Back when I taught college photography classes, I would force my students to do some practical flash duration comparisons. Why? Because flash duration is a very important thing to consider when choosing the right lights to make images. If the assignment requires moving fashion models, jumping athletes, or any other action, then the best choice for capturing sharp images are units that have short flash duration. Simply put, flash duration is the amount of time that the flash is on, typically between 1/200th and 1/3,000th of a second, but these vary widely with the amount of power output and type of flash unit. So please compare the flash durations at full power when shopping for or renting strobes. Shorter flash duration is the best choice for freezing motion.
The image below was lit with some old Elinchroms, one 250R (flash duration at 250 watt seconds = 1/6200th) and one 500r (flash duration at 500 ws = 1/4000th). Its nice and sharp! Here is another action shot I shared in a prior post: Pizza Guy.