Training? Feeling a Little Run Down?

Runners are notorious for digging a hole and jumping in. We'll push, push, push, thinking that if we just push a little harder, we'll break through that wall hindering us. While sometimes a little push is just what you need, other times, REST is what you need. So how do you tell the difference of when to push and when to rest? Listen to your body, know the difference between, "I don't wanna" and "I can't" and know the signs of fatigue and over training.

Do you feel that burn after a hard workout or a hard run? That's from pushing your body past what it's used to. Challenging yourself to harder more intense workouts (resistance training or aerobic training) over a period of time is called progressive overload. Progressive overload is how you train your body to adapt to the new conditions being put upon it. The key, however, is making sure that along with the progressive overload you are also giving your body time to recover. Ever notice how most marathon plans have you run a 20-miler followed by a day of rest and then the following week's "long run" usually isn't as long. That's progressive overload or stress adaptation. Build up. Back off a little. Build up. Back off a little. Overloading the body and then giving it a chance to recover, adapt, and heal before placing more stress upon it, is a great way to train.

The S.A.I.D. principle (Specific Adaptation to Imposed Demand) refers to the idea that your body adapts to the specific type of stress put upon it. So, when an endurance runner pushes to finish that 20-miler in a specific time frame, his/her body is adapting to that specific type of stress being put upon it.

The problem is many athletes (aerobic or anaerobic) don't give their bodies time to adapt before imposing more stress on their bodies. The create a recovery deficit....that hole they've dug and can't get out of. They're constantly stuck in the recovery period or worse, they become injured. This is called overtraining.

Often I hear a runner say, "but it's in my plan" or "but my plan says." Runners often mistake a training plan for LAW. A training plan is merely a guide to help you reach your goal. A training plan sis like a travel plan...a map. Change will most likely need to be made along the way. A plan doesn't know the factors you may be dealing with in a given week...the stress of the job, lack of sleep from a sick child, dealing with allergies, that pothole you stepped in and twisted your ankle, that unplanned work trip thrown at you. Some times life has a different plan for you than what your race training plan had in store of you. A training plan is based on an ideal world. A training plan also, does not know how long your particular body may need to recover after that first 20-miler. The plan is your map. You are the driver and your running coach is your AAA consultant.

Some common signs of over training include:

• persistent achiness, stiffness, or pain in the muscles and/or joints (beyond the typical delayed onset muscle soreness felt a couple of days after a workout)
• waking up with an elevated pulse (good idea to take your waking resting pulse frequently to give you a base from which to compare)
• lack of energy
• fatigued and/or achy muscles
• frequent headaches
• feeling lethargic or sluggish
• drop in athletic performance
• not able to complete your normal workout
• depressed, moody, unmotivated
• nervousness
• lack of sleep and/or appetite
• weight loss
• lowered immune system

An elevated pulse is also a good indicator of possible overtraining or even sickness such as a respiratory infection. If your waking resting pulse is elevated more than a few beats, you could have an infection or be suffering from overtraining. In either case, taking a day off may be the best thing. Rest is the best thing for overcoming overtraining. If rest doesn't do the trick, schedule an appointment with your doctor.

Other Causes of Fatigue When Training Include:

Improper Hydration can also be a source of fatigue. Most people in general don't get enough water (2-3 liters) each day. If you fall into that category and you're also not replacing the water you're losing through perspiration from running, you're risking dehydration. A sure sign of dehydration is fatigue. In addition to your normal daily hydration requirements, you should drink 12-16oz of water about an hour before your run. One good way to determine how much you need to drink after your run is to weigh yourself before your run (without your running shoes), then weigh yourself immediately after your run (without your running shoes). For every pound lost, you should drink 16oz of water. Don't have to drink all that immediately after your run. Drink some and then make sure you get in the remainder within a few hours after your run. No need to weigh before and after every run, but if you do it on a mild day and once on a really hot/humid day, then you'll have a frame of reference to help you determine how much to drink after runs in various conditions.

