Understanding recovery - training for running

Running & FitNews, June, 2001 by Pete Pfitzinger, Scott Douglas

There are two components to improving your speed and endurance. The obvious one is your training. Running, in all its training variations, is needed to improve your lactate threshold, fat-burning ability, VO2max, and a host of other factors that allow you to run faster and longer over time. However, training is only half the formula for performance improvement.

To improve, your body must recover from training and adapt to a higher level of training stress. If you understand recovery, you can optimize your training. Poor management of recovery leads to overtraining, which overwhelms your body's ability to adapt to training stress and can cause fatigue, depression, lowered immunity, burnout, and injury risk.

To optimize your training and avoid burnout find the correct balance between your training and recovery. Training provides the stimulus for your body to adapt, but recovery is when those training gains occur. Supercompensation occurs when a workout or training stimulus raises your fitness to a higher level.

Turning Genes On and Off

The process of adaptation begins with your genes. Training provides stimuli that turn specific genes on or off. When the gene responds, your training changes the rates at which your body makes and breaks down specific proteins. For example, endurance training turns on genes for the production of mitochondrial protein (where energy is produced). More endurance training leads to more mitochondria in your muscles so that you can produce more energy aerobically. Your muscles and cardiovascular system adapt over days and weeks to the cumulative effects of repeated training.

Factors Affecting Recovery Rate

Runners vary greatly in how long it takes to recover from and adapt to a workout. Your genetics determine your predisposition to this adaptation; some of us are programmed to adapt more quickly than others. Lifestyle factors such as diet, quantity and quality of sleep, general health, age (we tend to recover more slowly with age), gender (women recover more slowly because of lower testosterone levels), and various life stresses (such as work and relationships), all influence how quickly you recover from and adapt to training. This is why every training program must be unique--there are simply too many variables among runners, and even for one individual from one time in your life to another.

Experience and understanding--trial and error--teach you how much training your body can positively adapt to in a given time. In order to train effectively you must go through this self-discovery process intelligently and systematically. Determining this balance can be tricky because it is hard to isolate variables. However, depending on the intensity of your workout and the other factors related to recovery, it generally requires from two to 10 days to recover completely from a hard workout.

The training stimulus that a particular type of workout provides is very specific. The energy systems that are stimulated by a long run are not the same as those for a tempo run or a lactate threshold session. So while you may need three to five days between tempo runs and three to five days between long runs and five or more days to recover from VO2 max intervals, you won't need to have a full recovery between a long run and a tempo run. This is an important principle to understand as you plan your schedule.

The Hard/Easy Principle

The hard day/easy day training pattern follows from the physiological principle of stimulus and response-hard training provides a stimulus for your body to improve, but rest is then needed to allow your body to recover and adapt to that higher level. A recovery or easy day may consist of an easy run, a light cross-training session, or total rest. There are several good reasons to follow this principle.

* Preventing Glycogen Depletion--You can store only a limited amount of glycogen in your muscles and when you do back to back hard days you run the risk of depleting those glycogen stores, reducing your performance and increasing your need for recovery.

* Preventing Illness--High intensity training temporarily suppresses your immune system making you more vulnerable to infection for as much as 12 to 72 hours. The clear implication is to avoid another hard training session until your immune function recovers from the previous hard session or race.

* Minimizing the Effects of Delayed Onset Muscle Soreness--Microscopic muscle damage occurs from eccentric muscle forces (lengthening) that occur when you are breaking or running downhill. The resulting microscopic damage causes pain and inflammation, which reaches a peak at one to two days after your hard session and as you probably know too well, can last for several days. Another hard workout before your muscles have recovered is not likely to be very productive.

Recovery Days

Recovery days should be easier than hard sessions in the volume (distance) and the intensity of training. Some recovery days need to be for total rest. Sometimes a recovery day should be for cross training. The most common mistake runners make in their training is to train too hard on recovery days. The result is that the quality of your hard days declines. Over the long term you will suffer mediocre performances, frustration, and the potential for over training. Your recovery days shouldn't impose additional training stress on your muscles or your nervous system.