by KWalker on Wed Jan 30, 2013 7:09 pm
I have to correct a few things here since Racing Weight relies on some bad BMR calculators/usage and some old broscience. In general it has some good guidelines, but gives calorie calculations that are too high and misinterprets research on a number of subjects.
For BMR use 14-16 cal/lb for maintaining weight, 11-13 to lose weight. In general, it is recommended that endurance athletes aim for 4-6g/kg/day of CHO, but this bumps up towards 7 for hardcore endurance athletes and under for those that ride very low volume. With this and your BMR as well as free calorie tracking software it is very easy to figure out how to be in a deficit, fuel your rides, and make sure that you are on track. Lyle McDonald has some excellent articles on how this accounts for the thermic effects of food and activity as well as general activity factor. Add demands of rides on top for total calories/day and end up with a moderate deficit. I find 500cal is good because you will make errors portioning throughout the day and it allows for variance up or down.
As for PWO shakes, Alan Aragon lots of others have some great info on this myth of broscience, which I practiced for many years. The studies on the subjects were all done on FASTED subjects (15hr fasts or more) who were put through depletion protocols first. If you are not fasted when you start exercising and have a decent amount of liver glycogen (even after sleeping), your stores are fine for all but the longest and most intense workouts. Also, the magic window is then not magic. Your body can get glucose from a meal for up to 6 hours after, so you will still be processing glucose from the meal during your riding and often times after it as well. The glycogen replenishment rate does double after exercise and GLUT4 receptors are apparently more active, but they stay active for a long time after and you remain insulin sensitive for quite some time after as well. In many cases the drinks that bodybuilders slam are way too high in calories and simple CHO to shuttle the majority to muscle glycogen stores and many sugars are metabolized by the liver and turned into lipids, especially fructose. Fat cells are equally sensitive to storage and CHO can easily be stored as fats at this time.
So as a whole since you can only replenish around 75g of CHO to glycogen during this not-really-a-window-window a decent meal with around that much CHO is ideal. If its a big ride, have another an hour after and so on. If not, don't worry about it.
Also, studies show that there are NO performance differences in meal composition after training whether it be CHO only, protein only, or protein/CHO. The only differences were found when athletes were given several exhaustive workouts within 8hrs of each other. Otherwise, the body replenishes at a fixed rate unless you do an extremely high volume of work, in which it raises slightly on average (think pro tour riders or distance runners who simply HAVE to eat more CHO than normal to do what they do). In addition, studies have found that a moderate portion of fat does not impair absorption during this period as well.
My general recommendation to people is center CHO around your rides in portions that your body can absorb and utilize. Eat most of your CHO after and in the evening as replenishment rates are slightly higher then and studies on several different active and non-active target groups indicate that evening-predominant CHO intake leads to less bodyfat gain/more bodyfat loss, more weight loss, better biomarkers, increased energy, and higher reported happiness.
I do not have time at work right now to Evernote this, but Lyle McDonald, Alan Aragon, Layne Norton, and others have some good resources in this regard especially Aragon's research review (which has one article that pulls together every study on the magic window and rips them apart, as well as others on what can and cannot use before, during, and after exercise).
What this would look like generally:
Before workout if AM: I wouldn't wake up an hour early to get a mondo breakfast unless its a big/draining ride. You won't re-top up liver glycogen during this time and if you have been eating well all along should have enough glycogen to fuel your ride.
Before workout if PM: Eat well throughout the day- you can absorb 50g of CHO as glycogen every 60-102min, so its fairly easy to get what you need from well-rounded wheels with healthy, least-processed starches. 2-3hrs before you can get away with a bit more CHO so have a diverse meal with enough starches to fuel your workout, but I wouldn't go over 75g of CHO unless its a big, long workout. You can also choose to snack beforehand by hunger, using dried fruits or small things that are easy to process (100-200cal) in time.
During your ride eating depends on the ride. People advise a 50% replacement rate, which is hard for me to hit. I find that in a 2 hr ride a bar and a sports drink is what I can do for normal rides. If its vo2 work or hard shit, its basically gels, sports drinks, and dried fruits. Longer than 2hrs and I attempt for 1.5 bars an hour just breaking them in half and eating every 30min. You body will use some of this as glucose for fueling your ride, and the rest will help spare glycogen. Not eating does not make you burn more fat for fuel. It just makes you deplete more glycogen and slows recovery. Fat usage is determined by individual physiology, your training, intensity level of the ride, and various fitness markers. Fasted low output training can be useful upon waking for those concerned ONLY with weight loss in the base period doing relatively low intensity. Anyways, eat during your rides, whatever it is that is CHO rich to keep you fueled. Avoid fiber, lots of fats, and proteins as they are difficult to process and utilize for energy in the short term.
After your ride: As I said above its pretty easy. If you burned 1000kj and one big meal puts you at your mark for the day then that's all you have. If it doesn't, eat by comfort aiming to hit your energy totals and daily intake. If you did something really hard or killed a ton of KJ, try to follow up the big post ride meal with another if you can, but if it impedes a nap, sleep, or other recovery don't fret it.