2x20 Outside vs Trainer...?

Triathlon Forum
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I normally do my weekly 2x20min interval session outside. There is a nice stretch of road that I can hit without stopping for about the right amount of time, turn around and come back. My HR is right around 150 for this workout.

Just now I tried to do the same workout on a trainer. It was KILLING me to keep my HR above 135. It literally felt like I was working my ass off 5 times harder than outside, but at a much lower HR.

Is this normal? Is the workout worthless if I don’t hit ~150 for the 2 intervals? Or should I just not try to do an interval session on the trainer?

FYI, max HR ~187, 40k TT avg HR ~158. I think I used one of Dr Coggans formulas to come up with the 150 target for the interval.

Any help appreciated.

Thanks,
Sean

2

at high level riding, namely threshold work, I find that I go about 5 beats lower on the trainer than on the road bike, consistantly

my coach adjusts for this, my HR levels on the trainer is different than on the road

this is probably common I suppose, I do 60% of my training and most of my hard riding on the trainer, year round, and have adapted to it (two+ years of this trainer program)
.

3

I’d suggest three things:

  1. Guide yourself by perceived effort (PE) for the first few sessions on the trainer. Stay in tune with your pulse, make note of where it drifts during the session, but don’t worry about it.

  2. Sustained power output – or average speed, in the absense of a CT or PowerTap to measure wattage – is the important metric to record & analyze for cycling, not HR. Start recording how far you travel for your 20-min intervals, and/or switch to timing yourself for 8-mile efforts instead, recording your times for future comparison.

  3. Compare trainer sessions to trainer sessions, and your outdoor rides to other outdoor rides. “Relentless progression” is the goal, so just baseline each type of session separately and drive yourself toward relative improvement every single week.

Whatever you do, keep up the intervals! You’d be surprised how few triathletes actually have the discipline to incorporate them consistently into their training, and your relative improvement should keep you motivated!

-Mike

4

I find a similar trend, where my percieved exertion goes up for a given HR on the trainer. I think one reason is that it “sounds” like I’m working harder since I can stay more in tune with my body. I notice how much I’m sweating, I’m can hear my breathing, I can feel my heart beating. It’s just plain mentally easier to ride outside, which plays into the “percieved”/subject part of it. It also is physically harder to ride indoors as there is no coasting, and no wind to cool you.

I’m curious about your HR being so much lower than your TT hr. My 40K TT hr is 183, and I just did a 2 x 20 yesterday with a 179 bpm and a 180 bpm. Does that mean I’m going too hard on the intervals? Can you find where you found that target HR?

5

Personally I cannot go nearly as hard on the trainer. You think about and notice the pain so much more.

Good on ya for doing the 2x20’s. I try to do a set at least once every other week. I’m still slow, but getting less so.

6

I have this same exact problem. Both my HR and Power are reduced on a trainer vs. the road. I wonder if it has something to do with the constant resistance of the trainer versus always constant changing condinditions on the road…

Whatever it is, unless there is snow or ice on the ground, I’m outside.

7

My Max HR should have read 175, 187 is my run max hr.

Anyways, the formula I used was something like:
Take your 95% 40k TT HR, this is about your LTHR.
add 5 to that number, thats your target tempo HR, -10 is about your endurance training zone, -30 recovery.

I found that this correlates pretty closely to my zones as described by the karvonen formula.

Ideally I’d be using power, but that’s something I can’t afford right now.

Sean

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This is commonly noticed. Coggan has replied on other forums that they effect has to due with (and I’m paraphrasing from hazy memory here) that it has to do with reduced momentum of the trainer versus on the road. He says this can be reduced by using a trainer with a bigger fly wheel.

9

I now understand it’s a pretty common thing. My question is how should I deal with it? Are the physiological adaptations gained from a 2x20 trainer session that is 10-15bpm lower than a session outside the same?

Sean

10

Several comments:

Stated max of 187, 40k TT of 158, inability to elevate HR to 150 HR

Comments:

*Delta between max and 40k TT too great. Proper training would reduce this.

*Work intervals at 150HR—again, this number seems very low given the max you indicate, unless these are early season cruise pace efforts.

