance; however, ME and MS sessions did not affect technical ability during a subsequent maximum intensity swimming.

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.

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.

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.

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.

Physiological and Tactical On-court Demands of Water Polo.

Botonis, PG, Toubekis, AG, and Platanou, TI. Physiological and tactical on-court demands of water polo. J Strength Cond Res 33(11): 3188-3199, 2019-The purpose of the present review is to provide a quantification of the specific game's activities performed by elite water polo players and a comprehensive overview of the physiological requirements reflecting physical and tactical on-court demands in water polo. Game analysis demonstrates that various swimming movements occur throughout a match play, although approximately 50% of these are recorded in horizontal body position. The various offensive and defensive tactical actions transiently modify the playing intensity, which overall corresponds to the players' lactate threshold. Even play corresponds to 60% of total game actions, whereas the respective percentage of power-play and counterattacks may exceed 30%. The ability to perform high-intensity activities with short recovery periods is critical for water polo players. Elite water polo players present a high level of aerobic power and endurance as indicated by their maximal oxygen uptake and speed at the lactate threshold. Depending on the positional roles, outfield players are characterized as centers or peripherals. The overall physiological load seems to be similar between players at various positions, despite that centers execute more dynamic body contacts, whereas peripherals more swimming bouts. Despite limitations concerning the experimental setting, the current findings indicate that the incidence of fatigue deteriorates playing intensity and performance. Nonetheless, data from the reviewed studies should be cautiously interpreted because in some of the studies, players' substitutions were not allowed. A high conditioning level is essential for water polo, as it is associated with superior technical and tactical efficacy and lower decline of physical or technical performance within the game.

Severe hypoxemia induced by prolonged expiration and reduced frequency breathing during submaximal swimming.

The purpose of this study was to examine the metabolic responses during submaximal swimming with self-selected normal breathing (N) and prolonged expiration along with reduced frequency breathing (RB). Ten male swimmers (age: 23.1 ± 2.2 years; VO2max: 47.3 ± 7.2 ml · kg-1 · min-1) performed 75-, 100-, 175-, 200-, 275-, 300-, 375- and 400-m trials with N and RB at intensity corresponding to 90% of the critical speed. In RB condition, all trials longer than 75 m were interspersed with 25 m of self-selected N in regular intervals. In RB, oxygen saturation during recovery was decreased compared to starting values after 75, 100, 175, 275 and 375 m (78-91%, P < 0.05), while it remained unchanged after all trials in N condition (98 ± 2%, P > 0.05). Lactate concentration was higher in RB than in N after 400 m (4.3 ± 1.5 vs. 3.3 ± 1.7 mmol · l-1, P < 0.05). During recovery after the 375-m trial, partial pressure of carbon dioxide was increased and pH was decreased in RB compared to N condition. Prolonged expiration along with RB provokes severe hypoxemia during the recovery period after swimming, which is restored with self-selected N during submaximal swimming.

Concurrent Strength and Interval Endurance Training in Elite Water Polo Players.

This study compared the effects of different high-intensity interval training (HIIT) intervals performed concurrently with strength and specific water polo training on performance indices of elite players. During the precompetition season, 2 water polo clubs were assigned to either HIIT of 4 × 4 minutes (n = 7, HIIT4 × 4) or HIIT of 16 × 100-m swimming efforts (n = 7, HIIT16 × 100). Both clubs applied the swimming (6% above the speed corresponding to blood lactate concentration of 4.0 mmol · L) and strength training (85-90% of 1 repetition maximum, 5 repetitions, 4 sets) twice per week concurrently with specific water polo training. Before and after the 8-week intervention period, maximal bench press strength was measured and a speed-lactate test (5 × 200 m) was performed to determine the speed corresponding to lactate concentration of 4.0, 5.0, and 10.0 mmol · L(-1). Maximal strength was improved in both groups (HIIT4 × 4: 14 ± 4% vs. HIIT16 × 100: 19 ± 10%). Improvements in speed corresponding to 4.0, 5.0, and 10.0 mmol · L(-1) were shown only after HIIT4 × 4 (9 ± 5, 8 ± 3, 7 ± 2%, respectively; p < 0.01). However, HIIT16 × 100 was more effective in the differential velocity between 10.0 and 5.0 mmol · L(-) development (19 ± 20%, p = 0.03). During the precompetition season, HIIT and strength training together with specific water polo training performed concurrently improves muscle strength and allows specific adaptations enhancing swimming performance of elite water polo players.

Performance Decrement and Skill Deterioration During a Water Polo Game are Linked With the Conditioning Level of the Athletes.