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If you're running less than an hour, water is perfect. If you're running an hour or longer, a sports drink will be a better choice especially on hot/humid days because it will help replace vital electrolytes (mainly sodium and potassium) lost through sweating.

Alcohol consumption should be decreased during training. Excess alcohol consumption can increase your chance of dehydration in several ways. Alcohol decreases your body's production of anti-diuretic hormone. This hormone is used by the body to reabsorb water. Having less of this hormone causes you to urinate more increasing your fluid loss. Side Note: The average beer is about 4-5% alcohol. When you drink a 200ml beer, you don't just urinate 200ml of water, but more like 320ml of water which calculates out to 120ml of dehydration. (Sorry, for the bad news.)  

Lack of Sleep is a big-time cause of fatigue. Your body does most of it's repair and rebuilding while you sleep. If you're not getting enough sleep, then you're not giving your body time to heal. Plain and simple. Sleep requirements can vary from person to person. Teenagers need about 9 hours on average (mine seem to need about 15!). Most adults need 7 to 8 hours a night for the best amount of sleep, although some people may need as few as 5 hours or as many as 10 hours of sleep each day. Fatigue can result when your normal sleeping hours are shortened for whatever reason—stress of a new job, a new baby, or that heartburn you got from the 5-meat pizza you ate just before bed. If you're not getting your normal amount of sleep, then you need to back off on your training until your sleep hours are back to normal.

Low Iron Levels can be another cause of fatigue. If you've ruled out other possible causes of fatigue, it may be worth having your doc take a blood test to check your iron levels. This can especially be problematic for some women during their menstrual cycle. Sometimes just a change in diet can help boost your iron levels, but sometimes an iron supplement may be needed. (Check with your doctor before taking an iron supplement.) Good food sources of iron include: turkey, clams, enriched breakfast cereals, beans/lentils, pumpkin seeds, blackstrap molasses, canned beans, baked potato with skin, enriched pasta, canned asparagus.

Sometimes you may not experience the fatigue during your run. For some the fatigue may come after the run. Insufficient Post-Run Re-Fueling can be the culprit. If you've had an intense workout, it's normal to feel tired, but if you're feeling fatigue that just won't go away, you may not be giving your body enough refueling carbs and protein after your run. A good rule of thumb is to consume a 4:1 ratio of carbs and protein within 30-45 minutes of finishing your workout. Oddly enough, lowfat chocolate milk has the optimal ratio of carbs to protein to help refuel tired muscles.

Avoiding the Woe-Is-Me Vortex

Interesting observation....last night when I was around mile 8 in a 13-mile run, I really began to fatigue. I was
feeling every foot landing as if my feet were cement blocks. So, I began to coach myself telling myself what I tell my runners... to look up and out, not down. Engage your core. Shoulders back. Work the lean.

While looking up, I noticed some thick fancy concrete posts with wrought iron fence in between the posts that line the front of a swanky neighborhood on the route I was running.  I was curious. How many posts were there? Funny what you think of when delirium kicks in. I started counting the posts as I passed. (There are a lot of them.) Before this point, my body was giving into the fatigue slowing me to a 9:20 pace. Funny thing happened however, after counting the last concrete post, I glanced at my GPS. My pace had dropped to 8:17 and didn't even really realize it. I had shifted my focus from my concrete feet to the concrete posts.

Take away from this for me is that sometimes when we fatigue during  a run, the "woe is me" factor may be slowing us down more than the actual fatigue. My head had bought into the fatigue hook, line, and sinker. Yes, I was fatigued. I was needing hydration. But I wasn't as bad as my head was telling me. Mile 9 averaged out 14 seconds faster per mile than miles 7 and 8.

So, use those external distractions to avoid being sucked into the "woe is me" vortex. Look around, take in your surroundings. Better yet, run with a buddy. Conversation is one of he best distractions. Or if you're hard up for a distraction...count concrete posts. Worked for me!

