Whether you're training for a local sprint or a full IRONMAN, training at the right intensity levels in your run sessions will pay off big time! But how do you know when to run 'hard', when to run 'easy', what exactly is 'hard' or 'easy', how long to hold different intensities, and when it's better to use heartrate or pace? In this episode, we'll drill down on these and other topics with run experts Jeff Raines and Elizabeth James.