Recovery is one of the keys to high performance in sports but is little appreciated by most athletes. The commonly accepted road to success is hard workouts, and the more the better. That isn’t entirely wrong, but without paying close attention to the recovery side of the training equation, hard workouts spaced closely together are not possible. If you recover quickly and more completely following hard training sessions, then your body is ready to go hard again sooner. That leads ultimately to peak performances.
As a highly motivated athlete who pays only lip service to recovery, you may experience a deep and compelling fatigue following a few weeks of high-workload training. You wake up in the morning tired. You are unable to complete even the easiest workouts. Fatigue haunts your every step throughout the day. And this goes on relentlessly for days or even weeks. You’re overtrained.
How could this situation have been avoided? The answer is recovery. Recovery has several components, the two most critical being rest and nutrition. What you eat plays as great a role in your day-to-day performance as anything else in your training arsenal does, yet many athletes get it wrong. Let’s take a closer look at overtraining and how food choices impact your capacity for quick recovery.
Effective training is more than workouts. It is a carefully balanced state of well-being between stress and rest. When this balance is achieved, your fitness improves at a steady rate. When rest exceeds stress (a rare occasion for serious athletes), the body quickly achieves a high level of readiness to race. This takes only a few days and is referred to as tapering or peaking. The result is what athletes call “form”—a readiness to race at a high level of performance due to the elimination of fatigue. Go beyond these few days of reduced training stress and fitness quickly erodes. You may have experienced the latter situation if you were injured or sick and couldn’t work out.
When stress only just exceeds rest for a few days, the body adapts and becomes more fit. This is the purpose of training: Overload the body with the right amount of stress, then allow it to rest. During rest, the body’s adaptive processes take place—muscles grow stronger, enzymes become more abundant, the heart increases its ability to pump blood, and other seminal physiological and psychological changes occur. This is the ultimate goal of the endurance athlete.
On a more sinister note, when stress greatly exceeds rest for more than a few days, the athlete begins to experience unrelenting fatigue and exhaustion. The body’s capacity to adapt is compromised, and the defense mechanisms intended to prevent death are initiated. This is overtraining.
Overtraining may not result simply from too much exercise and too little rest. The stress component could also be related to work, school, relationships, finances, relocating, or a myriad of other stressors that make up your nonathletic life. Such stress when combined with what may otherwise be a perfectly appropriate level of exercise will produce overtraining if rest is inadequate, just as surely as too much exercise produces overtraining. In this case, you are “overliving” rather than overtraining. Regardless, the body experiences much the same negative consequences.
All of this is not to say that you shouldn’t push yourself in training or that you should never experience fatigue. In order to grow as an athlete, you must regularly flirt with overtraining. You will have days when you are tired and even some when you can’t (or at least know you shouldn’t) complete the workout. This state of fatigue is called “overreaching” and is an early point on the path to both greater fitness and, if allowed to continue for too long, overtraining. Some amount of overreaching is necessary for the serious athlete. The difference between overreaching and overtraining is that when you are overreached, you quickly recover with a day or two of rest. By paying close attention to the elements of recovery, especially sleep and nutrition, you can avoid overtraining and steadily improve your fitness.
How long does it take to progress from being overreached to overtrained? The answer, as with most such questions, starts with “It depends.” Many variables may influence the answer. Studies that have dramatically increased the training volume for 5, 7, and 10 days were unable to produce a significant decline in performance, although the athletes showed signs of overreaching. In other research, it took 15 days to produce verifiable overtraining in a group of cyclists who increased their volume by 50 percent. And in one study with young, highly fit rowers, it took 3 weeks to fully achieve overtraining. It may well be that youth and a high level of fitness provide some immunity from overtraining and may delay its onset for up to 3 weeks. On the flip side, older or less fit athletes, including novices, may well achieve an overtrained state in 2 weeks or even less if the stress of overreaching is great enough.
Fatigue is a primary limiter standing between you and better performance. If you could delay or resist the sensations of fatigue, you would go faster and last longer at a given effort level—the ultimate purpose of training. Yet we never rid ourselves of fatigue, which is actually a good thing because this prevents us from damaging our bodies or perhaps needlessly expending physiological resources. But understanding what brings on fatigue during a race or workout may point to strategies that could raise your fatigue threshold, allowing you to go faster or farther.
