IIRC one reason for healthy, fit people dropping at exceedingly high rates is because there's many small blood vessels that bend at almost 90-degrees in the heart. During exercise, these blood vessels expand and the bend radius decreases, allowing for an increased flow of lipid nano particles into deeper branches of the heart vessels. Many fit people won't wait 1-2 weeks to exercise after receiving their shot, so they end up maximizing their exposure to the lipid nano particles when they're at their highest concentrations.

IIRC one reason for healthy, fit people dropping at exceedingly high rates is because there's many small blood vessels that bend at almost 90-degrees in the heart. During exercise, these blood vessels expand and the bend radius decreases, allowing for an increased flow of lipid nano particles into deeper branches of the heart vessels.