I do them every night in bed and for some strange reason I hold them for 12 seconds six times then 6 seconds 6 times! Some people have told me to hold them on and off very quickly, others said hold for 20 secs

I wish I had done them with all my pregnancies (only started doing them at the end of the last one) as now I have problems at the gym when i'm doing plyo lunges, scissors etc. So make sure you do them they're really, really important!!