FOOD ON THE RUN
You're planning an active day, so food is an issue. What snacks do you pack? What kind of breakfast do you eat? The answer is easy once you understand how the digestive system works. You can then decide how to fill your stomach perfectly for any day's activity.
If you are going skiing, avoid a big, fatty, high protein breakfast; the bacon-and-eggs-and-hash-browns staple; especially if you're not used to altitude. It takes a lot of energy to digest protein and a long time to do it. A goodly portion of blood is diverted to the digestive system during digestion.
Here is where your skiing endurance and your digestive process start to duke it out. Blood is what transports oxygen, and at altitude, you need all the oxygen you can get. Air is thinner at altitude, and doesn't contain as much oxygen as it does at lower elevations; which is why flatlanders gasp for breath after a ski run. You want to have all your blood ready to carry every bit of the oxygen you breathe in.
A grain breakfast; toast or oatmeal, is quickly and easily digested and good for any day of hard action such as skiing, snowboarding or mountain biking. When packing snacks, though, remember that beef jerky is high dose protein.
For snacks, put together your own version of trail mix, but be sensible about sugar. Don't avoid it, GO for it! Sugar is sugar, whether it comes from M&M's, raisins or other fruit. In fact, that little handful of raisins has as much sugar as a candy bar, (though no fat).
If you are in a sprint-length contest, you can actually use sugar to give you a big burst of energy out of the start; a good thing if you're tired. Chow down something sugary as you are waiting to start. But it's important to test yourself to see how long you can go before the sugar rush wears off and you sag. Some people can go the full length of a skateboard routine, which can be five minutes, some can stay up for a full run of a ski race, about a minute and a half, those who are out of condition will use up all that sugar in 30 seconds. Use a stopwatch to test yourself, noting how long the sugar rush lasts before something starts burning from fatigue.
For long, sustained activity like non-extreme cycling, snowshoeing or hiking, you don't have to avoid protein so assiduously. Munching on strips of jerky and peanuts can keep your energy levels balanced throughout the day.
The most important tip: read the ingredients before you choose a energy drink. If it's mostly water, sugar and food coloring with a little bit of vitamin C; pass it by. The best drink for being active is plain water, but if you're drinking a lot of it, make sure you keep up your levels of salt and potassium.