Whats your limiter?

MarkAshton

I have been doing 2x20 intervals recently. I have been progressing but I am wondering whats stopping me from going harder.

For me, I am 99% sure its my legs. If I push too hard, they will either slowly produce less and less power, or cramp up and cause me to stop for a few seconds. Breathing wise I feel ok (unlike when doing a 5 minute interval which is very CV taxing).

I just wanted to know what other people "feel" when they are on the limit of a 20 minute interval i.e. whats stopping you going harder?

Setarkos

IIRC 20min intervals are done very close your lactate threshold so your are producing lactate more quickly than your body can get rid of it, so that is your (and probably everybody elses) main limiter when doing 20min intervals.

MarkAshton

Setarkos wrote:

IIRC 20min intervals are done very close your lactate threshold so your are producing lactate more quickly than your body can get rid of it, so that is your (and probably everybody elses) main limiter when doing 20min intervals.

I understand that (the science bit), but I want to understand what people "feel" stops them from pushing harder?

Tom Dean

fitness

wardieboy

For me it's cramp. I can spin at 115 rpm but find that if I do for longer periods I can feel the twinges of a cramp coming on. Lowering my cadence to 90-95 seems to be optimal for me at the moment, I do find that I feel like I am sometimes reigning in the power but know if I push too hard I will end up cramping.

springtide9

Tom Dean wrote:

fitness

+1

MarkAshton

springtide9 wrote:

Tom Dean wrote:

fitness

+1

So if you were to explain this to an alien? Your breathing so hard you cant breath any more? Your legs are about to cramp up? You legs just turn to jelly?

For me, I am never sure what's making me not go harder when cycling. Running is easy for me to describe.

Herbsman

OOps, feel? I don't feel anything limiting me.

springtide9

MarkAshton wrote:

springtide9 wrote:

Tom Dean wrote:

fitness

+1

So if you were to explain this to an alien? Your breathing so hard you cant breath any more? Your legs are about to cramp up? You legs just turn to jelly?
For me, I am never sure what's making me not go harder when cycling. Running is easy for me to describe.

The reason why you can't go any faster is that your fitness is not good enough. It's the same for us all.
There are some fairly standard relationships out there that define relationships between intensity and duration.

As with running, the faster you ride, the shorter the duration you can keep it up for. e.g. Your 10k pace is very unlikely to be the same as your Half Marathon.

okgo

Only sometimes do your legs give up before your breathing does, usually when your legs have been hammered the days before.

If you're not fatigued then yes, the thing holding most people back is a combination of everything, fitness sums it up. The fitter you are the harder you can push without your body producing lactic acid. Wiggins could ride for an hour what I would have to kill myself to do for 5 minutes! Obviously an extreme example where genetics will come into play, but for most people its fitness not genetics limiting them!

Setarkos

springtide9 wrote:

Your 10k pace is very unlikely to be the same as your Half Marathon.

It'll be fairly close though

springtide9

Setarkos wrote:

springtide9 wrote:

Your 10k pace is very unlikely to be the same as your Half Marathon.

It'll be fairly close though

True, and the same generally applies on the bike. You can pretty much cycle at 90% of your FTP for a couple of hours.
But just like the bike, your 1500m pace is slightly different to your 10k pace.

And if you've done a reasonable amount of endurance training, you'll also probably manage a good 80% of your FTP for 4 hrs or more.

And look where this is leading us.....
http://home.trainingpeaks.com/articles/ ... score.aspx
http://home.trainingpeaks.com/articles/ ... oggan.aspx

twotyred

I just wanted to know what other people "feel" when they are on the limit of a 20 minute interval i.e. whats stopping you going harder?

My legs are my limiter which is probably as it should be for a threshold session. But in the end, as I'm pretty well trained, genetics is my limiter.

JimboPlob

okgo wrote:

Only sometimes do your legs give up before your breathing does, usually when your legs have been hammered the days before.

