Utilising Indoor Measured Power for Outdoor Riding

[Splash]

Originally Posted by shovelhd

Just test on the road bike. Simple.

Are you meaning to test Bike 2 on the NEO and note any differences in wattage outputs between the P2M crank PM and the inbuilt NEO PM and then adjust your outdoor riding wattage (FTP, zones, etc.) to meet both indoor and outdoor PM's?

Splash

[shovelhd]

No. Test outdoors on the road bike with the P2M. Offset 7% for the other bike on the trainer. It doesn't have to be any more complicated than that.

[Megalodon]

Originally Posted by 11.4

I've usually found with athletes that there's a lot more than a 7-8% differential. You don't recycle the metabolized oxygen around you on a trainer, so you have to blow it away effectively or the quality of your air supply goes down. You also develop a bubble of humidity and heat around you on a trainer -- same kind of issues. Plus you don't change your bike's position like when you tilt it, ride uphill or down, and so on. Psychologically they are very different beasts, which alone is worth 10-15% (probably more like 25% in my particular head). There's simple heating effect on a trainer. And on and on.

The air "quality" in a reasonably sized room won't be affected by trainer workouts of typical duration. A coach started this meme years ago but misplaced a decimal point.

Heat and humidity dissipate rapidly to the rest of the air in the room. There is no meaningful "bubble" of hot, humid around you.

Riding indoors a lot decreases your outdoor power so it would be one heck of a tenacious bubble.

The real reason power is lower indoors is altered muscle recruitment due to the inability of almost every trainer to simulate outdoor kinetic energy. There's a detailed explanation on the UK time trial forum.

[shovelhd]

Welcome to the forum. I do not agree with you. No fan pushing hot crappy air can duplicate the convection cooling of the outdoors. It's a factor. The trainer not letting up is another. The bottom line is that intervals that I can complete on the road will be very difficult to complete at the same power indoors. This is by a highly trained national class athlete that has a very good RPE meter. That's why the offset is needed.

[Megalodon]

There's a lot of folklore surrounding indoor training. "Bad air" is one of the most ridiculous explanations for lower power output indoors. Perhaps the most ridiculous is the idea that you experience greater saddle discomfort indoors due to the lack of oncoming air providing lift for your torso.

Evaporative (not convective) cooling is the main source of heat removal (80%). The slightest breeze or body motion (pedaling) would quickly disperse any hot/humid air "clinging" to your body.

You're not overheating due to hot/humid air until you start to drip sweat yet before you reach that point you can easily complete a short interval where you can observe decreased power.

[93legendti]

I don't know anything other than I spend a fair bit of time on the trainer, when life interrupts, as much as 8 hrs per week and one miserable winter 5 rides x 2.5 hrs per week, which also coincided with the form of my life.

I get saddle discomfort much sooner indoors. Don't know why, but it requires me to get out of the saddle every 5-7 minutes for 30-60 seconds.
Outdoors maybe once every 10-15 minutes, even if I try to get out of the saddle every 10 minutes. I suspect it's the un weighting that goes on outside and the occasional stop. Although I plan my solo rides so I barely ever have to stop.

Same saddle, pedals, bars and bar tape as all my other bikes. Same shorts, same body glide application before riding. Same calf and pirformis stretches before riding. Same water bottles. Same gloves.

[bikerider888]

Wanted to comment on this thread as inside training is a staple year round for me, and I'm highly in tune to cooling and "road feel" issues and use a powermeter (quarq).

I agree with the previous poster, it is fantasy that lower O2 levels exist and same with humidity. Stating such things as "fact" without science that backs it up is specious.

But the thread brings up two important points and if you do significant workouts indoors these points are key.

1. Cooling. Without adequate cooling you will suffer from heat stress and PE will go up dramatically for a given power level. I've done testing with cooling vests and various fans and can attest to this.

My strategy is to train in my garage where I can vary the level of outdoor (cold!) air. I use a huge fan on a remote so I can fine tune that as well. Optimal setup for me is arm warmers + gloves, with tons of cool air removing heat generated. 45 to 55deg is optimal. Above 65degrees and I suffer during intervals. Over 70 and I won't attempt FTP or VO2 work.

2. Road feel. This is where the reduction in indoor vs outdoor FTP comes into play. I also think this is the most important factor in selecting a trainer or rollers, much more so than entertainment options or cost.

I have hands on with kurt, kickr, cyclops fluid, trutrainer, kreitler rollers and inside-ride emotions. I rate the road feel of the inside ride rollers nearly identical to the road and I take no adjustment indoor vs outdoor. In fact I feel that FTP and especially VO2 work is easier indoors than outside due to much lower variation in cadence & power. Vo2 work is hard regardless but I'll do in on the rollers by choice assuming it's below 65deg ambient.

I found the kickr to be the next best option, assuming you prefer a trainer. There still was a difference vs the road in inertial feel and muscle activation, but it was less than other options. Might take a wattage reduction, but I wouldn't arbitrarily drop 10% from the start.

I suspect many of those (even national caliper) riders are lacking adequate cooling or riding something with crappy road feel, if they feel the need to drop 5, 7 or 10% power for indoors.

Just my 2cents.

[Megalodon]

Originally Posted by 93legendti

I don't know anything other than I spend a fair bit of time on the trainer, when life interrupts, as much as 8 hrs per week and one miserable winter 5 rides x 2.5 hrs per week, which also coincided with the form of my life.