Fatigue seems to vary according to the duration and intensity of exercise. An 800-meter runner and a marathon runner may both fatigue greatly during their races, slow down, and struggle to the finish lines, but their specific reasons for fatigue aren’t the same. Or are they? What causes their fatigue? Currently there are three ways of explaining fatigue.
Catastrophe theory. This is the oldest model, having been around since the 1920s. It’s the one accepted by most exercise physiologists. This model proposes that exercise stops when something catastrophic occurs in the body, especially in the working muscles.
Other than overheating and severe dehydration, which can obviously limit performance, the catastrophe model proposes that there are at least two common physiological reasons for fatigue during endurance events: the accumulation of metabolic by-products such as hydrogen ions, especially from lactic acid release (the 800-meter runner); and the depletion of energy stores such as glycogen and glucose (the marathoner). The catastrophe model proposes that when either of these situations occurs, the body is forced to slow down. It’s much like a car running out of gas or the fuel lines becoming clogged. A catastrophe has just happened and the body stops functioning normally.
Central Governor theory. The second way of explaining fatigue originated in the physiology lab at the University of Cape Town in South Africa in the 1990s. Here, noted exercise physiologist Tim Noakes, PhD, proposed that fatigue occurs in the brain, not in the muscles.
In this model the body is constantly sending signals to the subconscious brain regarding the current status of the working muscles. For example, fuel levels and metabolic by-product buildup are being monitored by the brain. This is a bit like the operation of the thermostat in your home, which gauges the temperature and turns the heating or air-conditioning system on or off as needed. At some point the brain may make a decision, again subconsciously and the result of perceived exertion, to slow down due to the current status of the body. It’s proposed that this central governor for fatigue evolved to protect the body from damage caused by excessively hard work.
Psychobiological theory. This theory is a bit like the central governor model, but with a twist. Samuele Marcora, PhD, at the University of Wisconsin proposed in the early 2000s that it is indeed perceived exertion, a subconscious calculation made by the brain during exercise, that limits performance. He proposed that exercise stops well before fuel levels and metabolic by-product accumulation suggest it is absolutely necessary.
In a part of the forebrain known as the anterior cingulate cortex (ACC), subconscious decisions are made regarding conflict resolution and response inhibition. Essentially, this means that during exercise the ACC is weighing the cost of continuing at a given intensity versus the reward for doing so. Dr. Marcora has shown that “fatigued” athletes are able to overcome the sensation at what appears to be the end of exercise to failure and produce a greater output if the reward is big enough.
You have probably experienced this at the end of a race. You may have been slowing down, but when you saw the finish line, you had the capacity to somehow speed up or even sprint. You were willing to overcome the suffering because the reward, an awe-inspiring finish or perhaps a slightly faster time or higher finishing place, was great enough to overcome the suffering you were feeling. He further suggests that this system evolved to keep us from needlessly wasting energy in the pursuit of food when the prospect of success in finding it was low. But should food appear (perhaps a deer on the horizon), increasing the likelihood of getting it, then the suffering becomes tolerable.
Some common signs of overtraining in endurance athletes are listed in Table 7.1. Note that not all of these signs will be present if you allow yourself to become overtrained, and some symptoms that you experience may not even be listed. Overtraining is a condition that is unique to individual circumstances, although certain characteristics are common, such as decreased performance and chronic fatigue.
It’s also quite possible that some of these symptoms, including decreased performance and chronic fatigue, signal an illness such as chronic fatigue syndrome, Lyme disease, mononucleosis, or another viral infection. Even if you’re certain your symptoms are caused by overtraining, it’s wise to consult your physician just to be sure you don’t have some other health condition.
