Mashing vs spinning.
 

Okay probably this was answered but I might as well ask since you guys bring up threads like Shimano vs Campy all the time.

Anyways.

Here is my question(it's not which is better).

When you are mashing, are you mostly using your heart to go up the hills and when you are spinning are you using your legs more?

It would seem that on spinning you use your legs much more than your heart and mashing uses your heart alot more.

Right?

When you spin at high rpm it puts more load on your cardio system. Lower rpm puts more load on your muscles. Think of it this way, when you are pedaling at low rpm uphill, how long are your muscles in a contraction phase? Compare that to what you'd get at a higher cadence (say 60 rpm vs 85 or 90 rpm). At a higher cadence the contraction phase is shorter. I heard someone explain it by adding that at the high rpm you are bringing in O2 at a faster rate, thus helping to delay onset of lactic acid accumulation and accompanying muscle soreness.

It can take time to adapt to pedaling at 90-95+ rpm if you are not used to it.

For the same power to the wheels, at lower cadence, your leg muscles have to work harder for each stroke. For the same power to the wheels, at higher cadence, your legs move around more, so there's some energy cost associated with that, and your cardio works a bit harder, but your leg muscles can do less work per stroke.

Power = Cadence * Pedaling Force (* constants)

So why is it that when you are mashing, your heart rate jumps through the roof?

Because generally, when mashing, it's because the hill is steep. So you pedal really hard. So much so that the power output goes up quite a bit. Thus the for the same power to the wheels disclaimer.

If you pedal just as hard on each pedal stroke but at a higher cadence, your heart rate should jump even higher since you'll put out even more power.

Your heart rate will always go through the roof if you ride really hard, whatever the cadence.



For a given power output, your heart rate will tend to be higher if you are spinning.

I've tried the following on my trainer before. Pedal at a steady relaxed effort in a relatively big gear (and thus low cadence). Shift down a gear, maintaining the same perceived pedaling effort (based on my legs, not on my cardio). As expected, the cadence goes up. Less obviously, the speed goes up a bit, too. You can tell based on the pitch of the sound the resistance unit makes. It makes sense, though, since with a higher cadence and the same pedaling force, I necessarily (according to the laws of physics) am making more power. Downshift another gear. Same result. A few more times. Eventually, I'm still pedaling at the same relatively relaxed leg effort, but my cadence is now at about 110-120 RPM, at which point I start going anaerobic. I was hoping to find an optimal cadence for my body, but all I found out is that I have chicken legs, and my optimal cadence tends to be stratospheric.

That said, on relatively flat ground, I find that the harder I try to ride, the higher my naturally chosen cadence. Maybe 50 RPM when tooling around in a social ride with friends. 80 RPM for easy relaxed riding. 90-100 RPM for endurance riding like in a century. 110-120 RPM when trying to go pretty hard (but sustainable for minutes at a time). I've found myself naturally selecting cadences as high as 130 RPM when trying to go really hard. Not sprinting... just staying seated and spinning along. I do this because I have chicken legs and have trouble maintaining high pedaling forces. But I can spin along at relatively high cadences with low pedaling force and be much more comfortable. Your balance between cadence and pedaling force may be different from mine, and it may be worth doing a similar experiment on a trainer to see what you find most comfortable and to get a firsthand feel for the relationship between power, cadence, and pedaling force.

I'm still pretty low on the endurance scale. I wind up going back and forth between mashing a little and spinning to give the legs / cardio system a break while the other does the work.

I've been doing a ton of base miles lately to build up the endurance and been working on high cadence drills also. My average cadence for these rides has definitely gone up a bit. We'll see how that translates once I start doing hill work again once I get out of base training mode.

At first glance I thought you meant heart as in `he's got a lot of heart' in boxing or something. I like this reading too though ...

I actually find that lower cadence/bigger gear is better for my recovery. When I am on the front I usually will ride at a cadence of 90-95. When I move off into the draft I will go to a bigger gear and drop my cadence down to 80-85. The bigger gear and lower cadence helps my recovery while drafting and also gives me more torque to cover gaps if they open.

You may have some mental ties to pedaling slow, making it feel more comfortable, but it actually preserves your legs the other way around. It's much easier to accelerate from higher RPM than lower -- just like in a car, so you build less fatigue with each surge. You should always downshift before corners in a pack, and downshift pretty much any time you touch your brakes.

It can be comfortable to feel that pressure on the pedals from low cadence, but it tires your legs faster.

I'm sure your right, but at 50 I don't race and this works for me in fast group rides. My endurance is almost totally governed by my cardio rather than muscles fatigue so this helps my HR recover. Also it is pretty relative I am probably riding at around 20-22mph in a 53/15 when drafting and closing a gap for me is ramping up the cadence to 100 and getting to 27mph quite a bit different than racing.

amen!

I don't know whether I'm just a mutant, but my heart rate goes crazy every time I've lifted weights in the past. Definitely not an aerobic activity, but all the same I find it elevates quite a lot under those conditions.

I guess it depends on your goals, but at 50, you can still do a lot to improve your cardio and get parity with your leg performance. The suffering is so much sweeter when your legs and lungs fail at the same time :)

There's a 55 year-old guy here who is getting top-10 in the local TT series, at 26mph, which is faster than me ;)

Well, the best thing I can do to improve my performance right now is to get more weight off the engine. I have gone from 205 to 185 but I need another 10lbs at least. Don't get me wrong in two years I have gone from being able to manage 18mph to routinely riding in the 20s and holding my own with groups in the low 30s in the sprint zones. I am pretty happy about that but I don't have the discipline or wish to get into interval training and pushing as hard as I know I could.

I do my racing vicariously by reading the posts in the racing forum:)

Yeah, it's more important to keep it fun, and it sounds like you're really improving your overall health :beer:

Find a nice long hill that you can ride in high gear low cadence and ride it at a certain speed like 10 mph. Take a look at your heart rate then shift to a lower gear and maintain the same speed. If you are like me your heart rate will go up but you will feel your legs getting some good rest.

cool good advice guys.

Thanks!!