If you're not fatigued then yes, the thing holding most people back is a combination of everything, fitness sums it up. The fitter you are the harder you can push without your body producing lactic acid. Wiggins could ride for an hour what I would have to kill myself to do for 5 minutes! Obviously an extreme example where genetics will come into play, but for most people its fitness not genetics limiting them!

But riding at FTP for an hour, surely its not breathing. In the last few minutes, maybe if you can empty the tank. I personally am only limited by breathing on short duration efforts i.e. 5 mins or less.

Alex_Simmons/RST

Setarkos wrote:

IIRC 20min intervals are done very close your lactate threshold so your are producing lactate more quickly than your body can get rid of it, so that is your (and probably everybody elses) main limiter when doing 20min intervals.

Efforts such as 20-min intervals at ~ FTP is typically 10-15% above power at lactate threshold.

Our primary limiter is our rate of ATP production/regeneration.

Setarkos

Alex_Simmons/RST wrote:

Efforts such as 20-min intervals at ~ FTP is typically 10-15% above power at lactate threshold.

Should've said MLSS, got that mixed up - my bad. (Closely related anyway)

Our primary limiter is our rate of ATP production/regeneration.

Which lactate levels (MLSS and LT) are a direct indicator for.

Alex_Simmons/RST

Setarkos wrote:

Alex_Simmons/RST wrote:

Efforts such as 20-min intervals at ~ FTP is typically 10-15% above power at lactate threshold.

Should've said MLSS, got that mixed up - my bad. (Closely related anyway)

Yes, an improvement in one is matched by an improvement in the other, which should be no surprise given it's the same underlying metabolic processes that're involved.

Part of the problem is the myriad of definitions for "threshold", even when talking about BL values. Which is why power output is so good, since it's what you can actually do, rather than an arbitrary response measurement.

Setarkos wrote:

Alex_Simmons/RST wrote:

Our primary limiter is our rate of ATP production/regeneration.

Which lactate levels (MLSS and LT) are a direct indicator for.

Yes, although I'd say that our power output (or O2 utilisation) at MLSS/LT is a better indicator than what our BL level happens to be.

Setarkos

The question was, what people "feel" when they can't push any harder in a 20min interval. If they push really hard in the last few minutes it can be breathing but that's because they are well above threshold then. If it's a steady effort what happens is that ATP from glycogen is produced at a rate which is to fast for the body to oxidise NADH/H+ to NAD+ without reducing pyruvate to lactate. So lactate accumulates in the muscle inhibiting ATP production so saying it's ATP production/regeneration or lactate accumulation is really splitting peas if it's not a chicken-and-egg-problem.

Otherwise regarding the usage of power, I completely agree with you but that wasn't really the point of discussion, was it?

Alex_Simmons/RST

Setarkos wrote:

The question was, what people "feel" when they can't push any harder in a 20min interval. If they push really hard in the last few minutes it can be breathing but that's because they are well above threshold then. If it's a steady effort what happens is that ATP from glycogen is produced at a rate which is to fast for the body to oxidise NADH/H+ to NAD+ without reducing pyruvate to lactate. So lactate accumulates in the muscle inhibiting ATP production so saying it's ATP production/regeneration or lactate accumulation is really splitting peas if it's not a chicken-and-egg-problem.

The primary difference is that the point of excess lactate production is a relative marker, not an absolute one.

IOW people will have different ATP production capacity at the same BL level, and it's the volume of ATP that dictates our power output (limits).

Setarkos wrote:

Otherwise regarding the usage of power, I completely agree with you but that wasn't really the point of discussion, was it?

The OP was wondering what was stopping him from going harder in his long intervals.

The answer is an inability to sustainably generate more ATP. He could feasibly train to do that yet see no change in his BL level at threshold.

Trev The Rev

MarkAshton wrote:

I have been doing 2x20 intervals recently. I have been progressing but I am wondering whats stopping me from going harder.

For me, I am 99% sure its my legs. If I push too hard, they will either slowly produce less and less power, or cramp up and cause me to stop for a few seconds. Breathing wise I feel ok (unlike when doing a 5 minute interval which is very CV taxing).

