Sprint Swimming Research Articles

Hypercapnic warm-up and re-warm-up-A novel experimental approach in swimming sprint.

The purpose of this study was to determine the effective warm-up protocol using an added respiratory dead space (ARDS) 1200 ml volume mask to determine hypercapnic conditions, on the swimming velocity of the 50 m time trial front crawl. Eight male members of the university swimming team, aged 19-25, performed three different warm-up protocols: 1) standardized warm-up in water (WUCON); 2) hypercapnic warm-up in water (WUARDS); 3) hypercapnic a 20-minute transition phase on land, between warm-up in water and swimming test (RE-WUARDS). The three warm-up protocols were implemented in random order every 7th day. After each protocol, the 50 m time trial front crawl swimming (swimming test) was performed. The fastest time trial swimming of 50 m front crawl was achieved after the hypercapnic transition phase (RE-WUARDS) protocol and was 27.5 ± 1.6 seconds, 1.2% faster than hypercapnic warm-up protocol (p = 0.01). This result was confirmed by a higher swimming average speed of the exercise test after RE-WUARDS compared to WUARDS (p = 0.01). The use of ARDS provoked a state of tolerable hypercapnia (obtaining carbon dioxide concentration in arterialized blood pCO2 > 45 mmHg) achieving a post-warm-up of WUARDS value 49.7 ± 5.9 mmHg (compared to the control condition which was a statistically significant difference p = 0.02) and before time trial RE-WUARDS 45.7 ± 2.1 mmHg (p = 0.01 compared to WUCON). After breathing through the 1200 ml ARDS mask during the 20-minute re-warm-up phase, there was a trend of faster time trial among participants compared to the control condition, and statistically significantly faster times compared to WUARDS, indicating that further study is appropriate to verify the efficacy of the proposed method to improve swimming efficiency.

Factors Relating to Sprint Swimming Performance: A Systematic Review.

Swimming performance depends on a wide variety of factors; however, the interaction between these factors and their importance varies between events. In sprint events, the characterized pacing underlines its specific development, as swimmers must achieve the highest possible speed while sustaining it to the greatest extent possible. The aim of this review was to identify the key factors underlying sprint swimming performance and to provide in-depth and practical evidence-based information to optimize performance. The review protocol was not registered. PubMed, Web of Science and Scopus databases were searched up to October 31, 2023. Studies involving competitive swimmers and investigating sprint swimming performance were included, while studies conducted with young or masters' swimmers, triathletes or waterpolo players or not investigating sprint swimming performance were excluded. The Downs and Black Quality Assessment Checklist was performed on the included articles to assess the methodological quality. After applying the PICOS framework, 39 of the 1330 articles initially identified were included according to the PRISMA guidelines. The included records focused mainly on dry-land strength and in-water forces of both upper and lower limbs. A wide range of kinematic variables were also examined, together with the importance of anthropometric and various physiological parameters. This review highlights the importance of developing muscular strength and effectively transferring it to performance in the water. The evidence suggests that muscular development should prioritize enhancing velocity and effective displacement, rather than merely increasing force and performance in loaded tests. However, further research is needed to confirm this. While in-water forces have been well studied, there is a notable lack of analysis regarding drag. The optimal balance between stroke rate and stroke length should be determined individually, with a primary focus on achieving a high stroke length from a high stroke rate. Although anthropometry may play an important role in performance, the interaction of these traits appears to be complex, suggesting that other factors may be more important in determining performance outcomes. From a physiological perspective, the results indicate that the lactate peak and rate of accumulation should be thoroughly developed. Notwithstanding, this review shows the lack of a solid body of knowledge on the importance of anaerobic and especially aerobic factors. Finally, the absence of a list of potential confounders, together with the lack of high-quality studies involving elite swimmers (level 1 and 2), complicates the interpretation of the results.

