I'm 1m85 / 6'1" and big-framed (swimmer build - or was 35 years ago), my optimum weight in the Foreign Legion was about 85kg / 13st 5lb / 187lb. It dropped to 76kg / 11st13.5lb / 167.5lb on Ops in Chad in 1984.
In basic (and more after) there I was doing lots of phys - mainly endurance (lots of long-distance running and tabbing, fartlek, hillwork, with and without weight) and upper body strength, (press-ups, dips, pull-ups, rope climbing - arms & legs and arms only - using one rope and two ropes) concentrating on optimal endurance and a balanced power-to-weight ratio (although that wasn't scientifically explained - it's just what we did). An overly developed muscle-man physique was a drawback. Gym bunnies suffered in basic and tended to be derided by the DS as being vain and overly interested in their appearance as opposed to being physically effective.
In 2REP we dropped with what we needed and carried it all, up hill and down dale. So the weight carried could be enormous. When I became a radio-telegraphist, as part of a three-man team I carried either the SSB transceiver, the antenna set or the generator set - we all split up the spare batteries. This on top of all personal kit, weapon and ammo, rations and water. You did not any extra useless muscle bulk on your body to carry as well.
p.s. I wish my weight was somewhere close to above now