I've spent up to 17 hrs/week riding indoors so I understand.

Originally Posted by 93legendti

I get saddle discomfort much sooner indoors. Don't know why, but it requires me to get out of the saddle every 5-7 minutes for 30-60 seconds.
Outdoors maybe once every 10-15 minutes, even if I try to get out of the saddle every 10 minutes. I suspect it's the un weighting that goes on outside and the occasional stop. Although I plan my solo rides so I barely ever have to stop.

Post #29 in this thread explains it all:

http://www.timetriallingforum.co.uk/...4861&p=1444959

Indoors on the VeloTron or any of my other trainers or rollers except my Lynx, I need to use the more padded Fizik Aliante. I can ride the less padded Antares outdoors or on the Lynx.

[Megalodon]

Originally Posted by bikerider888

I agree with the previous poster, it is fantasy that lower O2 levels exist and same with humidity. Stating such things as "fact" without science that backs it up is specious.

A few years ago, some coach posted some calculations on his blog and claimed that O2 would be depleted riding a trainer in a room. He misplaced a decimal point.

There are a lot of industrial safety studies regarding O2 and CO2 in enclosed spaces as well as for submarines and spacecraft. CO2 toxicity actually becomes an issue long before O2 depletion. I actually have a CO2 meter and it's not an issue unless you're in an airtight space the size of a closet. And even if you were, you could just add a minimal amount of ventilation or throw the door open every half hour.

Originally Posted by bikerider888

1. Cooling. Without adequate cooling you will suffer from heat stress and PE will go up dramatically for a given power level. I've done testing with cooling vests and various fans and can attest to this.

2. Road feel. This is where the reduction in indoor vs outdoor FTP comes into play. I also think this is the most important factor in selecting a trainer or rollers, much more so than entertainment options or cost.

I have two cooling vests myself. One phase change and one is a military surplus pumped chilled water vest with the potential for developing some exotic cooling solutions. It's 50-55F in my garage this time of year and I find that I still sweat more than my headband can handle and need to wipe with a towel periodically. In the meantime, my hands and feet get cold enough to become numb.

Since most cooling during exercise is evaporative I think I would benefit more from increased air flow and dehumidification rather than colder air. I'm now thinking of adding multiple 30" industrial fans but should I wish to ride indoors in warm weather I would probably need insanely high powered fans and an air conditioned space.

I have Kreitler rollers and a Kurt Kinetic trainer with the heavy flywheel. I don't use either these days. I've also owned a cheap Performance and CycleOps trainer in the past. I also have a VeloTron which I reverse engineered to try to improve its kinetic energy simulation and a Veloreality Lynx which was designed specifically to simulate the kinetic energy of outdoor riding.

In the winter, I found it possible to match and even exceed outdoor power but it required an adaption period followed by double the training load. Unfortunately, once I returned to outdoor riding, I couldn't match my indoor power. This tells me cooling was adequate during the winter but it was not the only factor, the other being kinetic energy or "road feel."

[11.4]

Hey, Megalodon, you have only four posts on this forum and they're all in this thread. You have a lot of equipment and some interesting data. Tell us more about yourself.

This is an issue that has actually been worked over in detail for applications as esoteric as exercise bikes and treadmills on the international space station and for exercise programs on submarines. The body metabolizes only a very small amount of the oxygen it respires, and generates only a relatively small amount of carbon dioxide in the process, hence the calculations that say the "bubble" issue is false. However, the body responds quite significantly to minimal changes in relative O2 concentration in the air. A relative half percent decline is a huge difference in humans. The effect with small carbon dioxide changes is even more pronounced. On top of this, the increase in relative humidity of the space immediately around the body during a hard trainer workout also causes a significant change in respiratory behavior. These small changes have been documented in great detail in studies of breathing apparati and respirators for firemen and others. A lot of my professional work is in this area and these studies are pretty conclusive. Those who diss the "bubble" issue base it on studies that don't actually involve sufficient exercise to make a difference, involve assumptions that it takes a significant oxygen or carbon dioxide change to make a difference, and involve assumptions that the body can compensate for significant changes because the body can compensate for absolute changes in oxygen supply at altitude. The body doesn't respond to these changes as if it were calculating oxygen depletion or carbon dioxide accumulation on a volumetric basis.

[bikerider888]

Originally Posted by Megalodon

I have two cooling vests myself. One phase change and one is a military surplus pumped chilled water vest with the potential for developing some exotic cooling solutions. It's 50-55F in my garage this time of year and I find that I still sweat more than my headband can handle and need to wipe with a towel periodically. In the meantime, my hands and feet get cold enough to become numb.

In the winter, I found it possible to match and even exceed outdoor power but it required an adaption period followed by double the training load. Unfortunately, once I returned to outdoor riding, I couldn't match my indoor power. This tells me cooling was adequate during the winter but it was not the only factor, the other being kinetic energy or "road feel."

Nice - I used a phase change vest and even lugged it to some races, but it was cumbersome.

At 50deg I still go through 3 or 5 headbands and sweat a bit, but extremities are cold (hence gloves, arm warmers). I'm happy when it's cold enough outside that I know I can get the temp just right.

This morning was just right for a long (2 hr) set at 90 to 92% FTP. The longest period of focused work I'll do indoors, which would be a total pain to do outdoors.

I found the same thing re indoor vs outdoor. After a period of indoor intervals outdoors felt a little off, and vice versa.