Effects of two warm-up protocols on isokinetic knee strength, jumping ability and sprint swimming performance in competitive swimmers

The purpose of this study was to examine the effects of different dryland warm-up protocols on knee isokinetic strength, vertical jumping, and sprint performance in competitive swimmers. Twenty-four male swimmers were randomly assigned to the FIFA 11 + group (n = 12) or the post-activation performance enhancement (PAPE) group (n = 12). The FIFA 11 + group performed the FIFA 11 + warm-up program three times per week for 6 weeks, whereas the PAPE group consisted of performing general activities and three sets of five drop jumps. Performance test included concentric (con) and eccentric (ecc) isokinetic strength of the quadriceps (Q) and hamstrings (H) of the dominant (DL) and non-dominant (NDL) limbs at three angular velocities, countermovement jump (CMJ), squat jump (SJ) and a 50-m time trial. The conventional (Hcon: Qcon) and functional (Hecc: Qcon) ratios were calculated pre- and post- intervention. The FIFA 11 + group showed a significant increase in DL-Hcon (p < 0.05, ES = 1.0-1.8), and NDL-Hcon (p < 0.05, ES = 1.0-1.6) in all angular velocities, and DL-Qcon (p < 0.05, ES = 0.9) at 60°·s− 1. The PAPE group significantly improved DL-Qcon at 180°·s− 1, 240°·s− 1 (both p < 0.05, ES = 1.0), and NDL-Qcon at 240°·s− 1 (p < 0.05, ES = 0.9). Additionally, FIFA 11 + showed significant improvement in DL-Hcon and NDL-Hcon (both p < 0.05, ES = 0.9–1.8) compared with PAPE. FIFA 11 + increased DL-Hcon: Qcon60 (p < 0.05, ES = 1.1) and NDL- Hcom: Qcon60,240 (both p < 0.05, ES = 1.2) compared with PAPE. Both groups significantly improved CMJ (FIFA 11 + p < 0.01, ES = 0.4 and PAPE p < 0.01, ES = 0.3), SJ (both p < 0.01, ES = 0.6) and 50-m swimming performance (FIFA 11 + p < 0.05, ES = -0.8 and PAPE p < 0.05, ES = -0.6).Both warm-up protocols showed similar improvements in jumping ability and sprint swimming performance. The FIFA 11 + seemed more efficient in improving lower limb isokinetic strength and conventional strength ratios in male competitive swimmers.

The complexity of agility testing in water polo: Reliability and validity analysis of sport-specific protocols

ABSTRACT This study aimed at evaluating the reliability and discriminant validity of a newly developed in-water agility test through a progression in complexity. Thirty-eight young male water polo players were divided into elite (n = 20; 16.2 ± 0.5 years) and non-elite (n = 18; 15.8 ± 0.6 years) groups. Players performed 20 m Freestyle Sprint Swimming Test (20 m FSST), Change of Direction Speed (CODS), and the Functional Agility Test without (FAT) and with shooting (FATS). The cognitive (CD) and technical deficits (TD) were calculated by subtracting time results of CODS from FAT and of FAT from FATS respectively. Excellent reliability was found for the 20 m FSST, CODS, and FAT (ICC from 0.954 to 0.982) and good reliability for the FATS (ICC = 0.838). Elite players outperformed non-elite players in 20 m FSST (g = 1.25), CODS (g = 1.08), and FAT (g = 1.14). There were no differences in FATS (g = 0.29), CD (g = 0.14), TD (g = 0.50) and shooting efficiency (g = 0.04). Increasing protocol’s complexity resulted in similar performance between groups eliminating differences in physicality. Although designed to mimic in-game performance, the results suggest discriminant validity only for physical attributes among young players, raising the need for further improvements in the testing protocol to better meet the cognitive and technical demands.

Blood flow restriction combined with swimming sprint training does not improve performance in moderately trained swimmers

Blood flow restriction combined with swimming sprint training does not improve performance in moderately trained swimmers

Neither an Individualised Nor a Standardised Sodium Bicarbonate Strategy Improved Performance in High-Intensity Repeated Swimming, or a Subsequent 200 m Swimming Time Trial in Highly Trained Female Swimmers.