*Should not be any more difficult to elevate HR on a trainer unless it is a device that does not offer progressive resistance similar to road. Cyclops fluid and blackburn magnetic trainers are two such devices that are not viable training tools. Something definitely out of wack if working like a dog at 135 HR.

  • If anything, a good indoor training device, such as a computrainer, wind-resistance windtrainer, Tacx, should make it easier to elevate HR because it eliminates distractions and variables like potholes, wind, road surface, etc.

  • 2 x 20’ intervals on a trainer an exercise in tedium. Better to break up the intervals into shorter efforts, anywhere from 1.5-4min, and you can vary the intensity slightly from one interval to the next using HR zones relative to Lactate threshold, a number which can only be determined by a test or a workout protocol and not some contrived formula involving subtracting your age, etc.

11

Both my HR and Power are reduced on a trainer vs. the road.

The relationship between power output and speed is EXACTLY THE OPPOSITE when you are on a trainer vs. when you ride on the road. Anyone who has ever downloaded data from a PowerTap from each type of ride knows exactly what I’m talking about.

Think about it: How do you go faster on a trainer? Simply by generating more power. How do you go faster on the road? By riding downhill or with a tailwind. However, when the grade descends or the wind is behind you, you are actually generating LESS power.

Want to generate tons of power on your bike outside? Do hard hill repeats, and of course your average speed will take a dive.

Bottom line: Do trainer rides AND outdoor rides. Compare similar rides over time using the metrics that you track (HR, avg speed, power output). And finally, maintain focus on “relentless progression” every single week across both types of workouts.

-Mike

12

Stated max of 187, 40k TT of 158, inability to elevate HR to 150 HR

Yeah, my max bike HR is more like 175, though that is an estimate based on what I’ve seen. Run maxHR is a tested 187

It did feel like an exercise in tedium:) I’ll try some shorter intervals on the trainer.

*Should not be any more difficult to elevate HR on a trainer unless it is a device that does not offer progressive resistance similar to road. Cyclops fluid and blackburn magnetic trainers are two such devices that are not viable training tools. Something definitely out of wack if working like a dog at 135 HR.

Its a nashbar fluid trainer. Does this fall into the category above?

Thanks,
Sean

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Sean, the fluid trainers are not any good sorry to say.

I have done a lot of indoor training over the years to say the least, and would not even bother to do an easy spin on such a device—lousy feel, tough to get in a rhythm, gear changes produce disproportionate resistance, legs just feel like they are mashing, etc. I will not coach an athlete who has such a device either, simply because they will not be able to do the prescribed workouts, similar to what you have experienced.

To the extent you are interested in the concept of indoor training, you might review the many articles I have written on the subject–can’t seem to do attachments here so you can see them on the link below.

In the interim, I would do my intervals on the road versus frustrating yourself with a less than optimal workout on your current trainer.

www.triathloncoach.com

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Mrbotiggles, I’m no expert but I have similar nubers to you and time trialing once/twice a week this season I think I’ve got my numbers pinned down.
My run max is 182 and like you my bike max is about 175 although never tested I presume I could get it nearer to 180 if pushed. Anyway I’ll ride a 40km tt at an average of 164. 10 mile tts 23 mins ave hr 166( I’m hoping to get this figure higher with a proper warm up.) If I’m doing intervals then I’m between 155-170depending on length. I found that the only way to raise my heart rate when doing intervals was to do them on a slight drag and to keep on timming myself. I hope this helps.

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Dude, I have a nashbar fluid trainer. Those things are not calibrated correctly at all. At the low end, the resistance is close to outside, but it slopes up way harder than outside. My 2 x 20’ on an the trainer is something like 18.5 - 19.5 mph, outside it is more like 22.5 - 23.5 mph. It’s like pedaling through syrup. I don’t know if that’s a bad thing or not, just an observation.

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Dear Oracle, it is hard to imagine any plausible basis for your blanket statement that intervals of 1.5-4min duration have no relevance for a triathlete.

I consider myself a triathlete, and for many years the aforementioned intervals have formed the backbone of what most would consider pretty strong bike performances; 4hr34min in Hawaii, fastest overall bike splits at IMC, IM Japan are examples.

