To breakfast or NOT? This question has been troubling me lately.
_____________________
>"With training and proper diet, the serious athlete can increase glycogen stores in the muscle from 500 Calories to 1,500-2000 Calories."
This is not a trivial thing to accomplish. It requires first and foremost a lot of muscle mass, something that most long distance hikers do not have. Then it requires well timed glycogen depletion followed by loading, the first day of which you will have larger glycogen stores, but on each additional day you will likely not have as much glycogen stored.
Also keep in mind that most of the glycogen stored in your liver will be burned up overnight while you sleep.
>I think it is safe to assume that at start I will have enough glycogen for at least 3hrs
Easily, but to tap into those stores, your body will go into a catabolic state. THAT'S why breakfast is so important. It slows or reverse the catabolic state that we enter overnight, boosting metabolism for the rest of the day, and sparing muscle in the process.
________________________
>Your body won't burn much fat until your blood sugar levels get low enough to signal a lack of ready energy, and this doesn't happen until you burn (or store as fat) all the carbs you've just eaten plus and glycogen stored in your liver. Fat burning is highest in a fasted state. Increasing your protein intake will help spare muscle to make sure you DO burn fat instead of your valuable muscle.
What you are are saying is that to get the maximum fat burn I need to finish using up my carbs and glycogen reserves? If I follow your reasoning then to get max fat burn I shouldnt carry any food.
>Your body burns fat and carbohydrates to produce energy. Carbohydrates are stored in the form of glycogen in your liver and muscles and glucose in your bloodstream. Carbohydrates can be consumed on their own to produce energy via anaerobic energy production. They are also used via aerobic energy production to to burn fat. It's sort of like the relationship between charcoal and lighter fluid. Charcoal (fat in the analogy) burns slowly and requires a higher energy fuel like lighter fluid (carbohydrates in the analogy) to initiate combustion. After the fire is going only a small amount of starter-fuel is required to maintain combustion. I know that personally it takes me about 15-20 minutes of steady-state exercise to shift from burning mostly carbohydrates to burning mostly fat.
http://www.backpackinglight.com/cgi-bin/backpackinglight/xdpy/forum_thread/5516/index.html?skip_to_post=39210#39210
But this says that I need steady small amount of carbs to keep the fat burn going – like I thought.
______________________
>>Your body burns fat and carbohydrates (AND PROTEIN) to produce energy. Carbohydrates are stored in the form of glycogen in your liver and muscles and glucose in your bloodstream. Carbohydrates can be consumed on their own to produce energy via anaerobic energy production. They are also used via aerobic energy production to to burn fat. It's sort of like the relationship between charcoal and lighter fluid. Charcoal (fat in the analogy) burns slowly and requires a higher energy fuel like lighter fluid (carbohydrates in the analogy) to initiate combustion. After the fire is going only a small amount of starter-fuel is required to maintain combustion. I know that personally it takes me about 15-20 minutes of steady-state exercise to shift from burning mostly carbohydrates to burning mostly fat.
I don't know where that reference comes from, but in a fasted state (assuming your liver and muscle glycogen are partially depleted after and overnight fast)) it would take anywhere from 15-40 minutes of steady state aerobic exercise to make the shift from burning mainly carbs to mainly fat. If you've just eaten a lot of carbs, these will also have to be burned off first before you really hit you fat stores. If your liver is also full of glycogen, it will take even longer. Fat burning is not an on-off thing. When you first start exercising after a carb-dense meal you may be burning 30% fat/70% glucose. By the time you've burned off most of your carbs you may be closer to burning 80% fat/20% glucose. You do NOT need any carbs to burn fat efficiently…quite the opposite. But if you are not used to exercising in this state (essentially burning ketones for energy instead of glucose) then it can take time to adjust. This is why a lot of elite endurance athletes now practice "fat loading' instead of "carb loading". Once your body is used to it, burning fat gives you access to greater and more even burning energy stores. This is all in theory. in practice, how much fat you burn will be dictated MAINLY by how many fewer calories you eat than you burn. If you eat carbs all day long, but also burn them off as you eat them, and go do bed with a calorie deficit for the day, you will still burn fat. You just need to be careful that you get plenty of protein, plus 'enough' calories to keep your body from digging into your muscle stores for energy. As a general guideline, a safe amount to cut calories without risking muscle loss is to eat 80% of your maintenance calories (the amount of calories that would keep you at a steady weight). That's not always easy to work out when your hiking though!
>>What you are are saying is that to get the maximum fat burn I need to finish using up my carbs and glycogen reserves? If I follow your reasoning then to get max fat burn I shouldnt carry any food.
Yes, that would certainly get you maximum fat burning, but you would also pretty quickly start burning muscle too. Like all things in life it's a balance. Try and stick to the 80% rule of thumb and you should be fine.
__________________________
Going through these past discussions, it seems to me that breakfast with high fibre/protein/low carb would be best as they are likely to break the fastened state of the body from the night and allows me to go quickly to fat burning mode. Am I getting this right?