TABLE 7.1
Physiological
Decreased performance
Decreased strength
Decreased maximum work capacity
Changes in heart rate at rest, exercise, and recovery (high or low)
Increased frequency of breathing
Insomnia
Loss of appetite
Increased aches and pains
Chronic fatigue
Psychological
Depression
Apathy
Decreased self-esteem
Emotional instability
Difficulty concentrating
Irritability
Immunological
Susceptibility to illness
Slow healing of minor scratches
Swollen lymph nodes
Biochemical
Negative nitrogen balance
Flat glucose tolerance curves
Reduced muscle glycogen concentration
Delayed menarche
Decreased hemoglobin
Decreased serum iron
Lowered total iron-binding capacity
Mineral depletion
Elevated cortisol levels
Low free testosterone
Overreaching that spirals downward to overtraining often starts, in part, with diet. You train hard to achieve very high performance goals. Knowing that several hard workouts are needed weekly for success, you repeatedly push yourself to the limit. The vigorous exercise may result in a decreased appetite for hours afterward. Or you restrict calories in an attempt to achieve a predetermined racing weight. Combined with incomplete recovery, the reduced caloric intake leads to greater fatigue and lackluster training. Being highly motivated, you continue this pattern of hard workouts, limited food, and inadequate recovery for 2 to 3 weeks—and you’re overtrained. One consequence of the early stages of overtraining is even less appetite, which further exacerbates the all-too-common state of the overtraining syndrome you’ve managed to create.
This lesson is driven home quite effectively in a study conducted by David Costill, PhD, and his colleagues at Ball State University. The researchers doubled the training workload of a group of competitive collegiate swimmers for 10 days. After a few days, about 30 percent of the swimmers experienced much greater difficulty in maintaining the quality of the training sessions than did the others. The scientists found that the swimmers who were merely muddling through with the high workload were eating almost 1,000 calories per day less than those who were successfully coping. The low-calorie swimmers were well along the path to excessive overreaching in a matter of days. Had the study continued longer, there is little doubt that those taking in the fewest calories would eventually have wound up overtrained.
Besides intense exercise, other training factors that may contribute to a reduced appetite are high temperatures and humidity. Emotions related to stress and mood may also produce this effect, as may acute exposure to training at high altitude. Don’t ignore a poor appetite when, following exercise, you experience fatigue that is not reduced after a day or more of complete rest or much lighter workouts. Be cautious with your training at this time, and carefully monitor your food intake to ensure that you are getting adequate calories and nutrients.
While many studies implicate nutrition in the process of becoming overtrained, none specifically addresses the dietary requirements of avoiding this condition. However, some research does suggest likely dietary scenarios associated with overtraining.
Depending on body size, a well-trained and properly fed endurance athlete may have up to about 2,000 calories stored away as carbohydrate. Most of this resides in the muscles as glycogen, with smaller amounts in the liver (glycogen) and blood (glucose). Compared with the potential energy available from fat and protein, glycogen and glucose are quite limited, representing only 1 to 2 percent of the body’s total energy stores. Nevertheless, this fuel source is critical to success in endurance activities. As previously mentioned, there is an old saying in exercise physiology that illustrates this phenomenon: “Fat burns in a carbohydrate flame.” As stored carbohydrate is depleted, the body can no longer efficiently use fat, the body’s most abundant fuel, for energy; it must turn to protein to keep the fat-burning flame flickering. This is a time-consuming metabolic process associated with heavy fatigue and rapidly decreasing pace despite a high effort. Failure to maintain glycogen and glucose stores can easily lead to poor performance and perhaps to overtraining.
During intensive endurance exercise, the body shifts from primarily using glycogen to keep the flame burning to relying on blood glucose and, finally, on liver stores of glycogen as fuel slowly depletes. This process of shifting the energy source may take 60 to 90 minutes, depending on your fitness level and exercise intensity. The most common form of exhaustion in extensive endurance sports is closely related to this depletion of carbohydrate fuel. Carbohydrate intake both during and immediately following exercise is critical to success in endurance sports.
There is considerable research showing that consistently low carbohydrate intake during and following exercise may contribute to overreaching and eventually to overtraining. As the training intensity increases, this becomes even more critical. High glycemic load foods are a necessity in Stages II, III, and IV of recovery, as described in Chapters 3 and 4, in order to maintain glycogen and glucose stores and help prevent overtraining. Just a few days of inadequate eating at these critical times, when training intensity increases, can easily set you up for a disastrous season.
