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Unexplained leg weakness. Need a diagnosis!

Aldo82Aldo82 Posts: 4
I have a totally unexplained weakness and cramping in my left leg when cycling which has prevented me bike training for 8 weeks now. I've been to physio, Osteopath and to see a sports doctor and still don't have a diagnosis. So I thought I'd ask for advice on the internet instead!

I'm a relatively experienced ironman athlete and was training for my 4th ironman. Bike training was going really well and I'd bumped my FTP up to the highest its ever been.

Then during a maximal 20 min FTP test my left calf felt like it wanted to cramp from about halfway through the effort. It didn't, but the crampy feeling remained throughout and then was really bad on the cool down. Once I stopped though I felt mostly fine. Worth saying that this wasn't painful. Just weird.

Biked again a few days later and the problem came on about 80% through the session. I had to back off.

Took a few days off then the next time I biked the problem came on sooner. Then the next time I biked it came on at even lower power and I struggled to get through Mont Albert - 1 on trainer road. The cramp feeling was the same but also I felt I was losing power in the left leg. No pain just loss of power.

So I had 9 days off and had 3 physio appointments to treat the calf directly. I tore it years a ago and it is quite knotty so the physio worked on that. The next time I biked I lasted just 30 mins at an average of barely 150 watts.

I saw an Osteopath to check if this was coming from my back and he felt things were fine in that area and mainly focussed on my calf. The next time I cycled, I lasted just 18 mins. I have a wattbike and when the problem is happening it is clear on the polar plot as my left leg output drops significantly.

I tried to battle on for the next week or so trying easy bikes every so often with stretching and foam roller work and whilst I did get through an hour one time, it was at an average of around 160 watts, 40 or so below ironman intensity. I tried Leavitt - 5 on trainer road which has an If of 0.67 and I had to stop after 45 mins. It was too much.

So, I decided to take 2 weeks off. In that time I saw a sports doctor who did an ultrasound on my calf and he felt it looked OK. After the 2 week break and armed with the fact that the sports Dr didn't seem worried, I tried a bike again and I lasted just 12 minutes. The worst its been!

So I'm 8 weeks on and I am no better, in fact I am worse. To add to the confusion, I am able to run. I have taken time off the run too along the way but ultimately I don't have the problem running and so the physio and sports Dr have both said carry on. Whether I run or I have a break from running, there doesn't seem to be any impact on cycling problem.

I have googled the problem and haven't found anything about a calf problem that only affects cycling and not running. Given the ultrasound all clear results, this is therefore probably a referred problem which I guess could be related to bending at the hip in the cycling position.

I don't have pain but I have loss of power and a crampy feeling (but hasn't actually reached cramp) so what could it be? Piriformis syndrome affecting sciatic nerve? But why pain free? Or a vascular problem which is stopping blood supply? It has to be something!

Impossible to diagnose over the Internet I know but I would be interested to know if anyone has ever come across similar and if so, what was the diagnosis? Even if this gets better I feel it will be hard to come back without a diagnosis as I will never know how to stop it happening again.

Any thought appreciated!


  • sungodsungod Posts: 12,663
    might be worth trying a specialist centre like iseh, i've used then a couple of times with excellent results, the in-house facilities are way beyond what's likely to be available to 'standalone' therapists/doctors, and there's a multidisciplinary team which reduces the delay/miscommunication that can occur if you are going between separate organisations
    my bike - faster than god's and twice as shiny
  • webboowebboo Posts: 2,673
    I had a condition when running where my left calf would cramp/ get too painful to run on. So I would have walk home, it would be reasonably pain free the next day and within a couple of days it felt ok to run. However the same thing would happen if tried to increase the distance of my run.
    In the end I just stopped running and rode my bike( I never experienced it Cycling) However when rockclimbing I was pushing hard off my left foot and I felt something pull and it felt very similar to the above. I had physio on it and they thought it was a calf tear, but it cleared up very quickly with treatment. Which puzzled them and they wondered about a differential diagnosis. One of the physio’s who had worked with a professional football team mentioned a little known condition which is some how your muscle is getting a message there is hard work coming it’s way and it goes in to shut down mode.
    So it feels ok to train on but soon as you push hard it goes in to spasm.
    I don’t know whether this will of any use but you could be experiencing something similar. The main advice was avoid stretching before exercising and a gradual warm up.
    Subsequently I did rupture my Achilles on that leg whether it was connected who knows.
  • Aldo82Aldo82 Posts: 4
    Thanks for the replies so far. Iseh looks really interesting. One thing that bothered me about the sport Dr i saw is he didn't have the facilities to look at me whilst cycling or straight after when the problem was happening so perhaps I could get that investigation there.

