Researchers combined data from seven studies to compare running-only training, cycling-only training, and mixed cross-training. The participants were trained or recreationally active individuals who exercised for at least four weeks. The main goal was to see if mixing sports improved specific running fitness or race times compared to focusing on just one activity.
The analysis looked at fitness measured on a treadmill and a bike, plus running performance in timed trials. Results showed small, non-significant trends favoring the specific sport being tested, but no clear advantage for cross-training. Running performance results showed no meaningful differences between the groups.
The evidence comes from a limited number of studies with varied methods and older training protocols. Because of these uncertainties, the findings should be interpreted with caution. There were no reported safety concerns or adverse events in the studies reviewed. Readers should understand that current data does not support claims that cross-training maintains specific performance better than single-sport training.