The Halftime Fartlek is a versatile, effort-based workout you can do throughout your training program. I like to use with athletes who are returning to serious training after some time off and want to avoid the track for a few more weeks. I’ll also use it with runners who are peaking for a key race or time trial. The basic framework of the workout is the same in each case, but the duration of the intervals and the accompanying effort level can be adjusted to suit your needs.
How does it work? In its most basic form, the halftime fartlek is a set of descending intervals of a pre-determined length at a given effort level. The recovery between intervals is half the time of the last one you completed, hence the name of the workout.
Scenario 1: Early Season
Say you’re just getting back into serious training after a few weeks of well-deserved downtime following a big race and aren’t ready to step on the track yet. You can set up the halftime fartlek as such:
Run 5-4-3-2-1 minutes at 5K–10K effort (Note: Effort is the key word here—don’t worry about hitting specific pace.)
For recovery, take 2:30 of easy jogging after the 5:00 interval, 2:00 after the 4:00 interval, and so forth.
You can shorten the length of the intervals and perform multiple sets, such as:
Run a set of 2:00-1:00-30 sec at 5K effort with recovery half the duration of the preceding interval (1:00 minute, 30 seconds).
Repeat for 3–5 sets, with 2–3 minutes recovery between each set.
Scenario 2: Race Week
On the opposite end of the spectrum, suppose you’re approaching a big race and want to keep your legs moving in the final days leading up to it. The halftime fartlek is a great workout to do on the roads or trails 2–3 days beforehand. Adjust the length of the interval and effort level based on the distance you’ll be racing.
For example, heading into a shorter race such as 5K, I’d suggest the following variation of the halftime fartlek:
4-3-2-1 minute pickups at 5K race effort
Recovery is—you guessed it—half the duration of the interval you just completed
That’s 10 minutes worth of broken-up running at race effort a couple days out from your big event. It’s enough to keep your legs and lungs engaged without wiping you out before the starter’s gun goes off. Of course, it’s up to you to keep yourself under control during the workout and not go harder than you should just because you’re feeling good.
For a 10K, simply bump up the duration of the intervals and back off the intensity a little bit. Two to three days before your 10K race, try the following workout:
4-3-2-1 minutes at 10K race effort with halftime recovery.
3 minute recovery jog
3-2-1 minutes slightly faster than 10K race effort, with halftime recovery
If approaching longer distances such as the half marathon or marathon, try the following version of the halftime fartlek four days before your race:
8-6-4-2 minutes at goal race effort with halftime recovery between intervals