Originally Posted by smoke
so what i’m reading is that the high-protein diet is the wrong thing for cyclists to do (not a problem; i never got on that bandwagon). your main point is to eat carbs right after a ride. i’m currently at 70 kilos, so you recommend 100-105 grams of carbs. that’s about 400 calories. and that will stave off the muscle destruction. does that also increase fat usage?
and you talk about eating on the bike, but you don’t say how much. or when. i’ll usually eat a bowl of muesli ½-1 hour prior to a ride, and i never get hungry, so i don’t eat. my longer rides are usually 3-4 hours. my last long one was 5½ hours, and i never got hungry and didn’t eat until the last hour. should i be eating a few gels every hour whether i feel the need or not? when does the muscle breakdown begin?
Sounds like you're pretty close. No need to change your gym-training, so stick with your current programme. You might want to add some intensity to it, one day in the 5-7 rep range. You should balance gym-workouts with cycling however, more time in the gym should match less time on the bike and vice-versa.
However, not eating on rides and afterwards is where you're losing the muscle. Fat-burning occurs at a fairly constant rate, about 60-90 calories per hour. The muscle breakdown occurs around the 2-hour mark as glycogen and blood-sugar gets low. So while riding longer than 2-hours does burn more fat, you start burning muscle as well and fat-burning drops off after carbs are depleted. The high levels of adrenaline and epinephrine during exercise and high glucagon from low-blood-sugar has the opposite effects of insulin and triggers the break down of fats and muscle simultaneously. In order to keep glucagon low, you need to keep blood-sugar high. Eat 200-calories/hour in gels, energy-drinks, bananas, baked-potatoes, etc. This wards off the muscle-breakdown and allows you to continue to ride past 2-hours and keep on burning fat at a higher rate. Also adrenaline and epinephrine is part of the flight-or-fight response and suppresses feelings of thirst and hunger; your brain is on drugs! This is the dopamine effect that gives the "runner's high". Recall the heroin rat experiment...
Total fat-usage is based upon total-calorie burned daily due to the limited rate at which fat-conversion and metabolism can occur; about 1000 calories per day. In order to burn this many fat calories, you have to burn off a total of about 3500-4000 calories per day (120-150km). That means you have to eat 2500-3000 calories. This requires a medium level of fitness. I wouldn't worry too much about burning more fat, that's pretty linear with exercise below LT (time and mileage). To burn more fat, just ride more, but make sure you supply carbs to match.
Based upon your total calorie intake, in order to maintain a certain calorie-deficit, say -500/day, I'd recommend the following breakdown:
2500 calories total = 15-20% fat, 45-55% carbs, 30-40% protein
3500 calories total = 10-15% fat, 50-70% carbs, 20-25% protein
5000 calories total = 7-10% fat, 70-80% carbs, 15-20% protein
There's nothing wrong with protein-intake, just low-carb is the issue. Various studies show up to 2.0-2.5g/kg of protein body-weight daily is where the protein-intake plateaus with minimal benefits after that for serious body-builders. Cyclists don't need that much, so about 1.0-1.5g/kg body-weight is about all you need to rebuild muscle-tissue. Cyclists' goals isn't to build more muscle-mass anyway, just enough to balance what's lost. Again, more protein doesn't seem to cause any adverse effects as long as you've got sufficient carbs.