Inconsistent swimming performances are often observed following sodium bicarbonate (NaHCO3) ingestion, possibly because the time taken to reach peak blood buffering capacity is highly variable between individuals. Personalising NaHCO3 ingestion based on time-to-peak blood bicarbonate (HCO3-) could be a solution; however, this strategy is yet to be explored in swimming, or adequately compared to standardised NaHCO3 approaches. Therefore, six highly trained female swimmers ingested 0.3 g·kg BM-1 NaHCO3 in capsules to pre-determine their individual time-to-peak blood HCO3-. They then participated in three experimental trials, consisting of a 6 × 75 m repeated sprint swimming test, followed by a 200 m maximal time trial effort after 30 min active recovery. These experiments were conducted consuming a supplement at three different timings: individualised NaHCO3 (IND: 105-195 min pre-exercise); standardised NaHCO3 (STND: 150 min pre-exercise); and placebo (PLA: 90 min pre-exercise). Both NaHCO3 strategies produced similar increases in blood HCO3- prior to exercise (IND: +6.8 vs. STND: +6.1 mmol·L-1, p < 0.05 vs. PLA) and fully recovered blood HCO3- during active recovery (IND: +6.0 vs. STND: +6.3 mmol·L-1 vs. PLA, p < 0.05). However, there were no improvements in the mean 75 m swimming time (IND: 48.2 ± 4.8 vs. STND: 48.9 ± 5.8 vs. PLA: 49.1 ± 5.1 s, p = 0.302) nor 200 m maximal swimming (IND: 133.6 ± 5.0 vs. STND: 133.6 ± 4.7 vs. PLA: 133.3 ± 4.4 s, p = 0.746). Regardless of the ingestion strategy, NaHCO3 does not appear to improve exercise performance in highly trained female swimmers.

Evaluation of pool-and-weir fishway efficiency for the upstream spawning migration of Qinghai Lake's naked carp

Przewalski's Naked Carp (Gymnocypris przewalskii) is a typical migratory fish species of the Qinghai Lake region (China). This study focused on the Gangbei Channel fishway located in the Shaliu River, a tributary of Qinghai Lake. A fish passage study was conducted during the peak of the upstream migration of G. przewalskii, and entry proportion and passage efficiency in the Gangbei channel fishway was monitored in real-time using PIT-Telemetry. A detailed hydraulic characterization of the fishway was done using a 3-D numerical model validated by in-situ measurements, and combined with empirical swimming ability data for the species. The results showed that: (1) the proportion of released G. przewalskii entering and passing the fishway were 13% and 5%, respectively; (2) discharge, fish body length, salinity, and diel period were key factors affecting the attempt rate of the G. przewalskii; (3) The critical swimming speed and sprint swimming speed at 50% of G. przewalskii reaching fatigue were 1.02 m/s and 1.91 m/s, respectively; (4) Based on the swimming ability of G. przewalskii and the hydraulic characteristics of the fishway, the flow velocity at the weir sections of the fishway exceeded the sprint swimming ability of G. przewalskii, creating a velocity barrier. Data derived from this study will be used to provide a more comprehensive theoretical basis and data reference for the eco-hydraulic reconstruction of pool-and-weir fishways providing an efficient upstream passage for the conservation of G. przewalskii and other species.

Which Strength Manifestation Is More Related to Regional Swimmers' Performance and In-Water Forces? Maximal Neuromuscular Capacities Versus Maximal Mechanical Maintenance Capacity.

To explore the association of the load-velocity (L-V) relationship variables and ability to maintain maximal mechanical performance during the prone bench-pull exercise with sprint swimming performance and in-water forces. Eleven competitive adult male swimmers (50-m front crawl World Aquatics points: 488 [66], performance level 4) performed 1 experimental session. The L-V relationship variables (L0[ie, maximal theoretical load at 0 velocity]; v0 [ie, maximal theoretical velocity at 0 load], and Aline [ie, area under the L-V relationship]) and maximal mechanical maintenance capacity were assessed at the beginning of the session. Afterward, sprint swimming performance and in-water force production were tested through a 50-m front-crawl all-out trial and 15-s fully-tethered swimming, respectively. Only v0 presented high positive associations with 50-m time and swimming kinematics (r > .532; P < .046). The L0, v0,and Aline showed very high positive associations with the in-water forces during tethered swimming (r > .523; P < .049). However, the ability to maintain maximal mechanical performance, assessed by the mean velocity decline during the prone bench pull, was only significantly correlated with stroke rate (r = -.647; P = .016) and stroke index (r = .614; P = .022). These findings indicate that maximal neuromuscular capacities, especially v0, have a stronger correlation with swimming performance and in-water force production than the ability to maintain maximal mechanical performance in level 4 swimmers.

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

ABSTRACT 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.

