(1) Background: warm-ups precede physical exertion and has been shown to have positive and negative effects on performance. Positive effects include elevating body temperature, heart rate, and VO2. Negative effects include increasing fatigue and blood lactate concentration. The most effective warm-up format is still unknown, particularly in competitive swimming. The purpose of this systematic review was to determine the most beneficial warm-up for maximal performance in sprint swimming events; (2) Methods: a structured search was carried out following the Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) guidelines in the PubMed, SportDiscus, and Google Scholar databases until March 2021. Studies with double-blind and randomized designs in which different types of warm-up were compared to each other or an identical placebo condition (no warm-up) were considered. Fourteen published studies were included. The effects of warm-up on sprint swimming performance, rating of perceived exertion (RPE) and blood lactate concentration (La-) were investigated. (3) Results: in half of the studies, swimmers performed significantly better after a regular warm-up; however, the effect of warm-up on performance was small. Warm-ups had a medium to large effect on RPE and a small to medium effect on La-. (4) Conclusions: the findings of this review suggest that warm-ups do influence performance, although the magnitude is small. Future studies are needed in larger populations to clarify whether warm ups improve swim performance, to what extent, and the potential role of variables related to participant characteristics and swimming competitions.
Keywords: blood lactate; performance; rating of perceived exertion; swimming; warm up.