Hi Betty,
I have asked about exercise in general as I am not sure what I should be doing and I got this advice, I think from Kath which made sense.
"It's not possible to build muscle on a VLCD, so no. Gentle exercise is a very good idea indeed as making exercise part of your life will help you keep the weight off in the long run. High intensity exercise should really be avoided while you're on a VLCD because (even if you feel great while you're doing it) with virtually no carbs in your diet, your body doesn't have the ready stores of glycogen that you need and will struggle to convert body fat quickly enough to be used for fuel.
Always remember that if you're exercising, particularly if it's structured exercise e.g. at the gym, you need to drink extra water before, during and after your workout.
Exercise shouldn't speed up your weight loss, basically because if you are doing enough exercise to make a significant difference to your losses, then you should be eating more "
I hope that helps. I suppose it depends on how fit you are now and what exercise you are used to. But don't push it if you are on a VLCD I would say.