/jog/walk sequence two to four times. Warm up for six minutes with two lots of 30-second pick-ups. Cool down for four minutes.You’ve got…45 minutesYou should: Go for a tempo run“You’ll be working at the high end of your fat-burning zone, an effort where you can only

stretchYou've got...An hour (or more)You Should: Combine a tempo run with resistance training and stretches"These ancillary exercises help correct muscle imbalances," says Pierce.Here's HowIncrease your pace to 30 seconds slower than 5K race pace run

Alternate fast and slow running for 35 minutes, alternate three minutes of running 15 seconds per mile faster than 5K pace with three minutes' slow jogging. Warm up and cool down for four minutes each.You've got...An hour (or more)You should: Do a tempo run

Tempo workouts, speedwork, long runs, not to mention work, family and life in general... how can a runner fit it all in? One time-efficient solution: combo workouts, which blend elements of quality runs to make the most of every minute you have

routine within three to four weeks," says David Allison, a running coach based in Arizona, US. So stick to a basic mix of speedwork, tempo runs and long runs, but make some weekly tweaks and adjust these workouts."For example, if you ran four one