Been back riding seriously for six months or so. I’ve found recently in my workouts that my legs give out on intervals long before I am actually that tired aerobically.
For example, When I do 3-4min vo2 intervals around 120% FTP, I sometimes find them very difficult to complete not because I am huffing and puffing or my HR is incredibly high (last night got up to 86 percent max HR) but because I lose strength in my legs.
Is this normal? I feel like sometimes these types of efforts should be as hard on a HR basis as they seem to be for my leg strength. Am I looking at things the wrong way, or do I need to take a different approach to training to correct for this?
Been back riding seriously for six months or so. I’ve found recently in my workouts that my legs give out on intervals long before I am actually that tired aerobically.
For example, When I do 3-4min vo2 intervals around 120% FTP, I sometimes find them very difficult to complete not because I am huffing and puffing or my HR is incredibly high (last night got up to 86 percent max HR) but because I lose strength in my legs.
Is this normal? I feel like sometimes these types of efforts should be as hard on a HR basis as they seem to be for my leg strength. Am I looking at things the wrong way, or do I need to take a different approach to training to correct for this?
Common experience for runners who get into cycling… cardio engine can rev much harder than the puny cycling muscles can handle. Definitely also consider upping cadence, as per other suggestions.
What power and cadence are you doing for those intervals? Type of trainer? Erg mode or no? Getting out of the saddle at all?
This is normal for me and I’ve been cycling for 10+ yrs. For most bike intervals and efforts my hr is never the limiter it’s always the legs. And I have big quads and glutes so I’m also surprised as I thought the big leg guys wouldn’t be more cardio limited but it’s def not that way for me on the bike.
Interesting, hadn’t thought about that. Looking back at my workout yesterday - for 4 minute intervals my cadence started around 95-100 and gradually decreased as I got more tired and finished most intervals around 80. Thoughts?
Thanks for the reply. Yesterday’s workout was 1hr Z2 followed by 4x4 at 120% FTP, 4x1 at 125% FTP, 4x30sec at 130% FTP. The shorter intervals I have no problems with. FTP is currently 282 so 120% target is 353 watts. Cadence starts 95-100 and gradually decreases to 80 at the end of the interval as I get tired. Saris Hammer H3 on erg mode, and no I stay seated the whole time usually.
Thanks for the reply. Yesterday’s workout was 1hr Z2 followed by 4x4 at 120% FTP, 4x1 at 125% FTP, 4x30sec at 130% FTP. The shorter intervals I have no problems with. FTP is currently 282 so 120% target is 353 watts. Cadence starts 95-100 and gradually decreases to 80 at the end of the interval as I get tired. Saris Hammer H3 on erg mode, and no I stay seated the whole time usually.
So you did an incredibly hard workout and are wondering why your legs are tired before you start breathing hard?
The intervals are too short for you to start breathing hard.
Normal. Some athletes are limited by their cardiorespiratory system and some are limited by their muscular system. If I had to guess you have a history of training other sports longer than you’ve been cycling.
For example, When I do 3-4min vo2 intervals around 120% FTP, I sometimes find them very difficult to complete not because I am huffing and puffing or my HR is incredibly high (last night got up to 86 percent max HR) but because I lose strength in my legs.
Sounds like you’re not recovered or possibly overtrained.
Thanks for the reply. Yesterday’s workout was 1hr Z2 followed by 4x4 at 120% FTP, 4x1 at 125% FTP, 4x30sec at 130% FTP. The shorter intervals I have no problems with. FTP is currently 282 so 120% target is 353 watts. Cadence starts 95-100 and gradually decreases to 80 at the end of the interval as I get tired. Saris Hammer H3 on erg mode, and no I stay seated the whole time usually.
Turn off erg mode. Constant watts with a 20% drop in cadence is a 20% increase in torque demand as you are tiring.
Retest your ftp. My guess is it’s too high, if you can’t hold 120% ftp for 4 minutes. What method do you use for testing your ftp?
Same as lightheir and lassekk - Cycling was the first sport I did and then grew into triathlon, still, legs always give out before the cardio. I think pretty normal.
You say you are “back riding seriously”. Did your legs used to not give up first?
Just to be clear in responding so this point doesn’t get lost: 353 is 125% of 282; 120% of 282 would be 339. OP either miswrote 120%x282=353, or misrode 4x4’@125%.
Classic cycling vo2max intervals should be limited to 120% ftp. 125% is unlikely to be sustainable for the typical 3-6m duration, by most people.
Again that assumes an accurate ftp (sustainable for about an hour). Soooo many people use some short ramp test or a 20m test without the blow-out, or whatever that overestimates what they can truly hold for an hour. That’s only made worse when escalating to things like vo2max.
I have the same problem as OP. I use 20min test as FTP basis. I can’t even do workouts with 3min intervals at 120% without my legs failing on the last couple reps. However, I am able to do 90min rides with an IF in the range of 0.90-0.93 on threshold workouts which always made me think my FTP was pretty accurate. Do I have spaghetti legs or just a poor understanding of how FTP should translate into achievable workouts?