Friday, April 23, 2010

Breakfast and Your Morning Workout

So my friend Jeff is involved in Plyometric training early in the morning and asked my opinion about not eating before his workout. This is a great question and in a general sense, I am a firm believer in eating before exercise. There are so many variables though, that this isn't so black and white. Such variables could be type, length, and intensity of training, duration of preworkout fast, substrate content of preworkout meal, training status, and your individual GI tolerance of exercising fasted or postprandial.

In Jeff's case, he is doing explosive, full-body exercises at high intensity for about an hour. He wakes up at 5:30 and is at the gym at 6:00 for an hour-long workout before work. Just as he puts gas in his car so he can drive, he needs to fuel his muscles so he can exercise. If his last meal was at 6PM the night before, his liver glycogen levels are most likely depleted. Remember liver glycogen is what is responsible for maintaining blood sugar levels, so if he is running "on fumes" he could notice several symptoms associated with hypoglycemia (low blood sugar) such as light-headedness, mental stress, and fatigue - none of which contribute to a max-potential workout experience.

In Jeff's case, I suggest he try waking up 15 minutes earlier for a light breakfast such as toast with jelly and a glass of juice or water for about 60g of carbs (240kcals) 45 minutes before his workout. Other light yet carb-dense options could be low-fat yogurt, cereal, or oatmeal. If this isn't a possibility or he has GI discomfort, he could try a late-night snack. Yes, I know I just suggested the controversial topic of eating before bed but as long as he doesn't have reflux or sleep issues as a result, this may sustain blood and liver glucose levels long enough to last through his morning workout. Some general recommendations that I have came across include 1-2kcals of carbs/lb 1 hour before workout. For me, I workout in the afternoon and time a carb-dense lunch with a protein shake about 1-2 hours before my workout. The best way to find out what works best for you is trial and error. For example, if you are doing High Intensity Interval Training (HIIT) through sprints, you may want to be a little more conscious of what you eat than if you were going to cycle for an hour or two.

Thursday, April 15, 2010

Eggs!

About a week ago I saw an episode of History channel's Modern Marvels all about eggs. It was a really cool segment about the production and use of one of our most affordable protein sources. If you happen to see the episode on hulu or History's website, I definitely recommend checking it out. Anyways, I wanted to talk about eggs because it seems that everyone in the gym has their own theory about them. Some people stay clear from them, others throw out the yolk, and some just eat as many as they can. My take on them? Well, I absolutely love them because of their taste and value and usually eat 3 full eggs almost every day of the week (If I eat more, after 3 I generally get rid of the yolk). I had my lipid profile checked monthly for about 6 months and in my case, my cholesterol and triglycerides were just fine. I'll also note that I have no family history of diabetes or coronary heart disease. In other words, I'm not too worried about my cholesterol rising from so many egg yolks. This is because I am considered a compensator meaning my liver compensates for the increase in dietary cholesterol by suppressing endogenous cholesterol (the liver usually produces about 1,000mg/day). In one journal article, researchers estimated that as many as 2/3 of Americans are able to compensate for the increase in dietary cholesterol. (Howell)

So What About EGGS?
Despite the various opinions, one thing is for certain - eggs are an extremely good source of affordable, high-quality protein. Not to mention, they are an extremely versatile food that can be consumed anytime. One large egg contains 6 grams of protein and 97% of that protein is in the form of readily available amino acids - including all of the essential AAs. If you throw away the yolk though, remember you are only getting 3.6g of protein from the egg white. The yolk also contains all of the fat and cholesterol found in eggs. The average large egg yolk contains about 5.6g of fat and 210mg cholesterol (The DRIs suggest less than 300mg/day). Before that scares you, it is important to note that of this fat, only 1.6g of it is saturated. The rest is mono- and poly- unsaturated (considered the good fats). If you are only eating 1-3 eggs/day, I am a big advocate for eating the yolk. Obviously if you have high cholesterol and respond well to a low cholesterol diet, or have a family history of heart disease, this many whole eggs may not be recommended in your diet as the American Heart Association recommends no more than 3/week. As for the rest of us, 2 eggs/day has not been shown to increase your risk of heart disease (Katz et al)

