Performance Limiter: Muscles over Cardiovascular System

During the last 3 years, I started taking roadracing quite seriously. Before that I did some “competitive” running (Sub3 marathon) and was a Just-for-fun mountainbiker. Since starting to use TrainerRoad 2 years ago, I am making improvements (FTP around 300/75kg, 31 years old) and perform quite well at smaller local races (front group for the win, if the race profile suits me).

However, my main obstacle with regard to racing as well as recovery is ALWAYS muscle soreness. In a race my limiter is always my muscles starting to blow up or even starting to cramp. It´s never my heart rate. It even feels sometimes like I could have gone harder from a cardio point of view, but my muscles just will shut down at some point. This is not only bike related; also when I did the running stuff, muscular problems where always my main limiter. Even though I cannot be 100% sure (I did not test), I do not think that this has to do with unbalanced electrolyte levels, because I consider my diet to be quite good and balanced.

With TR workouts, this becomes especially obvious when doing sustained long intervals at threshold or even sweet spot. Often this workouts are far more taxing for me than hard VO2 Workouts. Same goes for races: Sprinting is quite good and flat races with short but punshy climbs are my favourite ones. Longer, sustained climbs are nightmares for my muscles. My goal ist not to become a great sustained climber, but to get somehow over those longer hills to stay with the front group, so I can play my strengths.

My questions:

  1. What´s the best way to train? Doing even more longish interval efforts to get my muscles used to it or doing the opposite and concentrating a bit more on VO2 max stuff that get my heartrate up? I am a bit afraid of sacrificing my short-power strengths, if I go for more sustained intervals.

  2. Any advice for recovery and nutrtion? I feel that increasing the protein and carb intake with shakes directly after workouts helps just a LITTLE bit. The sames goes for stretching and blackball rolling.

Many thanks in advance!


Sounds like you may know the answer already, muscular endurance could potentially be the limiter, so as you have said more sweetspot and long intervals will definitely help this. Assuming you aren’t already at the upper limit of what you can already do in this zone.

My question would be, have you completed a base, build, peak cycle. If not it is something that is definitely worth doing, and if so it may be worth extending the base period, or trying to substitute some of the weekend sessions for longer rides.

For your current sweetspot sessions, what kind of duration are you doing, and is there any potential for a progression there. For example if your standard SS session is 3x20min, moving to a 5x15 or 4x18min session is a nice progression that shouldn’t be too hard to handle.

I wouldn’t worry about your short period power for a couple of reasons, firstly it doesn’t sound like it limits you, it sounds like long efforts limit you and thus you should focus on those. Especially given that you are road racing which is predominantly an aerobic sport. Secondly, it takes longer to train the aerobic system than the anaerobic system, any losses in the anaerobic system that you lose because you focused heavily on longer period training for a few weeks can quickly be regained. You could even just add one anaerobic session a week during this period which should maintain your top end power.

Finally, it may be worth incorporating some on and off bike strength work into your schedule. Doing some low cadence (50-60rpm) intervals on the bike would be useful. Something like 6x5min at threshold at a low cadence helped me a lot, and doing gym work as well will help. I don’t think you need to do these year round but doing them or a few months one or two times a week should help.

Anyway, those are my thoughts, hope it is in some way helpful.

Also, I find my muscle soreness much reduced and performance during sessions much greater when I have a lot of glycogen on board. I really focus on getting my glycogen levels topped off in the 8 hours before a session (with lots of low gi carbs, wholegrain rice and oats) and it helps during and after. I find if i have a fish and vegetables or something to that effect immediately after the session it helps a lot. I also almost religiously take a ‘treat’ before any hard session, like a cookie or something to up my blood sugar and I find it helps, or maybe I have just developed a dependence on it. Also, I do intervals in the evening, so I plan my nutrition through the day rather than the night before, not much experience with hard sessions immediately in the morning.


Yes, I did the full base/build/specialty cycle. But the focus was never on sustained power. I always did general build + rolling road race. Was even thinking about dloing short power build to play my strengths even more.
I do some extra SS session besides the plans. Mostly kind of short ones like garrowby (5x3-4 minutes spent between 88-92% FTP). Sounds like I should try to progress and focus on longer ss intervals.

If you’re doing extra SS work, you should try really extending your intervals. With some practice you can and should be able to ride hours, not minutes in SS. I started experimenting with this by skipping rest intervals in TR SS workouts. I prefer to do these efforts either freestyle while watching race footage, 85% FTP on flats, 95% for climbs or as 95/85 O/Us in 5min sets and 30-60min blocks.

