|
Optimal Nutrition for Exercise
DIET
The starting place for any nutritional program is a good, well-rounded diet, high in fiber, fruits and vegetables, and adequate protein while being low in empty calories and the “bad” fats (trans fats, hydrogenated fats).
Watch your quantities. Athletes may need higher amounts of protein and calories than sedentary people, but be careful. A lot of runners think they can eat more because they are exercising more – and then wonder why they aren’t losing weight! The formula for losing weight is simple: burn more calories than you consume. Keep the calories about the same while increasing your exercise, and the pounds will come off. Sure, an increase in muscle will cause you to weigh more while making you skinnier because muscle is denser than fat, but don’t fall into the trap of thinking that running or walking an extra mile or two will allow you to eat that extra piece of pie or those donuts. It’ll require more like an extra hour or two of exercise to burn off those extra calories!
High protein/low carbohydrate diets are good for losing weight, but may limit endurance. There is a good case to be made for high protein. Endurance athletes actually have higher protein requirements than body builders because we have more tissue breakdown to recover from. The conventional wisdom is that you need a high carbohydrate diet to build endurance, but in my experience (and I run races of over 100 miles), I have not found the high protein/low carb diet to be a hindrance as long as I carboload before my races, and remember to fuel before and during long runs (explained below).
Avoid simple sugars as part of your diet and learn about the Glycemic Index. The Glycemic Index measures how fast a food is likely to raise your blood sugar. High GI foods convert to sugar quickly, and low GI foods convert slowly. For fueling and recovery from runs, high GI foods are the way to go -- at that point you want the ready access to the energy. For your regular diet, however, try to stick to the lower GI foods.
On a day-to-day basis, the high GI foods are more likely to go into fat storage. They flood the blood stream with sugar, which needs to be removed. Insulin removes blood sugar by storing it in your fat cells, so the pancreas secrets insulin to do that. If you eat a lot of sugar at one time, you’ll get a quick energy surge as your blood glucose shoots up, then your body reacts by producing a sudden surge in insulin to remove the blood sugar. If you’ve been eating a lot of sugar regularly, your body starts becoming resistant to the insulin, so the pancreas pumps out even more. The excess insulin eventually causes your blood sugar to drop below normal, and so you need to eat more sugar to get your blood sugar back up, and the cycle repeats. This is, somewhat simplified, the beginning of adult-onset diabetes – probably not the outcome you were looking for. Insulin secretion is really the enemy here. More insulin secretion results in more fat storage. For that reason, smaller meals eaten more often will cause less of an increase in blood sugar at each meal, which thereby requires less insulin to be secreted and so results in less fat storage than the same number of calories eaten in fewer meals.
Diet in Preparation for a race:
In the days before a long run, shift towards getting more of your calories from carbohydrates. This is called Carbo-Loading, a very misunderstood concept. Here is what it is really all about:
In the past, people used to deplete their glycogen stores (glycogen is the name for stored blood sugar) about a week before the event so they could really “tank up” at the end of the week by eating massive amounts of carbohydrates, but that’s proven to be too hard on your physiology and simply isn’t necessary.
It’s enough to increase the percentage of calories in your diet coming from carbohydrates during the last 2-3 days before the long run. Many people get this wrong and instead eat extra calories from carbohydrates. Extra calories result in extra fat. Not the best. Instead, cut back some on protein and fat and replace those calories with carbohydrates so that the total calories are about the same.
Runner’s World published a “night-before” carbo-load system whereby you go for a 15-20 minute easy jog and finish up with 2-3 minutes at top speed, then eat a high carbohydrate meal within 15-30 minutes. This has worked for me for the lower intensity of 12-HR and 24-HR runs, but I haven’t tried it for the higher intensity of a marathon PR attempt.
