Stress plus rest equals growth. In the book Peak Performance, running coach Steve Magness and his co-author Brad Stulberg coined this equation. It succinctly summarises that improvement is a two-step process, and the importance of the recovery run.
This same principle applies to running. To improve, you have to train smart and recover well. Without sufficient rest to allow the body to adapt, there will be no improvement. Or, as exercise scientist Joe Friel put it:
“A hard workout only creates the potential for fitness. It’s realized when you recover afterwards.”Joe Friel
How quickly a runner recovers from a hard session or a hard week of training is determined by a variety of factors. Some of these factors are inherent and genetically determined. Recovery times also increase with age. What many people tend to overlook is that the ability to recover is a trainable skill.
The Purpose of a Recovery Run
In the introduction to running training intensity, I put my ability to avoid injuries partly down to utilising recovery running as an intensity designation distinct from easy runs. The book Advanced Marathoning by Pfitzinger and Douglas echoes this sentiment. They note that runners must be conscious of how they approach recovery runs.
While the easy run is intended to be a separate training stimulus, recovery running has another purpose. Exercise science, however, has yet to determine a physiological benefit with regards to immediate recovery. Regardless, the run still serves several vital functions.
According to Pfitzinger and Douglas, a recovery run will improve blood flow through the muscles. Increased blood flow and being warmed up reduces stiffness and soreness of the muscles. Furthermore, as noted by Joe Friel (#), most advanced athletes report that “active recovery” reduces fatigue and stimulates adaption. Almost every experienced runner will give you similar anecdotal feedback.
There is another reported benefit of recovery runs, as well. As mentioned in this article by noted endurance exercise reporter Matt Fitzgerald, they serve to increase your fitness. By running at an already fatigued state, even a short and light recovery run will act as an additional stimulus for overcompensation for the body. The result is that recovery runs can increase fitness as much as faster and longer runs, Fitzgerald claims.
The Intensity of a Recovery Run
As we now know, recovery runs serve a vital function. Because of this, they are a crucial part of a well-made training plan. However, overdoing it on recovery days is a common mistake. Inevitably, this will lead to trouble.
Sure, you may get through a few weeks of running too hard on recovery days. But, eventually, the cumulative fatigue will catch up to you. Initially, you might struggle to get through workouts as prescribed. And, then, if you keep it up, your body is likely to break down and succumb to an overuse injury.
Intensity Control Through Pace
There are a couple of ways to ensure that you hit the right intensity of a recovery run. By using a training pace estimation tool such as VDOT, you can calculate your easy-pace range. My recommendation is that you keep your pace on recovery days no faster than the slow end of this range.
Pfitzinger and Douglas suggest that recovery runs should be 2 minutes per mile (1 min 15 seconds per kilometre) slower than half marathon pace. Keep in mind that both these pace suggestions are for flat surfaces.
Heart Rate Monitoring For Intensity Control
In my opinion, a heart rate monitor is the most effective way to control the intensity of a recovery run. This way, you can be sure that your average heart rate does not exceed the recommended 70% of HR Max.
During my first recovery runs with a heart rate monitor, I was shocked by how much I had to slow down. And keeping the heart rate in the recommended range was impossible when running uphill. However, it was the heart rate monitor that taught me the correct intensity of a recovery run.
After using heart rate readings as a guideline, most runners develop a feel for how they should run for recovery. Some recovery days, you feel good and will run near the upper heart rate limit. Other days, however, you will feel stiff and sore, and heart rate will be lower on account of muscular fatigue.
How Long Is a Recovery Run?
Another interesting point of discussion is the distance you should run on your recovery days. Different coaches and scientists have differing opinions on this matter.
Renowned coach Tom “Tinman” Schwartz for instance, suggests recovery runs should be 10-15% of your weekly distance. Tinman reasons that adding mileage to your recovery runs results in improved strength. And, he continues, shorter recovery runs might give your legs pop but leave you performing worse on race day.
For moderate to high mileage runners, this number will be very high. A more traditional approach is to keep recovery runs between 8-12 kilometres. Another method is to stick to time, with 45 minutes to an hour being the standard guideline.
My recommendation for runners who are adding in recovery runs to improve recovery and increase mileage is to start conservatively. Begin with 30 minutes, and increase the duration as you notice a positive physical response from the extra stimulus. Adding too much load, too soon, defeats the purpose of a recovery run. As your body adjusts to the new training load, you can increase the duration of these runs towards Tinman’s recommendation.
Other Things to Note About The Recovery Run
To optimise the effect of a recovery run, you should keep a couple of points in mind. Soft surfaces are less taxing on the muscles than pavement. If possible, it is beneficial to stick to trails or similarly forgiving surfaces during recovery runs. Grass, for instance, is particularly suited for recovery running. Just remember not to get caught up with the pace!
Similarly, hills are strenuous for the body. Going uphill requires extra effort, while downhills give the muscles extra pounding. Sticking to flat routes will ensure optimal recovery response.
The timing of a recovery run is also essential to maximise its effects. Ideally, you want to follow the hard-easy principle and add in the recovery run the day after a hard run. Another possibility is to add in a recovery session in the evening after doing a morning workout. You want to experiment to figure out what works best for you. However, you should always try to get in a recovery run no longer than 24 hours after a hard effort, to reap the full rewards.
Lastly, remember the first part of the equation in the opening paragraph. Stress plus rest equals growth. Focusing on rest without stressing your body will not yield results. To recover properly, you need to tax your body in a way that necessitates recovery.
For runners who run less than five times per week, recovery runs are not a necessary part of the training plan. Instead, you are better off focusing on improving aerobic capacity through easy running on non-workout days.