I just wanted to know what other people "feel" when they are on the limit of a 20 minute interval i.e. whats stopping you going harder?

"Feel", this does not exist when you train with power. Power meter data is the be all and end all of everything, stop worrying about feel. It is only your fitness which is holding you back. You see the power meter data tells all. The power meter data does not show feel, or if it is your legs or heart or lungs which give out first, this is because it is not relevant. All that matters is the power. This is why cadence is a red herring. You can be gasping for air at low force high cadence or legs screaming high force low cadence but is the power that counts. Forget all this feel stuff. Concentrate on power.


To answer the original post though, being an old timer who can remember how cycling feels and used to be able to pace my efforts even without a power meter (amazing skill but useless in the modern world), I found it was always my breathing which was the limiting factor. Pain in the legs is something I was always able to tolerate but the close to black out gasping for air pain I found very hard to cope with. This was the case no matter how fit or unfit, well trained, not trained for months, overweight or at race weight. For me it was always my breathing which was the weak link. Now I train with power and I don't feel anything, I just ride at the decided power and ignore all feelings, it is amazing how I can keep the power on for so much longer.
I have found some odd things show up in the power data though. After long efforts at high power there is a sudden stop in the power, zero power for several minutes of which I have no memory. There might be a problem with my power meter which I have sent back to the manufacturer - again.

danowat

Trev The Rev wrote:

"Feel", this does not exist when you train with power. Power meter data is the be all and end all of everything, stop worrying about feel. Forget all this feel stuff. Concentrate on power.

I'm never sure if you are serious or not, you've changed your opinion on things so many times, I've lost track.

Feel is still important, even if you are using power.

As for "limiting factor", if I am pushing very, very hard, say 150% of FTP at the end of a 10, then my whole body is screaming, legs, CV system, it's all pushed to the very limit, so in that instance, it's just my whole fitness that is the limiting factor.

Other distances and intensities provide different limiting factors, at the end of a 100TT or a 12hr TT, it's definately the legs.

Trev The Rev

danowat wrote:

Trev The Rev wrote:

"Feel", this does not exist when you train with power. Power meter data is the be all and end all of everything, stop worrying about feel. Forget all this feel stuff. Concentrate on power.

I'm never sure if you are serious or not, you've changed your opinion on things so many times, I've lost track.

Feel is still important, even if you are using power.

As for "limiting factor", if I am pushing very, very hard, say 150% of FTP at the end of a 10, then my whole body is screaming, legs, CV system, it's all pushed to the very limit, so in that instance, it's just my whole fitness that is the limiting factor.

Other distances and intensities provide different limiting factors, at the end of a 100TT or a 12hr TT, it's definitely the legs.

It is intentional to keep you unsure as to whether I'm being serious or not.

danowat

In that case, your posts are completely worthless, how can anyone take anything you say seriously, when you yourself admit to being a troll?.

Why not cut the crap Trev, and offer a vaild, reasoned, coherent and above all honest opinion?, rather than trying to be Inflammatory all the time?

Trev The Rev

danowat wrote:

In that case, your posts are completely worthless, how can anyone take anything you say seriously, when you yourself admit to being a troll?.

Why not cut the crap Trev, and offer a vaild, reasoned, coherent and above all honest opinion?, rather than trying to be Inflammatory all the time?

When I give an honest opinion people get really upset. Your problem is you take it all rather too seriously and being the the sort of person who is sometimes the butt of the joke you are unable to see the satire.

danowat

If you're the sort of person who get's their kicks doing that, fill ya boots.

pilch

danowat wrote:

In that case, your posts are completely worthless

"you are worthress arec barrwin"

Tom Butcher

I rarely feel I'm running out of breath - and it's rarely what I'd call pain in the legs - more they just stop doing what I tell them to. I can feel I'm pushing as hard as I can but people are riding away from me at a speed I know I could have matched 20 minutes before. I remember coming back from a long layoff once and doing a fast group ride in the hills and noticing I was really gasping for breath but that was notable because it's not something I was used to to that extent except maybe in a sprint.