Pfitzinger Pete - Advanced Marathoning

Long runs seem to cause the most variability in recovery time among runners, although replenishing glycogen stores generally requires only 24 to 48 hours. Some runners are able to recover relatively quickly from long runs, whereas others are wiped out for days after one. The variability in recovery time depends on your training history, the genetic and lifestyle factors discussed previously, the type of courses you train on (downhills cause more muscle damage and greater recovery time), and the weather (the same long run in 85-degree F [29-degree C] weather will take longer to recover from than one on a 50-degree F [10-degree C] day).

Interval workouts put your muscles and cardiovascular system under the most stress and generally require the longest recovery time. Later in this chapter, we’ll discuss strategies that you can use to speed your recovery.

Regardless of the type of workout involved, the pattern of workout and recovery is basic to effective training. Generally known as the hard/easy principle, this dictates the structure of your training over the weeks and months leading up to the marathon. Let’s investigate the rationale for following the hard/easy principle.

Conventional wisdom calls for following the hard/easy principle of training, which is typically interpreted to mean that a hard effort is always followed by 1 or more recovery days. A recovery day may consist of an easy run, a light cross-training session, or total rest. During your marathon preparation, however, it’s sometimes best to violate this training pattern and do back-to-back hard days. The appropriate interpretation of the hard/easy principle is that 1 or more hard days should be followed by 1 or more recovery days. Let’s investigate the physiological rationale for following the hard/easy principle and look at two situations in which you should do back-to-back hard training days.

The hard day/easy day training pattern follows from the physiological dogma 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 a higher level. Three reasons to follow the hard/easy principle are to prevent total glycogen depletion, to prevent illness, and to minimize the effects of delayed onset muscle soreness (DOMS).

Preventing Glycogen Depletion.As discussed in chapter 2, your body can store only a limited amount of glycogen. With a typical runner’s high-carbohydrate diet, you probably have enough glycogen to get you through a 20- to 22-mile (32 to 35 km) run or a hard interval workout. It takes about 24 to 48 hours to completely replenish your glycogen stores. When you do two hard workouts in a row, therefore, you risk going into the second workout with partially filled glycogen stores, becoming depleted, and having a bad workout. Although glycogen depletion is potentially a problem on the second hard day, with a bit of planning it needn’t be an insurmountable problem. Three hard days in a row, however, would very likely lead to glycogen depletion and a more-prolonged recovery period. By following the hard/easy principle, you give your body time to build up your glycogen stores so you are prepared for the next hard workout.

Preventing Illness.Moderate training makes your immune system stronger. Various studies have found that people who get regular exercise have 20 to 50 percent fewer colds than do sedentary folks. After high-intensity and prolonged exercise, however, the immune system is temporarily suppressed, creating an “open window” during which you’re at increased risk of infection. Although immune function varies greatly among individuals, studies indicate that the immune systems of healthy, well-trained runners are typically suppressed only after exercise lasting more than 1 hour at about marathon race pace or faster. Immune system suppression after high-intensity running has been found to last from 12 to 72 hours. Interestingly, there is evidence that immune system suppression is linked to carbohydrate depletion and that restocking carbohydrate quickly may help restore your immune function to full strength in less time. The clear implication is to not do another hard training session until your immune function recovers from the previous hard session or race. Allowing at least one easy day before the next hard workout typically provides enough time for your immune system to return to full strength.

Minimizing the Effects of DOMS.Contrary to many runners’ beliefs, high levels of lactate (lactic acid) in your muscles aren’t what make you sore for several days after a hard effort. Essentially, all the lactate you produce in a race or workout is eliminated from your body within a few hours. DOMS is caused by microscopic muscle damage that occurs primarily from eccentric (lengthening) muscle contractions, such as when you run downhill. During downhill running, your quadriceps muscles contract eccentrically to resist the pull of gravity and keep your knees from buckling. The resulting muscle damage leads to inflammation, which causes soreness. It takes 1 to 2 days for this process of muscle damage, inflammation, and pain to reach a peak, and the effects can last for up to 5 days. While you’re experiencing DOMS, your muscles need time to repair. The damaged muscles are also weaker, so any workout done before the soreness goes away not only will be painful but also will likely not be intense enough to improve your marathon fitness.

The physiology of DOMS favors an approach of 2 hard days followed by 2 easy days, because it takes 1 to 2 days for DOMS to kick in, then it takes another couple of days for the soreness to dissipate. By doing back-to-back hard days, you may sneak in your second workout before soreness and muscle weakness develop. You would then have 2 days to recover before the next hard effort.

We’ve seen several reasons why you should follow the hard/easy principle in your training and that a hard day doesn’t always have to be followed by an easy day. A pattern of 2 hard days in a row followed by 2 (or more) recovery days may actually allow you to handle, and recover from, more high-quality training. Let’s look at two specific situations in which you should do back-to-back hard days.

During weeks that you race, you need to train but also to rest for the race. In Daniels’ Running Formula , renowned exercise physiologist and coach Jack Daniels, PhD, recommends back-to-back hard days during race weeks rather than alternating hard and easy days (Daniels 2005).

For example, say you’re following a strict hard/easy schedule and have a race on Saturday. If you did a long run on the previous Sunday, then you would run hard Tuesday and Thursday and easy on the other days. Doing a hard session on Thursday, however, doesn’t make sense because you would still be tired from that effort for Saturday’s race. If, however, you do back-to-back harder workouts on Tuesday and Wednesday, as detailed in figure 3.2, you would still get your hard sessions in but would have an extra day to recover for the race. Although this modification still doesn’t provide the optimal amount of time to recover for Saturday’s race, it’s an intelligent compromise that allows you to get your high-quality training while also racing reasonably well.