Concurrent Sprint Swimming Interval and Dryland Training: Performance and Biomechanical Variable Changes within a Mesocycle

Concurrent Sprint Swimming Interval and Dryland Training: Performance and Biomechanical Variable Changes within a Mesocycle

Combined warmup exerts an ergogenic effect on the speed of sprint swimmers: A systematic review with meta-analysis

This study review and analyze studies that measured the effect of combined strength/power warmup (COMB) versus traditional (TRAD) on the post-activation performance enhancement (PAPE) of swimmers. For this, we performed a systematic review was carried out with meta-analysis based on descriptors related to PAPE in swimming. A total of 138 articles were identified, of which 15 were selected. Comparisons between the COMB condition and the TRAD warm-up were performed for the following set of variables: a) power in 50- and 100-meter events, b) start performance, c) test time of 50- and 100- meters, and d) instantaneous speed in 50-meters events. The data extracted from the studies showed acceptable homogeneity (I²=0.000). When we observed the confidence intervals, it was verified that there were no differences between the COMB condition and the TRAD for power in 50 and 100 m events (Hedges g'=-0.12; 95%CI=-0.376; 0.136; p=0.357); time in 50- and 100-meter races (Hedges g'=-0.139; 95%CI=-0.314; 0.036; p=0.118); start performance (Hedges g'=-0.313; 95%CI =-0.643; 0.018; p=0.064). The COMB condition had an ergogenic effect on instantaneous speed in the 50 m event (Hedges g'=-0.282; 95%CI=-0.402; -0.162; p≤0.001). In conclusion, the present meta-analysis concluded that the COMB intervention does not exert an ergogenic effect on the performance of swimmers for the set of analyzed variables, except for instantaneous speed in 50 m events. Future studies may compare other forms of warmup versus the TRAD. Keywords: Warm-up exercise; Musculoskeletal and Neural Physiological Phenomena; swimming; athletic performance.

Lower and upper extremity contributions to propulsion and resistance during semi-tethered load-velocity profiling in front crawl swimming

ABSTRACT The study estimated lower and upper extremity contributions to whole-body front crawl swimming using semi-tethered load-velocity profiling. Nine female and 11 male (inter)national-level swimmers performed 20 m semi-tethered sprints, each with five progressive loads for lower (leg kicking), upper (arm stroke), and whole-body front crawl movements. The theoretical maximal speed (v0) and load (L0), and active drag (Da) were expressed as a percentage of the sum of both extremities for the movements of each extremity to calculate their contributions. The difference of whole-body values minus the sum of both extremities was used to estimate whole-body reserves. Lower (upper) body contributions were 43.8 ± 2.8% (56.2%) for v0, 37.3 ± 7.1% (62.7%) for L0, and 39.6 ± 5.6% (60.4%) for Da. Statistically significant whole-body reserves were found for v0 (−30.9 ± 3.9%, p < 0.001) and Da (−5.7 ± 11.7%, p = 0.04). V0 reserves correlated very highly with whole-body v0 in males (r = 0.71, p = 0.014) and moderately in females (r = 0.47, p = 0.21). The lower extremities contribute substantially to front crawl load-velocity profiles of highly trained swimmers. Higher sprint swimming speeds are associated with an efficient speed transfer from lower- and upper- to whole-body movement.

From dry-land to the water: training and testing practices of strength and conditioning coaches in high level French sprint swimmers.

The aim of this study was to explore training and testing practices from Strength & Conditioning (S&C) coaches who manage groups of high-level French swimmers in elite training centers. The transfer of abilities from dry-land to in situ condition was also investigated. 24 French S&C coaches completed a survey via an online platform. Frequency analyses were made for quantitative and qualitative responses, the level of significance set for this study was p ≤ 0.05. Core stability, Strength & Power were the three most targeted qualities. Core strengthening in all its forms, Bench Press & Squat were the three most prescribed exercises. 79% of S&C coaches adapted exercises according to different parameters. Most of the coaches indicated that dry-land S&C sessions were preferentially placed before in-water sessions. Very varied exercises were used in-water to make the transfer from dry-land more effective. 87% of participants monitored the training load and 38% assessed the force and velocity parameters for some S&C exercises. Dry-land training practices of S&C coaches were mostly in line with scientific recommendations. In the light of results of the questionnaire, it would appear that testing procedures might be a key issue for transferring qualities from dry-land to in situ.

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.

