You could use a electric metronome. They clip on to your waist and they are about the size of a watch. They can beep up to 250 beats/sec (4.17 strides per sec.) If you wanted to use it tempo or submax SE type runs would be best. You can get them at a muisc store or online. Sieko make one it costs about $20 us. Korg makes one that fits in your ear but it only goes up to 210 beats/sec. Is it worth while? Maybe. The only problem I see using them is that an athlete might tighten up trying to keep up with the sounds of the beep.