Saturday, January 22, 2011

Iron deficiency anemia - some stats

ACSM Conference Highlights new research:

Iron-deficiency anemia in the general population of men is 2%. However, in cross country and distance runners 18-22 years of age, 21% were deficient.

For women, the percentage of iron deficiency anemia in the general population is 14%. However, 50% of female athletes are iron deficient.

For more information about iron deficiency anemia see my previous post on "Iron for Performance" dated October 14, 2010.

Friday, January 21, 2011

Weight Gain During Marathon Training

A question came up recently about weight gain during marathon training. Many new runners training for a marathon are confused about why they would gain weight while running all those extra miles. I have a few theories about why this is happening.

1) Most people overestimate the calories they burn on a run. The amount of calories you burn depends on your weight, gender, lean muscle mass, and intensity and duration of your run. The Garmin 405 cx watch will calculate how many calories you burn based on your hear rate during a workout. This is slightly more accurate than just using your gender and weight. It is known that the faster you run the more calories you burn. So someone running for an hour at a 6 min mile pace will burn more calories than someone running for 2 hours at a 10 min mile pace.

2) Newer runners will experience increasing muscle fiber recruitment, strengthening of tendons, and increasing bone density all of which contribute to extra weight. Newer runners or runners increasing their mileage also experience increases in muscle glycogen storage. For every gram of glycogen that is stored, 2-3 g of water is stored along with it.

3) There is an increase in plasma volume. This translates to extra weight as well.

4) Many runners have very detailed training regimens, but have absolutely no nutrition plan. This can lead to over consumption of calories and/or not combining macronutrients (carbohydrates, protein and fats) appropriately.

5). Many new marathoners believe that they can eat whatever they want because of all the mileage. Not only can this lead to weight gain, but it also can lead to poor recovery in between workouts and minimized training effects.

6) The other phenomenon I have seen is that a runner, in an effort to lose weight, will under consume calories. This runner's metabolism slows down and the runner gains weight or struggles to lose weight.

7) There are lots of myths associated with eating for marathoning. One that comes to mind is the big pasta bowl eaten the night before a marathon. Although pasta can be part of a healthy diet, it is usually covered in high fat sauces. There are many other healthier carbohydrate options that you can consume on a daily basis leading up to a marathon - not just for one pre-race meal.

Tuesday, January 18, 2011

What is the deal with the cupcake craze?

In the last few years, cupcake shops have opened up everywhere. My first experience with a cupcake shop was the "Teacake Bake Shop" in Emeryville, CA. I was out with my three daughters and they noticed the cute shop with pink and brown colors. There was something about the color scheme that drew me in. I ended up buying 4 cupcakes, 1 for each child and one for myself. I believe I spent about $12.00 that day.
I still can't believe I spent that much money for 4 tiny cakes with frosting. They put the cupcakes in a cute little brown box with pink accents. And as far as taste goes, they were very delicious. As some one who bakes all of her cakes from scratch, I can truly appreciate a cake made from real ingredients. However, as a dietitian I have some concerns.
1) These cupcakes can pack a punch in terms of calories. Depending on the bakery, the type of frosting, and the size of the cupcakes, they can contain anywhere from 200 to 500 calories. For example, the "Sprinkles" Red Velvet Cupcake with cream cheese frosting contains a whopping
497 calories and 27 g of fat and 16 g of saturated fat and 45 g of sugar.
2) Since they are so small, can you just eat one?
3) These cupcakes do not have any nutritional value at all. At least ice cream contains calcium, a nutrient important for bone health.
4) Cupcakes really appeal to children. And at 45 g of sugar for one cupcake, it's like feeding your children 9 teaspoons of sugar at one time. At least soda, only contains 6 teaspoons of sugar. Well, I don't recommend soda. That was a joke.
5) Eating a food item with sugar causes your blood sugar levels to rise sharply. Your pancreas responds by producing insulin which later causes an increased uptake of blood sugar leaving you feeling fatigued or lethargic. Not a fun feeling. And not ok for a diabetic.
6) Let's say a person needs about 2,000 calories per day to maintain weight and be healthy. Of course calorie needs are multifactorial. The recommended fat intake for this person would be about 67 g of fat per day. The Red Velvet Cupcake mentioned above provides 39% (26g) of fthat person's fat needs for the day. This is significant.
7) Let's say this person has elevated blood cholesterol levels (>200mg/dl), she should not eat more than 22 g of saturated fat a day, if any. This cupcake provides 16g of saturated fat - 73% of the upper limit. JUST IN ONE TINY CAKE.
My suggestion: Don't eat them. LOL. Ok, if you are going to eat them, have them after running a marathon or competing in a really long distance event. However, the empty calories won't help with your recovery. Seriously, have one. Don't make it a habit, but at least know what is in them.