Running Strong As You Age

I hear it all the time...."I'm just not running like I used to." It's a given. We all age and as we age the activities we do may change and the ones we stick with doing may not have the same intensity as they once did, but there's a lot that one can do to keep that intensity alive as long as possible. Actually a lot longer than you might think.

I'm 45 and silly me thought that as I got older, the competition would begin to wane. Oh contraire! The exact opposite is happening. I used to place in the top three in my age group quite frequently at local races, but that's getting harder and harder to do. Once I moved into the 45-49-year-old bracket, the competition got a lot tougher. There are a lot of fast runners in their 40s, 50s and 60s.

What's the key? Well, the other day, a client of mine mentioned how surprised he was to learn how muscle-specific different sports can be. He's a runner in his 50s and he's a really good runner. He's coming to me to improve his upper body and core strength and endurance. He is right, different sports can be pretty muscle-specific. It's not until you try a different sport or do some general fitness training that your realize maybe you're not in as good a shape (overall) as you thought.

Soccer is probably one of the best sports for full-body conditioning. You're using just about every muscle in your body as well as moving your body through the three different planes of movement--frontal (lateral movements), sagittal (forward movment like running), and transverse (rotation and twisting). It also involves a great deal of cardio from the constant moving around and running involved in the sport.

Runners tend to think it's all about their lungs and their legs and while those are major aspects of running, that's not all there is to running. A strong core and upper body is also needed to ensure powerful movement in the legs and in maintaining good running form. Youngsters in their 20s and early 30s tend to be involved in multiple activities--golf, tennis, soccer, softball, Frisbee football, volleyball, working out at the gym, etc. Because of this variety of activity, the upper body gets a good workout without the individual realizing they're strengtheing their upper body and core. Then somewhere in our late 30s, 40s and 50s, due to work, family, just life in general, many of the activities fall by the wayside. Somehow many manage to hang-on to running. Maybe it's because we can fit it in whenever. Maybe it keeps us sane. Maybe it's because it's cheap. But, over the years, that core and upper body fitness begin to wane. Don't use it; you lose it. Probably wasn't that obvious because as runners we tend to be lean. But lean doesn't always mean fit.

A runner needs muscular endurance in the upper body and core just as much as in their legs. You're swinging your arms just as much as your legs are moving forward. There's no resistance to your arm movement other than some air, but they're still moving. If your upper body doesn't have muscular endurance then a domino effect can begin to happen. First the arms fatigue causing you to round your shoulders and slump. This puts more stress on your core. If your core is not strong, then it will begin to fatigue as well, causing even further decline of your running form. By now your legs are taking the full brunt of the domino effect. Not only has the core stopped providing a strong support and power system for the legs, now the legs are having to deal with poor running form and soon fatigue will consume the legs as well. What's that I see? Could it be? Yep! The dreaded WALL! You're about to smack right into it.

Not only can you hit that dreaded wall, you can begin to suffer from injuries like calf pulls or strains, issues with your Achilles heel, IT band problems, pulled hamstrings, muscle cramps...the list goes on. Sound familiar? Are you beginning to have issues in your legs that you never experienced when you were younger? Could be specific to your legs, but it could very well be related to something higher up--a weak core and/or upper body.

So, what's an older runner to do? Invest a little money in an exercise mat, a medicine ball (or a set of dumbbells or weight plates) and work that core! Whatever the resistance form you choose, it doesn't need to be very heavy. An 8lbs, 10lbs, or 12lbs medball will do fine. 10lb, 15lb, or 20lb dumbbells will work nicely too. Use the core workout and your new toys to work that core. If you don't have a medball most of the exercises can be done with just body weight, a dumbbell, or a weight plate). Do the workout 2 or 3 times a week and you'll be well on your way to a much stronger mid-section. Check back in with the blog on Sunday for an upper body workout for runners.

Note: Remember, if you have any upper-body health-related issue or this is the first time you've attempted an upper body workout, it's recommended that you check in with your doctor first to get his/her approval.

