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 (La_max), time to reach La_max, and maximal lactate accumulation rate (VLa_max), 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 La_max. The VLa_max, a potential index of anaerobic lactic power, was calculated. The blood lactate concentration, swimming speed, and VLa_max differed between the sprints (p < 0.001). The La_max was highest after 50 m (13.8 ± 2.6 mmol·L^-1, mean ± SD throughout), while the swimming speed and VLa_max 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 VLa_max in each sprint correlated positively with the speed and with each other. In conclusion, the correlation of the swimming speed with the VLa_max suggests that the VLa_max is an index of anaerobic lactic power and that it is possible to improve performance by augmenting the VLa_max through appropriate training. To accurately measure the La_max and, hence, the VLa_max, we recommend starting blood sampling one minute after exercise.

Lower fatigue and faster recovery of ultra-short race pace swimming training sessions

Ultra-short race-pace training (USRPT) is a high-intensity training modality used in swimming for the development of specific race-technique. However, there is little information about the fatigue associated to this modality. In a crossover design, acute responses of two volume-equated sessions (1000-m) were compared on 14 national swimmers: i) USRPT: 20×50-m; ii) RPT: 10×100-m. Both protocols followed an equivalent work-recovery ratio (1:1) based on individual 200-m race-pace. The swimming times and the arm-strokes count were monitored on each set and compared by mixed-models. Blood lactate [La^-] and countermovement jump-height (CMJ) were compared within and between conditions 2 and 5 min after the protocols. The last bouts in RPT were 1.5-3% slower than the target pace, entailing an arm-strokes increase of ~0.22 for every second increase in swimming time. USRPT produced lower [La^-] ([Mean ± standard deviation], 2 min: 8.2±2.4 [p = 0.021]; 5 min: 6.9±2.8 mM/L [p = 0.008]), than RPT (2 min: 10.9±2.3; 5 min: 9.9±2.4 mM/L). CMJ was lowered at min 2 after RPT (-11.09%) and USRPT (-5.89%), but returned to baseline in USRPT at min 5 of recovery (4.07%). In conclusion, lower fatigue and better recovery were achieved during USRPT compared to traditional high-volume set.

Associations Between Selected Biological Features and Absolute and Relative Swimming Performance of Prepubescent Boys Over a 3-Year Swimming Training Program: A Longitudinal Study

The study aimed to investigate the effect of 3-year swimming training on selected biological variables in prepubescent male swimmers and to determine the best predictors of absolute (VS_a) and relative (VS_r) swimming velocity for 50 m and 400 m front crawl. Twenty-one 10-year old boys subjected to endurance swimming training (4 x 70 min per week) and 18 boys consisting a control group were assessed semi-annually for basic anthropometric and respiratory characteristics, breath-hold time (BHT), VO_2max, leg explosiveness (HJ), and abdominal strength endurance (ASE). After three years of training, BHT (p < 0.001), VO_2max (p < 0.01), HJ (p < 0.01) and ASE (p < 0.01) were greater in the swimmers than in the controls. VS_a and VS_r expressed as a percentage of baseline velocity increased more for the 50 m than for the 400 m distance (p < 0.001 and p < 0.01, respectively). The 50 m VS_a and VS_r positively correlated with those obtained for the distance of 400 m (in both cases p < 0.001). Baseline VS_a was negatively correlated with the increase in absolute swimming velocity for both distances (50 m: r = -0.684, p < 0.001 and 400 m: r = -0.673, p < 0.001). The best predictors of VS_a for 50 m and 400 m front crawl were HJ (r₂ = 0.388; p < 0.001) and VO_2max (r₂ = 0.333; p < 0.001), respectively. The key predictors of VS_r for both distances were age (50 m: r² = 0.340, p < 0.001 and 400 m: r² = 0.207, p < 0.001) and, after excluding it from analysis, HJ (50 m: r² = 0.176, p < 0.001 and 400 m: r² = 0.104, p < 0.001). These results suggest that regardless of prepubescent boys’ initial abilities and exercise capacity, improvement in their swimming performance mainly depends on increases in power and neuromuscular coordination.

Evaluating the Usefulness of the Modified Swimming Anaerobic Sprint Test (SAST) Based on the Relationship with the 100- and 200-m Freestyle

The construction of specialized physiological tests for swimmers is often based on those previously used in versions on land. So far, no attempt has been made to adapt the RAST test to conditions of an aquatic environment. The aim of the study was to evaluate the relationship between the results from the 6 × 25 m front crawl test (Swimming Anaerobic Sprint Test—SAST) and 100- and 200-m freestyle performance. In a group of 22 swimmers (9 girls, 13 boys, mean age 17.2 years, body mass 67.6 kg, body height 1.76 m), the SAST was performed (10-s interval between repetition). To determine speed (v), stroke rate (SR), stroke length (SL), and stroke index (SI), the test and races were recorded with the use of cameras. The analysis included times from the competition and fatigue indices (the decrease in SI during the SAST). Analysis of variance was performed, and a correlation matrix was created considering variables from the SAST and competition. The indices describing the 200-m event differed from those recorded for the SAST and 100 m freestyle race. The SAST results (v, SL, SI) were strongly correlated with the 100- and 200-m performances. Fatigue indices have not been shown to correlate with competition performance. The SAST may be useful in the context of predicting results for the 100- and, to a limited extent, 200-m freestyle races.

