No.
The name is wrong, the plan is right
I always use Jan Ullrich as the poster boy of this concept. Every year he would enter the season overweight and badly out of shape. He would get stomped in early season races and his team would have to send him off to special training camps to find his form.
He would end up having to “rush” his form to get in shape for the Tour……but it was fragile fitness. He lacked the foundation entering the year to build on….rushing his form always led to at least one jour sans. In the meantime, -7 was putting in the miles all winter, building the foundation.
Back when we had our first daughter, I relied on our lunch time rides for my training (I was in the bike biz at the time and it was a fast ride). But 3-4 1-hour rides during the week and maybe a 90 min ride was not enough for me to build “deep” fitness. I could get fit enough to race, but if I took any time off at all, my form would collapse. Again, fragile fitness.
Yea, I wish I could consistently get 9 hours of training every week. I did really well in 6-7 hours a week last year. Nothing but Sweetspot in base, getting up to 120 minutes TiZ. And then mixed in a threshold or VO2 block here and there. Hit my all time high of 340 FTP and had a few wins in local races. You can get a lot of progress with 9 hours.
That’s the issue with words like “fragile fitness”: I don’t disagree with anything you wrote about Jan Ulrich, I’d just add the detail that he was competing for a podium at the TdF, the most prestigious stage race there is. Just surviving it is hard. Calling this an example of fragile fitness doesn’t seem right, he was among the best of the best in the sport of cycling at the time.
Oh, and loads of drugs were involved. To be fair, his competition was all jacked up, too. 
I understand what you are saying, but I would just say that any training plan is an attempt to optimize fitness under constraints. And all you need to do to conclude that your fitness is fragile is to raise the bar. You can do that all the way to a top placement in the TdF.
My view is that your fitness isn’t fragile, but that you have a fitness budget and over drafting comes with a price. You gotta know your limits and either stay within them or be willing to pay the price. Some events will just push you deep in the red (think Unbound) no matter how you slice it. If you want, you could call the effects of over drafting “fragile fitness”.
Same text, different font…
But how that fitness plays out can be very different. As I noted above, lacking a solid foundation can mean your fitness evaporates more quickly. And the science backs this up…gains at the higher trianing zones are lost faster than gains in the lower training zones.
So if most of your training is HIIT oriented due to time constraints, your fitness will disappear faster.
He was one of the best of the era. He won the Tour de France for Pete’s sake. He won the Vuelta, the Gold medal in the RR, and multiple world championships.
from my own data. And the other stuff you said.
I feel like the hardest thing from these posts (and the Z2 threads, and any other of the type) is that it’s so hard to convey all the different viewpoints.
New cyclists, truly time-limited cyclists, those of us trying to find every optimisation, or those training and racing at the elite/pro level all have such different perspectives and understandings.
I always worry that someone will come onto the forum and get so dejected about training the wrong way, or building the wrong fitness that they get overwhelmed.
100%…it is a really bad medium for such nuanced discussions.
I’ve said it before, but the answer is just “pick a plan”…it alsmot doesn’t matter which one. Once you get into a structured training regimen you will almost certainly see improvements (especially as less-experienced cyclists). Will it be the “best” plan? No one knows…but it will be better than what you are doing now.
right, the steps are pretty simple:
- start by riding consistently, following a plan is a good first step
- then ride more, thats where it MIGHT get messy if you prioritize the plan instead of riding more
- then pay attention to how you spend your time, learn what works and doesn’t for YOU
We all understand the adaptations endurance rides give you, nobody in this thread is disputing that. I just think using the same term, fragile/brittle fitness, for why Jan Ulrich wasn’t more successful than he was and amateur athletes who pack their training plans with more intensity than they can handle is a bit stupid. By that token the every cyclist’s fitness is fragile once you set the bar high enough. The term suggests that the athlete is deficient when this is not necessarily the case. That’s why I don’t think it is a useful way to think about your training, and e. g. the mental model of an account with overdraft fees is better, because whether your fitness suffices is all a question about the demands you place on it.
Plus, I think there are instances where you want to put all eggs in one basket and peak only once in a year, but really, really high. An athlete training for the Olympics comes to mind: if the Olympics are my A++ event, then I might not care that the rest of the season is lackluster. Is that an example of fragile fitness or smart goal setting and execution?
PS Cycling isn’t the only example that comes to mind. Soccer had a similar scheduling problem a few years back when things like the Champions League were too close to the Euro and World Cups. Players couldn’t focus on one event well. Imagine being coached by several people with very different goals who want players to peak at different times …
This is great advice. Part and parcel of the last bullet point is to learn how much you can handle and either staying within your means or at least knowing what the consequences are if you overdo it.
In my experience at least, this is a life-long process. Sometimes I feel like I have gotten the hang of it. But on other days I make pretty stupid mistakes while training.
No, that’s not the reason.
Expressions, analogies and mental models should help us understand what is going on and how to rectify it. “Fragile fitness” is in my mind not very helpful. The bank account with overdraft fees in my opinion is. It isn’t perfect, of course, no analogy ever is, but I think it helps keep perspective and shows how you can remedy a situation. Importantly, “fragile fitness” doesn’t give athletes the right mental model to rectify the situation. Saying an athlete has “fragile fitness” is like saying “someone is living beyond their means”. Someone making $40k per year can live beyond their means just like someone who makes $1 million. Their lives will look completely differently, and the remedies will be completely different, too.
Jan Ulrich is the millionaire who spent his whole earnings on a single event (gross oversimplification, I know, but you get the point). Whereas many forum members who burnt out on a training plan fall more into the former category. Note that the spending habits were different, too, Ulrich was banking for a single event whereas most amateurs went bankrupt because they were spending more than they earned each month. Plus, I’m sure Ulrich and his coaches knew what they were doing, and that this wasn’t accidental but a deliberate choice on their part. These subtleties are not captured by calling both (rightly or wrongly) an example of fragile fitness.
This was me a few years ago. I didn’t get dejected per sae, but it’s all so confusing with all the different view points.
I feel like TR has done a great job on the podcast and other mediums talking about the one thing that really trumps everything when training: consistency.
But what would the internet be (especially forums and other places of dialogue) if it wasn’t full of conflicting information 
I didn’t make that equation. 
I think you just proved @redlude97 correct.
Every time there’s one of these threads there’s a bunch of what appears to be 50+ men who get really riled up about Z2 vs intensity.
I’m usually at a loss because it just doesn’t seem that crazy of a concept that what works for one won’t work for all. It wouldn’t surprise me in the least if doing more Z2 was a more sensible training approach for older athletes whose kids are grown and life demands have lessened to allow them to do traditional base and polarized.
I mean this with no disrespect, I’m going to be there myself before too long and I hope to be going strong like some of you are. I plan to be fully onboard the Z2 train when life makes such a thing remotely possible. I just don’t get why we argue about this topic as if there was only one answer.
And for my parting-shot humble-brag at the brittle fitness debate, I’ve gone sub-9 at Leadville the last 2 years on TR low volume plans. Proper fueling plays a far bigger role in extending my 2-hour fitness to all day fitness than “brittleness”. But I am fully ok with disclaiming that maybe I’m just a special little snowflake and individual results will vary.
You can make a solid case that doing more Z2 work as a younger athlete is more important since they lack the aerobic foundation when first starting out.
Whether they have the time for it is a different discussion.
As an anecdote. I raced xc last weekend on the back of on average 1 easy ride per week for the last 6 months plus around 3hrs running/wk.
I was really surprised how well I went.
Put it down to a lifetime of riding bikes. The opposite of ‘fragile fitness’.