The Paleo Diet for Athletes (21 page)

Will I gain weight?
There have been several studies showing that eating a diet rich in both fat and protein produces about the same or increased weight loss over time as eating a conventional diet.

One such study conducted by Brown and associates at the University of Otago, in Dunedin, New Zealand, fed 30 cyclists either a diet of high fat (50 percent) or high carb (69 percent) for 12 weeks. They were training between 6 and 25 hours per week. The cyclists did not gain weight when eating mostly fat. (An interesting side note to this study is that the subjects increased their bone density on the high-fat diet.)

The bulk of such studies typically show the same thing: The key element in weight loss is calorie restriction and expenditure through exercise, not the type of food eaten. So, no, you won’t gain weight eating a Paleo diet in Stage V every day unless you eat excessive calories or exercise less than you did before the dietary change.

In fact, many athletes report a decrease in weight when they switch over to Paleo even without changing their caloric intakes or training routines. This probably has to do, at least in part, with the insulin response common to high-carb diets. Eating high glycemic load foods such as starches in Stage V releases insulin into the bloodstream, which in turn causes the body to store calories as fat. This phenomenon is much less likely to happen during and immediately after exercise (Stages II and III), when the body’s demand for carbohydrate in the form of glycogen is
high to fuel exercise and restock expended glycogen stores. But by the time this exercise-related demand for glycogen is reduced in Stage V, sugar spikes in the blood will result in the release of insulin and the conversion of the carbohydrate to stored body fat. This factor is why the timing of your food intake relative to exercise is so important.

Another reason following a Paleo diet in Stage V may produce a loss of excess body weight without your focusing upon calories has to do with satiety. People are simply not as hungry when they eat “real” foods such as fruits, vegetables, and animal protein instead of highly processed foods made with starch, sugar, and salt. Putting away a dozen cookies is easy for most people. But how about a dozen carrots? A turkey breast is very filling, so you stop eating when satisfied. Can the same be said for pizza? Real foods are high in fiber and protein. These nutritional elements have been shown in numerous research studies to be hunger satisfying. The same can’t be said of highly processed foods. You’ll simply eat less without the psychological stress of “dieting” when you focus your Stage V diet on real food.

Will I train and race as well?
You may experience a drop in performance, especially in your rate of recovery, in the first 2 or 3 weeks after making a sudden change in your diet. This change is normal. You need to hang in there beyond this initial period to experience a positive adaptation. If you do that, then your training will return to normal and may even exceed your prior levels. Here’s an example of that.

A study conducted at the University of Copenhagen, as reported in
Medicine and Science in Sports and Exercise,
had 15 men eat either a high-fat or high-carbohydrate diet for 4 weeks. At the end of each 4-week period they were tested with a run to exhaustion on a treadmill at 80 percent of max VO
₂
. The research team found that there was no difference in total time until they had to stop. Additionally, the improvements in max VO
₂
were the same. The only significant difference was that the subjects’ RERs were lower on the high-fat diet, which is a good thing. That means their bodies were conserving glycogen and using greater amounts of fat for fuel. This study is like many others showing similar results.

The downside of most dietary changes intended to reduce body weight is the loss of muscle mass along with fat loss. Several studies have shown that reducing daily calories while eating a conventional, high-carb diet results in a significant loss of muscle. While there is no research using athletes who lost weight, most studies with nonathletic populations have shown that weight reduction on a high-protein diet, similar to Paleo, results in little or no loss of muscle compared with a conventional diet. This positive change probably has to do with the abundance of branched-chain amino acids in the Paleo Diet.

As discussed in
Chapter 4
, how much protein you eat on a daily basis depends on your training load. The more hours you work out weekly, the more protein is needed in your diet. If weight loss is an objective and you find it necessary to cut back on calories, be sure to keep your protein intake, especially from animal sources, at the recommended level.

CHAPTER 7

O
VERTRAINING AND
D
IET

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.

BEYOND FATIGUE

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.

WHAT IS FATIGUE?

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.