While most athletes have no difficulty eating carbohydrate, especially from starchy sources, a few overly zealous recent adherents to the Paleo Diet do. It is not unusual for those new to the Paleo concept to overdo it and omit all starches and sugars from their diets including during Stages II, III, and IV. For the athlete exercising less than about an hour a day this is unlikely to result in overtraining. In fact, at this level of training volume there is little need for sugar and starch. A 24-hour adherence to the Paleo Diet as suggested for Stage V will work just fine. As the volume of training increases, however, the need for carbohydrate to replenish fuel stores also increases. For the athlete training 3 or more hours per day including intensities approaching and exceeding the anaerobic threshold, consuming adequate carbohydrate, especially from starchy sources, is critical to avoiding overtraining.
If carbohydrate is so important for avoiding overtraining, you might wonder why the Paleo Diet for Athletes suggests eating more fat and less carbohydrate during the base (general preparation) period of training—might not this set you up for overtraining? No, it won’t. Plenty of research indicates that well-trained endurance athletes actually continue to have good results on a diet that is somewhat higher in fat and lower in carbohydrate than is typically recommended by nutritionists, especially when intensity is low, as in the base period.
A classic study reported in the prestigious journal Medicine and Science in Sports and Exercise used well-trained runners as subjects. The runners spent 7 days eating each of three diets, then tested at the end of each 7-day period for running time to exhaustion at a fixed intensity just below anaerobic threshold. On their “normal” diet, they ate 61 percent of their daily calories as carbohydrate and 24 percent as fat. Their “fat” diet was made up of 50 percent carbohydrate and 38 percent fat—similar to the diet recommended here for your base period. The runners’ “carbohydrate” diet included 73 percent carbohydrate and 15 percent fat. Protein stayed about the same (12 to 14 percent) in all three trials. The testing revealed that the fat diet produced the best average times to exhaustion (91.2 minutes), compared with the carbohydrate (75.8 minutes) and normal (63.7 minutes) diets.
In another, more recent study, 11 duathletes ate high-fat (53 percent fat) or high-carbohydrate (17 percent fat) diets for 5 weeks each. At the end of these periods, they completed a 20-minute time trial on a bicycle ergometer and ran a half marathon. There were no significant differences in performance between the two sets of test data, regardless of the diet. On the bikes there was a 1-watt difference, and for the run there was a 12-second difference in finishing times.
The take-home lesson from these studies and others is that substituting fat for carbohydrate in the base (general preparation) period will not harm your training or promote overtraining, so long as you use the postworkout recovery methods in Chapter 4 to replenish carbohydrate stores. In fact, a higher-fat diet proves to be beneficial because the body becomes more efficient at burning fat for fuel while sparing glycogen, one of the same benefits we seek in doing long, low-intensity endurance training in the base period. But as the intensity of training rises in the build (specific preparation) period, more carbohydrate is necessary to restock the significantly depleted glycogen stores in the muscles. Shifting your diet between carbohydrate and fat in the base and build periods of the season, with protein remaining relatively constant, will not contribute to overtraining and will boost your fitness.
Of course, as described in Chapter 4, the fat you add to the diet in Stage V of your daily recovery during the base period should be largely monounsaturated and polyunsaturated, especially omega-3. These fats are found in foods such as fish, avocados, nuts, eggs enriched with omega-3, leafy green vegetables, meat from free-ranging animals, and in olive and flaxseed oils.
Recovery following challenging workouts is essential for avoiding overtraining. If nutritional action is not taken after a hard training session, the body may not be ready to go by the next workout, leading to a gradual decline in performance over the course of a few days, followed by overreaching and, ultimately, overtraining. More and more research suggests that, as with consuming carbohydrate immediately after such sessions, taking in protein improves the recovery process. This enhancement is a result of greater glycogen stores that restock faster, along with quicker rebuilding of damaged muscle tissue. Including protein in your Stage III and IV nutrition, as described in Chapter 4, will go a long way in promoting recovery while helping to avoid overtraining.
