15x90s will be 15 lots of a hill that takes about 90seconds to run up, I assume. Happy to be corrected.
10 min, 10 min, 5 min will be the time for each effort. So, 10minutes at tempo, then a 3 minute recovery, another 10, another 3 minutes recovery, then 5 at tempo: a pretty challenging session.
15x90s will be 15 lots of a hill that takes about 90seconds to run up, I assume. Happy to be corrected.
10 min, 10 min, 5 min will be the time for each effort. So, 10minutes at tempo, then a 3 minute recovery, another 10, another 3 minutes recovery, then 5 at tempo: a pretty challenging session.