I know a physician’s assistant. She is exceptional at her job and teaches on the side as well. The common refrain is, “those who can’t do, teach”, but magine how intelligent and dedicated you’d have to be to do both… She, like me and several of my friends, is also an avid enthusiast when it comes to cycling. She’s counts her years of cycling in decades. She’s toured the United States on a bike, including crossing it.
So we’re out on a ride the other day, a particularly easy ride because we were coming up on the A-100, and she mentions that we should ride slower on a regular basis because “it’s better for fat burning”. She also added that if you ride too fast, you burn muscle instead of fat”.
Both of those statements have some truth, but they’re not entirely accurate, either. Speed is relative, burning fat off of those stubborn places isn’t.
See, I am an above average cyclist. I spent three years (my lightest three years, by the way) pushing myself so I could be in the fast, above average group. There were countless times I almost covered my top tube in the morning’s breakfast. A number of times I choked up some bile… Folks, I rode hard and I lost a fair amount of weight back then. I went from 171 down to 150 – I’m currently 175 but like to think that extra few pounds are due to my massive legs. Back then, my wife complained I was too skinny, and she was correct. Looking back at photos, I was. I like me between 170 and 175, it’s a good balance. Unfortunately, pulled pork sammiches have a tendency of getting in the way. Let’s not go too far down that rabbit hole, though, because I’m not about to eat like a bunny, either.
The whole “ride slower because it burns more fat” notion is derived from the idea that at a certain heart rate “zone”, a person typically burns more fat… That would be “zone two”. The other side of that coin, as my PA friend stated, is zone 5 or the anaerobic zone – and that zone does burn muscle (and possibly the upper end of zone 4, too). I have to be going faster than 25 miles an hour (with no tailwind to help) to hit it, though. She’s closer to 22 or 23 – and that’s where the “speed” in her hypothesis gets dicey.
My zone two is somewhere around a 17-1/2 mph average. It’s enough to get the blood pumping, but hardly fast enough to call it a workout – and that’s a solo average, just to be clear. Her zone two is probably 15 or 16 mph. My average is a bit higher because I trained my body to ride faster with less energy output…
Now, here’s why I’m a little skeptical about the whole “riding fast burns muscle” idea:
Folks, I didn’t get those guns taking it easy in zone two. Those are all zones three, four and five – with a smattering of zone two in between the hard days as recovery rides so I could still ride every day.
In the end, the heartrate zone training theory is likely sound and based on decent science but all too often the science of the day is twisted to manipulate a desired effort level. A walk, it could be said, is better for losing weight than a jog. There are definitely benefits to walking over jogging (less impact, etc.), but walking to lose weight is vastly worse for getting to the goal, which is weight loss, because it takes one longer to get to that goal.
The reality is, riding slow may be better for thee, but not for me – because I don’t want to ride slow, and it only works if you’ll do it.
Ride hard, my friends. Don’t buy into the hype.