Big boned or small boned? Tall or short? All of the top distance runners are short, skinny, small boned, and have long legs relative to their trunks. So I'd do that.
Wouldn't folk with the perfect body type still have a target weight for their chosen activity?
Sometimes tangible numbers can be a helpful instead of having everything floating about in the ether, I was just looking for something with a little science behind it that I could fill an empty space in my understanding.
Just found this.
By Frank Horwill
Most coaches use the Stillman height/weight ratio table for distance runners. The average man is allocated 110 lbs (50kg) for the first 5 feet (1.524m) in height. Thereafter, he is allocated 5½ lbs (2.495 kg) for every additional inch (O.025m) in height.
Thus, a man 6 feet tall (1.829m) would be allocated 110lbs (50kg) plus 12 x 5½lbs (2.495kg), which comes to 176 lbs or 12 st 8lbs (80kg). The exceptions to the rule are Japanese wrestlers, heavyweight boxers and certain rugby players, who aim to exceed this weight. Females are allocated 100 lbs (45kg) for the first 5 feet (1.524m) and 5lbs (2.268kg) for every inch thereafter. Therefore a woman who is 5 ft 6ins (1.676m) tall would be given 100 lbs plus 6 x 5lbs, which totals 130 lbs or 9st.4lbs (59kg).
These allocations are considered healthy guidelines for non-active people. However,
a distance runner needs to weigh less, about 5 to 10 per cent less. This makes our 6 foot tall male requiring to be 8 to 17 lbs
less than his 1761bs, around 168lbs to 159 lbs. And our female of 5ft 6ins should be around 6 lbs to 13lbs
less, around 124 lbs to 117 lbs.