Measuring fitness by using a turbo.

chrisw12

I've had enough of trying to measure where I am(fitmess wise) by using outdoor means and want something a bit more controlable.

Am I right in thinking that if I

1) Keep the tyre pressure constant
2) Keep the turbo settings constant

then I can use speed/distance travelled (on my rear mounted computer) to see if I'm progressing?

In other words, if I do say 7 miles in 20 mins one week then do 7.2 miles the next week, then I have made a progression.

It seems too obvious/easy, but I feel I'm missing something.

phil s

Wouldn't you also have to keep temperature constant and make sure your hydration/rest levels are broadly similar as well?

BeaconRuth

With my physics-teacher hat on, yes of course you can. If all conditions are the same and you deliver a greater amount of work in the same amount of time, then you've achieved a higher average power. You could look at speed, cadence or distance - all would be a perfectly adequate means of understanding whether you're improving or not.

As a tester, Chris, you're really quids-in when you've got records of your turbo sessions going back over a period of time, with race performances to match up against different turbo 'outputs'. Knowing exactly what I can do on a turbo in terms of cadence for given settings, is absolutely critical to me - and I know all the settings and speeds/cadences for the different intensities for different types of training. So if it's a threshold session, I know it's resistance X with gear Y and cadence Z. If I can achieve cadence Z+1 that represents a great improvement! It may seem sad, but it motivates me anyway. :oops:

I haven't raced yet this year but through experience my turbo is telling me pretty much how I'm going. I can't deny it's a bit nerve-wracking until I get out there and prove my legs are still there though! :oops:

Ruth

NJK

chrisw12 wrote:

I've had enough of trying to measure where I am(fitmess wise) by using outdoor means and want something a bit more controlable.

Am I right in thinking that if I

1) Keep the tyre pressure constant
2) Keep the turbo settings constant

then I can use speed/distance travelled (on my rear mounted computer) to see if I'm progressing?

In other words, if I do say 7 miles in 20 mins one week then do 7.2 miles the next week, then I have made a progression.

It seems too obvious/easy, but I feel I'm missing something.

If 1 & 2 are the same as well as how rested or motivated for the test you are then yes.

You could also track heart rate over the same speed and distance.

Maybe increase the test to 30mins as this will include a more aerobic contribution to the test and i would reccomend tetsing every 4wks.

chrisw12

BeaconRuth wrote:

With my physics-teacher hat on, yes of course you can. If all conditions are the same and you deliver a greater amount of work in the same amount of time, then you've achieved a higher average power. You could look at speed, cadence or distance - all would be a perfectly adequate means of understanding whether you're improving or not.



I haven't raced yet this year but through experience my turbo is telling me pretty much how I'm going. I can't deny it's a bit nerve-wracking until I get out there and prove my legs are still there though! :oops:
Ruth

Thanks Ruth (and others)

The bit I've bolded is why I posted in all honestly. Did my first proper race and was poor. My exterior indicators (normal training loops, training times etc) suggested that things were going fine. I've realised that my training needs fine tunning now and it seemed ideal to use the turbo as a consistent guide.

You say about nerve-wracking and to be honest I've lost a lot of confidence which I think I'll be able build back up with the turbo and seeing real increases and not increase induced by wind speed etc.

nmcgann

chrisw12 wrote:

I've had enough of trying to measure where I am(fitmess wise) by using outdoor means and want something a bit more controlable.

Am I right in thinking that if I

1) Keep the tyre pressure constant
2) Keep the turbo settings constant

then I can use speed/distance travelled (on my rear mounted computer) to see if I'm progressing?

In other words, if I do say 7 miles in 20 mins one week then do 7.2 miles the next week, then I have made a progression.

It seems too obvious/easy, but I feel I'm missing something.

Naa - it's time to buy a power meter

Neil (just teasing!)

SteveR_100Milers

Chris, I was trying this during the winter, especially as I got a fluid trainer with a fixed proportional resistance that I believe is supposed to represent a typical resistance of an average sized rider on the flat on a windless day....Even trying this approach, and still getting my HR into the high 80%'s for some reason the sessions on the turbo do not seem to translate into an improvement on the road. The only way I can go faster is to ride outdoors on hilly loops (like today which hurt like hell after so long off the bike) and timing myself up the climbs which provides the motivation.

Which event did you ride by the way..? Did you do the PTW 2 up 25 last month? I would have done but couldnt ride, and since Ive lost 2 months then I have given up any ambition for the Welsh champs and the BAR this year...

Alex_Simmons/RST

While the concept of using speed on an indoor trainer as a proxy for power makes sense as it should provide a repeatable resistance, the problem is that most turbos don't. I'm not talking about the tyre pressure or number of turns on the resistance knob etc.

All trainers heat up over time and they all are vary their resistance vs speed relationship during your workout as a result. Some more than others. Even the high end ergo brake controlled units like Computrainer need some time to warm up before they settle down to providing a reliable power resistance level. Some units like the Kurt Kinetics are pretty good as well after a good warm up. Other units are terrible in this regard and constantly drift in their speed vs power relationship. Fluid trainers are notorius for it.