ACTN3 Polymorphism: Comparison Between Elite Swimmers and Runners

Background

The human ACTN3 gene encodes α-actinin-3, an actin-binding protein with a pivotal role in muscle structure and metabolism. A common genetic single nucleotide polymorphism (SNP) at codon 577 of the ACTN3 results in the replacement of an arginine (R) with a stop codon (X). The R allele is a normal functional version of the gene, whereas the X allele contains a sequence change that completely stops production of functional α-actinin-3 protein. The ACTN3 R577X polymorphism was found to be associated with power athletic performance especially among track and field athletes. The aim of the current study was to compare allelic and genotype frequencies of the ACTN3 R577X polymorphism among runners and swimmers specializing in different distances, and >non-athletic controls.

Methods

One hundred and thirty-seven runners, 91 swimmers and 217 controls, participated in the study. Runners were assigned to two subgroups according to their event specialty—long-distance runners (LDR) and short-distance runners (SDR). Swimmers were also assigned to two subgroups according to their main swimming event—long-distance swimmers (LDS) and short-distance swimmers (SDS). Genomic DNA was extracted from peripheral EDTA-treated anti-coagulated blood using a standard protocol. Genotypes were determined using the Taqman allelic discrimination assay.

Results

Runners’ genotype and allele differed significantly between LDR, SDR, and controls, with the lowest prevalence of RR genotype and R allele among LDR. XX genotype and X allele prevalence was significantly higher among LDR compared to the other groups (p < 0.01 for all). On the other hand, swimmers’ genotype and allele frequencies did not differ significantly between subgroups (LDS and SDS). Yet, LDS had significantly higher RR genotype and R allele frequencies compared to LDR.

Conclusions

The findings suggest that while ACTN3 R577X polymorphism is a genetic polymorphism that may distinguish between SDR and LDR, it cannot differentiate significantly between SDS and LDS.

Trial Registration

ClinicalTrials.gov: NCT01319032

Key Points

ACTN3 R577X polymorphism is largely associated with running events specialization, with high prevalence of RR genotype and R allele frequency among short-distance runners compare to long-distance runners.

Unlike in running, ACTN3 R577X polymorphism is not associated with swimming specialization.

The inability of the ACTN3 R577X polymorphism to distinguish between swimmers specializing in different events, presumably since other factors such as body physique, technique, tactics, etc., are more likely to determine such a distinction.

Differences in MCT1 A1470T polymorphism prevalence between runners and swimmers

Skeletal muscle is the major producer and user of lactate in the body. Therefore, transport of lactate across cells' membrane is of considerable importance. Lactate transport is mediated by proton-linked monocarboxylate transporter (MCT1). The A1470T polymorphism (rs1049434) in MCT1 gene influences lactate transport, with T allele associated with reduction of lactate transport rate and elevation in blood lactate levels. The aim of the current study was to compare allelic and genotype frequencies of MCT1 A1470T polymorphism among Israeli track-and-field athletes, swimmers, and non-athletes. Genomic DNA was extracted from 173 track-and-field athletes (age 17-50), 80 swimmers (age 16-49), and 128 non-athletes (age 19-29). Track-and-field athletes were assigned to three subgroups: long-distance runners, middle-distance runners, and power event athletes. Swimmers were assigned to two subgroups: long-distance swimmers and short-distance swimmers. Genotyping was performed using polymerase chain reaction. T-allele frequency was significantly higher among long-distance swimmers (45%) compared with long- and middle-distance runners (27% and 30%, respectively; P < 0.01). In addition, T-allele frequency was significantly higher among short-distance swimmers (40%) compared with power event athletes (25%, P < 0.01). Overall, T-allele frequency was significantly higher among swimmers (42%) compared with runners (27%, P < 0.001). More research is needed to clarify whether this polymorphism displays advantage for swimming performance.

The influence of sex, stroke and distance on the lactate characteristics in high performance swimming

Background

In order to achieve world-class performances, regular performance diagnostics is required as an essential prerequisite for guiding high performance sport. In high performance swimming, the lactate performance diagnostic is an important instrument in testing the sport specific endurance capacity. Although the role of lactate as a signaling molecule, fuel and a gluconeogenic substrate is accepted, lactate parameters are discussed concerning stability, explanatory power and interpretability.

Methods

We calculated the individual anaerobic threshold (IAT) of Bunc using the swimming-specific lactate threshold test by Pansold.

Results

The cross-sectional analysis (ANOVA) of n = 398 high performance swimmers showed significant effects for sex, stroke and distance on the IAT, the percentage of personal best time on the IAT (% of PB on IAT) and maximal lactate values (max. bLA). For the freestyle events the IAT decreased, % of PB on IAT and max. bLA increased from 100 to 400 m significantly in men and women. Women showed significantly higher % of PB on IAT with descriptive lower IAT in 7 of 8 analyzed events. Men showed significantly higher max. bLA in 5 of 8 events. In the second step, the analysis of 1902 data sets of these 398 athletes with a multi-level analysis (MLA) showed also significant effects for sex, swimming distance and stroke. For initial status and development over time, the effect sizes for the variables distance and sex were medium to large, whereas for stroke there were no or small effect sizes.

Discussion

These significant results suggest that lactate tests in swimming specifically have to consider the lactate affecting factors sex and distance under consideration of the time period between measurements. Anthropometrical factors and the physiology of women are possible explanations for the relative better performance for lower lactate concentrations compared to men.