Thanks to a link from a poster in another thread, I'm pretty sure I have a small diastasis recti. Have signed up for a 12 week post partum exercise programme that specifically helps bring together the abdominal muscles. It says it's suitable up to 4 years after the birth (hoping it works as my DC is not yet 2). In the meantime is there any cardio style exercise that won't worsen it 
for days when I don't want to walk outside? Or is it better to wait til I've completed the 12 week programme? Thanks.