Fuel Your Engine With Quality Foods and Keep Fatigue at Bay

Yesterday, I posted somewhat of a check list to help you determine the possible source(s) of your running or training fatigue—overtraining, improper hydration, lack of sleep, low iron levels, lack of post-run refueling. Good nutrition for everyday running as well as during your training can also play an important part in keeping fatigue at bay.

USDA National guidelines specify that your daily caloric intake should consist of 45-65% carbs, 20-35% fat and 10-35% protein. The trick is making sure that those percentages consist of the right types of carbs, fats, and protein.

The fad diets of the late 90's and early 2000's had us all believing that carbs were our worst enemy. Fact is your body runs on carbs. Without carbs your brain couldn't function properly. As with most things, however, there's a good side and bad side to carbs. Unfortunately most Americans consume far too many of the bad or simple carbs (refined and processed grains and sugar). Cakes, doughnuts, pastries, white bread, candy, yada, yada, yada. More than likely if it's packaged and the first ingredient is sugar, it's not going to be good for you. There are several reasons these foods are bad. First simple carbs usually have a high GI (glycemic index) and can spike your blood sugar levels. You'll have that burst of energy and then soon after crash. Not only will it leave you feeling tired and fatigued, you'll soon feel hungry again and you'll be grabbing for something else to eat. Also, unless you're going to be active soon after eating those simple carbs, those calories will more than likely not be burned and will turn into fat. Foods consisting of simple carbs also often pack a double-whammy of being loaded with saturated fat or even trans fats both of which can lead to high cholesterol. Increased fat and a sedentary lifestyle can lead to obesity and for some to Type 2 diabetes. See a vicious cycle here?

The good or complex carbs that are found in whole grain foods take longer for your body to process. Because it takes longer, it leaves you more satisfied and it also allows your body to make use of those calories as energy. Foods high in complex carbs tend not to be loaded with extra sugar and/or fat. Being active is also important even if you're eating complex carbs. If you're sedentary, even those good carbs can turn to fat. But if you're active, those carbs will be the fuel to sustain that active lifestyle.

Simple carbs aren't all bad. If you need a little pick-me-up, the sugar fructose, found in fruits, vegetables, and honey can provide an immediate source of energy. This type of simple carb is much better for you than that candy bar, because the fruits and veggies also are nutrient dense. So along with that fructose, you're also getting a lot of vitamins and minerals as well as fiber. Speaking of fiber, eating a diet rich in fiber will help decrease your chance of colon cancer as well as help keep you "regular." A "clean" system will also help keep you from feeling sluggish. Who wants to run with an extra "load" anyway?

A diet high in fatty foods can also make you feel sluggish. That's why it's not recommended to eat much fat before a run...it can literally slow you down. Just like with carbs, there are "good guys" and "bad guys" for fats. Good fats are comprised of the liquid or soft monounsaturated and polyunsaturated fats and Omega 3 fatty acids. These types of fats play an important role in your overall good health. Monounsaturated fats include olive oil, canola oil, peanut oil, avocados, nuts, seeds. Polyunsaturated fats include vegetable oils (i.e., safflower, corn, sunflower, soy and cottonseed oils), nuts, and a variety of seeds. Omega 3 fatty acids are found in foods such as salmon, mackerel, herring, flaxseeds, flax oil, and walnuts.

Saturated fats and trans fats are the bad guys. Both of these types of fats increase the amount of cholesterol in your blood and a high level of cholesterol in your blood is associated with increased risk of coronary heart disease. Saturated fats are found in animal products (i.e., meat, poultry, seafood, eggs, dairy products, lard, butter), and coconut, palm and other tropical oils. Trans fats need to be avoided altogether. Now your body actually does need some saturated fat. Choosing leaner cuts of meat, turkey, and chicken will help keep the amount of saturated fat to a minimum. As a rule of thumb, try to limit your daily intake of saturated fats to about 7% of your total daily calories.