Effect of Foam Roll recovery method on performance in water polo players: a randomized controlled trial

ABSTRACT Objectives This intervention study aimed to evaluate how the use of Foam Roller (FR) as a recovery strategy affects water polo performance after a seven-week (28-session) program. Design A randomized controlled trial. Methods Thirty water polo players (14 male amateur players and 16 female sub-elite players) were assigned by means of sealed opaque envelopes to the control group (CG) or Foam Roller Group (FRG) and performed the same total number and intensity of training sessions. Test protocols were performed before (pretest), in-test (week 5), and after the intervention period (posttest). These included water polo-specific performance tests such as in-water boost, throwing speed, and 20 m sprint swimming tests. In addition, during the intervention, heart rate (HR), the scale of perceived exertion of the session (sRPE), and total quality recovery scale (TQR) data were recorded. Results There were no differences in the baseline values in any of the variables analyzed between CG and FRG. A small decrease in in-water boost was observed in CG (−2%, ES = -0.35 [−0.95: 0.26], p = 0.016, very likely small) and in FRG (−2%, ES = -0.33 [−0.93: 0.27], p = 0.021, likely small). No significant changes were found in either the 20 m swim test or the throwing test in CG and FRG. No clear differences among groups and weeks were found in sRPE, TQR and HR. Conclusion The findings indicate that the use of FR as a recovery tool after training and matches is not useful in water polo players.

Front Crawl and Backstroke Sprint Swimming have Distinct Differences along with Similar Patterns Regarding Trunk Rotations

Background: Front crawl and backstroke share similar trunk rotating characteristics and tempt coaches to transfer teaching parts from one stroke to the other intuitively. However, the degree of similarity has yet to be determined. The coordination of the pelvis and the 7th cervical vertebrae (C7), during yaw and roll rotation, when sprint swimming front crawl, and backstroke was studied. Methods: Thirty-four swimmers were assessed on their performance in25m-sprint of each stroke. Using inertial sensors, each segment’s time series of angular displacement was calculated. Their amplitudes, mean autocorrelation values, max cross-correlation coefficient, phase lag, and relative power at the main frequency were analyzed. For all comparisons, the p-value was set to 0.05. Results: Pelvis yaw and roll and C7 roll amplitudes were greater at backstroke, C7 yaw was greater at front crawl. Autocorrelations ranged from 0.79 to 0.82 except for the pelvis at front crawl in yaw which was 0.72±0.16. Relative power at the main frequency ranged from 47% to 52% except for the yaw pelvis’ at the front crawl which was lower (32.81±14.09%). Backstroke had larger mean values in all cases and roll had larger mean values than yaw. Cross-correlation between the two segments yielded higher values at roll. At roll direction, the leading segment in the front crawl was the pelvis while in backstroke, it was the C7 which was true in all cases. In all cases, the coupling was slightly deviating from in-phase mode except from backstroke yaw which yield phase lag values of -13.35±1.14% of stroke cycle time. Conclusions: Although both strokes share similar characteristics their intersegmental coupling differs. The findings of the study imply that proper focus should be given to enhance only a positive transfer of learning between the two strokes.

Effect of the identical training process on the functional state of high-level sprint swimmers of both genders

Purpose: to study the effect of an identical training process on the functional state of high-level sprint swimmers of both genders.&#x0D; Material and methods. The heart rate variability indices, central hemodynamic parameters and PWC170/kg measurements were compared between 86 male and 42 female swimmers with sports qualifications from first-class athlete to Master of Sports International Class, and separately, – between 38 males and 9 females (Masters of Sports and Masters of Sports International Class), 28 males and 16 females (Candidates for Masters of Sports), and 22 males and 17 females (first-class athletes).&#x0D; The results. In the general group (86 males vs. 42 females) only the greater value of PWC170/kg in males by 12.64 % (p&lt;0.001) was revealed, without any differences in heart rate variability and central hemodynamics. Masters of Soprts and Masters of Sports International Class, as well as Candidates for Masters of Sports, didn't have gender differences in all indicators studied. In first-class athletes, there were no gender differences in heart rate variability and central hemodynamic parameters, except for PWC170/kg, which in males was greater by 11.27 % (p=0.036).&#x0D; Conclusions. A comparison of 86 male and 42 female swimmers with sports qualifications from first-class athlete to Master of Sports International Class, who differed by age and training experience, showed no significant differences in HRV and central hemodynamic parameters except for PWC170/kg, which was 12.64 % higher in males (p&lt;0.001). There were no significant differences between all studied indices in 38 male and 9 female swimmers with sports qualifications Master of Sports and Master of Sports International Class, with no differences in age or training experience. Comparison of 28 male and 16 female swimmers with sports qualification Candidate for Master of Sports, not differing by age and training experience showed no significant differences in HRV and central hemodynamic parameters, except for PWC170/kg, which was greater in males by 11.27 % (p=0.034). In 22 male and 17 female swimmers with sports qualification first-class athlete, not differing by age (males have greater training experience) there were no differences between all studied indices.

