Cyclist / jogger here. Monthly i clock like 80-100hrs for cycling alone.
Really cannot ride and run so fast across pedestrian crossings, be it traffic lights or zebra crossing.
Tops is 10kmh, ie 6.00 pace..... actually at that pace also got a wee bit of risk (but generally it's still acceptable risk esp if you have good lights on you).
Technically if talking about legality, it would be walking pace, eg not more than 8kmh tops.
At night esp, do use sufficient lux lights (with horizontal cutoff = best), shine the hotspot onto the ground in front, let the road users have sufficient time to react. Safety lah.
Some zebra crossings have shrubs/hedges that block vehicles' visibility (eg Peck Seah St at Tg pagar, just outside Guoco Twr). Either that or you use helmet mounted lights.