In much the same way, taking in adequate protein throughout the day is quite beneficial to your physical well-being and capacity for training. It has been our experience that most endurance athletes eat far too little protein; instead they concentrate their diets around carbohydrate, especially from starches and sugars. Such an amino acid-poor diet will eventually catch up with these athletes. Protein is necessary to repair muscle damage, maintain the immune system, manufacture hormones and enzymes, replace the red blood cells that carry oxygen to the muscles, and provide energy for exercise when carbohydrate stores are tapped. The following indicators of inadequate dietary protein overlap considerably with the markers of overtraining listed in Table 7.1.
Frequent colds and sore throats
Slow recovery from workouts
Irritability
Poor response to training (slow to get in shape)
Chronic fatigue
Poor mental focus
Sugar cravings
Cessation of menstrual periods
The highest-quality protein is that which is most available to the body for absorption and includes large amounts of all of the essential amino acids. Animal products fit that definition and should be included in meals throughout the day. And the more you train, the more critical this is for avoiding overtraining.
Of the essential amino acids, four stand out as being critical to recovery: leucine, isoleucine, valine, and glutamine. The first three are the branched-chain amino acids (BCAA). During exercise, blood levels of BCAA and glutamine decline, contributing to a unique type of weariness called central fatigue—common in events lasting several hours. A training program that is challenging will likely leave you feeling chronically fatigued for days and may well be the result of inadequate protein intake.
Inadequate fluid intake during and after exercise may be a nutritional contributor to overtraining. But it’s unusual for athletes, or nearly anyone for that matter, to fail to replace body water losses throughout the day when it’s readily available.
The key to avoiding the overtraining consequences of dehydration is quite simple: Drink according to your thirst. If thirsty, drink. When no longer thirsty, don’t drink. It’s pretty simple. There is no reason for elaborate drinking schedules or daily water volume goals. Thirst does indeed work. For example, a study of 14 elite Kenyan runners whose water losses and rehydration were tracked for 5 days supports this notion. No instruction was given on how much to drink. During training they drank nothing and typically lost 2.7 percent of body weight daily. On average they took in 4 quarts (3.8 liters) of fluids daily based entirely on thirst. No changes were reported in daily hydration status, body weights, or responses to training over the course of 5 days.
It’s not unusual for athletes to take in excessive amounts of water the day before a race to prevent hydration on race day. There is no reason for this. Your body does not store water like a camel’s does. If you drink an excessive amount, meaning more than necessary to quench thirst, you will soon urinate to remove the excess. And by drinking excessively you temporarily dilute electrolyte stores. So there is nothing to be gained by drinking copious amounts of fluids the day before or the morning of a race. Here again, thirst is the key. Pay attention to your body.
How about the oft-repeated stipulation that none of the water you take in can come from caffeinated beverages, as they cause a net loss of body fluid? Research contradicts this oft-repeated belief. Athletes do not appear to lose any more body stores of water following caffeine ingestion in the hours preceding exercise than those who did not use a caffeinated drink. And also be aware that fluid comes not just from drinking but also from the food you eat.
Much of the research seems to support the notion that a yellow urine color is a good indicator of significant dehydration, but not all of the research is in agreement. More research is needed in this area. While having yellow urine may indicate some level of dehydration, such a color by itself is not proof of dehydration. Metabolites, the end products of metabolism such as urea, are often expelled in the urine and provide color even though you are well hydrated. The same goes for B vitamin supplements. They will provide a bright yellow color to your urine. The best indicator of dehydration is thirst. It works. Just pay attention.
Many studies have reported that athletes make poor dietary choices, contributing to low vitamin and mineral status that is compounded by normal losses during periods of increased training. For example, a study of Dutch elite athletes showed that the female swimmers had an inadequate iron intake, while cyclists were not getting enough vitamins B1 and B6. Similar research on women runners has shown repeatedly that due to restriction of calories, extremely high carbohydrate intake, or vegetarian eating patterns, these athletes are often low in iron, zinc, magnesium, and calcium. Among both male and female runners, dietary zinc and iron have been shown to be low. Inadequate iron intake has also been confirmed for a group of cross-country skiers; 50 percent of Nordic women skiers in a Winter Olympics had prelatent iron deficiency, and 7 percent were anemic. In a study of 1,300 German athletes in various sports, 21 percent had low levels of serum magnesium, and 14 percent lacked iron. There is little doubt that many athletes do not meet their nutritional needs when it comes to micronutrients. Such deficiencies may well contribute to the onset of overtraining.
