Effects of metformin during swimmer training performance

INTERVENTION: G11.427.410.698.277.311.250 D02.078.370.141.450 D26.660 The present project will be divided into two studies and will involve a total of 20 participants. Both experiments will be carried out using a double‐blind and randomized model, where the participants will ingest before the tests a capsule containing 500mg of metformin or a placebo capsule containing 500mg of corn starch. The experimental and placebo situations will be separated by 72 h, respecting the metformin wash‐out. The capsules will be administered 60 min before the evaluation, respecting the peak action of MET. Participants will be instructed not to consume any type of supplement, food or energy and / or alcoholic drink that may interfere with the results. In all experiments, before performing the tests, the swimmers will perform a 1000m warm‐up, coordinated by the responsible technician and with moderate intensity. There will be a total of each visit of the participant will last about 2 hours and 30 minutes (including time of absorption of the compound, heating and evaluations). The first experiment will aim to investigate the influence of metformin in maintaining performance during a typical series of swimming and in the parameters obtained by the 30 s test in tied swimming (effort performed tied to measure swimming force). During the typical series, also known as "Vel‐2", the parameters related to swimming mechanics, the subjective perception of effort (PSE) and the blood concentrations of lactate ([La‐]) and glucose ([Gli]) , will be determined. In addition, neuromuscular fatigue will be assessed using the Twitch Interpolation technique, previously applied to the series and immediately afterwards. One week before this experiment, all participants will be familiarized with the performance of the maximum voluntary contraction (CVM) and with the electrica CONDITION: D26.660 G11.427.410.568.800 Healthy swimmers under the influence of metformin or placebo during a high‐intensity interval training PRIMARY OUTCOME: Metformin is expected to improve swimmers' performance during the typical treining series The use of metformin is expected to show a lower fatigue rate through neuromuscular parameters SECONDARY OUTCOME: It is expected that there will be an increase in acidosis and glycemia during efforts Metformin is expected to favor recovery from acidosis during recovery INCLUSION CRITERIA: The inclusion criteria include that the participant have experience in the sport for three years or more, participate regularly in competitions at the state or national level, have been training regularly for the past 2 years and present a medical certificate