1. Threshold pace
The pace you could race at for about one hour (10K to 1/2 marathon depending on your ability). Workouts using Tempo pace are to promote strength and also to increase your tolerance to lactic acid buildup in your muscles (also called Lactate Threshold or Anaerobic Threshold workouts). These are usually combined with a very short recovery time. The columns for this pace are found in the columns of the chart with the heading "LT".
2. Interval pace
The pace you race at for about 3K or 2 miles. Workouts using Interval pace are to promote aerobic capacity (also called VO2MAX), i.e. the ability for your body to take in oxygen to the bloodstream. I like to call these "heavy breathing" workouts by the end of each interval you should be breathing pretty hard, and as the workout continues you will start to breathe heavy earlier in the interval. These are usually combined with a moderately short recovery time. Your Interval paces are found in the columns of the pace chart where the heading reads "INT".
3. Repeat pace
The pace you could race 1 mile all-out at. Workouts using Repeat pace are to promote good running form along with running efficiency and economy. These are not all out sprints! Don't do them too fast and lose proper running form or you will defeat the purpose of the workout. Work on your leg turnover being quick and light (think of running over eggshells or hot coals!) and your upper body staying relaxed. Your Repeat paces are found in the last 2 columns on the pace chart and have the title "REP".
Contact Joe O'Leary if you have any questions.