Fueling during the event:
If your event is longer than a couple of hours, you will need to fuel along the way. That’s about the limit of glycogen you have stored to fuel an intense effort. Remember the Women’s Marathon in the 1984 Olympics? Gabrielle Anderson from Switzerland staggered around the track on the way to the finish line, falling down, dragging herself back up, falling down again, getting back up again, and repeating that cycle until she finally reached the finish line. She had completely depleted her glycogen stores, and since the brain requires glucose, her body had to break down proteins to get the glucose out of them. That’s a very slow, inefficient process. What happened was she would break down enough protein to free up some glucose, which would revive her enough to take a few steps. Those few steps would use up all her available glucose, causing her to collapse again and then wait for more glucose to be freed up. That’s what happens when you completely deplete your glycogen stores. Carbo-loading helps, but not enough to skip fueling altogether for a marathon or even most long runs.
When we race, we activate the Fight or Flight Response. In order to get more blood and oxygen to the muscles in your legs, arms, lungs, etc. and thereby support your ability to fight your way out of danger or run away from danger, the body very creatively shuts down non-essential processes. Eating something puts a demand on the digestive system, causing one of two things to happen: either the digestive system will work properly and take some of the blood flow away from the muscles supporting your activity, or the digestive system will shut down, causing the food in your stomach to rot, ferment, or go rancid depending upon whether it is protein, carbohydrate, or fat. Neither result is ideal. You want the fuel you take in to be easily processed, preferably as close to liquid as possible. If it’s not liquid, then at least make sure it’s something that sits easily on the stomach and is easily digested. Gels are easier than solid food, and both need to be taken with water to dilute them. I prefer a complex carbohydrate like maltodextrin, which is mostly composed of medium-chain carbohydrates with some simple and long-chain carbohydrates as well. Some manufacturers spike it with simple some sugars like fructose for more immediate energy. That’s OK to do, but some people find fructose a little hard on their stomach, so experiment with different products until you find one that you can easily tolerate.
Concentration has to do with particles per volume. It makes no difference if the particle is a small simple sugar (2-carbon atoms) or a long-chain carbohydrate (up to 30 carbon atoms). For the same amount of energy as with maltodextrin, you would have to consume 5-10 times as much simple sugar. That would be too heavy. Another way to say it for 1/5th to 1/10th of the concentration, a broad spectrum complex carbohydrate like maltodextrin will give you same amount of energy. Being less concentrated, it will sit more easily in the stomach than will an equal number of calories taken entirely from simple sugars.
As far as vitamins are concerned, they really aren’t necessary in something you consume during activity. Since it takes anywhere from 2 to as long as 12 hours for a vitamin to actually be absorbed and utilized, it is unlikely they can be of much use during the event, and may in fact be counter-productive since they also increase the concentration of the fuel you’re consuming. You may not have a choice in this area, however, since most products tend to have some vitamins in them. B vitamins make more sense during longer events since they are necessary for energy production and in fact can be used more quickly.
For most people, electrolytes similarly aren’t necessary during the event, with 3 exceptions: if you are going to out for more than 5-6 hours, if you drink too much water (it’s possible), or if you sweat too much. In those cases, a sports drink will be useful, as most contain electrolytes, as might be some of the electrolyte products discussed below under Supplements.
There are drinks that contain a 4:1 of carbohydrate to protein. There have been some studies indicating that these formulas increase endurance during the event and speed recovery after the event more than straight carbohydrate. Not all studies support that claim, however. I have run with some and used them for recovery with some success. You’ll have to test them out yourself to see if they work for you.
Immediately after exercise:
The most important time to fuel is during the first 15 minutes after stopping exercise. Your muscles are like a sponge at that point, so take advantage of that unique condition to replenish your glycogen (stored carbohydrate) stores. For those shorter, fairly easy runs, a little bit after the run is enough. However, if your workout was intense (because it was fast or long), eat that little something within that 15-minute window and then have a meal containing both carbohydrates and proteins within the next 2 hours.
SUPPLEMENTS
The most important thing to know about supplements is contained in the name. They are designed to supplement a good diet, not take the place of one.
Capsules are generally preferable to tablets. The process of making a tablet can actually be destructive to a number of ingredients. The pressure necessary to form a tablet often generates enough heat to actually destroy some of the more heat-sensitive nutrients like the B vitamins and vitamin C. Besides, 50% of the “stuff” in a tablet is an additive of one sort or another (glues, gums, binders, fillers, flowing agents, dilutants, emulsifiers, flavorings, colorings, coatings, waxes, shellacs, preservatives, etc.). You don’t need to take those. Further compounding the issue, many tablets don’t dissolve well, if at all, even passing through you intact in many cases. Capsules or powders tend to be the better choice.
