The aims of this study were to use a specific all-out 30-sec tethered test to determine the anaerobic parameters in elite kayakers and verify the relationship between these results and sports performance. Twelve elite slalom kayakers were evaluated. The tethered canoe system was created and used for the all-out 30-sec test application. Measurements of peak force, mean force, minimum force, fatigue index and impulse were performed. Performance evaluation was determined by measuring the time of race in a simulated race containing 24 gates on a white-water course. Blood was collected (25-µl) for analysis of lactate concentration at rest and at 2, 4, 6, 8 and 10-min intervals after both the all-out test and the simulated race. The Pearson product moment correlation shows a inverse and significant relationship of peak force, mean force and impulse with time of race. Blood lactate concentrations after the all-out test and the simulated race peak at same time (4 min). Additionally, no interaction was visualized between time and all-out test/simulated race for blood lactate concentrations (P <0.365). These results suggest a relationship between the parameters of the all-out test and performance. Thus, the tethered canoe system is a useful tool for determining parameters that could be used in training control of slalom kayakers.

No abstract

This study is aimed at testing the acute melatonin administration (oral; 6 mg) on aerobic tolerance at cycloergometer and analyzing the consequences on biochemical and hematological parameters. Methods: The maximal aerobic capacity intensity (iMAC) at cycloergometer of eleven male healthy men (24.18±3.92 years-old; 87.07±12.48 kg; 1.82±0.05 m; 26.18±3.63 kg/m 2 ; and 16.28±5.77 % of fat) was individually determined and used to perform a time to exhaustion (tlim) trial of 30 minutes after melatonin or placebo administration. We observed 48-72h interval between tests, performed in a double-blind experiment design. In order to determine hematological and biochemical parameters we collected venous blood samples before and after tlim. Statistical significance was set at 5%. Results: The intensity and the lactatemia corresponding to the maximal aerobic capacity were 120.88±18.78 W and 3.32±1.03 mmol.L-1 , respectively. The tlim with placebo (33.94±15.26 min, confidence interval = 24.92-42.95) was significantly lower than the tlim with melatonin (41.94±17.22 min; CI = 31.76-52.12; p = 0.03; 19.06%; effect size = 0.49). All of the 21 analyzed blood physiological variables resulted in no significant variation after tlim when placebo was compared to melatonin, except for total sera cholesterol (lower after exercise with melatonin). Conclusion: Acute melatonin administration enhanced aerobic tolerance at iMAC in 19% at cycloergometer; however, the biochemical and hematological variables assessed were not significantly modulated.

In summary, MLSS and CF tests on a tethered canoe system may be used for aerobic assessment of elite slalom kayakers. In addition, CF may be used as an alternative low-cost and noninvasive method to estimate MLSS, which is related with slalom kayakers' performance.

Information regarding the aerobic power on canoe slalom performance is scares. Moreover, the comparison of maximum oxygen uptake (VO2max) via specific and non-specific ergometer for slalom kayakers may improve training prescription and controlling over Olympic cycles. Lastly, it is still unknown to what extent the VO2max delimitate the high performance in this sport. To test this perspective, a highly qualified sample is desired. In overall statistics, Slovakian athletes gathered 14 Olympic medals over the last sixteen years. Therefore, the main aim of this study is to compare the aerobic power of Olympic medallists and Non-Olympic Slovakian kayakers via specific and non-specific evaluations from Beijing 2008 to Rio 2016 Summer Olympic Games. Forty-two male canoe slalom athletes from Slovak national team were evaluated between the years 2006 and 2016. Slovakian athletes were tested for specific (i.e. paddling ergometer) and non-specific (i.e. treadmill) incremental protocols for VO2max determination. Over the last three Summer Olympic Games, the VO2max of Slovakian Olympic medallists was consistently lower than most of the Slovakian team. Moreover, disregarding the medallist characteristic or the moment, Slovakian kayakers presented higher VO2max on treadmill (57.7±6.8 mL . kg -1. min -1 ) when compared to paddle ergometer (46.9±6.5 mL . kg -1. min -1 ) (p=0.000; ES=1.6). Based on the collected data over the last ten years, we suggest that although aerobic power may play a relevant and indirect role on performance of slalom kayakers, does not delimitate the high performance in this sport.

