"loop" can all be typed with one finger, as the letters are all together on the qwerty keyboard, and the "o" repeats itself.
"while" on qwerty is sort of a chore.
What matters is the token count and logprob. It hurts but it's true
Usually for speed and avoiding strain you want to incorporate as many fingers as possible. In fact it's a common mark against dvorak online that "ls -l" is all typed with the right pinky (not an issue in the workman layout luckily).
When you can touch-type, it's better to have keys spread to use separate fingers. That way, you divide up the work. You have one finger still lifting while the other's already starting the next press.