Why is it harder to ride my trainer?
 

Gday,

Just a question i was hoping somone could answer. Decided to spend some quality time with my trainer last night instead of going out on the road. I have noticed this before, but it seems that on the trainer ( Minoura 850 rim drive) the work out is harder than when riding on the road.

By this i mean that the it seems i have to work a lot harder with my legs to hit a target heart rate that i have set fior the work out ( nothing high, only 150 bpm) that on the road i could cruise around and achieve no worries at all.

does anyone know why this is? is it a trait of rim drive trainers vs a normal trainer?

cheers

Graham.

The road has a bit more challenge to it- working with or against wind, inclines and declines, road surfaces, etc. They all contribute to your riding and heart rate. On a trainer, it's just spinning out the legs, and without those other factors, you'll find that you would have to work a lot harder to get the heart rate up.

Koffee

I think it's about motivation factor.
1 When you're on the road, it's enjoyment, scenery and climbs even bridges make ride more interesting. Ever noticed how you ride better in company of other riders than by yourself?
2 If your room is warm, and there is no fan to cool off, you'll be dripping sweat in no time. Another distraction.
There will be other pointers from other members.

Trainers are differant. Some are harde than the road, some are easier. As Koffee mentioned, the road in your case is offering more challenge.

In my case for example, I have a Performance Fluid Force trainer. It has a progressive resistance designed to it. When I am going 15-16mph on my trainer, the resistance I feel is equivalent to pushing well over 20mph on level road.
I can easily ride several hours on the road on level ground at 20mph. But if I try to ride 20mph on my trainer, I can only last about 10 minutes.

Also, there's a lack of linearly conserved momentum. And there's no coasting. There is only rotational momentum provided by the rear wheel's inertia which is of course counterbalanced by the trainer's resistance unit.

On my trainer, I use HRM to monitor my effort, and cadence meter to pace my cadence, while selecting proper gear for my intention. So the work I put in is similar to on road. Yet I find I do better road work for reasons above.

1) No wind. You overheat and your power limit is defined by how much heat you can dissipate. You'd be amazed how much cooling even a float day has.

2) The roller on a trainer is small; it has much higher rolling resistance than a flat road. Pump your tyre really hard to minimise this.

(Both of which are covered in MIT's Bicycling Science :) )

cheers, thanks for the replies.

did a ride again last night on the trainer as it was raining and yup its definatley harder. Motivation isnt such a bad factor, im motivated enough to do it, also i have fans on me etc and an airconditioner to circulate air so i dont think heat is an issue.

The rolling reisitance theroy makes the most sence to me, as well as the fact that i only need to spin.

OKi guess my next question is , given that i require a higher power output via my legs to maintain set heart rate, is that a training advantage? i.e produicng higher wattage at lower than usual heart rate?

I wonder how that effects my trainer. I'm using a rimdrive trainer and from what I can tell, the amount of effort and work between a rimdrive and tyredrive trainer seem to be the same for me. And both seem higher than when I'm on the road. I'm still standing by the lack of forward linear momentum and inertia theory. When you're moving on the road, you conserve momentum.

The trainer imparts a frictional loss to give you something to pedal against.

Most trainers will also have a flywheel to increase the inertia so the pedaling motion is a little more realistic. This is an attempt to make up for you and your bikes mass being stationary on the trainer.

If you are light with little frontal area and ride a highly efficient road bike this could explain why even a well tuned trainer may require more power at the same speed than you do on the road. Conversely, if you're heavy, wide, and are used to riding your mountain bike uphill in the sand with a strong headwind, the trainer may seem to go with relative ease.

To further complicate things the change in power required by the trainer versus speed probably doesn't match the change in power required on the road versus speed very well either. The trainer may be harder at 15mph than the real thing but easier at 30mph.

For the intended purpose of the trainer none of this matters very much. The typical trainer does a more than good enough job of providing resistance to get a workout which is a reasonable simulation of pedaling down the road. Use your gears to get the desired heart rate at the desired cadence. Don't worry about how fast the tires are spinning. It's a meaningless number unless you are actually traveling at that rate.

I train by heartrate and time as that seems to make the most sense. I actually have no idea of my "virtual speed" or "virtual distance". Also, my computer picks up wheel rotation from the front wheel so there's no easy way for me to measure that anyways. Subjectively speaking, I do feel more worn out after an hour on the trainer than I do in two or even three hours on the bike. I know some of it is psychological as well.

I ride my time, HR and percieved excertion. I do intervals sometimes on the trainer and after 5 - 8 to 10 minute LT intervals and some warmup, down time I am beat. I can sit there for hours though at a normal riding HR and be fine (if I do not get bord first... happens quickly.

Ultimately, the trainer will never be the same as the road for the same reasons the treadmill isn't the same as the road: you're not moving a machine and body through the world. Trainer fatigue, for example, doesn't include bum-numbness from road vibration - something that regularly upsets trainer-heavy riders.

OK, everyone. Expain this one. I can't get the same heart rate on a trainer that I can on my bike. I have a recumbent trainer with HRM. I seem to start running out of breath at around 135-140 on the trainer, and around 170 on the bike. Maybe the HRM's are different, but I wouldn't think that they would be THAT different.

Maybe it's from the ram-air effect you get from your mouth being pressurized due to forward movement through the air. You get more oxygen than on the trainer.

Someone should try a high-speed fan directly in the face while riding the trainer, let us know what happens.