Dropping Weight, Not Performance
As athletes and people who often want to watch what we eat, I thought this question posted by a reader on the Active.com website was particularly interesting
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Dropping Weight, Not Performance
Q: Hey Gale – I’d love to get your take on something. I’ve been researching this next topic for my cycling group: encouraging riders to determine whether or not they’re eating enough when training. (Who better to write this than Mr. Bonk himself?)
When I did some analysis on my own caloric intake and taking into account the variables of (1) Body weight, (2) Riding intensity, and (3) Duration, I quickly realized I was consistently training at a caloric deficit. Ok, so the simple answer could be: eat more, right?
Now here’s where it gets tricky. If you have a rider who wants to deliberately subject themselves to burning more calories than they take in for the sake of weight loss (and I must confess I have a few pounds I’d like to shed), the $10,000 question is, at what point does your caloric deficit begin to affect performance on the bike? I found the following statement and I think it is pretty revealing:
“If you ride at too hard of an intensity you’ll be depleting the glycogen stores within your muscles rather than training your body to burn off fat.”
So, given the above statement, how would a rider know when they’ve taken the advantage of calorie-burning from exercise to the point of glycogen-depletion from muscle tissue, which presumably would be the threshold at which a rider would begin to experience fatigue and a negative affect on performance?
When I read the literature on manageable and safe weight loss, there seems to be a consistent figure of 1.5 to two pounds per week that is considered safe and reasonable for weight loss. Heck, I’ve lost that amount on one ride from becoming both dehydrated and malnourished! Yes, Mr. Bonk may not be a good example, but in our cycling world there are many riders looking to find that balance between maintaining fitness and reducing weight.
Can you help? Thanks – G.A.
A. Mr. Bonk, you have several good questions. Let me try to hit each one:
•How many calories per day can you cut without cutting performance?
I’ve never seen any specific research on this, but my personal experience and experience with other athletes yields an answer of 200 to 500 calories per day, average.
I write “average” because if you do a big ride on a weekend day, you might find yourself at an 800 to 1,000 calorie deficit at the end of that day. If you keep trying to maintain an 800 calorie per day deficit over the long haul, performance will suffer. People that have no sport performance expectations can run that low, but competitive athletes cannot.
The day of the big ride, you might end up being low by 800 to 1,000 calories, but the next couple of days will likely find you eating a little more. There is nothing wrong with that, as long as you keep the weekly deficit at an average of 200 to 500 calories per day. Bigger people can usually go to the higher end and smaller people on the lower end.
If you need formulas to estimate caloric needs, see the column Maintaining Your Lean Mean Racing Machine.
•”If you ride at too hard of an intensity, you’ll be depleting the glycogen stores within your muscles rather than training your body to burn off fat.”
It’s not exactly black and white. A point of clarification is that we are producing energy aerobically (primarily burning fat) and anaerobically (primarily burning glycogen) all the time, in concert. Even as you sit relaxed in your chair, reading this column, you are producing some energy anaerobically.
The percentage of energy coming from aerobic production changes as exercise intensity increases. So, yes, as you ride faster you will increase the percentage of energy that comes from glycogen and decrease the percentage that comes from fat and oxygen.
Whether or not you will actually deplete your glycogen stores within the muscles (i.e. “bonk”) depends on how well your muscles were stored with glycogen before the ride, how fast you are riding and how well you are refueling during the ride.
Also know that higher-intensity exercise burns more calories per hour and does rev-up your metabolic engine. Increasing your base metabolic rate is a good thing.
Not bonking and not over-consuming calories during a ride takes some experience and the ability to increase or decrease calories on the fly, or by plan. This means increasing or decreasing your ride fuel rate depending on the type of ride you’re doing, the condition of your fuel stores coming into the ride and whether or not you are trying to lose weight.
2 comments
I’ve twice followed Dr. Steven D. Spainhower’s method of weight loss from his book The Sports Nutrition Handbook. He recommends a daily calorie deficit of 500-1,000 to lose weight (or a postive amount of the same to gain weight). He recommends eating 6 meals a day (I love that part). Some days I have to consume 7,000 calories. You have to do some serious eating to do that. I’ve heard that one of the major challenges in the Tour de France is just that, re-fueling the athlete at the end of the day. I’ve heard they intravenously feed them because they can only eat so much solid food.
The first time I used his system I did it over a month that I had no races. I went from 215 to 200 with no performace loss during training. I’m once again following his system with a goal of losing 10 pounds (200 to 190) by the end of May. I have an Ironman on June 22nd. I started the program 6 days ago and have lost 2 pounds. My water % is stable at 53% – 54%. The key also is the proper mix of fat, carbs and protein based on the type of racing you do. As an endurance athlete my calorie goals are: fat 20%, carbs 60% and protein 20% however not to exceed 139 grams of protein a day (he explains this in his book). Also, it is VERY important to eat often so your blood surgar levels do not deplete causing your body to automatically convert carbs to fat. If you continue to feed your body, it does not fear going hungry and will metabolize food more effectively and not convert all your carbs to fat.
My business partner, a 38 year old female, is in very good shape. She cycles about 250 miles per week. She only eats about 1,200 calories a day. She is 30 pounds over weight! She is starving her body and it hangs on to fat to preserve its health. She is as stubborn as a mule and does not believe me when I tell her she has to eat more to lose weight. She is probably buring about 3,500 calories a day.
When I train I consume all my body can effectively absorb at 400 cal/hours. I drink Ultragen (1st Endurance product) to recover right after training. I learned my lesson the hard way. In my first IM I consumed 1,000 cal/hour (what I was burning) and during the first mile of the run really did a number on the sidewalk and had to walk 7 miles to recover from a very upset stomach. Then doing the el Tour de Tucson, 109 mile century, I consumed 250 cal/hours and become very light headed at the about mile 85. The key is to understand how much your body can consume and only take that amount in during training/racing. Also, I learned from Brian Shea at Personal Best Nutrition (http://www.personalbestnutrition.com/) to only mix drink at a 6% or less osmolity. That will allow it to obsorb quickly. Heavier than that will only take longer. With a 24 oz water bottle that is about 175 calories. When I mix my hydration I’ll put 400 cal in a bottle (one hour bottle) and chase it down with water to create the 6% mix. Give Brian a call (732) 546-8436. He is very helpful. He is also an IM triathlete with a PB of 9:31 in Florida ‘03. He knows his stuff.
If you have any questions, please e-mail me.
Very interesting Mike. I think an important point you made that we should stress is that everyone is different and we all need to figure out what works for us. I figured it out for the 1/2 iron, but understand that the IM is completely different. I’ll be taking this summer’s training seriously to determine what my stomach can tolerate on the run after a long bike. Should be fun…..
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