The Paleo Diet for Athletes (22 page)

IF IT ISN’T OVERTRAINING, WHAT IS IT?

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

Common Symptoms of Overtraining

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

OVERTRAINING AND DIET

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.

MACRONUTRIENTS AND OVERTRAINING

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.

Carbohydrate

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.

Fat

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.

Protein

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.

Water

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.