I still hate the summer.
But I hate it a little less since I started cycling last year.
Firstly, the time around the summer solstice has to be a boon for any road cyclist. Morning twilight begins at 5:00am, meaning that for my long weekend rides, I can get out on the road hours before the traffic volume starts to pick up. Even better, since the evening twilight hits at 9:30pm, I get three hours of daylight after work that can be spent on my bike. That's plenty of time for a un-rushed 20-40K pedal.
Secondly, the heat affects me less when I'm on my bike. The cooling mechanism of perspiration is greatly helped by the fact that, when you're cruising along at 25-30 km/h, you're creating your own wind. Any water loss is easily made up for with the liquids I carry around on my water-bottle cages. And I just sweat less.
Thirdly, when it's all about food, summer is the time when, for me, cycling matches running in terms of exercise efficiency. Heck, sometimes, cycling is more efficient than running.
(Warning: Math Geekery Ahead)
The math bears that last premise out. In the winter, early-spring or late-fall, it's no contest. Running wins hands down. When conditions are ideal (i.e., below 10°C), I can easily manage an average of five-and-a-half minutes per kilometre over my longer runs. The number of calories burned while running is a linear equation based on distance. You don't burn any more calories by running faster (or vice-versa); it's all about how far you go.
Running roughly burns 1.03 calories per kilometre per kilogram. I burn 81 calories per kilometre. Given a 5:30/km pace, I can get a 10K run done in about 55 minutes. So:
Total calories burned = 81 x 10
Calories burned per minute = (81 x 10) / 55 = 14.72
Calories per hour = 883
On a regular bike ride, I usually average around 24 km/h. If I go for a 25K ride, I'm out there for a little over an hour -- an hour and three minutes to be exact. At that speed, I burn 31 calories per kilometre. So:
Total calories burned = 31 x 25
Calories burned per minute = (31 x 25) / 63 = 12.30
Calories per hour = 738
Based on those equations, I burn an extra 145 calories by running for an hour vs. cycling for an hour. That might not seem like much, but it's all the difference between having a beer with dinner, or not.
But in the summer, the heat really affects my running times. Once it starts getting above 20°C -- like it has every evening this week -- my running times slow down significantly. I ran 13K last night in 1:16:30 and I was a bit of a wreck afterward. (I believe the proper, technical term for last night's post-run condition is 'jibbering mess'.) When I run in the summer, I'm down to 6:00-6:15/km.
Let's recalculate for a hypothetical summer 10K run in an hour and two minutes:
Total calories burned = 81 x 10
Calories burned per minute = (81 x 10) / 62 = 13.06
Calories per hour = 783
My cycling performance doesn't change until the air temperatures hit 30°C. So, we're down to a 45 calorie advantage for running. And only a third of a beer.
But here's the thing. Unlike running, cycling effort isn't a direct function of distance. It's based on speed. When you cycle faster, you burn more calories per minute. And it's not a linear curve either; it's exponential. I even put together a graph:
Once I hit an average of 25km/h for my cycling pace, I'm up to 13.28 calories burned per minute, and right up at the same efficiency as running in the summer. And it's not like that speed is difficult at all to acheive. My 26K bike ride on Tuesday averaged 25.4km/h. When I'm out working on speed intervals, I average 26-27km/h. On flat straightaways, I can maintain 30km/h easily; it's only the preponderance of traffic lights, stop signs and tricky intersections that bring down my overall average speed.
So all this to say that I've been cycling a hell of lot more than I've been running lately. And it's just a hell of a lot more fun.
That's not to say that there are no downsides to cycling. When you're cruising along a nice, flat stretch of road at 30-35km/h, there's no way to avoid the swarms of aphids and gnats out in abundance at this time of year. I must have swallowed twenty or thirty of them on my last ride.
Oh well. Extra protein, I guess.
