No. No they are not. They are not bulky in any way shape or form. Sprinters are streamlined, mid distance are wiry, distance runners are... weird little imp creatures. The only bulky people in the oval are the throwers. The guys who played hs/college football stand out in the field because they look bulky in comparison. They tend to have trouble whittling down excess size while maintaining power. As a group they never outmatch pure track athletes.
If you've only ever seen these people while in motion and barely clothed you'd have no idea how slim they are in person, next to everyday people, in street clothes.
(Relay runners are sprinters. Literally the athletes you see in the open sprints are also in the relays.
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