If you are a speed-power athlete or train speed-power athletes and you’re doing anything that involves anything more than 15 minutes of continuos work of anything except extremely low intensity activity you’re probably doing something wrong. This allows for dynamic warmups (of which mine are typically 45-60 minutes), general strength, weight circuits and similar training methods that have short but intermittent rest periods, and slow continuous tempo running.
Spending significant time in an aerobic state sends mixed signals to an athlete training for speed-power activities. In the research world, this is known as the interference effect. The interference effect indicates that mixing endurance training with speed-power training will likely lead to compromised results, especially on the speed-power side of the spectrum. Venture beyond 15 minutes with care.