    On the muscle shutting down at fear of hard work in some ways that's plausible at the start as I had done a lot of work on the bike - maybe too much - but I would expect that to be settled down by now as I haven't pushed the muscle at all. Plus why doesn't it happen when running which surely uses the calf much more?
  • svettysvetty Posts: 1,904
    If it was a blood supply (claudication) issue it should manifest itself when running too - especially running uphill. If this doesn't happen I doubt it's vascular.....
    FFS! Harden up and grow a pair :D
  • zefszefs Posts: 484
    Have you done a professional bike fit? If something is off on the fit you may not feel it during regular rides but when you start adding more/harder training it can cause injuries (that make you have to stop) and can go away only when you address the problem.
  • Aldo82Aldo82 Posts: 4
    Hi, thanks for all the replies. I'm away at the moment so hadn't had chance to check back.

    Yes I've had a professional bike fit and the fit has felt bang on for many months of hard training. Since the problem I have started playing with the fit a little but nothing has made a difference.

    As I'm away, I'm having another 2 weeks off the bike and hoping when I get back I can get on the bike and all will be better!
  • zefszefs Posts: 484
    Could be overuse of the muscles, doing too much too soon.
  • mustolmustol Posts: 134
    Don't know if this will help or not, but I have had a similar issue. I took up road cycling about 8 years ago, aged 40. About a year later, I sometimes started to lose feeling/power in my left calf and foot - when it got bad, my foot would sort of cramp up - the toes will curl and I could not put any power down with my left leg. My left heel would also drop quite noticeably. This would be worse on long steady efforts - frustrating as hell! I also suffered from some lower back issues and when my back felt tight, the problem was worse. Anyway, I have been to see several physios/osteopaths and have had tests at hospital including an MRI scan. The tests didn't reveal any clear physical issues. Physios/osteopaths came up with a few possibilities and I was given various different exercises to do, but for years it never really got any better.

    I've felt all along that there is some kind of nerve irritation involved, possibly piriformis syndrome - but what is clear from all the reading I've done is that it's almost impossible to diagnose and even harder to fix - targeting the piriformis muscle without working other muscles around is tricky! The other thing that was mentioned by a physio was that my glutes weren't activating properly - but the work he did and exercises he gave me made no difference. I did feel that this diagnosis was the best so far - when I did hard efforts on the bike, I felt soreness in the big muscles on my right leg, but not my left - as if the left leg muscles hadn't been working properly.

    I started doing some left leg single leg pedalling whilst out cycling and on a gym bike. I wouldn't actually unclip the right foot, but just tried to let it float and get the left leg doing all of the work. This seemed to help straight away - I was really able to focus on what the left leg was doing and trying to feel that I was using the big muscles i.e. glutes and quads. Over the last couple of years, the problem has gradually eased - it feels like I'm using the bigger muscles. There is still a feeling a slight weakness in my left leg and I still occasionally get that feeling in my left calf/foot, but am able to shake it off quite quickly. It certainly isn't spoiling my riding anymore and am able to do some hard training efforts. I did a lot of cycling last week - from Sat to Sat, I did 250 very hilly miles, spread over 7 rides and my symptoms were very minor. It's been a long process, but I seem to be getting there.

    Might be worth giving it a try! Anyway, hope you get it sorted out - be patient, I'm sure you'll get there.
  • thejazmanthejazman Posts: 12
    Hi Aldo

    Sounds like it could be an electrolyte imbalance.

    Often if we're deficient in magnesium, iodine, zinc or selenium amongst other minerals we can get the exact symptoms that you are describing. To know for sure you'd need to test for your electrolytes.

    My personal recommendation is to seek the support of a functional medicine practitioner. If you PM me I can give you some practitioners depending on where in the world you are based, Also if you Google 'What is Functional Medicine' you can find resources there.

    Good luck

  • Same. I've been encountering this leg cramps recently when I do cycling. There was even a time when I did cycling around the woods and my legs suddenly got cramped, I sat there for almost 1 and a half hour holding my leg. Luckily, I have my important devices with me and notified my parents right away.
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