Trans fats include partially hydrogenated vegetable oils, commercial baked goods (i.e., crackers, cakes, cookies), fried foods (i.e., doughnuts, French fries), shortening, many types of margarine. Your daily intake of trans fats should be less than 1% (preferably 0%!). The remaining fat in your diet should come from sources of monounsaturated and polyunsaturated fats.

Protein is important because it provides the amino acids needed for building and maintaining your body tissue. There are 20 amino acids. Eleven of these amino acids (dispensable) can be made by the body. Nine of them however (indispensable amino acids), come from a variety of food sources. Foods that are high quality or complete protein sources have all nine of the indispensable amino acids. Animal food sources are complete proteins. Soy and quinoa (pronounced keen-wa)are the only plant food sources containing complete proteins. Other plant food sources are considered incomplete proteins because they are missing one or more of the indispensable amino acids. Combining plant food sources can create a complete protein such as combining beans and rice or peanut butter and bread.

Food really is the fuel on which our bodies run. If you're putting in premium food, then your engine will purr like a kitten. Put in the low-grade stuff and you're engine might just stall. Making sure you fuel your body throughout the day is key as well. Many people skip breakfast or eat very little for breakfast and then wonder why they poop out before lunch. Breakfast truly is the most important meal of the day. It's your first fueling.

Eating 5 or 6 mini-meals is a great way to provide the energy you need throughout the day. Think about it. You skip breakfast and so you're starving by lunch. If you skimp on lunch, then you're more than likely going to stop by the convenient store on the way home and load up on simple carbs (which won't satisfy you). So by dinner time you're so ravenous that you lose all control and before you know it you've eaten dinner plus that half gallon of Rocky Road!

If you eat each meal (breakfast, lunch, and dinner) and have a midmorning, midafternoon, and post dinner snack, you'll keep that engine (your metabolism) firing all day long which actually will have you burning more calories. Lowfat traditional or Greek yogurt, peanut butter on whole wheat bread, a handful of almonds, fruit, raw veggies, granola bars...all of these make great snacks. Now, keep in mind that eating more frequently doesn't mean eating more calories. You're still eating the same amount of calories, just spread out over smaller meals throughout the entire day.

FATIGUE.....It's Such a Drag!

Fatigue...It's a dirty little 7-letter word. We've all experienced it and the source of it can be almost too numerous to count.

Most of the time the source of the fatigue is temporary—late nights at work; a new baby in the house; exam time; a stressful relationship. Regardless of the cause, if you don't get on top of it, and set in place some steps to counteract the fatigue, you'll may go into that non-functioning zombie state from pure exhaustion.

Runner's can experience fatigue as well. It can be the stress-of-life-induced fatigue, but there can also be many other more running-specific sources for the fatigue.

One of the main causes of fatigue in runners is overtraining. Overtraining happens when you don't provide your body ample amount of recovery time. This often happens with runners using and over zealous marathon (or any race distance) training program. A good rule of thumb to follow when training is to alternate hard and easy days. Hard and Easy don't always refer to distance. The terms also refer to intensity. A short run can be "easy" if it's a 3-4 mile run at a conversational pace. Or short can mean "hard" if it's an interval workout at the track. Long can be "easy" if it's a leisurely 10-miler or it can be "hard" if it's a 10-miler at race pace.

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Throwing in a day or two of cross-training is a great way to give yourself an aerobic workout while giving your "running muscles" a break. And even a complete day of rest (meaning not doing anything) once or twice a week is much more beneficial that going full steam 7-days a week.

Overtraining can also be due to repetitive exercise when resistance training. If you don't vary your workouts and you're constantly subjecting your body to the same stress over and over, those muscles can become overtrained. A good rule of thumb is to wait at least 48 hours before working the same muscle groups again. So for example, if your do a chest/triceps workout one day, you should wait at least 2 days before working those muscles again. Professional bodybuilders will often workout a muscle group so hard in one workout, that they'll wait an entire week before working that muscle group again.