An athlete who is deficient in vitamins A, B6, C, or E is at high risk for a weakened immune system and illness related to overreaching. In the same manner, deficiencies of the minerals zinc, magnesium, copper, and iron may also result in impaired immunity. All of this once again underscores the importance of eating a diet that is rich in micronutrients once you are into Stage V of recovery. Macronutrients are no longer the issue.
The most micronutrient-dense foods are vegetables and meats, including fish and poultry. However, eating a lot of cereal grains negates the benefits because these foods contain high amounts of phytates, which decrease the body’s absorption of minerals such as iron and zinc.
Just as eating an inadequate diet can set you up for overtraining, relying on supplements instead of nutrient-dense foods to provide vitamins and minerals can also be detrimental. For example, excessive amounts of vitamin A, vitamin E, and zinc have been shown to weaken the immune system, thus contributing to overtraining symptoms. An excessive intake of iron promotes bacterial growth and can induce a zinc deficiency. The best way to ensure a balanced diet is to eat plenty of vegetables, fruits, and meats—not to take pills or eat lab-designed food products marketed to athletes. Science has yet to catch up with Mother Nature when it comes to producing nutritious food.
There are no preliminary symptoms to warn you when you have gone too far with an imbalance between stress and rest. The progression from a normal and recurring state of overreaching to full-blown overtraining is so gradual that you won’t recognize the impending doom. By the time you realize that you’ve pushed too hard, it’s too late, and your only recourse is loss of fitness by greatly reducing or even eliminating the training stress.
If you are overreached, as indicated by an unusually high level of fatigue and suspect overtraining, take 3 to 5 days of complete rest, and then do a short, low-intensity workout. If you feel normal, you were only in an advanced stage of overreaching and are free to gradually return to regular training (but do so cautiously). But if after several exercise-free days the test workout feels like a wearisome burden, you are probably overtrained or are sick and should see your doctor. Take another 3 to 5 days of complete rest before retesting your status as before. Continue this pattern until exercise becomes fun again, which may take weeks or even months. Throughout the process, be sure to eat a nutritious diet made up primarily of fruits, vegetables, and meats, including fish and poultry.
It is far better to prevent overtraining in the first place than to deal with it after the fact, especially when you consider that it can take weeks if not months to recover. So what must you do to avoid it?
At its essence, overtraining results from training mistakes, and two are particularly common. The first is an imbalance between stress and rest, which usually occurs when the athlete suddenly increases the training workload in either volume or intensity—or both. The second scenario involves cutting back on recovery by substituting more challenging workouts for easy ones. Athletes have even been known to do both: suddenly increase the workload and eliminate rest and recovery days. In either situation the increased stress at first will result in improving fitness but also in a lot of fatigue. A few days of such increased stress may actually be beneficial. It’s when the pattern continues for several days or weeks, depending on the work capacity of the individual, that it becomes problematic. Given the work ethic, the motivation, and, in some serious endurance athletes, the obsession, such an extended period of high stress probably seems like a sure route to success. It is not; it is a sure route to failure.
The best way to avoid this pitfall is to follow a long-term, periodized training plan that schedules weekly rest and recovery days, monthly rest and recovery weeks, and annual rest and recovery months. This plan should also provide for a gradual progression in the training workload and fit your unique characteristics, including sport experience, age, susceptibility to illness and injury, and goals.
Nutrition often plays a role in the onset of overtraining. Even a suitably aggressive training regimen that leads to an acceptable level of overreaching may be undermined by a diet that does not encourage quick recovery. In our experience, such a diet is usually lacking in total calories, protein, or micronutrients. This is all too common for the serious endurance athlete who concentrates on sugar and starch, eats a vegetarian diet, or is concerned about body weight and so reduces calories despite a high workload. Any one of these scenarios will diminish recovery in what might be an otherwise appropriate training program.