mikkysgl says:

hey there fellow runner's+ pals....i am working off a training schedule to improve my endurance, and one entry I do not understand:
5X15-sec strides.

so if i am doing an endurance run for 50 minutes, and it calls for 5X15-sec strides, what does that mean?

i appreciate any help

 soofsoof says:

It means that within your 50min run, maybe after 30-40 minutes of running, maybe less, but anyway at least after a few minutes of worm-up, you do 5 stirds, each a 15sec long:

you start picking up your pace, such that the last 5-10 second are in a fast aerobic pace, then slow down to your usual jog, and start over again after 30-60 seconds.

You can check the training section of runnersworld.com for mor info.