Got a marathon coming up? A century bike ride? A sunup-to-sunset day hike? If so, is carbo-loading a smart way to fuel your body for the challenge?

In a column published last weekend in Canada's Globe and Mail, author Alex Hutchinson (Which Comes First, Cardio or Weights?; sweatscience.com) cites a recently released British study that tracked the training and dietary patterns of 257 participants in the 2009 London Marathon.

"Sure enough," Hutchinson writes, "day-before carbohydrate consumption mattered."

Details are outlined in Hutchinson's column. A few key findings:

• Depleting carbohydrate stores prior to a major physical challenge then binging on carbohydrates, a process commonly endorsed in the 1960s, is now strongly discouraged.

• A day before the 2009 London Marathon, runners who ate more than 7 grams (0.25 ounce) of carbohydrate for every kilogram (2.2 pounds) of body weight (g/kg) ran 13.4% faster than a comparable group of runners who ate fewer carbohydrates but were otherwise identical (in age, body mass index, training and marathon experience).

• A higher ratio of carb intake to weight (10 grams per kilogram, or 0.35 ounce per pound) is considered best for elite athletes, though consuming such a quantity of carbs can be daunting. A 154-pound runner would have to eat 16 cups of cooked pasta the day before a race to reach that level.

• The use of sports drinks or gels can help raise carbohydrate stores during day-before preparations. See the intake infographic that accompanies Hutchinson's column.

• Hutchinson points out people planning modest activity don't need to gorge on carbs since most people don't deplete their carbohydrate reserves until after 90-120 minutes of vigorous exercise. "That means you don't need to binge on pasta before a soccer game or 10km race," he writes.

• Hutchinson's parting thought: "Whatever nutrition plan you follow, make sure to try it out in the weeks before the competition. Don't do anything new right before the race."

I don't run marathons, but based on Hutchinson's column I plan to up my carb intake prior to my next major long-haul hike. Consuming a gel or similar energy food the night before I launch myself from the trailhead? I had not previously considered such a move. I'll give it a try. What's been your experience with carbo-loading?

Competiton photos by Yitka Winn.