References

Howell W. Diet and Blood Lipids. Nutrition Today. 1997 June;32(3)

Katz, D, et al. Egg consumption and endothelial function:
A randomized controlled crossover trial. International Journal of Cardiology 2005 March;9(1)

Wednesday, March 31, 2010

The Most Underrated Post-Workout Remedy

After an intense workout, almost everyone has their recovery drink ready to go. Whether it is whey protein, a carb replacement drink, or a simple Gatorade, aggressive marketing deems these [often expensive] remedies as necessary. However, one that doesn't come with a lot of attention happens to be quite possibly the best, as well as the cheapest. I'm talking about milk! OK OK before you think I'm crazy just hear me out. If you still think I'm crazy after this article, well, post your comments and I will respectfully shut you down and prove you wrong. No I'm kidding ;) so let me know what you think! Unfortunately not everyone is able to enjoy milk post workout. As many of us age into adulthood, production of lactase, the necessary enzyme to digest the sugar in milk, decreases significantly thus causing lactose intolerance. However, if you are able to enjoy milk comfortably, then I suggest adding a healthy dose after your workout and the following is why.

Milk is an extremely good source of high quality protein and amino acids, carbohydrates, lipids, and micronutrients (e.g. Calcium and electrolytes). In addition, the fluid and electrolyte composition are important in rehydration. In one study, researchers analyzed effects of postworkout consumption of [isoenergetic, isonitrogenous, and equal macronutrient ratio] fat-free milk, fat-free soy protein, and carbohydrate drinks. They concluded that "postexercise consumption of milk promotes greater hypertrophy during the early stages of resistance training when compared with soy or carbohydrate consumption" (Hartman et al)

Milk protein is a combination of casein and whey protein. Whey has high concentrations of branched chain amino acids (BCAAs) and is more quickly digested and absorbed whereas casein is a slower digested and absorbed protein. The typical ratio of casein to whey in milk is 3:1. This is important because it causes milk to be more slowly digested and absorbed meaning blood amino acid concentrations stay higher longer. This is often the exact reasoning for supplement companies to discredit milk with their ground-breaking, faster absorbing hydrolyzed proteins. Many times I have come across the mentality that hydrolyzed proteins are better than complete proteins because they enter the bloodstream quicker and significantly increase the rate of protein synthesis. Although they do enter the bloodstream quicker than complete protein (Koopman et al), one recent study concluded that this doesn't equal better or more protein synthesis (Deglaire et al). In fact, this study actually concluded the opposite, that hydrolyzed protein is less readily absorbed, more easily used for energy, and leads to significantly less protein in the bloodstream and muscles than a complete protein.

I am not saying don't use these alternatives to milk (especially since I use Optimum Nutrition's Gold Standard Whey) but rather suggesting considering your options and goals before making a purchase. I know milk isn't as convenient as a powder, but I would definitely suggest drinking a glass of fat-free milk when you get home if you can tolerate it. If you have any questions, let me know!

References

Hartman J, et al. Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters. Am J Clin Nutr. 2007 Aug;86(2)

Koopman R, et al. Ingestion of a protein hydrolysate is accompanied by an accelerated in vivo digestion and absorption rate when compared with its intact protein. Am J Clin Nutr. 2009 Jul;90(1)

Deglaire A, et al. Hydrolyzed dietary casein as compared with the intact protein reduces postprandial peripheral, but not whole-body, uptake of nitrogen in humans. Am J Clin Nutr. 2009 Oct;90(4)

