I think this is the most likely answer.. low blood flow at rest means these things drift about doing some amount of damage when they bump into the sides of the vessel.

High blood flow for any bursty type activity like stop/start sprints, and suddenly these razors are propelled with a lot more force and like any shrapnel at speed, will do lots more damage.

I think this is the most likely answer.. low blood at rest means these things drift about doing some amount of damage when they bump into the sides of the vessel.

High blood flow for any bursty type activity like stop/start sprints, and suddenly these razors are propelled with a lot more force and like any shrapnel at speed, will do lots more damage.