Water, carbohydrates, and electrolytes are key to long duration high-intensity exercise. Caffeine tends to have ergonomic effects. A recent review (Burke 2008) is pretty detailed on this topic.
Bicarb and other buffers work to increase lactate threshold. But the response/negative response to the dose is individual. Most people don't get it right and thus negate any positives.
From a carb perspective, adding carbohydrates to a diet, as opposed to protein or fats, has several advantages. Leptin, insulin, and blood sugar levels are being up-regulated, but due to the temporary lack of enzymes, the body is unable to store body fat. The body’s first order of business is to refill glycogen stores, which takes about 24 hours. After that fat storage starts.cycling nutrition
The use of a carbohydrate source that contains glucose (as glucose, sucrose, maltodextrin) in combination with fructose in a glucose: fructose ratio of 2:1 has been shown to maximize carb availability. That only leads to performance benefit if you are exercising for more than 1.5 hours when glucose availability becomes an issue.
Carb cycling works best for people who are already rather lean. (Males under 10 % or females below 16% bodyfat.) If you are not at that level, a traditional diet will serve you just fine.
From a calorie perspective, the first step in the process is determining your weekly calorie budget, and to do this, we’re going to calculate your total daily energy expenditure (TDEE). Here’s part one of the equation, which involves determining your basal metabolic rate (BMR), or the calories you need each day just to live – your coma calories, if you will:
Men = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years)
Women = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)cycling nutrition
The amount of calories you consume is determined by macronutrients or “macros.” Protein, Carbs and Fat makeup macronutrients and they are the 3 factors in fat loss and muscle gain. Each person has a different amount of macros needed to achieve their goals.
Don’t stressfully discipline yourself ‘not to eat’ as well as count calories as well as putting yourself with an unrealistic starvation diet plan. The nutrition plan depends on what intensity the ride is at. If you're climbing a lot of hills in that 48 miles, then you will have periods of relatively high intensity, which will mean more calories are burned, so you might need to eat something to keep you topped up.
However, if the 48 miles is over rolling/flattish terrain, then 48 miles in 3 hours is low intensity for a seasoned cyclist, meaning fewer calories are burned, so less important to bother taking on board food.
You're going to have to trial and error it, to see how your body copes and how you feel. You could also base it on time (rather than miles), and assume that your body should have adequate glycogen stores for 2 hours - so if you're out for 3 hours, then consider eating something halfway through. Not sure that 4 Jelly Babies is enough in this scenario though. cycling nutrition
But, if you are only cruising along, on a relatively flat course for 3 hours, I wouldn't bother with any additional energy products, as it better to get your body to adapt to going without for this intensity of exercise.
Your diet and training have to be in proper order first. If those are dialed in, then some people respond well to supplements on top of everything else. Therefore, most supplements don't really do much extra for you. But overall, supplements aren't worth the money other than for convenience.