Changes due to increased training load

frost said:

...This obviously caused CTL to drop (not to mention a dramatic drop in FTP). Last weekend I was on a first long ride for ages which ended ~190 TSS. Not very surprisingly,with CTL in thirties I got very close to a total bonk at the end of the ride.

I'd say you've answered your question here. Increasing CTL should bring about an increase in FTP, hence they share the same physiological adaptations.

frost said:

This got me thinking about the old power wisdom "ftp is how hard you can ride,ctl how long you can ride hard".

I'd rather say that ftp is the highest power i can maintain for 1hr, whilst ctl is a measure of how well "trained" i am (ie fitness). The two are linked. The words i tend to remember are "the more you train, the more you can train."

frost said:

Combination of jet lags,intercontinental flights and heavy training got me overtrained some time ago and I had to cut training quite a bit. This obviously caused CTL to drop (not to mention a dramatic drop in FTP). Last weekend I was on a first long ride for ages which ended ~190 TSS. Not very surprisingly,with CTL in thirties I got very close to a total bonk at the end of the ride. At summer season 190 TSS I would call an "extended warmup" ;-)

This got me thinking about the old power wisdom "ftp is how hard you can ride,ctl how long you can ride hard".
What actually happens in the body with increased "base" or CTL that allows riding harder for longer? Increased glycogen storage is clearly an adaptation but what more?

Definitely best answered by the ex.phys. blokes but let me see if I can make a mess of it :-)

There are three main energy sources for endurance exercise: fat, glycogen, exogenous CHO (bloodstream -> consumed). PC (phospho-creatine) is important for sprinting of course but contributes negligible energy to a 3-4-5 hr ride.

I belive the most important adaptations are:

(1) "Fat burning" (Kreb's) enzymes IIRC whose levels are linked to training volume/duration - loosely speaking "endurance" training. This energy store is essentially unlimited in healthy adults.

(2) Glycogen stores increase with endurance training but glycogen alone only gets you so far (at a decent pace!).

(3) Ability to utilize exogenous CHO? Not sure is this is an adaptation or more a result of (re) learning to properly fuel during long rides.

You might find this of interest or some links off the main page re #1

en.wikipedia.orgCitrate synthaseOpen ↗

As I said, it's really best answered by those who know this area inside and out. Apologies in advance!

frost said:

What actually happens in the body with increased "base" or CTL that allows riding harder for longer? Increased glycogen storage is clearly an adaptation but what more?

The adaptations are likely more specific to the composition of the CTL than of the CTL itself. Therefore, it could be difficult to precisely pin down the adaptations associated with an increasing CTL without looking at the composition of training leading to that increase.

rmur17 said:

Definitely best answered by the ex.phys. blokes but let me see if I can make a mess of it :-)

There are three main energy sources for endurance exercise: fat, glycogen, exogenous CHO (bloodstream -> consumed). PC (phospho-creatine) is important for sprinting of course but contributes negligible energy to a 3-4-5 hr ride.

I belive the most important adaptations are:

(1) "Fat burning" (Kreb's) enzymes IIRC whose levels are linked to training volume/duration - loosely speaking "endurance" training. This energy store is essentially unlimited in healthy adults.

(2) Glycogen stores increase with endurance training but glycogen alone only gets you so far (at a decent pace!).

(3) Ability to utilize exogenous CHO? Not sure is this is an adaptation or more a result of (re) learning to properly fuel during long rides.

You might find this of interest or some links off the main page re #1

en.wikipedia.orgCitrate synthaseOpen ↗

As I said, it's really best answered by those who know this area inside and out. Apologies in advance!

Very clear and well outlined answer so definately do not apologise! Very good link(s) also, thanks.

I cannot find old 'Optimal training' coach textbook from my junior track&field years for a reference but if I remember right the increase in glycogen storage is sizeable. Of course as you said one only goes so far with glycogen but on the other hand on a certain (relative) pace one consumes portion of glycogen so an increase in glycogen storage should give an "increase in sustainability" in same relation.

But the interesting part is that of fat metabolism that leads to two new questions:
1) based on that (for the lack of better word) 'sustainability' increases with increased training load and if all of that cannot be attributed to increased glycogen storage then the level of fat metabolism related enzymes must increase even with relatively high intensity training (say L3-lower L4)?

2) When one is very close to his/her genetic potential in FTP/VO2Max and there is very little gains left in that area some of the competitive edge comes from higher fat metabolism which would in part support the large amount of lower intensity training in that case (eg. pros).

Or is it just overcomplicating a very simple thing: train more and more specificly [img]cyclingforums.combiggrin.gifOpen ↗[/img]

Fightin Boba said:

The adaptations are likely more specific to the composition of the CTL than of the CTL itself. Therefore, it could be difficult to precisely pin down the adaptations associated with an increasing CTL without looking at the composition of training leading to that increase.

So you say that the oversimplification of the question renders it impossible to answer and I should just take a look at the adaptations related to training zones?

frost said:

Very clear and well outlined answer so definately do not apologise! Very good link(s) also, thanks.

I cannot find old 'Optimal training' coach textbook from my junior track&field years for a reference but if I remember right the increase in glycogen storage is sizeable. Of course as you said one only goes so far with glycogen but on the other hand on a certain (relative) pace one consumes portion of glycogen so an increase in glycogen storage should give an "increase in sustainability" in same relation.

But the interesting part is that of fat metabolism that leads to two new questions:
1) based on that (for the lack of better word) 'sustainability' increases with increased training load and if all of that cannot be attributed to increased glycogen storage then the level of fat metabolism related enzymes must increase even with relatively high intensity training (say L3-lower L4)?

2) When one is very close to his/her genetic potential in FTP/VO2Max and there is very little gains left in that area some of the competitive edge comes from higher fat metabolism which would in part support the large amount of lower intensity training in that case (eg. pros).

Or is it just overcomplicating a very simple thing: train more and more specificly [img]cyclingforums.combiggrin.gifOpen ↗[/img]

Table 2 here is another good summary ...

cyclingpeakssoftware.comlevels.aspOpen ↗

rmur17 said:

Table 2 here is another good summary ...

cyclingpeakssoftware.comlevels.aspOpen ↗

Yes, that or similar description is what I was referring above "I should just take a look at the adaptations related to training zones".
What I wanted to know is if there is some adaptation/effect on simply gaining training load (sustained stress on body) regardless of composition but I guess that could be summarized that the training load adaptation is a sum of adaptations of individual training sessions.

frost said:

So you say that the oversimplification of the question renders it impossible to answer and I should just take a look at the adaptations related to training zones?

Without knowing the composition of the CTL we are speaking of, it is possible to perhaps generalize about, but difficult to specifically answer the original question. Using Table 2 http://cyclingpeakssoftware.com/power411/levels.asp as a guide, you can estimate the adaptations that might be occuring with you particular training composition. Think of your training composition as defining the breadth (and to some extent the depth) of those adaptations, while raising CTL with the composition as increasing the depth of those adaptations. You can surmize that the adaptations of a more traditional CTL-raising base period involving a steady diet of L2 riding might be of different breadth and depth than a more contemporary 'base' period (involving SST and higher levels) raising CTL to the same level.