Most nutrients should be taken with food -- they came from food, so taking them with a substantial meal already digesting means that you already have in place all the cofactors necessary to properly digest and absorb the nutrients in the supplements.
Supplements to pay attention to include:
1. Multivitamin – to make sure all the bases are covered.
2. Antioxidants – to combat the damage from the free radicals that are created as an automatic byproduct of metabolism. The increased metabolism from exercising creates more free radicals, which are pro-oxidants, and so you need more protection. Vitamins C and E, and Beta-Carotene (pro-vitamin A) in particular, along with some minerals that have anti-oxidant properties: Zinc, Selenium and Chromium. A good multi should have all of these, but you will want higher quantities than a Centrum-style formula.
3. Iron – runners can get deficient. Pay attention to this. Best obtained from food sources, however. Heme iron (from meats) is the best absorbed and utilized. Vegetarians can get it from iron-rich vegetables. Supplements are always available, but tend to be constipating. Try to find iron in the form of a true amino acid chelate (it'll mention the name of the amino acid the iron was reacted to. Something like iron (or ferrous) glycinate, for instance. The ferrous sulfates and fumerates of the world are famous for binding people. A good iron supplement will necessarily cost more.
4. Alpha Lipoic Acid – the only anti-oxidant that is both fat and water soluble, according to numerous studies it also increases the muscles ability to uptake glycogen by 50%, an excellent thing for runners, particularly during the carbo-loading phase.
5. MSM – Methylsulfonylmethane, biological sulfur, helps reduce inflammation and muscle soreness, as well as manage pain. Coincidentally, it also helps with allergies and asthma. For joint and tendon problems, take it along with the next item.
6. Glucosamine Sulfate (with or without Chondroiton Sulfate) – for joint pain and tendon and ligament repair. Chondroitin is somewhat controversial. There is a large faction that believes that in fact it is useless, but all the reasons and research they cite are factually wrong. A better argument is that while some people seem to need the Chondroitin, many don’t, and since as a raw ingredient Chondroitin costs 3 times as much Glucosamine, if you don’t need it, you’ll save money skipping it. A book called The Arthritis Cure recommended 1,500 mg Glucosamine along with 1,200 mg Chondroitin Sulfate. Whichever form you use, it is a long-term project. Arthritis sufferers need to take it for a month before they notice results, but at that point they report more pain relief than with painkillers. Good taken with MSM.
7. Electrolytes – Most commonly spoken of as “salt tablets”, these are the minerals you lose when sweating. Hyponatremia, a potentially fatal state brought about by drinking too much water, is really a condition of having massively depleted your electrolytes. Most sports drinks and gels contain them, but they may not have enough for you. Check the labels. Sodium and Potassium are the main electrolyte minerals, and Chloride and Magnesium are the minor ones. Many people need to supplement further. There are several encapsulated products in the market -- Succeed and E-Caps are two brands used by ultra-runners. There are also electrolyte drinks and powders to make your own drinks. Clif and Gookinaid both offer them, as do other companies.
8. Potassium-Magnesium Aspartate – an electrolyte complex that has dozens of studies showing it improves endurance. Theoretically, any Krebs-cycle intermediate should work in the place of aspartic acid, so if you see orotates, or citrates, malates, etc., they may be as good. I can only attest to what I have read in the original research studies, and they all tested the aspartate form.
9. Co-Enzyme Q10 (also known as CoQ10) – probably one of the best things you can do for the heart, it also strengthens the immune system and is an essential cofactor in energy production. It’s called a co-enzyme rather than a vitamin because the body manufactures it, but since it does so in ever decreasing amounts throughout your life, some researchers put forth the argument that it should be considered a vitamin after “a certain age.”
