"The challenge of weather for the marathon is more significant than for many other events," he says. "That said, we love Canada. The issues we really modify for our athletes are ones of footing or safety."
But despite the cold temperatures in southern Ontario, Gillis does almost all of his running outside.
"With the mileage that I do - which is over two hours of running a day - I prefer to be outdoors," he says. "The time seems to go by faster. It's all about preparing before you go out the door and making sure that you dress properly."
Eric runs over 200 kilometres a week now - and that will increase in the coming months. Aside from the actual running, there's core and stability work, recovery, massage and physiotherapy as well as psychology and motivational sessions.
"So when you bring it all together, it's more than 40 hours a week," Scott-Thomas explains. "It's a full-time job."
A full time job - with a few perks. For Gillis, one benefit is that he gets to enjoy a lot of food.
"One of the things I enjoy about running this much mileage is that I do get to eat a lot. I look forward to my shake after every morning run, it's banana, chocolate, milk and peanut butter, lots of peanut butter," he laughs.
Good nutrition is part of the plan, along with competition day weather conditions in London.
"We expect temperatures in the high teens, maybe around 20 degrees," Scott-Thomas says. "The difference between start to finish can be four or five degrees, so you have to be prepared for that. But in reality, we also have to be prepared for extremes."
It's a combination of preparation, passion and hard work for Gillis and the other Speed River Track Club athletes gearing up for the Summer Olympics in London. Visit our international cities index to get instant updates on weather conditions around the world.