I am often asked: How much time should you take to recover from an interval on the track? The best answer is “it depends”. It depends on the intensity of the interval, the time of the year and the rate of your adaptation.
The Reader’s Digest answer is – you goal is to gradually decrease your rest period over time; gradually increase the number of repeats; gradually increase the repetition distance. If you do those things you will inevitably improve your conditioning regardless of where you start and what paces you are running.
Generally, recovery intensity is one at which you allow your body to be able to complete workouts at prescribed paces. During the recovery for interval training we may jog or walk between each interval effort. In well trained runners, jogging pace roughly equates to a pace that is well slower than your marathon race pace about 60% of your vVO2MAX. With less well trained athletes walks are most likely necessitated.
Old school used heart rates to determine recovery in the past however, due to “drift”, “lag” and environmental impacts, they are notoriously inaccurate (HR continues to rise after finishing hard intervals and have high variances due to environmental and physical elements). Generally, more exercise physiologists now recommend heart rate monitoring only for novice athletes to help them learn intensities and get in tune with their bodies. Once this is learned, pace & time is the best training guide.
What are some considerations in determining your recovery?
Time of year is one consideration. In Arizona, we are a bit more laid back during the heat of summer. Remember, summer speed work (our off-season) is to maintain leg speed so that it isn’t so traumatic when you return in the fall. It isn’t as critical to maintain short rest breaks nor is it critical to do the longer repeats (1200s or longer for example). In the heat down here it’s a case of getting a few reps (4-8 often) with rest which allows you to repeat the effort. If you need a little more time – so be it. Again, the goal is to prevent loss of leg speed not to peak for a race.
Early in the racing season typically we may be lenient as well on rest times between intervals. During this period we typically have you take a walking recovery and it may last a minute or longer for the longer interval efforts. The goal here is to slowly bring you back to running faster by increasing the number of intervals and lengthening them. This way you begin getting used to those race paced efforts to come.
Some early season workouts are strictly for that “base conditioning”. Our “speed-strength” workouts incorporate exercise sets or stadium stairs into interval repeats. These are tough because we are building general conditioning in the context of maintaining 5k-type speed. Your rest in fact isn’t a rest. It’s your sets of exercises. This becomes a continuous circuit training-type workout. In this case, we don’t want lingering recoveries. It defeats the purpose of building you up. Since the total distance of the workout is modest (1-2 miles), and pace is not all out, a continuous circuit workout is just the trick.
As we progress the issue of recovery takes a couple turns. Now depending on your goals and target race distances, your interval distance, pace and recovery times will vary. Tracksters (800-1500 meters), middle distance (5k-10k) racers and the longer distance (everybody beyond 10k) runners will workout slightly differently.
Intensity is a key consideration in determining the nature of your rest period. The faster the pace of the interval; the longer the rest and less likely to jog it. The more modest the speed (5k-10k pace); the less recovery needed or desired (1:00 reducing to as little as :15). Faster than 5k-paced intervals will typically run 1:30 on down to :30 seconds or so. Very fast intervals (mile pace or faster) often have “full recoveries” of 3:00-5:00. Depending on the time of year it may be more important to complete the prescribed number of reps – even if you have to extend the rest period – than to stick to a shorter rest period and gradually get slower and slower with each repeat. This may defeat the purpose of running that pace (assuming it was the appropriately assigned pace in the first place).
Generally however, as the racing season progresses there are three interval goals: lengthen the interval distances, shorten the recovery times, and increase the paces. The recovery periods need to be planned to allow you to complete the workout intervals at the prescribed paces. You increase the paces only after you have performed better at the races or in your time trial.
Is there any such thing as a “best” workout?
Well, not exactly but some cool research on interval workouts revealed some interesting results. Veronica Billat PhD from France has done quite a bit of work on the affects of interval training. Billat tested this by measuring body chemistries while changing the time spent running at the specified paces as well as varying the breaks. The bottom-line on her research is that a 15-15 approach yielded optimal results. Run 15 seconds at about your mile pace or just faster then jog 15 seconds and repeat for 15-25 hard intervals. Just set your count-down timer on your watch to 15 seconds and go for it. The beauty of this workout is that it is very time efficient. Including warming up and cooling down you’re done in well under an hour!
For endurance runners, longer repeats can move up to 2-mile repeats with jogging 400 in between. It becomes a continuous workout. One “ideal” workout is to build up to 5 X 3:00 @ your vVO2max pace. The goal is to maintain progressively longer continuous efforts with brief recoveries to improve stamina (effort over time). [For instance if you fade in later miles of a 5k or 10k race, you need specific stamina intervals to improve that aspect of your racing.]
The other recovery angle is how many of these quality workouts can we put into your schedule and still allow optimal ongoing recovery (too much of a good thing isn’t good). The answer for this is again “it depends” and we will explore that in another post.
If you’re not sure what paces you should run intervals in or the rests you should be taking, contact me for a program. I’ll prescribe those paces based on a time trial and your goal paces and distances.