Sunday, March 28, 2010

Low Carb Dieting

If you are exercising, it is imperative that you fuel your muscles. The best way to do this is by ensuring that you eat adequate amounts of carbohydrates. I am not sure why it began, but the myth that carbohydrates are fattening is just that - a myth. As I have said before, carbohydrates are not fattening, excess calories are. Athletes are especially dependent upon carbohydrates as their muscles are constantly being used and depleted of glycogen. When you exercise hard, glycogen stores in your muscles are the main source of energy. You also have stored carbohydrates in your liver and blood (blood glucose). The liver glycogen is broken down and feeds into the bloodstream to feed your brain and muscles as well as maintain blood glucose levels. This is significant because those who are avoiding carbohydrates aren't able to maintain glycogen levels - thus directly decreasing the length and intensity of their workout. In a 2007 study, researchers had cyclists maintain a specific pedal speed until fatigue on two occasions. The first was after a 3 day low-carb diet in which they averaged about 75 minutes. The same cyclists then followed a 3 day high-carbohydrate diet and repeated the workout. This time, fatigue didn't set in until nearly 130 minutes. In conclusion, the researchers suggested that the increased glycogen levels were associated with improved performance and energy homeostasis (Green et al. 2007). It is worth noting that trained muscles have the ability to store about 20 - 50% more glycogen than that of untrained muscles (Sherman et al. 1981). I cite this because if you are just starting to exercise, simply eating a ton of carbs doesn't necessarily mean you will have incredible workouts. Rather, the take home message here is that your muscles will adapt to the training so that significantly more carbohydrates can be stored in your muscles and later used as energy. To wrap up, most exercise and health professionals suggest 55-65% of total kcals from carbohydrates for athletes. This will ensure that you are both adequately fueled for your workouts and able to replenish glycogen after exercise.

References:
Green, H., M. Ball-Burnett, S. Jones, and B. Farrance. 2007. Mechanical and metabolic
responses with exercise and dietary carbohydrate manipulation. Medicine & Science in Sports & Exercise

Sherman, W., D. Costill, W. Fink, and J. Miller. 1981. Effect of exercise-diet manipulation
on muscle glycogen and its subsequent utilization during performance. Int J
Sports Med 2:114-118.
39(1):139-148.

Friday, March 19, 2010

Lose the Carbophobia!

In the world of sports nutrition, I have encountered several different mentalities with regards to carbohydrates. High GI carbs post-workout, no carbs before bed, avoid fructose-rich fruit, carbs shouldn't be mixed with fatty meals, and my personal favorite, low-carb dieting for weight loss. All of these ideas have modest logic however little scientific evidence has supported these claims. I will briefly go over these common misconceptions and, in my next post, place special emphasis on low-carb dieting. Please email me with questions and comments. Enjoy!

Brief Breakdown of Carbohydrates
Carbohydrates are our main energy source and provide 4 Calories per gram. However, not all carbohydrates are the same. They can be classified into two categories: simple and complex. Simple carbs are mono and disaccharides and are found in table sugar, fruits, milk, honey, and prepared sugars such as high-fructose corn syrup (HFCS). Complex sugars, such as starch in plants and glycogen in muscles, are long chains of simple sugars that breakdown to release sugars. Sources include potatoes, brans, wholegrain flours, breads, and pastas, vegetables, and nuts. Another classification of carbohydrates is the Glycemic Index (GI) based on how slow or fast 50 grams (200 Calories) of that sugar will increase blood glucose levels. This system was initially used by diabetics to help control their blood glucose but many athletes have found its individual ranking of foods as a potential advantage to increase performance. In theory, low GI ranked foods consumed pre-workout help endurance athletes by providing constant energy through the slow release of glucose whereas high GI foods consumed immediately post-workout rapidly refuel depleted muscles, which brings me to my first rebuttal.

High GI Carbohydrates Post-workout
Some athletes feel that immediately after a workout it is necessary to spike insulin levels to create an anticatabolic response and re-synthesize glycogen. Unfortunately, there are flaws in this logic and research has shown that spiking insulin immediately post-workout provides no benefit. Before I continue, exists one exception for the athletes who undergo two or more exhaustive workouts within 6-8 hours of each other, however this is not the majority of us and this information may not apply to them. For the rest of us, the Glycemic Index shouldn't be stressed for several reasons. First, it is very sensitive to portion size, origin, and preparation of the food. Second, glycemic response varies greatly in each of us on a day-to-day basis. And third, well-trained muscles readily take up carbohydrates from the bloodstream (meaning insulin spikes don't necessarily occur in athletes).

