Effective Danio rerio Endurance Exercise Training Model

Exercise training as a stimulus for increased exercise performance is well studied in humans. Scientists also have used model organisms: cats, rodents, and famously; shrimp, to study exercise adaptations. The use of zebrafish ( Danio rerio ) as a model to study exercise is an underutilized resource, despite their lower cost, maintenance, and space requirements. Developing zebrafish as a model to study exercise would allow experimentation into a widely used vertebrate model. In order for zebrafish to be a model for exercise training studies the training dose needed to induce performance increases must be determined. Therefore, the purpose of this research was to establish a minimum exercise training dose needed to increase swimming performance. Adult zebrafish were tested for their pre‐training maximum absolute sustained swimming speed (U crit ). The fish were then swim trained during 14 sessions over the course of 3 weeks. Each training session was 120 minutes long, with not more than 3 consecutive days of training in a row. During the first training session each fish trained against a 50 cm/s water flow rate for the first 1.5 hours, followed by 60cm/s water flow rate for the last 15 minutes. Subsequently, the duration of 50 cm/s swim speed was decreased and the duration of the 60 cm/s speed increased progressively over the course of the 3 week training period. The fish rested for a day following the last training bout and then post training U crit was measured. The average pre‐exercise training value was 56.8 cm/s. The average post‐exercise training U crit value was 63.4 cm/s. Post training Ucrit was 12% higher than pre‐training values (p<0.003). In conclusion, exercise training can increase endurance swimming ability in zebrafish, supporting the viability of using zebrafish as an animal model for studies of exercise training.