During marathon training, the goal of the weekly long run is to prepare for race day in all aspects - including hydration and nutrition. Over the next 15 weeks, you will have many chances to learn what will work best for you on the day of the marathon. There is no magic answer that suits everyone in terms of which drinks, how often and what quantity, so now is your chance to experiment with these details and determine your hydration plan for key training runs and race day.
Here are the basics. Given that you will be training through the hot summer, hydration will be crucial, especially on long runs. Dehydration has a negative impact on physical and mental performance, and can even lead to sickness or injury.
It's important to keep in mind that hydration starts before you head out the door. The day before your long run, moderately increase your intake of various fluids - including water, juice and sports drinks - to ensure you are well-hydrated for the next day's training. The morning of the run, sip away at a sports drink one to two hours before you lace up your shoes. If you drink coffee, have less than half your usual amount before the long run to avoid frequent pit stops and the diuretic effect of caffeine on your run.
Once you have started your long run, take sips of a sports drink every 3 to 5 km. It's best to start drinking early. If you wait until you feel thirsty, you will already be slightly dehydrated and your performance may suffer for the rest of the run. If you are super organized, drive the run course beforehand and hide water bottles in special spots along the way.
After the run, drink frequent and small amounts of various beverages for the next few hours. You can tell if you are maintaining adequate hydration if you are going to the bathroom every two hours or so and if your urine is fairly clear.
Nicole Stevenson is the ninth-fastest female marathon runner in Canadian history. She coaches many athletes, including 2010 Canadian marathon champion Krista DuChene and is a long-time competitor in the Canada Running Series.