A classic tempo is a slow 15-minute warmup, followed by 20 minutes at a challenging but manageable pace, then a 15-minute cooldown.
Tempo running improves a crucial physiological variable for running success: our metabolic fitness. Most runners have trained their cardiovascular system to deliver oxygen to the muscles, but they haven’t trained their bodies to use that oxygen once it arrives. Tempo runs do just that by teaching the body to use oxygen for metabolism more efficiently.
How? By increasing your lactate threshold (LT), or the point at which the body fatigues at a certain pace. During tempo runs, lactate and hydrogen ions–by-products of metabolism–are released into the muscles. The ions make the muscles acidic, eventually leading to fatigue. The better trained you become, the higher you push your “threshold,” meaning your muscles become better at using these byproducts. The result is less-acidic muscles (that is, muscles that haven’t reached their new “threshold”), so they keep on contracting, letting you run farther and faster.
But to garner this training effect, you’ve got to put in enough time at the right intensity. Tempo runs should never be too short and too slow. You need to get the hydrogen ions in the muscles for a sufficient length of time for the muscles to become adept at using them. Typically, 20 minutes is sufficient, or two to three miles if your goal is general fitness or a 5-K. Runners tackling longer distances should do longer tempo runs during their peak training weeks: four to six miles for the 10-K, six to eight for the half-marathon, and eight to 10 for 26.2.
Tempo pace should feel ‘comfortably hard’ as in you know you’re working, but you’re not racing. At the same time, you’d be happy if you could slow down.You shouldn’t be able “chat” with one another as go along. There will be time fro that in the cooldown!
Marathon tempo- do this challenging long run once or twice during the later part of your marathon training plan. After a warmup, run 10 kms at the easier end of your tempo pace range. Then jog for five minutes, then do another 5 kms. Maintaining that comfortably hard pace for so many miles will whip you into shape for long distances.
To ensure you’re doing tempo workouts at the right pace, use one of these four methods to gauge your intensity.
Recent Race: Add 30 to 40 seconds to your current 5-K pace or 15 to 20 seconds to your 10-K pace
Heart Rate: 85 to 90 percent of your maximum heart rate
Perceived Exertion: An 8 on a 1-to-10 scale (a comfortable effort would be a 5; racing would be close to a 10)