[stared]

When it comes to IQ - think as is you wanted to assign one number to describe individual's sport ability. It will serve[x] some purpose for average (from bed-ridden ill to a healthy athletic person), but most likely - it will be almost useless for sports(wo)men, where more specialistic predispositions are required (sometimes contradictory; e.g. a great heavy weight boxer won't be even an amateur marathon runner).

[x] Actually, it's used in military, to rate conscripts - if they should be enrolled.