I've been occasionally feeling sharp, split-second 'twinges' of discomfort or pain in my right leg. Initially it was just one small area of the medial hamstring a few inches above the knee, but now I feel it also in the upper calf a few inches below the knee as well as a more lateral area of the hamstring. The first twinge is usually just a little odd-feeling, but they get progressively more painful if they reoccur during the same ride. No residual pain, bruising, apparent effect on muscle strength or flexibility... but in the interest of not making this any worse I typically turn around and slow-pedal home once I feel it come on.

It's been going on for about a year now and has put me off racing or serious training for fear of making it worse. When it happens, it's usually 45 minutes or an hour into a ride at a tempo-ish pace but I've felt it both on shorter and easier rides. I used to experience them a couple times per month whereas now it may be every other month, but my ride intensity has also gone way down.

I began seeing a sports medicine doctor for this about a month after it began (it's being treated as a form of muscle sprain), but so far it has resisted the prescribed physical therapy of hamstring exercises and stretching. I also saw an out-of-network specialist with a chiro background who thought it might be fascia-related and recommended regular trigger point therapy, which I didn't pursue due to cost concerns.

Curious to hear if there have been others with similar symptoms, and whether they were able to be successfully resolved. I'm still fairly young so was hoping this would resolve itself as most of my past injuries have, but this one has continued to linger.

There's not enough to go on except to rattle of lists of possibilities. These sorts of things are hard to diagnose because it's not possible to duplicate the process and even if you could, there may be nothing to spot except the pain itself.

Often, the only proof of a correct diagnosis is the cure itself.

In your shoes, having started with a sports doc, I'd return and explain that the cure isn't working and ask that he explore other possibilities. In fact, I wouldn't have waited nearly a year before declaring it a failure.

Also keep in mind that these pain only cases can be tough because we often feel pain in the wrong place entirely, and the true issue could be something like a spinal issue, or electrolytes, or maybe as simple as a poorly aligned cleat.

I too have experienced similar symptoms primarily in both of my hamstrings. It starts off as a twinge then works into full muscle spasms (if I do not relent on my pace or limit my climbing). I chalked these symptoms off due to dehydration, loss of electrolytes, overuse of weak hamstrings and part of normal endurance training.

My 'cure' over several months of experimenting included:

1) stretching, using a foam roller to help stretch the I-band, glutes, hamstrings, gastros, quads and lumbar regions,

2)supplementing with Endurolytes during long rides, adding magnesium, calcium and potassium with meals before rides and adding Cytomax to my hydration during rides.

3) strength training incorporating squats, lunges, deadlifts, leg raises, shoulder presses, pushups, planks and lateral leg raises, and

4) I increased my seat height by an inch, moved my seat back about a half-inch and moved the cleats down about a quarter-inch. (I really need a professional fitting) and

5) taking five minute rest breaks every hour to get off the bike, properly hydrate and stretch during longer 4 to 8 hour rides.

With all this, the problem has ceased. YMMV, Hope this gives you some ideas for your own cure.

My instinct would be to hit them harder, whole legs, not just hamstrings, i.e. heavier weights, slowly working up to weight which you would fail to move after the 5th rep. But be very careful of form for the hamstrings. Have a trainer help you with that. And do exercises in the same range of motion as on the bike. I've always found that heavier weight heals faster. "Gotta stimulate 'em."

At one time when I was younger I played lots of tennis including tournaments. While visiting a chiropractor for a lower back issue, I brought up chronic soreness in my racket arm. He was either a body builder or power lifter and may have had some familiarity with muscle soreness. He prescribed a series of exercises, using a very light weight that had the effect of stretching the arm muscles. I had suffered with the condition for many months but to my complete surprise I felt relief in just a few days and in a few weeks it was gone. My suggestion is you find someone with a sports medicine background. If they happen to also be an athlete, even better.