Best thing that 99% of surfers can do to surf better, longer and catch more waves is lose weight. Period.
yes and no. I think Americans tend to be fatter and in poorer shape, generally speaking.
most of the crew I know are in shape.
changing body fat %, ie getting stronger, exchanging some fat for muscle, whatever weight you are might be more important than getting lighter per se.
all depends.
I'll tell you where my thinking comes from.
I used to basically train cardio/endurance, or whatever. swimming, bit of running, bike riding etc etc.
then I met Jan Carlton, who runs a CHEK training thing and got Fanning back into shape after he tore the hamstring off the bone in 2006/7.
She told me that surfers, even ones who surfed a lot and were ostensibly "fit" were weak and that a lack of strength in key areas was a structural problem and people who trained and resolved those weaknesses would massively benefit.
which Fanning did.
I took years to take that advice, wish I did sooner.
I'm the same weight I was then, same weight I was when I was 19, but heaps stronger now and surf better.