I’m not quite as fit as you, but close (I peaked at 4.7 W/kg last season). I would seriously caution you.
The issue is not your aerobic engine, that can handle an 11 km run easily. Your legs and ligaments cannot, they take more time to adapt. It reminds of a run I did on a business trip to Zürich, Switzerland: my hotel was directly on the foot of the Zürichberg, and when I arrived I decided to go for a run to stave off my jet lag. Since I hadn’t run in like 6 months, I thought I’d listen to my body and take it easy. I felt great, GREAT for the first 16 km. During the last two kilometers, I realized that the next few days were not going to be fun. In the end I did a little over 18 km with over 500 m of elevation. I couldn’t walk properly the next day.
Cycling and running are very different, running is all about managing impacts whereas you virtually have no impacts during cycling. Efficient running means your leg muscles should act like a spring whereas that isn’t a thing in cycling. I’d start ridiculously easy, think 15–20 minutes of easy running in the beginning. To your cardiovascular system that’s hardly a warm up. But you aren’t aiming to train your cardiovascular system here.
Also, keep the impact on cycling in mind: you are at 5 W/kg now. But if you want to get serious about running, you need to scale back your cycling. Is that ok with you? If you add a new type of sport or workout to your routine, even if that feels easy in isolation, it could have an impact on your cycling. I am re-learning that lesson for the umpteenth time after adding strength training to my routine. After the strength session, things feel easy … but I can clearly tell my muscles are fatigued when I am on the bike even after a full day’s worth of rest.
I’m pretty sure you’ll easily get in under 50 minutes. 5w/kg means you’re very fit and at only 60kg you’re perfect for running. A few years ago Tom Dumoulin, the pro rider, ran a 32:38 10k just for fun. That’s ~3:15/km. Granted, he probably was higher than 5kg/w at that time but even so, it shows you that if you have a good engine going you’ll be able to run fast.
I reckon you can do 3:45 - 4:00/km or ~ 37-40min for a 10k
Christ…I’m not nearly as fit as the OP…but I’ve peaked at 300 watts the last couple years. Running is torture…10 minute miles is serious work. Anything more than 1.5 miles at a time and I feel like my legs are going to snap off.
Add in 2 easy runs per week of increasing lengths depending on how you feel up to around 60 mins and you’ll be just fine, imo. Only concern I’d have is the barefoot shoes - have you run in the past? I know you walk in them, but running is a different game.
Provided you don’t get injured it should be easy. You are light which is what counts. I weigh 61kg and have an FTP of about 275W on the road bike. I have run 16 and change for 5k, 35mins for 10k 1:17 for a half and 2:47 for the marathon. My long runs were normally at about 7:10min/mile pace so 11k in 50 mins would be slower than my training pace for 22mile long runs. Not saying it wouldn’t take effort as I ran seriously for many years but you have the engine and you are not heavy which is what counts once you have trained muscles, tendons and ligaments to resist the pounding of weight bearing exercise.
in all seriousness… To get where you are requires more than hard training: you need talent.
OP at 300 FTP at just 60kg mean there is something there. So as long as you stay injury free and not try something too hard to quick or too often, you will make the 50… but I suspect you can do better than that…
I have no idea how to break this down for you, but your VO2max is probably in the neighborhood of mine with that number, likely a bit higher, and I’ve done a 36-min 10k back when I had a 240W FTP at 70kg as a triathlete (now closer to 300W), so I’d say you’re absolutely capable. Lots of factors there, with efficiency as a runner being key, but you’re light and that’s a good place to start as a runner.
I don’t know much about the accuracy of the Garmin estimates, but that number isn’t unreasonable for you. I’m a high-60s to 70 type guy. Essentially your aerobic capacity isn’t going to be the limiter for you. Efficiency, technique, fatigue might be factors but 50 min for an 11k is well within your physiological capabilities, IMO.
Haha - yes but not at the same time - I don’t run long distances anymore but my running fitness transferred pretty well to cycling (I did 269W for a 72min 30mile road bike TT last weekend) so going the other way should be doable provided you stay injury free. That said I still do the odd 5k parkrun in 18mins and a few winter 10k in 37 mins for interest in between the cycling so I can still run a bit…although since I’m nearly 55 then I do have to space them out to avoid injury. The key thing is the 60kg - that is why there are many eating disorders in running - lack of weight is key so if op is naturally like that you are on to a winner!
Oversimplifying it… bigger impact and you are pushing more weight (two rolling wheels is a huge equalizer). Essentially the bigger you are the less efficient you are. You have to run everything (no coasting downhills). Think of it like the entire ride is either uphill or steeper uphill. The lighter rider would have an advantage. 6 feet tall is also pretty tall in the endurance world, though not rare and more common in the middle distance realm due to stride length.
I have never been nowhere close to 5w/kg. At around 4w/kg I mainly ran one summer. The basic intense workouts were accumulating 4*2000m at 3.35-3.45min/km with 2min rests, and a 10k at 4.15ish. The latter felt very easy, from the go, mid-tempo kind. Never got to do an all out 10k but 37min was what I eyed.
All running specifics notwithstanding, my guess would be that with that engine a lot more ambitious target is appropriate, even a sub-40, if you have a reasonable gait. Just take it easy with the joints and ligaments, as many others others have said. Short, semi sprinted strides used in moderation and glute work are your friends
Yep - it’s weight bearing and thus you have to carry yourself rather than have the bike do it for you. In addition running reduces the size of your leg muscles if you do a lot as it inhibits muscle growth. That’s why triathlon is such a fine balancing act. The bottom line is if you have skinny legs it improves running economy - although doesn’t do much for your bike power! I run less than 15 miles/week now so it’s not much of an impact on my cycling - but when I ran 60miles/week it did! That said there is a happy medium. I ran a 2:48 marathon on 30 miles of running a week plus 2 weight sessions and 5 hours on the bike and I did a negative split so there are cross training benefits (and I went out super conservative because I thought I hadn’t ran enough!)