10. Phosphatidyl Serine (also known as PS) - the most important thing for us is that PS reduces cortisol, an adrenal hormone secreted in response to the stress of exercise. High cortisol levels have been associated with immune system suppression, decrease in calcium uptake by bones, muscle wasting, fat deposition, and accelerated aging. By safely reducing high levels of cortisol, PS can reduce the amount of damage created from which you would need to recover. Most people take it because it also helps with cognitive functions, particularly in the elderly. At some point we don’t make enough PS, and supplementation seems to become more and more necessary the older we get.
Q, Can’t you get everything you need from food?
A. This is a tricky question to answer because the strongest statement the FDA allows someone in the industry like me to make is that a diet high in anti-oxidants, high in fiber, and low in fat is one clearly associated with a lower risk of heart disease and cancer. The question is, do people get high levels of anti-oxidants in their diet? The answer I give is this: Not according to the Department of Agriculture. When several years ago they (with Johns Hopkins University) studied the dietary intake of over 30,000 people to see how many of them got just the recommended daily allowance of 10 essential nutrients, they found that not one person did! When they decided to ask an easier question, how many people got the RDA of just 8 essential nutrients, they found some, but only 12% of the people. This was the largest population study ever done at the time. Therefore, while it may be theoretically possible to get 100% of the RDA of the essential nutrients from a 1,500+ calorie a day diet, that is evidently not the way people actually eat. That says nothing about the “high levels of anti-oxidants” in the FDA statement above.
Furthermore in a study published in the’90’s, when some researchers at UCLA took a look at the studies that were the basis for the RDAs and now the RDIs (NHANES I and II), looking at vitamin C intake and longevity, they concluded that women who supplemented lived an average of 2 years longer than those who didn’t, and men who supplemented lived an average of 6 years longer than those who didn’t. The difference in results between the sexes was because vitamin C intake seemed to have the biggest impact on death from heart disease, and women don’t have the same risk as men until after they reach the age of menopause.
I might think these results studies make a case for supplementing your diet whether or not the FDA agrees. Draw your own conclusions.
Summary
Start with a good diet that has adequate amounts of carbohydrates to support endurance activity. The week before a major event lasting 2 or more hours, increase the percentage of your calories coming from carbs. If your run/exercise is going to be 2 or more hours long, then you will have to consume fuel along the way, and you want that to be as little taxing on your digestive system as possible. It’s important to replenish after exercise, and the optimal time is within the first 15 minutes after completing. Don’t forget protein to help rebuild torn down muscle. There is something called PS that can reduce the amount of damage that occurs, so you have less to recover from. Anti-oxidants will help neutralize the destructive effects of the increased amount of free radicals that are a natural by-product of the increased metabolism resulting from exercise. There are also other nutrients that can help with glycogen uptake, energy production, endurance, and recovery. (There are also a lot of products that people hype that have no demonstrable effect – another topic altogether!) Remember, none of these things are a magic bullet by themselves and nothing takes the place of good diet or good training; however, they can be a very useful adjunct if used properly.
Hope you found this helpful!
Bill Lockton
EXAMPLES OF FOODS ON THE GLYCEMIC INDEX
(Based on a scale with table sugar valued at 100)
LOW GLYCEMIC INDEX FOODS (55 or less) (best choice for everyday diet) Skim milk, Plain Yogurt, Soy beverage, Apple/plum/orange, Sweet potato, Oat bran bread, Oatmeal (slow cook oats), All-Bran™, Converted or Parboiled rice, Pumpernickel bread, Al dente (firm) pasta, Lentils/kidney/baked beans, Chick peas
MEDIUM GLYCEMIC INDEX FOODS (56-69) (OK for diet in moderation) Banana, Pineapple, Raisins, New potatoes, Popcorn, Split pea or green pea soup, Brown rice, Couscous, Basmati rice, Shredded wheat cereal, Whole wheat bread, Rye bread
HIGH GLYCEMIC INDEX FOODS (70+) (best choice for fueling or refueling) Watermelon, Dried dates, Instant mashed potatoes, Baked white potato, Parsnips, Rutabaga, Instant rice, Corn Flakes™, Rice Krispies™, Cheerios™, Bagel, white Soda crackers, Jellybeans, French fries, Ice cream, Digestive cookies, Table sugar (sucrose)
|
