Semi-serious cyclist/exerciser – need help

[lyle1152]

I'm a new poster so if this topic is been covered before just let me know.

Is there a book or guide for a semi-serious exerciser or cyclist on appropriate levels of Carbs, fat intake and calories? Also, I see that several studies show increasing fat on a low carb diet may help in endurance, any practical guide for this?

I originally used the Atkins diet to lose 35 lbs. After the initial weight loss I started exercising allot (4-5 times a week, netting about 11 hours of moderate (70% max heart rate) to high (85% max heart rate). I did not gain much or lose any wight for about 6 months. I honestly just seemed to slowly quit counting carbs and calories (it was not like I tried to go to a high carb diet but I think it just happened – because of sports drinks and power bars…ect)

Due to business and family commitments my level of exercise has dropped. It looks like 5 – 8 hrs will be the limit. Because of the drop in exercise I have started gaining weight and body fat. I don’t think I will be able to give 11 hours per week.

Again, I would like a book or guide to understand the concepts because I might be able to cycle more later so I would like to adapt the diet then too.

Thanks.

[readyami]

I've found it difficult to stay on a real low carb diet at 11 hours exercise. At about 6 hours, I began to have headaches. Active.com, a good resource, says that endurance athletes should get about 15% from protein, 60-70% from carbs, and the rest fats. Here's a link to a recent article:

I did strict Atkins for five months, then started triathlon training seriously, and had to give it up. I have maintained my weight (from Atkins loss) for almost a year at this level.

I will be doing the MS-150 in my state this weekend (cycling 150 miles in 2 days).

I think low carb is a super way to go to get the weight off. However, at higher levels of exercise, and especially long duration exercise, it is crucial for your body to have fuel to burn.

[readyami]

whoops....couldn't find the link...will have to get the article from my home computer.

[Kestrel]

Lyle, if you're going to try semi-serious cycling, etc, on low carb, then remember to get sufficient energy via saturated fats, such as butter. Don't depend on olive oil, etc, as they probably aren't metabolized the same. Don't shortchange on fats, otherwise you won't be doing well.

Remember to give yourself sufficient time to adjust to low carb. Older folks such as myself may well need more time to adjust than younger people.

[Meg_S]

Here is a link for eating for athletic performance

http://www.second-opinions.co.uk/athletic_diet.html

[dug]

fuel is in fat, protien and carbs, not just carbs. carbs are more readily converted to glycegen which is the actual fuel your muscles use, but the other fuels also get converted glycogen for use. I find that at about 50-60g carbs per day is sufficient for triathlon training. Of course everyone is unique so you will have to find the level that works for you. But it sems 50-60 is about what most athletes on here find keeps them from bonking.

[lyle1152]

First, thanks to everyone who responded.

When I find the right carb level for me,, let say for discussion it is 60 grams. What does everyone do on the days that they do high level excercise ( I ride for about 3 hours +- 15 minutes). Do you still keep to the 60? Do you go higher throughout the day or just during the high level exercise period? If it is just during the workout how do you apply the carb intake.

Thanks again.

[Meg_S]

I think that you have to figure that our through experimentation. For example, two years ago I would have had better performance on long steep hikes with a heavy load on the pack if I ingested a lot of carbs. Now.. I do *much* better and feel great with minimal carbs, and extra fat. Minimal = under 20. My body has adjusted to prefer fat for fuel, over time, if you choose, yours might as well... but obviously it's individual.

[PurpleStix]

Lyle, you might want to read the Zone series of books by Barry Sears. Features of his program include:

- it is oriented towards performance and health rather than weight control. However if one is over-fat, the problem will correct itself :)
- 40% carbs, 30% fat, 30% protein
- Protein requirement is calculated from your lean body mass (muscle+bone) and your level of activity. Then carbs and fats are adjusted to fit the formula.
- Eat all 3 macronutrients together in a meal, and eat low glycemic index foods to slow the entry of glucose into the bloodstream.
- There is a lot of information about fatty acids in the diet and their impact on health
- There is a high fat variant for endurance athletes. Sears came up with the 40:30:30 for football players and Olympic swimmers. However, Sears acknowledges that endurance athletes might do better with more fat, while maintaining the ratio of carb to protein.

My experience: A few years ago I did Ironman at 190#, with at least 60% of calories from carbs, high glycemic index foods like bananas and Gatorade, and lots of carb loading. In I never lost any weight at all that year, even though by best fighting weight is 175# and I was training 20+ hours per week :(

Personally, I am going with C:F:P 20:50:30 right now, about 110 g carbs because it is more important at this stage for me to lose fat, and (lucky me) I get ketosis with that fuel mixture. When I get within 15# of my goal, I will likely move towards 40:30:30, and fine tune the ratios at that point. This is just for my martial arts and biking around town. At the moment I have no plans to do triathlons or other endurance events.

Why 40% carbs?
1. I expect it would be difficult to eat and digest >60% fat and protein when there is a high caloric requirement.
2. Full glycogen fuel tank is good, and useful for anaerobic work.
3. IMHO the glucose system is better regulated with insulin than ketones with glucagon. The rapid weight loss in Atkins induction is from glucagon running crazy while its controller, insulin is at low levels. Insulin is a very responsive hormone which can be bad or good depending on your genetics, diet and activity levels.
4. Glucose and ketones are converted to acetyl coenzyme A, then enter Kreb's cycle, where fuel is broken down into energy, CO2 and H2O. I am just guessing here, but there may be more energy available if both fuels are pushing their way into Kreb's cycle instead of just one. That may explain in part why Zone-balanced eating correlates with high performance.

Be warned: in 'Enter the Zone', Sears shows a lack of knowledge about ketosis. He says it is an 'abnormal metabolic state', but later in the book he gives examples of the benefits of high fat diets for fat loss. I did the Zone for a day and tested positive for ketones four hours after the last Zone meal. It is unlikely that he ever tested his athletes for ketones, and they were probably in ketosis part of the time.

I don't know what the best mix is. I just know that it isn't 60:25:15 ;)