So, as a rule of thumb, you need to make sure your unit is well warmed up before you perform such tests or interval efforts, or you have a turbo for which this common phenomenon is well understood and/or is less susceptible.

The other point is that riding on the turbo doesn't replicate the actual feel of riding on a road and as such many people cannot produce the same power on a trainer that they can on the road (usually lower on a trainer but not always).

Now for many there is a typical ratio of trainer power to road power and getting better on one = getting better on the other, so it might be a moot point but on some trainers (like low inertia mag units), the power difference between trainer and road can be so large I question whether this relationship can break down.

As a corollary, the more you ride the turbo, the better you get at riding a turbo since you get used to the different feel (vs the road). This adaptation is not always translated to the road as it is a turbo specific attribute.

Used well, (good) turbos are very effective training tools and enable the most time efficient training.

chrisw12

Thanks Alex for the comprehnsive reply.

I had noticed that my turbo seemed to get easier as it heated up so what I do now is make sure I keep every trainng session the same by warming the turbo up for a set amount of time.

I appreciate what you (and Steve) said about training on a turbo will make you good at racing on a turbo (or words to that extent). Tbh the turbo time will be a small percentage of my traing time, I just want to use it for thhe classic 6x4min intervals. I'm hopeing that if I see an increase in these over the next 4 week block, then I will see an improvement in my pathetic 10 times.

BeaconRuth

Alex_Simmons/RST wrote:

...... it should provide a repeatable resistance, the problem is that most turbos don't..............All trainers heat up over time and they all are vary their resistance vs speed relationship................... Other units are terrible in this regard and constantly drift in their speed vs power relationship. Fluid trainers are notorius for it..........The other point is that riding on the turbo doesn't replicate the actual feel of riding on a road...... this adaptation is not always translated to the road as it is a turbo specific attribute...........

What a shame you said all that before you said -

Used well, (good) turbos are very effective training tools and enable the most time efficient training.

Of course not all turbos are accurate - but for many people they are accurate enough. I won 2 national championships by training on a fluid trainer that you point out is notorious for having a constantly drifiting speed vs power relationship. If I can get to a good standard of fitness with such an inaccurate turbo, surely others can too?

I assume what you're really trying to say (because you've said it so many times before) is that the only way to measure your performance accurately is with a powermeter - which is of course true. But for most of us is it necessary (I realise it might be desirable) to measure our performance that accurately?

Ruth

Mike Willcox

Any form of interval training which stretches your limits whether it be for 2 x 5 minutes with a 2 minute rest or the legendary 2 x 20 (boring on a turbo) or 30/45 second sprints all of which are trained for until the effort cannot be maintained will improve speed and endurance.

My gear selection and turbo selection are governed by my ability to struggle to sustain 100 rpm (ingrained - no need to measure) for the longer intervals and for sprints (when I get around to it) top gear max effort, max cadence.

It is the senstaion and feel of the effort required in the longer intervals for more than 5 minutes which can be translated to the road in a TT. IMO long intervals on the road do this the best. Measuring power would make no difference to me.

Alex_Simmons/RST

BeaconRuth wrote:

What a shame you said all that before you said -

True - give me a break!!

However the OP was really about whether the turbo could be an objective measure of performance change, rather than about its efficacy as a training tool.

Hey my sentiments about turbos are they are great for focussed training and like all forms of training - know thy tool so that you get the best out of it. Turbos are especially good for the time limited and/or weather constrained athlete and are far safer than riding the roads. Some of my clients actually prefer the turbo. I think they're sick, uhm I mean special

I was just pointing out some stuff so people know thy tool a little better and when "iso-speed" may not be actually "iso-power". Close enough (i.e. the speedo reading on turbo) is definitely good enough for the purposes of targeting the specific physiological adaptations sought from a workout (as long as the drift ain't too far out of the ballpark). But it might prove to be a misleading when attempting to use it as an objective measure of performance change.

BeaconRuth wrote:

If I can get to a good standard of fitness with such an inaccurate turbo, surely others can too?

Absolutely! I have a client that does >70% of her annual training volume on a turbo and made the podium at US elite championships (although she does use a power meter too ). Again I was referring to the objectiveness of a turbo's speedo as a measure of performance change rather than it's efficacy as a training tool.

BeaconRuth wrote:

I assume what you're really trying to say (because you've said it so many times before) is that the only way to measure your performance accurately is with a powermeter - which is of course true. But for most of us is it necessary (I realise it might be desirable) to measure our performance that accurately?

The only measure of performance is performance itself.
A power meter is the only objective measure of one's power.
Accuracy can be debatable at times (know thy tool).

With a turbo, you would be more concerned with precision than accuracy, which is what the OP is really asking about.

I have also said that you don't need a power meter to train using the principles of power, especially on a good turbo.