The growth-promoting effects of exercise in finfish: A systematic review and meta-analysis

Exercise training may be an effective tool for promoting growth and production efficiency in finfish aquaculture. Yet, changes in growth and feed conversion ratios (FCR) following periods of exercise can be varied and context dependent. Variation in species and training protocols (duration, intensity and regime) can misalign interpretations, and individual studies hold limited statistical power. To remedy this, we compiled data from 69 studies spanning 31 species to quantify the effects of exercise training on growth rates and FCRs. Using meta-analytic tools, we show that exercise training significantly increases growth rates across a range of taxonomically diverse finfish. Optimal training regimes were identified; effects were strongest when fish were exercised continuously rather than intermittently, at target swimming speeds <= 2 body lengths s-1, for longer durations of time. These results are most applicable to juvenile fish (mean length of fish in the analyses = 16 cm). Exercise training was also shown to decrease variability in growth rates, leading to fish that are more uniform in size. FCRs were unaffected by exercise, showing that exercised- and control-fish were equally efficient at converting food into body mass. Overall, our analyses show that exercise is a powerful management tool in promoting rapid growth, where fish can reach marketable sizes faster.