Slumping after hernia opp

I had an umbilical hernia operation and was off the bike, pilatus and gym (followed Chad’s quick programme) for 6 weeks. I notice that I am slumping on the bike, supporting my upper body with my arms. Question is;

  1. what is the more important mussels supporting me, core, back or abs?
    2)what exercise should I focus on the most ?

Anyone with experience , when can I start doing weight training.

I had an umbilical hernia repair about 20 months ago. For 2 months, all I did was walk. Returned to working out (weights, swimming, hadn’t started cycling at the time. ) after 2 months. Sadly, it has recurred. I would go slow and return to activity gradually.