No Carbohydrates After 9PM
One persistent theme I have encountered is that carbohydrates at night or before bed can lead to weight gain. This is silly in my opinion as the real culprit of weight gain is simply excess calories, not carbohydrates before bed. This is especially the case for those who train in the evenings whose muscles could properly recover from the post-workout carbs. One thing to keep in mind is that much more importantly than the timing of when to eat your carbohydrates, is actually meeting your estimated daily needs (see first post).

Avoid Fructose-Rich Fruit
I continue to be amazed when I hear people say to avoid fruit because of its fructose content. In this popular youtube video Dr. Lustig of UCSF goes as far as to associate fructose with poison. On a sidenote, if you watch this long video, I encourage you not to make any grand realizations. Nonetheless, fructose has been under a lot of scrutiny and since fruit contains relatively high amounts of fructose (about 6-7 grams), many bodybuilders see fit to avoid it. This is because fructose causes minimal insulin secretion and can potentially lead to fat synthesis in the liver. The problem here is that very rarely is fructose alone in foods. For example, all of that HFCS in our food contains almost equal ratios of glucose to fructose. Also, In many fruits, there is about a 1:1 fructose to glucose ratio (sometimes as high as 1:2). Bottom line, these food items can elicit an insulin response. As for increased fat synthesis, this has been evidenced in high intake of 50+ grams. This would mean 9 servings of fruit. Before you say that isn't so much, especially when combined with all the HFCS in our foods, fruit also contains almost as much fiber which, as Dr. Lustig claims, neutralizes the fructose. Now I'm not saying eat all the fructose you can, I'm merely proposing that fructose is dose-dependent. Within moderation, I would not overly stress it. Especially since fruit also contains vitamins, minerals, fiber, and phytochemicals important for muscle nourishment. *Note that these are the substances that soft drinks lack

No Carbohydrates With Fat
I feel like this mentality is related to the misguided idea that carbs are fattening. Again, excess calories are fattening and it is easy to forget about the butter on bread, mayonnaise in a sandwich, and oil in pasta that contribute a lot of fat calories to those carbs. In the bodybuilding world, this theory is likely more related to the idea that fat circulating in the bloodstream should not be available when insulin is raised because it will lead to creation of more adipocytes (fat cells). Insulin is an anabolic hormone but in reality, the type of fat (unsaturated or saturated) will make a significant difference in the insulin response of the carbs. For example, the insulin response to carbs ingested with unsaturated fats is likely to be unaffected whereas that of carbs ingested with saturated fats is raised. Nonetheless, these types of fat can lead to increased Triglyceride (TG) storage even if insulin isn't available. My take home point here is that fat storage is dependent upon multiple variables and not simply with insulin alone. This type of separation in meals could be difficult to follow and isn't shown to produce any weight-loss benefits. On the contrary, evidence has shown, eating a diet consisting of mixed substrate meals within your caloric recommendations is more beneficial.

Monday, March 1, 2010

Getting Started

Do you know your body's Calorie needs? Using the standard 2000 Calorie requirements on food labels is a great start however if you're looking for a more detailed and specific set of guidelines, I highly recommend spending just 30 minutes at fitday.com or mypyramidtracker.gov and providing a quick recall of yesterdays snacks, meals, and beverages. I personally use mypyramid however both are great resources and user-friendly. These sites will provide a detailed analysis of your submitted diet and compare it to suggested macro- and micro-nutrient and overall energy needs based on your gender, weight, height, and age (fitday also includes a physical activity option). Mypyramid calculates your Estimated Energy Requirement (EER) without incorporating physical activity (leisure and standard activity is included). At this site, it is calculated separately to estimate the cost in Calories of the training. Adding this with the EER should give you a relatively accurate idea of how many Calories you burn in a typical day.