I am seeing PT’s, doctors, etc. to help me on this, but thought I would look for some real world input. Here is my problem and it only really happens when racing. On the bike, generally 3/4 of the way through, sooner if the effort is higher, I experience my bike starting to tighten up on the very lower part, just above my short line. The feeling is super painful, but uncomfortable and not isolated to any one spot, i.e. it is not acute. BUT, when I come off the bike and get on the run, it feels like someone is sticking a knife in my lower back pretty much in the middle, just above my short line. It is pretty much debilitating. I have been able to fight through it and it can and will loosen up within a few miles, but basically the first three miles of my run are shot with the run/walk approach. I especially feel it when I am going up hills. Has anyone out there experienced anything similar, and more importantly, what did you do to prevent it? Bike fit, core strength, stretching the hamstrings? I would appreciate any input. Thank you.
If it’s happening only when riding, strikes me as likely a bike fit issue. Could you be too stretched out?
As some who just had surgery to repair a herniated disk 3 weeks ago, I cringe at hearing your story. Hammering in the aero position puts ALOT of stress on your lower back and spine.
Personal experience: I blew my disk the second time (in June) by hammering up a short steep hill and using my back for extra torque (uhhh, bad idea). Incidentally, I blew the first time in an OLY on the bike as well, but once I was able to stand up and run, the pain went away and I ran fine. Next day, uhhh, it was not so fine.
If you have a hard time standing up straight after the bike, or pain in your butt or hammie (like you wanna stretch, but streching is not helping), then by all means so see a good PT.
Otherwise, I start doing ALL of the above things you mentioned… core (both sides, front AND back - pilates is great for this), hamstring stretching say 10 minutes leg against a wall both legs, and yup, make sure your bike is fit correctly.
GOod luck. You DO NOT want to end up like me.
cerveloguy said wha I was thinking. Take a look at your reach.
I agree it could also be a bike fit issue so you need to get this checked.
I’m a sports massage therapist and work with alot of cyclists and triathletes. Every year I get a few in the couple of weeks before a a hilly race, saying they have “done their backs in”, reporting similar pain to what you have. On looking at closely at what they have been doing, I find that they have been riding lots of hills, probably more than usual. When climbing you are usually sitting further back on your seat, so therefore engaging more glute and hamstring. Hence lots of hills = more work for those particular muscles. Often the same happens when people are racing, hilly or otherwise. In this instance, often the pain they feel in the back is referred pain. I don’t usually work much on their backs, but focus on glutes and hamstrings, especially at the area around the sit bones. This is one of the few situations where the results are usually instantaneous. However if I’m in any doubt then they are sent for further assessment by someone with more training than what I have.
For self care, I get them doing general glute and leg stretching, not just hamsrings - adding an adductor stretch always seem to be helpful too. Plus lots of rolling on a pilates roller or tennis ball.
I used to get a similar pain coming off the bike, “only when racing” also. Not fun running the first mile or so feeling like I had an icepick in my back. For me it was a bike fit issue. I had lowered the front end which made me reach out more. As some of the others suggested, that may be your issue. Good luck.
Chris G - that is exactly how I would describe it! An ice pick in my back on the run right after I get off the bike. Frustrating part is that I was fit by a prominent fitter in Northern CA, but I am going to try someone new and even think about sizing down a frame. I ride a 54 cm P2C and am 5’10" (30 inch pant inseam), but maybe I need a 51 as the saddle is currently as far forward as it can possibly go. I was thinking though before we got into the discussion of reach that going down a size smaller in frame would have to make me bend over more…but if it is more reach than actual bend in the back that we are talking about, a smaller frame with shorter reach might be the ticket to solving my issues.
A shorter stem and or adjustable extensions may be an easier solution than a new frame, but then any excuse to buy a new bike is a good one in my book. Try riding with your hands farther back on the extensions and your elbows further back on the pads. That should give you an approximation of the fit you can acheive. Don’t tell anyone, but I actually solved my issue by adding a spacer back in 
I have nearly the exact same situation as you. I have sharp pains in my left lower back whenever I’m in a race. I suspect that it happens in a race b/c I’m in aero for such a long time whereas in training around somewhat suburban areas, I’m out of the aero position a lot. If you want to try to train through it, train out in the country and never get out of aero. As for what’s causing this, it could be different things. Is one leg longer than the other? This could be putting more strain on the side that hurts. What about your pelvis. If your pelvis is tilted, it could lead to one leg being longer than the other. Are your cleats positioned the same on both shoes. For me, the pain goes away once I’m off the bike so I don’t have any issues running because of it.
I ride a 54 cm P2C and am 5’10" (30 inch pant inseam), but maybe I need a 51 as the saddle is currently as far forward as it can possibly go. I was thinking though before we got into the discussion of reach that going down a size smaller in frame would have to make me bend over more…but if it is more reach than actual bend in the back that we are talking about, a smaller frame with shorter reach might be the ticket to solving my issues.
I’ve never noticed that reach was as much of an issue as seat angle. Of the two Cervelo’s I have used, neither allowed me to move the seat far enough forward to be able to ride well and/or be very stable. Whenever I have tried to ride farther back-around 78 degrees–I always have lower back issues.
I just borrowed a P2C from a friend and it is a 51. I am just a hair under 72" and normally ride a Yaqui. Interestingly enough, I measured the seat tube on both bikes and they were nearly the same. The biggest difference is the seat tube angle–Yaqui is a 81.5 with the nose (of an SM Azoto) about 3cm in front of the bb; the P2c is maybe 78, probably closer to 76, and I could only manage about 1 cm in front using a much longer saddle (Profile tri strike). I started out with the same drop on both bikes, but then dropped the front of the Cervelo with a negative rise stem. I needed a 130mm stem to increase the cockpit length and I have to ride the very end of the saddle to get my hip angle open enough to pedal hard. I raced the P2C this past weekend and was fine–as long as I was hanging off the end of the saddle. When I would slide back, my butt and hamstrings would really feel tight and I could not generate any power. Unfortunately, the clamp on the carbon seatpost cannot handle the pressure of riding that far forward without slipping. When you hit bumps it slips and I ended up about 2cm lower at the end. I rode pretty fast, but I doubt it would be sustainable for very long and the seat clamp issue would have been a problem had I not been nearly finished with the ride.
Chad
If your chiro says this is disc related ignore what I’m about to say.
Otherwise some areas to rule out are tight psoaz and QLs. I’m surprised no one has mentioned this. It is very common to get a tight psoaz which in turn tightens your QLs (lower back). A bad bike fit could be the root cause as well simply tightness.
When you get off the bike after hammering in the aero postion, does your butt stick out? If yes have your chiro show you how to stretch your psoaz and illiopsoaz (sort of under abs and acts like a hip flexor). If this is tight it can make your QLs scream in pain—espeically if you are stretched out on a bad position on the bike.
from personal experience, it sounds like you have really tight hamstrings that are contributing to, if not primarily causing the pain. I biked across the country a few years ago and had the same thing. being bent over on a bike, especially in the aero bars, pulls on your lower back, and if your hamstrings are tight they pull even more on your back. It probably hurts on the run because you use your hamstrings more running than you do biking. As other people have said, you probably want to get your bike fit checked out as well, a less agressive aero position might actually save you time by helping with the pain. stretch stretch stretch your hamstrings. it will take some time, but i really think that will help. i was almost at the point of quitting cycling until someone told me it was my hamstrings and totally something i could control. good luck!