I have torn the fibres between the Rectus abdominis muscles training in the gym. What do you recommend?

That's an unusual one to damage. Well done!

If you're anything like me then time off is not a joking situation.

The answer is rest, recovery and frozen peas.

Add Arnica tablets whether you believe in them or not (they work) and keep moving rather than immobilise the area.

Sorry for the old fashioned advice but its the best answer.

Best wishes

Earle