An elevated pulse is a good indicator of possible overtraining or even sickness such as a respiratory infection. If your waking resting pulse is elevated more than a few beats, you could have an infection or be suffering from overtraining. In either case, taking a day off may be the best thing. Rest is the best thing for overcoming overtraining. If rest doesn't do the trick, schedule an appointment with your doctor.

Improper hydration can also be a source of fatigue. Most people in general don't get enough water (2-3 liters) each day. If you fall into that categore and you're also not replacing the water you're losing through perspiration from running, you're risking dehydrated. A sure sign of dehydration is fatigue. In addition to your normal daily hydration requirements, you should drink 12-16oz of water about an hour before your run. One good way to determine how much you need to drink after your run is to weigh yourself before your run, then weigh yourself immediately after your run. For every pound lost, you should drink 16oz of water or sports drink. Of course you can't do this after every run, but if you do it on a mild day and once on a really hot/humid day, then you'll have a frame of reference to help you determine how much to drink after runs in various conditions.

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If you're running less than an hour, water is perfect. If you're running an hour or longer, a sports drink will be a better choice especially on hot/humid days because it will help replace vital electrolytes lost through sweating.

Lack of sleep, is a big-time cause of fatigue. Your body does most of it's repair and rebuilding while you sleep. If you're not getting enough sleep, then you're not giving your body time to heal. Plain and simple. Sleep requirements can vary from person to person. Teenagers need about 9 hours on average (mine seem to need about 15!). Most adults need 7 to 8 hours a night for the best amount of sleep, although some people may need as few as 5 hours or as many as 10 hours of sleep each day. Fatigue can result when your normal sleeping hours are shortend for whatever reason—stress of a new job, a new baby, or that heartburn you got from the 5-meat pizza you ate just before bed. If you're not getting your normal amount of sleep, then you need to back off on your training until your sleep hours are back to normal.

Low iron levels can be another cause of fatigue. If you've ruled out other possible causes of fatigue, it may be worth having your doc take a blood test to check your iron levels. This can especially be problematic for some women during their menstrual cycle. Sometimes just a change in diet can help boost your iron levels, but sometimes an iron supplement may be needed. (Check with your doctor before taking an iron supplement.) Good food sources of iron include: turkey, clams, enriched breakfast cereals, beans/lentils, pumpkin seeds, blackstrap molasses, canned beans, baked potato with skin, enriched pasta, canned asparagus

Sometimes you may not experience the fatigue during your run. For some the fatigue may come after the run. Insufficient post-run refueling can be the culprit. If you've had an intense workout, it's normal to feel tired, but if you're feeling fatigue that just won't go away, you may not be giving your body enough refueling carbs and protein after your run. A good rule of thumb is to consume a 4:1 ratio of carbs and protein within 30-45 minutes of finishing your workout. Oddly enough, lowfat chocolate milk has the optimal ratio of carbs to protein to help refuel tired muscles.

So, if you're experiencing fatigue, whip out this list and see if you can narrow it down. If this list doesn't pin down the cause for you, make an appointment with your doc.

Just Stop It!

During a recovery jog between intervals, Dena a running buddy of mine was telling me about a 10K race she had run the previous weekend. She said she felt awful at the halfway mark and she wasn't sure why. She knew that if it were a marathon she'd be blowing through those miles. She thought it had to be in her head. Somehow her brain was not letting her do what she knew she could do. This sounded like a great post for RunnerDude to investigate. Here's what I discovered.

Most runners already know they're a "head-case," but now there's science to prove it! You know that feeling towards the end of a race when it seems as if you're about to die and you can no longer control your legs?(Sometimes for me, that's before the race even starts.) That feeling could be all in your head. To be more specific, in your brain. A relatively new idea proposed by Dr. Timothy Noakes theorizes that the brain sometimes acts like a big brother during prolonged strenuous exercise. When "Big Brother" senses the body's normal operating system (homoeostasis) is getting out of whack, it's main priority is to protect his little brother—the heart—so Big Brother slows everything down by fatiguing the muscles. Noakes called this process The Central Governor Model. Kind of like a governor that's but on a school bus engine to keep it from going over a certain speed.

