question about allan wells training

The cross training effects of boxing (speedball) & circuits do have cross over benefits to sprint running. From the pure physiological perspective increased oxygen efficiency and higher anaerobic threshold will only be beneficial for a sprinter for multiple reasons.

I have been doing speed skating for the last 6 months as an alternate stimulus for sprint running and have had very positive cross over effects for sprinting. Cross training can work providing the balance is appropriate. In the case of the injury prone athlete cross training is a vital training ingredient.