I’m similar to you in size power (70kg/320w) and have always been better at short power as well. I used to struggle with SS and long Threshold work and can now spend 3+ hrs at 80-90% average. I know I’ve lost a bit in short power but that comes quickly for me and the increase in fatigue resistance is very noticeable when surging repeatedly over threshold.


Have you experimented with higher cadence? The old rule that lower cadence taxes your muscles and high cadence taxes your aerobic system might apply here.

(I realize that old rule is a bit controversial…)

Do you take a recovery shake? I found it to be a game changer, essentially eliminating muscle soreness and opening up bigger gains from the workouts. Like you, I eat pretty well and didn’t think I needed it, but after trying it, my body has clearly voted otherwise. You might want to try different brands to find one that works well for you.

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Sub 3 marathon shows you have a good aerobic engine. Muscles blowing or cramping could be as simple as race hydration and/or nutritions. What kind of racing and duration are we talking about? and what do you typically take in during said race?

Without getting into a religious debate on cadence, what type of cadence do you typically end up racing at? doing your TR workouts at? As @Mark_Rebuck said, lower cadence is more muscle fatiguing vs higher cadence which more cardio taxing. It is all relative depending on what you are accustomed to in training.

Longer high end tempo or sweetspot workouts should help w/muscle endurance. Check out the Spruce Knob, Cumberland, Gibraltar, Polar Bear series of workouts. I would aim for 80-85%. Also, vary the cadence for part of the workout (e.g., half at 85rpm, half at 90rpm). The point being to do part of the workout at a cadence that is not natural to you, which requires some concentration,.

Yes, I have and it helps a ton! A high Cadence has become quite natural for me.

Sometmes I take some almond milk mixed with a banana, honey and some whey protein. Not that huge amount of carbs. Perhaps I should raise the carb intake? How soon do you take the recovery drink? Directly after each workout? Do you use a certain type of brand?

Mostly road racing, 60-120km (35-75miles) with elevation changing from lmost zero up to 1500metres (5000feet). My cadence normally ends within the range of 90-95. During races I use some carb hydration mix in the bottle and gels (roughly 2 per hour).

Sounds like nutrition is probably sufficient. You can experiment w/more carbs/hour during your training to see what you can actually take in during sustained efforts at tempo and above.

Regardless, doing long sustained high end tempo / low sweet spot efforts might be good for you. For example, can you ride at 80% (250W) for 2hrs? 3hrs? You def have the aerobic engine for this, but do your legs have the muscular endurance.

80% for 2-3hrs sounds almost impossible to me :slightly_smiling_face:. In races I often ‘hide’ in the pack for the most part of the Race and then go hard for the final part. A breakaway on my own is not realistic for me.

So, it sounds like I know in which direction I have to train more: sustained, longer sweetspot and threshold efforts.

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The research I’ve seen referenced most frequently is to take on high-protein recovery nutrition within 30minutes of the workout. I unclip from the bike, walk straight to the kitchen, and mix up a shake. So I’m taking it within about 5 minutes to maximize the benefit of my residual elevated metabolism pumping the nutrients to the leg muscles.

Doesn’t sound to me like you need more carbs in the recovery shake, but you might want to check if it has enough protein. I’m currently using SIS Rego shakes, which give 13 g protein. Before I got into shakes, I would eat a hard boiled egg for protein recovery, but that’s just 6 g protein (and isn’t faster-absorbed whey protein), and apparently too little / too slow-acting for my body.

Hi, I am interested in this thread. I would like to know what you did to improve or if you are still having the same issues. I have the same. I cant stop having sore legs even during SSBLV.

To begin with, still my muscles shut down before my heart rate does explode, but I have made some experiences in the meantime.

There are several minor adjustments that I made:

  • Up my carbohydrate intake a bit more
  • Fuel for th rides
  • Recovery drinks direcly after the ride

Those definitely help a bit, but did not drasticlly change the way I felt. Still mucle soreness was present most of the time. Also the goodgement advices in this thread did not help. Honestly, adding longer sweetspot rides into my training regime made things even worse sometimes.