For decades most scientists, trainers, coaches, and runners have believed that the Cardiovascular/Anaerobic/Catastrophe Model was responsible for the fatigue. British physiologist and Nobel Prize winner Archibald Vivian Hill (he went by A.V.; wouldn't you?) proposed this model back in the 1920's. Basically he believed that a lack of oxygen to the muscles, a build up in blood acidity at your muscle cells, or both occurring at the same time was responsible for the fatigue.

Since Noakes proposed his new theory, more and more scientists, coaches, and runners have begun to question the original thinking. Basically it all comes down to fatigue. We know the symptoms, but what's causing them?" Is it a lack of oxygen to the muscles or is the brain constantly monitoring the body and acting as a governor by purposefully fatiguing the muscles when it fears the heart is in danger. The two main questions being asked are:

1. If a lack of oxygen to muscles is the cause of the fatigue, then why isn't the heart starved of oxygen? It's a muscle too. If the heart were starved of oxygen, then the runner would experience heart pains.
2. If the fatigue is purely caused by a physical problem (not enough oxygen getting to the muscles), then how do you explain runners who (even though they have to slow down) continue at a relatively good pace? Some runners can even pick up the pace when they near the finish.

If Noakes' model holds true and the fatigue is caused by the brain sensing a disturbance in homoeostasis, then a runner can tell the brain to "stop it!" More technically, the runner can recognize what's happening to him/her and make a conscious effort to override his/her subconscious. I didn't know what I was doing at the time, but when I ran the Baltimore Marathon in 2004, I think I did this exact thing to avoid bonking. At about mile 21, I started to get very fatigued. I was well hydrated, and had been taking gels regularly, and I hadn't gone out too fast like I usually do, so I was baffled as to why I was feeling fatigued. I remembered reading somewhere that if you feel fatigued, you should try speeding up because it will use different muscles allowing your fatigued muscles to recoup. So, I purposefully told myself to speed up and as a result, the fatigue dissipated and I ended with a good time and actually felt good after the race. I'm not sure that was The Central Governor Model in action, but it sure does sound like it.

So, the next time you feel fatigued during a race, tell your brain to "Stop it!" Of course the runner beside you may think your a nut case, but it'll be worth it.

Now, keep in mind that Noakes' model doesn't explain every case of fatigue. Sometimes fatigue may be a result of such things as increased levels of potassium which can hinder muscle contraction. And if you haven't pre-race-carb-loaded and you don't continue to refill your glycogen supplies during a marathon (especially if you're running more than two hours) then Hill's original theory could very well be the cause.

If you want to read more about Noake's Central Governor Model and more about the brain and running, check out the following books:

The Lore of Running (Dr. Timothy Noakes, Human Kinetics Publishers; 4 edition, 2002)

"Now revised, expanded and updated, Lore of Running gives you incomparable detail on physiology, training, racing, injuries, world-class athletes, and races. Author Tim Noakes blends the expertise of a physician and research scientist with the passion of a dedicated runner to answer the most pressing questions for those who are serious about the sport... Lore of Running is not only the biggest and best running publication on the planet. It's the one book every runner should own."—Amazon

Brain Training for Runners (Matt Fitzgerald, (forward by Tim Noakes), New American Library, 2007)

"Based on new research in exercise physiology, author and running expert Matt Fitzgerald introduces a first-of-its-kind training strategy that he's named "Brain Training." Runners of all ages, backgrounds, and skill levels can learn to maximize their performance by supplying the brain with the right feedback. Based on Fitzgerald's eight-point brain training system, this book will help runners resist running fatigue, use cross-training as brain training, master the art of pacing, learn to run "in the zone", outsmart injuries, fuel the brain for maximum performance, and more."—Amazon