What is the equation for IF?
NP/FTP
If you can compute NP in your head on the fly, then you should probably switch to a career in mathematics.
But most head units can display it
Haha, I don’t compute NP on the fly but a neat trick for doing TSS on the fly is just do IF^2 * 100 for TSS/hour. Most people know roughly how hard they’re riding relative to FTP, so if you’re riding @ 80% then you’ll get 64 TSS/hour. Then again most head units display TSS now too.
I only have 2 sets of data on this topic.
One of them, TSS and kJ do an identically good job of predicting fitness. Because the structure of the athletes training never really varied.
The other, kj negative correlates with fitness while TSS still correlates well, because the athlete started doing less long slower rides, and more racing/intense rides.
Of course I don’t know if this same trend would be true for the purposes of calorie estimation, or pacing, or if it would even be true for all people.
It is very hard to even correlate things with ‘fitness’ as you have to know a lot about the rider to even have some regular measure of fitness to test for, and some riders just won’t have anything available at all.
I think kJ may be one of the most under utilized metrics, if not the most underutilized metric that a LC triathlete could monitor.
IMO it’s way more important to know kJ in a IM or half then what TSS your attaining.
Then again most head units display TSS now too.
Yes!
I’ve been prescribing my wifes workouts in TSS this season. Fun times!
What aspect(s) of it do you find more useful?
I find it particularly useful for fueling - specific to my n=1 I have found that if my calorie intake is less than 50% of my kJ done for a half or IM - I’m in trouble.
I also find value in having a kJ target in racing knowing what I have done for a kJ in training - which allows me to dynamically adjust my pacing based on what the conditions are doing to my speed.
In training I find it to be a good absolute comparison of training load that removes a lot of the fuzziness of TSS/FTP estimation. Less than 20k kJ in a month means I’m really slacking, more than 30k means I’ve probably got an Ironman in the near future.
This has long been a point of debate between a few of us;
Does caloric burn increase as you increase power (w) output. In a static environment it seems that it does based on the math that’s been described above.
But what isn’t accounted for is the human body adapting and becoming more efficient over time to do the same amount of work.
You make a fat guy who sits on the couch hold 400w for an hour he’s going to burn a LOT of calories. You get a guy who rides national level TT to the same amount of work, I dont know if he’s going to have the same caloric burn.
In the latter case he has become more efficient over time at doing the same amount of work, and therefore should have a lower caloric burn.
So does the human body adapt to work over a period of time, and does that result in a lower caloric burn for the same amount of work done in a previous period?
I only have 2 sets of data on this topic.
One of them, TSS and kJ do an identically good job of predicting fitness. Because the structure of the athletes training never really varied.
The other, kj negative correlates with fitness while TSS still correlates well, because the athlete started doing less long slower rides, and more racing/intense rides.
Right, kJ and TSS will tend to be well correlated if the structure of training doesn’t change. However, they can tell you different things if the training differs a lot.
Here are some plots I put together when we were originally having this discussion back in (checking records …) 2005. Yup, a decade ago.
First plot, Coggan’s kJ and TSS totals over 20 weeks. Each dot represents a week’s total. Note the correlation coeff down in the right corner: 0.935
OK, so that seems to say that kJ and TSS are telling you the same thing, right? However, here’s the same plot but with each week labeled.
Pattern developing? OK, to make it really clear, look at the kJ/TSS ratio over the 20 weeks. If kJ and TSS were telling you the same thing, that ratio should be constant. If the ratio differed in a systematic way, then something must be systematically different.
So does the human body adapt to work over a period of time, and does that result in a lower caloric burn for the same amount of work done in a previous period?
My guess is this is correct. You become more efficient as you advance in your athletic ability. As someone else mentioned earlier, if I were to eat as much food as I supposedly burn on the bike, I would be overweight. I usually eat half or even less of the calories I burn on the bike.
Most cyclists don’t change their efficiency at a given power much.
Runners do change their efficiency at a given pace a bit.
So does the human body adapt to work over a period of time, and does that result in a lower caloric burn for the same amount of work done in a previous period?
My guess is this is correct. You become more efficient as you advance in your athletic ability. As someone else mentioned earlier, if I were to eat as much food as I supposedly burn on the bike, I would be overweight. I usually eat half or even less of the calories I burn on the bike.
Just to be clear I wasn’t correlating them with each other, but with a measure of fitness (a few measures of fitness)
and then really I was correlating the exponentially weighted moving average of each with those measures of fitness.
that is a cool way to visualize the structure of your training though.
Not terribly different calorie burns. There are certainly bio-mechanical gains to be found (in running and swimming–given the fixed motion of cycling, not much there to realize), but thermodynamically, not so much. Guys/gals that are able to push tons of watts (in whatever respective sport) do so because they have the hardware to burn a ton of calories (for us endurance folk, that’s going to be through more and more oxidative phosphorylation)
You’re not going to materially affect metabolic conversion efficiency. You might push more and more of your substrate utilization towards oxidative phosphorylation (this, perhaps is where I see value in both kJ and TSS for pacing/fueling in longer races) by up/down regulating mitochondrial density, but those processes are relatively fixed (Citric acid cycle will remain the citric acid cycle). That said, small changes here make a big difference.
Again, given the difficulty of determining these numbers is why things like FTP are so useful. Shifts in underlying “machinery” will show up in the composite question, “how much work can I do?”
