Recommendations for child's exercise bike?

[WalkingThePlank]

I'm looking for a child's exercise bike. A quick Google only shows a brightly coloured one for children but it is rather small. My child is 4'2".

I did search Mumsnet first but only came across a rude thread about child's exercise bikes equalling bad parenting. My child needs the bike for medical reasons.

Any ideas would be great.

Does your child have a bike already? If so, the easiest thing is to get a turbo trainer so the bike can just be fitted onto that. My 8 year old uses ours with his bike, and it has the advantage that it can be used by all the family

Thanks for that. Its a great idea. My nephew has one as he is a competitive cyclist. I should have thought of it myself.