The aim of the study was to examine whether physical and technical performance deterioration after a water polo game is related to the athletes' conditioning level. Blood lactate concentration was measured during a 5 × 200-m incremental swimming test in 10 male water polo athletes to calculate the velocities corresponding to 4.0, 5.0, and 10.0 mmol·L lactate concentration (V4, V5, and V10, respectively) and define their conditioning level. All athletes participated in 5 competitive water polo games. Before (Pre), at half time (Mid), and after (Post) the first 2 games, handgrip strength and repeated sprint ability (8 × 20-m) were measured. Pre and Post the next 2 games, ball throwing velocity, shooting accuracy, and 400-m swim were evaluated. Pre, Mid, and Post the last game, the eggbeater kick test was performed. Handgrip strength, repeated sprint ability, 400-m swim performance, and ball shooting accuracy decreased after the game (8.4 ± 6.2%, 6.3 ± 3.4%, 7.0 ± 4.1%, and 20.3 ± 23.4%, respectively, p ≤ 0.05). V4, V5, and V10 were not significantly correlated with changes in physical or technical performance after the game. Performance in 400-m swim correlated with V4 and V5 whereas changes in 400-m swim Pre-Post, correlated with changes in ball shooting accuracy and throwing velocity (r = 0.73 and r = 0.80, p ≤ 0.05). These data suggest that V4, V5, and V10 may not correlate with performance decline in water polo. Interestingly, the 400-m swim test is connected with the decline in repeated sprints, ball shooting accuracy, and throwing velocity after a water polo game in well-trained athletes.

Effects of Short-Interval and Long-Interval Swimming Protocols on Performance, Aerobic Adaptations, and Technical Parameters: A Training Study.

Dalamitros, AA, Zafeiridis, AS, Toubekis, AG, Tsalis, GA, Pelarigo, JG, Manou, V, and Kellis, S. Effects of short-interval and long-interval swimming protocols on performance, aerobic adaptations, and technical parameters: A training study. J Strength Cond Res 30(10): 2871-2879, 2016-This study compared 2-interval swimming training programs of different work interval durations, matched for total distance and exercise intensity, on swimming performance, aerobic adaptations, and technical parameters. Twenty-four former swimmers were equally divided to short-interval training group (INT50, 12-16 × 50 m with 15 seconds rest), long-interval training group (INT100, 6-8 × 100 m with 30 seconds rest), and a control group (CON). The 2 experimental groups followed the specified swimming training program for 8 weeks. Before and after training, swimming performance, technical parameters, and indices of aerobic adaptations were assessed. ΙΝΤ50 and ΙΝΤ100 improved swimming performance in 100 and 400-m tests and the maximal aerobic speed (p ≤ 0.05); the performance in the 50-m swim did not change. Posttraining V[Combining Dot Above]O2max values were higher compared with pretraining values in both training groups (p ≤ 0.05), whereas peak aerobic power output increased only in INT100 (p ≤ 0.05). The 1-minute heart rate and blood lactate recovery values decreased after training in both groups (p < 0.01). Stroke length increased in 100 and 400-m swimming tests after training in both groups (p ≤ 0.05); no changes were observed in stroke rate after training. Comparisons between groups on posttraining mean values, after adjusting for pretraining values, revealed no significant differences between ΙΝΤ50 and ΙΝΤ100 for all variables; however, all measures were improved vs. the respective values in the CON (p < 0.001-0.05). In conclusion, when matched for distance and exercise intensity, the short-interval (50 m) and long-interval (100 m) protocols confer analogous improvements in swimming performance, in stroke cycle parameters, and in indices of aerobic adaptations after 8 weeks of training.

Is Speed Reserve Related to Critical Speed and Anaerobic Distance Capacity in Swimming?

This study examines the relationship between speed reserve (SRes), critical swimming speed (CSS), and anaerobic distance capacity (ADC) and their efficacy in determining training adaptations. Swimmers with previous competitive experience participated in an 8-week aerobic training program (experimental group: E; n = 15, age: 22.29 ± 0.95 years) and a control group refrained from training during the same period (C; n = 6, age: 22.25 ± 2.22 years). Speed reserve was determined before and after training from the speed difference between the 50 and 400 m maximum tests. Both CSS and ADC were calculated using 2 different combinations of distances (50 and 400 m: CSS2/ADC2; 50, 100, and 400 m: CSS3/ADC3) by applying the distance-time linear regression model. CSS2 and CSS3 of the E group showed a negative correlation, whereas ADC2 and ADC3 showed a positive correlation, with SRes before and after the training period (r ≥ -0.66, r ≥ 0.88, p ≤ 0.05). CSS2 and CSS3 increased by 5.5 ± 3.2 and 6.0 ± 3.2%, whereas ADC2, ADC3, and SRes decreased by 12.0 ± 9.4, 9.0 ± 11.2, and 8.1 ± 8.4% with the training program (p ≤ 0.05). These findings suggest that SRes, as calculated from distances of 50 and 400 m, shows strong relationships with CSS and ADC and may be used as an indicator of training-induced changes. This information is expected to facilitate training control and evaluation in a day-to-day basis.

Physiological responses of water-polo players under different tactical strategie.