Here’s a good (I think? Ex phys folks feel free to correct me) article that hits some of the points:
http://www.academia.edu/1263975/The_effects_of_training_on_gross_efficiency_in_cycling_a_review
Table 1 is a nice compilation. If you remember your statistics – small n studies that show small effects are likely noise/bias. Add in to that most of the studies in the table don’t find significant differences, and that’s probably your best hypothesis.
that is a cool way to visualize the structure of your training though.
Thanks, but it’s just another example that looking at how two things compare on average often isn’t as important as knowing when they’re different.
Most cyclists don’t change their efficiency at a given power much.
Runners do change their efficiency at a given pace a bit.
So does the human body adapt to work over a period of time, and does that result in a lower caloric burn for the same amount of work done in a previous period?
My guess is this is correct. You become more efficient as you advance in your athletic ability. As someone else mentioned earlier, if I were to eat as much food as I supposedly burn on the bike, I would be overweight. I usually eat half or even less of the calories I burn on the bike.
Need to clarify your point so we aren’t talking past each other;
when you say cyclists dont change efficiency at a given power points, you are referring to my efficiency if i go ride today and put down 200w, 400w, 600w the efficiency is the same (lets say 25%) and is therefore relatively static.
What i am saying is that over TIME ie. today vs a year from now, my efficiency (the 25%) will change if i train and improve, and therefore my caloric burn at that same 200w, 400w, and 600w would be different than it is today.
Do we still agree or disagree?
What i am saying is that over TIME ie. today vs a year from now, my efficiency (the 25%) will change if i train and improve, and therefore my caloric burn at that same 200w, 400w, and 600w would be different than it is today.
You would become stronger but not more efficient. I’ve heard professional cyclists are less efficient than recreational cyclists. Think of a Ferrari vs. a Hyundai. Which one is stronger and which one is more efficient.
I suspect the efficiency would change at different power levels.
Over time, efficiency tends not to vary much in cyclists.
The researcher who studied lance and claim large changes in efficiency was often considered questionable, because that was unusual. Perhaps he got something wrong, or perhaps the drug use caused unusually large variations, or perhaps lance was just unusual. I don’t know.
Need to clarify your point so we aren’t talking past each other;
when you say cyclists dont change efficiency at a given power points, you are referring to my efficiency if i go ride today and put down 200w, 400w, 600w the efficiency is the same (lets say 25%) and is therefore relatively static.
What i am saying is that over TIME ie. today vs a year from now, my efficiency (the 25%) will change if i train and improve, and therefore my caloric burn at that same 200w, 400w, and 600w would be different than it is today.
Do we still agree or disagree?
This has long been a point of debate between a few of us;
Does caloric burn increase as you increase power (w) output. In a static environment it seems that it does based on the math that’s been described above.
But what isn’t accounted for is the human body adapting and becoming more efficient over time to do the same amount of work.
**You make a fat guy who sits on the couch hold 400w for an hour he’s going to burn a LOT of calories. You get a guy who rides national level TT to the same amount of work, I don’t know if he’s going to have the same caloric burn. **
In the latter case he has become more efficient over time at doing the same amount of work, and therefore should have a lower caloric burn. So does the human body adapt to work over a period of time, and does that result in a lower caloric burn for the same amount of work done in a previous period?
Not a very good analogy since most “fat guys on the couch” could not hold 400 watts for more than 60 sec at the most, unless they just happen to be ex-cyclists who gained a bunch of weight:)
Not a very good analogy since most “fat guys on the couch” could not hold 400 watts for more than 60 sec at the most, unless they just happen to be ex-cyclists who gained a bunch of weight:)
I know a guy who could do it, he wasn’t an ex-cyclist, but a cyclist to be, haha.
Not a very good analogy since most “fat guys on the couch” could not hold 400 watts for more than 60 sec at the most, unless they just happen to be ex-cyclists who gained a bunch of weight:)
I know a guy who could do it, he wasn’t an ex-cyclist, but a cyclist to be, haha.
Ya, I started to qualify it by saying “or unless he’s really naturally gifted” but OTOH I did say “most” so I was covering that possibility. JOOC, assuming decent aero-ness, what type of time for the 40K TT would 400 watts for an hour give you, something like 27-28 mph or so???
For someone of normal height that is 30mph territory.
Ya, I started to qualify it by saying “or unless he’s really naturally gifted” but OTOH I did say “most” so I was covering that possibility. JOOC, assuming decent aero-ness, what type of time for the 40K TT would 400 watts for an hour give you, something like 27-28 mph or so???
I only have 2 sets of data on this topic.
One of them, TSS and kJ do an identically good job of predicting fitness. Because the structure of the athletes training never really varied.
The other, kj negative correlates with fitness while TSS still correlates well, because the athlete started doing less long slower rides, and more racing/intense rides.
What goes around comes around:
https://groups.google.com/d/topic/wattage/KPXPhv6IekE/discussion
https://groups.google.com/d/topic/wattage/MCPe7u66Wzs/discussion
Etc.
Here’s a good (I think? Ex phys folks feel free to correct me) article that hits some of the points:
http://www.academia.edu/1263975/The_effects_of_training_on_gross_efficiency_in_cycling_a_review
Yup, it’s a pretty good review (although they apparently missed the first study from the 1930s showing that cycling efficiency improves with training.
Table 1 is a nice compilation. If you remember your statistics – small n studies that show small effects are likely noise/bias. Add in to that most of the studies in the table don’t find significant differences, and that’s probably your best hypothesis.
Except the effects size found by Hopker et al. was large, not small.