Chafing

Davo..
Maybe ask GP first..
Laying chest on table and lifting 1 leg at a time will improve your lower back. Improved flexibility is improved strength AND bodies ability to hold firm your seat.
I like walking with a bouncy ball. Bouncing in front of opposite step and then catching with stepped foot hand.. Repeat, side to side.. That opens up a humans natural energy torso channel.. Non muscular strength..

I’ve suffered with chafing in the past despite having a bike fit and purchasing the recommended Specialized saddle, new shorts, chamois cream etc. Recently had a big accident that necessitated having the bike thoroughly checked before agreeing to repairs. Mechanics identified that although saddle appeared fine, their laser tools identified that the saddle rails were very slightly bent. So together  with new wheel, bars, stem and pedals replaced the saddle with a Selle Italia. Have only used 3 times since, but this includes two 50 mile rides and no chafing. 

Have you had a proper, professional bike fit? Or a saddle fit? 

Where are you chafing? Legs or perineal area?

I would start with getting your sit bones measured as that will define the required saddle fit. And the bike fit will ensure that you're actually sitting on those sit bones rather than on something else.

It might be that you'll need to sacrifice the most efficient pedalling position for the one that generates least discomfort - might even mean that you need the geo of a hybrid.

Female-specific saddle might also help, or the current vogue for short nose male saddles.