The aim of this study was to investigate the effect of defense tactical strategy on physiological responses characterizing playing intensity in water-polo game. In the first part of the study, fourteen players were assigned to defending (n = 7) and offending (n = 7) groups and participated in nine 4-min plays applying three different defending systems: press, static-zone and zone-press, in front of the defense court of one goalpost. In the second part, 18 players participated in nine different real full court water-polo games consisting of 3X15min of live-time playing periods. Both in defense court plays and real games, the three defense systems were played in a counterbalanced order and heart rate (HR) was continuously recorded. Additionally, in defense court plays, blood lactate concentration (La) was measured at the end of each 4-min period. Mean HR within defense court plays was higher in press (153 ± 10 beats(.)min(-1)) than in static-zone (140 ± 11 beats(.)min(-1)) and zone-press (143 ± 16 beats(.)min(-1), p < 0.01). Furthermore, shorter amount of playing time was spent with HR ≤85% of HR peak in press (46.3 ± 22.8%) than in static-zone (81.8 ± 20.5%) and zone-press (75.7 ± 32.0%, p < 0.01). Likewise, mean La was higher in press (6.5±2.9 mmol(.)l(-1)) than in static-zone (4.7 ± 2.5 mmol(.)l(-1)) and zone-press (4.6 ± 1.8 mmol(.)l(-1), p < 0.01). In real games, however, mean HR was similar between tactical strategies (p > 0.05). Defenders and offenders showed similar HR and La responses across the tactical modes. In conclusion, defense tactical strategies affect physiological responses within a part of the game but do not affect the overall playing intensity of a real water-polo game. Tactical strategies similarly affect offenders and defenders. Key pointsWithin defence court plays, exercise intensity in press is higher than zone-press and static zone tactical systems.In real game the physiological response is similar between defense systems.Tactical strategies similarly affect offenders and defenders.

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.

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.

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.

The Method but Not the Protocol Affects Lactate-Threshold Determination in Competitive Swimmers.

PURPOSE: The study validated variables corresponding to lactate threshold (LT) in swimming. Speed (sLT), blood lactate concentration (BLLT), oxygen uptake (VO2LT), and heart rate (HRLT) corresponding to LT were calculated by 2 different incremental protocols and validated in comparison with maximal lactate steady state (MLSS). METHODS: Ten competitive swimmers performed a 7 × 200-m front-crawl incremental "step test" with 2 protocols: (1) with 30-second rests between repetitions (short-rest incremental protocols) and (2) on a 5-minute cycle (swim + rest time, long-rest incremental protocols). Five methods were used for the assessment of sLT and corresponding BLLT, VO2LT, and HRLT: intersection of 2 lines, Dmax, modified Dmax, visual inspection, and intersection of combined linear and exponential regression lines. Subsequently, swimmers performed two to three 30-minute continuous efforts to identify speed (sMLSS) and physiological parameters corresponding to MLSS. RESULTS: Both protocols resulted in similar sLT and corresponding physiological variables (P > .05). Bland-Altman plots showed agreement between protocols (sLT, bias: -0.017 [0.002] m·s-1; BLLT, bias: 0.0 [0.5] mmol·L-1; VO2LT, bias: -0.1 [2.2] mL·kg-1·min-1; HRLT. bias: -2 [8] beats·min-1). However, sLT calculated by modified Dmax using short rest was higher compared with speed at MLSS (1.346 [0.076] vs 1.300 [0.101] m·s-1; P < .05). CONCLUSIONS: Calculated sLT, BLLT, VO2LT, and HRLT using all other methods in short-rest and long-rest incremental protocols were no different compared with MLSS (P > .05). Both 7 × 200-m protocols are valid for determination of sLT and corresponding physiological parameters, but the modified Dmax method may overestimate sLT.

Metabolic responses at various intensities relative to critical swimming velocity.

To avoid any improper training load, the speed of endurance training needs to be regularly adjusted. Both the lactate threshold (LT) velocity and the velocity corresponding to the maximum lactate steady state (MLSS) are valid and reliable indices of swimming aerobic endurance and commonly used for evaluation and training pace adjustment. Alternatively, critical velocity (CV), defined as the velocity that can be maintained without exhaustion and assessed from swimming performance of various distances, is a valid, reliable, and practical index of swimming endurance, although the selection of the proper distances is a determinant factor. Critical velocity may be 3-6 and 8-11% faster compared with MLSS and LT, respectively. Interval swimming at CV will probably show steady-lactate concentration when the CV has been calculated by distances of 3- to 15-minute duration, and this is more evident in adult swimmers, whereas increasing or decreasing lactate concentration may appear in young and children swimmers. Therefore, appropriate corrections should be made to use CV for training pace adjustment. Findings in young and national level adult swimmers suggest that repetitions of distances of 100-400 m, and velocities corresponding to a CV range of 98-102% may be used for pacing aerobic training, training at the MLSS, and possibly training for improvement of VO2max. Calculation of CV from distances of 200-400, 50-100-200-400, or 100-800 m is an easy and practical method to assess aerobic endurance. This review intends to study the physiological responses and the feasibility of using CV for aerobic endurance evaluation and training pace adjustment, to help coaches to prescribe training sets for different age-group swimmers.

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.

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.

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.