Other triathletes who also make regular practice of the intervals I reference, in workouts that I provide are Gina Kehr, 9hr23 IM, top 10 Hawaii, 2nd IM Germany-France-USA, Mary Uhl 2nd IMW, and world champion Karen Smyers.

Done properly, the shorter intervals and varying rest intervals can be practiced for many months while realizing faster and more far-reaching improvement that is produced by the monotone training that too many people practice.

An important added benefit is that such improvement is realized without a notable change in training time investment; time being the primary limiter for so many triathletes, cyclists.

Allow me to clarify on the subject of viable magnetic trainers; the ubiquitous non-plug in magnetic variety (blackburn and others) do not offer progressive resistance where the pedaling gets more difficult as you either pedal faster or shift into harder gears. Fluid trainers do get more difficult but at a rate that is grossly disproportionate.

The Tacx plug in model that measures watts, and the computrainer are magnetic but do offer road-like feel and progressive resistance—good things and elevating HR is not a problem.

If you are interested in learning more detail and examples of the training I cite above, you can reference articles I have written at www.triathloncoach.com. Relevant articles include:
Indoor Bike Sanity, Rethinking Base Training, Training Backwards the Pyramid Turned Upsided Down.

18

The duration of the interval means nothing by itself; you need to know the total number of intervals as well as the rest period between each.

16 x 2:30 @ 40K TT intensity w/1:30 recovery is one example of a very effective set. As for the “2 x 20min” interval that started this thread, I’d be doing 10:00 recovery in between each interval.

-Mike

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Thanks, everybody for the advice. Until I can get a better trainer I’ll be trying to do my intervals outside.

Unfortunately, that will be quite a while:)

Sean

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Sean,

Something noticeably absent from your comparison is cadence. If you have a higher cadence on the road, compared to your trainer set, your HR will be higher on the road due to the increased cadence. When you stated that you feel like you are pedalling through syrup (or something like that, I don’t remember the analogy exactly) on the trainer…that again makes me think you are dropping your cadence while on the trainer.

Match your cadences AND your Perceived exertion, and I think your HR will come into closer ranges when outside compared to inside. There will always be the mental aspect of PE that can throw a wrench into this, but, X watts generated at Y cadence should result in nearly equal HR (as long as you are cooled similarly), regardless of whether you are inside or outside.

21

There are 2 main reasons why typically riding on a trainer feels (and is) harder than riding outdoors: (1) Heat load–when one rides outdoors, typically your body has no problem with excess heat, as it is siphoned off by the cooler air flowing around you at 20+ mph. Indoors, there is no way to easily do this, unless you set up an army of industrial fans around you. Excess heat absolutely affects the body’s work and efficiency as it has to shunt blood to different places (a lot more goes to the skin for cooling needs) and many of those places are not working muscles.

(2) Momentum: unlike riding outside on flat (or rolling) surfaces, when you ride on typical trainer, the mass and momentum of you, your bike, and (front) wheels play no part in your motion. So if you stop pedalling or reduce pedalling force even slightly or even momentarily, the trainer unit (and rear wheel) immediately begins slowing down (and will quickly come to a stop if you let it).

And, unlike riding outside, when you ride a trainer you must constantly pedal and apply force throughout the entire pedal stroke, including the top and bottom of the stroke (where a lot of us typically slack off on the outside on the flats). This is because the only moving parts on a typical trainer is the bike’s drivetrain, the rear wheel, the trainer’s small flywheel weight, and the trainer’s resistance device. If you actually had a spinning weight on a trainer to simulate the true momentum your body and moving bike represents outdoors, that weight would have to be quite massive or would have to be geared to spin at an extraordinary speed.

One thing about this lack of momentum on a trainer that is ‘good’ (from a training perspective) is that it somewhat simulates some aspects of hill riding, if getting on real hills outdoors is not easy for you.

But if you wanted to to (only slightly) make the trainer ride more like a bike on the flats, try this: if you have a trainer with an adjustable resistance unit (if not, you are out of luck here), crank down the the resistance to the min. you can, ride with the biggest appropriate gear you can (this allows the rear wheel to develop the most rotational speed and momentum), and put the heaviest rear wheel/tire combo you have on the bike.

Hope that helps.