Were the kids on Nick shows in the 90s on speed? According to this Saturday Night Live unaired sketch, yes. Yes they were.
Beck Bennett hosts this sketch sharing the behind the scenes of a fake Nick show called "Zap" starring Anna Kendrick, Nasim Pedrad, Taran Killam, and actual 90s Nick star Kenan Thompson.
The speed was the only way for the kids to maintain their 16 hour a day shooting schedule. Those child stars are relentless.