For most athletes the long ride is the most important element of training for triathlon. Biking is the longest portion of an event and the fitter you are the easier the run will be. Here are some quick tips for training the long ride in winter in Canada.
The Ride
Our long distance athletes are riding in the range of 2hrs in January , a duration that will remain through the winter while the ride itself will increase in intensity. From my experience riding over 2hrs indoors can have an overall negative effect on a majority of athletes due to the mental toll, adversely affecting their overall motivation. Building to two hours of hard-ish riding will set you up for a 2.5 to 3hrs start up outdoors in the spring. Remember that there's no coasting indoors, it's hotter, and harder mentally, hence the endurance difference. The only element not trained indoors is the shoulder musculature from handling the bike; another reason to do your strength work. All that said if you love riding 3 hours indoors go for it! Initially your rides will be done almost all at an easy intensity (zone 2). To add some varience to these rides consider adding in some standing portions. They don't have to be intense; just enough resistance to controls the pedals as opposed to having to push down hard.
Nutrition
If you are going over 90 minutes on your long ride it is highly recommended to supplement carbohydrate. This gives you a chance to experiment and learn about the fourth sport, race day nutrition. Your starting point for experimentation is an intake of 1 gram of carb per kilogram of body weight per hour. So if you weigh 70kg you should take in 70 grams of carb per hour. Try that and see how your stomach handles it. If you find you can do more that's awesome! If less, maybe try different foods. Indoors in winter this food can be anything you can easily digest since you can have it on a table beside you - sandwich, bananas, baked/boiled potatoes, rice bars/cakes. Outdoors in spring the foods will switch to be closer to those you will consume in your event itself. Included in the gram count is any fluid replacement drink you consume, something that is recommended as well to top up not only fluids but electrolytes. Don't start consuming your food till you've been riding for a half hour to allow your system to settle down on the bike; this goes for racing and training. Most athletes will also benefit by having a variety of flavours and textures to stimulate the appetite. There's something called flavour fatigue that can happen which has the effect of shutting down your intake mid-ride which is not a good thing.