Sex-specific transgenerational plasticity: developmental temperatures of mothers and fathers have different effects on sons and daughters.

Each parent can influence offspring phenotype via provisioning of the zygote or sex-specific DNA methylation. Transgenerational plasticity may therefore depend on the environmental conditions experienced by each parent. We tested this hypothesis by conducting a fully factorial experiment across three generations of guppies (Poecilia reticulata), determining the effects of warm (28°C) and cold (21°C) thermal backgrounds of mothers and fathers on mass and length, and thermal performance (sustained and sprint swimming speeds, citrate synthase and lactate dehydrogenase activities; 18, 24, 28, 32 and 36°C test temperatures) of sons and daughters. Offspring sex was significant for all traits except for sprint speed. Warmer mothers produced sons and daughters with reduced mass and length, and warmer fathers produced shorter sons. Sustained swimming speed (Ucrit) of male offspring was greatest when both parents were raised at 28°C, and warmer fathers produced daughters with greater Ucrit. Similarly, warmer fathers produced sons and daughters with greater metabolic capacity. We show that the thermal variation experienced by parents can modify offspring phenotype, and that predicting the impacts of environmental change on populations would require knowledge of the thermal background of each mother and father, particularly where sexes are spatially segregated.

The Effect of Post-Activation Potentiation on Swimming Starts in Adolescent Swimmers.

Post-activation potentiation (PAP) is a phenomenon in which there is an increase in induced momentum in sporting activities after muscle contractions. In swimming, the start of the race and the increase in speed in its first few meters are important. The aim of the present study was to investigate the effect of the PAP protocol, which included a simulated body weight start on the ground, on the swimming start and on the 25 m freestyle performance. The study included 14 male and 14 female swimmers, 14.9 ± 0.6 years old. All the swimmers performed three maximal attempts of 25 m freestyle swimming from the starting block on three different days in a randomly counterbalanced order. In each session, swimmers performed either a 25 m freestyle without any intervention before the swimming trial (CG), or performed four vertical simulated ground starts at maximal effort, 15 s before (15 sG) or 8 min before (8 minG) the swimming trial. The jump height, entry distance, flight time, and flight speed for each attempt were calculated. The CG entry distance was significantly longer than that of the 15 sG and 8 minG (3.39 ± 0.20 vs. 3.31 ± 0.21 and 3.25 ± 0.25 m, respectively, p < 0.001). Four simulated swim starts on the ground, 15 s or 8 min before the swim sprint, had no positive effect on the swim start or swim performance, and it is up to the swimmer to perform these jumps.

Blood Lactate and Maximal Lactate Accumulation Rate at Three Sprint Swimming Distances in Highly Trained and Elite Swimmers

We examined the blood lactate response, in terms of the maximal post-exercise concentration (Lamax), time to reach Lamax, and maximal lactate accumulation rate (VLamax), to swimming sprints of 25, 35, and 50 m. A total of 14 highly trained and elite swimmers (8 male and 6 female), aged 14-32, completed the 3 sprints in their specialization stroke with 30 min of passive rest in between. The blood lactate was measured right before and continually (every minute) after each sprint to detect the Lamax. The VLamax, a potential index of anaerobic lactic power, was calculated. The blood lactate concentration, swimming speed, and VLamax differed between the sprints (p < 0.001). The Lamax was highest after 50 m (13.8 ± 2.6 mmol·L-1, mean ± SD throughout), while the swimming speed and VLamax were highest at 25 m (2.16 ± 0.25 m·s-1 and 0.75 ± 0.18 mmol·L-1·s-1). The lactate peaked approximately 2 min after all the sprints. The VLamax in each sprint correlated positively with the speed and with each other. In conclusion, the correlation of the swimming speed with the VLamax suggests that the VLamax is an index of anaerobic lactic power and that it is possible to improve performance by augmenting the VLamax through appropriate training. To accurately measure the Lamax and, hence, the VLamax, we recommend starting blood sampling one minute after exercise.