-Aims: This study was designed to investigate the effects of 14 water environment adaptation days on motor behavior and physiological condition of swimming rats. Methods: Sixty male Wistar rats were divided into four groupsbaseline (Bl) and control (Co) groups-which did not perform the water environment adaptation; and sub (SubAnT) and (SupraAnT) anaerobic threshold groups, which performed 14 water environment adaptation days with sub or supra anaerobic threshold progressive loads (from the tenth day), respectively. The climbing-swimming prevalence (i.e. motor behavior) was analyzed during the water environment adaptation days. Lactate minimum test (LMT) parameters and muscular/hepatic glycogen content in addition to serum creatine kinase were also measured. Results: Animals from SubAnT and SupraAnT groups presented a lower climbing-swimming pattern throughout the extent of the experiment (p=0.000), especially after the 5th session. These results were achieved without an improvement in the LMT results or glycogen/creatine kinase. In addition, improvements of 26.6% and 25% for the LMT success rate (i.e. LMT reliability) were obtained only for SubAnT and SupraAnT animals. Conclusion: Overall, we demonstrated that a water environment adaptation period is necessary for lowering the climbing-swimming pattern without physiological improvement.

This study aimed to compare the aerobic power (treadmill running) and muscle power (bench press and bench pull) of Junior/U23 paddlers from Slovakia who won medals in international championships with that of those who did not take the podium. Forty-three Slovak Junior/U23 paddlers (sprint = 24, medalists = 8, non-medalists = 16; slalom = 19, medalists = 11, non-medalists = 8) were tested in 2018 and 2019 after the world championships. The maximal oxygen uptake (VO2max) and the velocity at maximal oxygen uptake (vVO2max) were determined by the incremental running protocol (0% slope and 1 km⋅h–1 increments every minute until volitional exhaustion). Mean maximal power from the entire concentric phase was recorded during bench press and bench pull exercises by the validated TENDO weightlifting analyzer. No interaction was obtained between medal and canoe discipline for VO2max (p = 0.069, F = 3.495), vVO2max (p = 0.552, F = 0.361) and absolute (bench press: p = 0.486, F = 0.495; bench pull: p = 0.429, F = 0.640) or relative (bench press: p = 0.767, F = 0.089; bench pull: p = 0.696, F = 0.155) mean maximal power. Conversely, a significant effect for the medal on the bench press (absolute p = 0.017, F = 6.170; relative p = 0.043, F = 4.384) and the bench pull (absolute p = 0.041, F = 4.470) mean maximal power were observed. Our study indicates the absolute mean power on the bench press as a prerequisite for success in international Junior/U23 championships of slalom and sprint canoeing. However, the mean power on bench pull seems to have a deeper influence on sprint paddlers when compared to slalom athletes. Regarding the aerobic power, the data from the treadmill testing did not reveal outcomes between medalists and non-medalists. This result can be associated with the lack of specificity of the incremental treadmill testing for canoeing, and future studies are encouraged to propose specific protocols to compare the aerobic power of medalists and non-medalists in international slalom and sprint championships.

In 1993, Uwe Tegtbur proposed a useful physiological protocol named the lactate minimum test (LMT). This test consists of three distinct phases. Firstly, subjects must perform high intensity efforts to induce hyperlactatemia (phase 1). Subsequently, 8 min of recovery are allowed for transposition of lactate from myocytes (for instance) to the bloodstream (phase 2). Right after the recovery, subjects are submitted to an incremental test until exhaustion (phase 3). The blood lactate concentration is expected to fall during the first stages of the incremental test and as the intensity increases in subsequent stages, to rise again forming a “U” shaped blood lactate kinetic. The minimum point of this curve, named the lactate minimum intensity (LMI), provides an estimation of the intensity that represents the balance between the appearance and clearance of arterial blood lactate, known as the maximal lactate steady state intensity (iMLSS). Furthermore, in addition to the iMLSS estimation, studies have also determined anaerobic parameters (e.g., peak, mean, and minimum force/power) during phase 1 and also the maximum oxygen consumption in phase 3; therefore, the LMT is considered a robust physiological protocol. Although, encouraging reports have been published in both human and animal models, there are still some controversies regarding three main factors: (1) the influence of methodological aspects on the LMT parameters; (2) LMT effectiveness for monitoring training effects; and (3) the LMI as a valid iMLSS estimator. Therefore, the aim of this review is to provide a balanced discussion between scientific evidence of the aforementioned issues, and insights for future investigations are suggested. In summary, further analyses is necessary to determine whether these factors are worthy, since the LMT is relevant in several contexts of health sciences.