However, that was the winter of 2019/2020. I was mostly following TR plans (SSB1 / SSB2 / General Build). Looking back, I think it was definitely too much threshold training with too little rest. So, adding more rest is the first thing I would look at.
For this winter season, I made a drastical change and switched to a polarized approach. This season, I started winter training in late November and since then I did not do a single SS workout. Only basic endurance (around 65% FTP in my case, no heart rate drift up to 2hrs) and hard intervals (VO2 max, 1 or 2 per week). I definitely feel fresher than the winter seasons before! of course, I cannot tell how performance will go in the long-term, but so far I am doing better than ever before.

I hate to say that, but I do not see myself going back to TR plans. I really like the guys behind TR and their workout library an general training platform (still use it fo my training), but for me it did only work for one winter. The second winter was hard, the third was breaking me. It is a bit funny, because I experienced all the things that advocates of a polarized approach preach.

What I think is really important: I do think that a lot of this has much to do with your mucle phenotype. I am more of a fast twitch guy (good sprint, etc.) and think that such a type is doing better with a more polarized approach. For slow twitch endurance guys I can still see the TR plans being a good strategy to implement.


Hummm, thanks for sharing, those are really interesting experiences…
After being on TR platform for 4 years, I finally found motivation to do a really focused indoor structure, in one part because I hate the plateau of fitness I got into those last years by riding hard outside all the time… and as I get old (40 this year), I just want to give it a shot to get to the best form of my life… I made quite a progress in the gym, I have 2 months of the classical plan behind and I am really curious what is going to happen.
My Garmin watch still wants to lower my ftp after each longer training session (from 253 to 245 on Sunday), but as long as I can finish the training, I am going for it.
For now, I decided to give it a try, trust the process and complete a full half year of TR plan and that we will see. Yeah, polarised 80/20 approach seems really sound in my opinion, so I hesitated a lot which direction to go. I try to fuel myself and get the best sleep as I can and will believe that sweetspot work will make me really strong for the spring. After all, my all-time best ftp was around 270W and I was never so “close” to it during winter, I usualy dropped to around 235…
But my goal is to get over 300 watts, so we will see I guess :slight_smile: If by May my ftp doesn´t go nicely higher, I will get back to the drawing board and reconsider the strategy…for now, I hope for the best :slight_smile:


Just curious what your weekly hours tended to be back then and now?

My first thought reading through the thread was just that general aerobic conditioning might improve the situation. When I see threads about muscles vs cardio, I almost always think the problem is cardio. I don’t think there are many times where strength or force production is the limiter on the bike, I think it is almost always cardio. I don’t think it matters if it feels like you cannot breath enough, or your heart is beating like crazy, or your legs feel like they are going to explode. The underlying issue with all those conditions is a cardio limiter (aerobic energy production) unless you are in one of those few situations where force production truly is the limiter.

If you are more of a fast twitch guy, you might over perform on ramp tests and then all of your subthreshold interval targets would be too high. I would guess a 20min test would give you a lower FTP and tempo / sweetspot / threshold power targets would be more reasonable.

I would think the same but I am REALLY sure that my aerobic base is good enough. in 2020 I rode 18.000km on the bike and run 650km. During the winter months I decrease my hours. With sweetspot I could not handle more than 8-10hours. With lots of Z2, 16hours is still fine for me. During summer time with outdoor riding, I sometimes reach the 20hours mark. In the end I really just think that it was a combination of too much middle intensity with a propably over-inflated ramp test (see below).

That is definitly true and one (very important) thing I forgot to mention. I think I overperformed the ramp test for sure. As a general guideline I decreased my ramp test result by 4-5%. Definitely the way to go. Still, I think that threshhold training drags me down over time. I am thinking of doing like a threshold block of maybe 3-4 weeks before the real season starts, but as a general training principle I will stick to a more polarized approach.

hmmm, I don’t know. Can you up that volume a little bit and see if it helps??? :joy: Just kidding of course. I’m a TT-type and I would not want to do 8-10 hours of sweet spot a week, even though I enjoy it quite a bit.

I am interested to hear how it goes with after the 3-4 week threshold block. I haven’t seen much information online about building a periodized plan for a year or season that starts with a polarized base. I don’t have a good understanding of what people do after the polarized block or if they just keep going indefinitely. The one progression I found sounds similar to what you described. Polarized ‘base’ phase, then threshold focused build, and then taper. It was for triathlon, so I believe the plan was for peaking for a specific race.

Yeah, in general that is the Idea. Build the engine first and become more specific towards Race phase. But I think for me it’s more a matter of changing the stimuli.

However, I will first see how the next weeks go and then decide.