Thank you for your comments and good wishes. Catrin, your story is very similar to mine - I overdid things last year (2012) in an attempt to catch up with the stronger riders in our group and train for organized rides. In 2011 I was sidelined with tennis elbow and returned to riding in January 2012. I had a lot of catching up to do, and I did catch up and even surpassed some of them, but I did so in big leaps rather than gradual steps. I love to climb hills, and easily rode 82 pain-free miles last September. In late October, some strange symptoms started popping up:

1. At the very start of each ride (within the first 15-20 minutes), I felt a sharp pain in the left groin area. After several minutes of this -- just as I was beginning to think of ending the ride -- I felt a light "pop" and the pain was gone. I continued riding, and this happened only during the first 15-20 minutes.

2. Then I started feeling pain at the front of my left hip every time I raised my knee off the pedal after unclipping. I ALWAYS unclip on the left side with the pedal in the 12 o'clock position (not intentionally; it's just the habit I developed when I first went clipless). Raising my knee off the pedal (against gravitational resistance) caused a sharp pain at the front of the left hip, and the pain worsened each time. By the end of a ride, I wondered if I'd be able to raise my knee off the pedal next time, and trying to unclip on the other side almost caused me to fall. [My doctor believes this particular pain is a strain or tendinosis of the Rectus Femoris muscle at its attachment point at the front of the hip. It hurts when I raise my knee against resistance, on or off the bike, and has nothing to do with the position of the cleat or the fit of my bike.]

But did I see a doctor? Noooooooo! The story continues:

3. So, I thought a few days off the bike would do me good. On one of those days I went out for a walk... a 90-minute walk. I've done that many times before 1-2 days/week. We live in a hilly neighborhood. Just a few blocks from home, I felt various pains in my hips, not severe but enough to raise a lot of red flags in the mind of a sensible person. But did that stop me? Nooooooooooooo! I pushed on and walked for 90 minutes, up and down hills. When I got home, my hips and upper thighs felt like I either WAY overdid or hadn't done any exercise in years. However, I'd done this walk many times before and was regularly active. The worst pain was on the right side, at the very top of the thigh (where I now suspect a torn hamstring).

4. I did some spin classes at the gym. Each time, even on the stationery bike where I warmed up, I felt the painful "catching" pain in my left groin, then a light "pop" when it released. Twice when I got off the upright stationery bike (where I warm up prior to the spin class), I felt a LOT of pain at the top of my left thigh, and also some on the right, so much I couldn't walk without a pronounced limp. But did that stop me from taking the spin class? Noooooooooooo! I didn't feel any pain while spinning, but the pain returned after the class and I limped back to my car.

In late November, I finally went to a doctor who also is a PT. I did my best to describe all the various pains and pointed to where they occur. He took an x-ray of my hips and found NO arthritis -- in fact, the joints are clean as a whistle! So, that leaves soft-tissue injury, or worse -- so I contacted my provider (Kaiser) to schedule an appointment with an orthopedic hip specialist. I took my report and x-rays with me and described all the pains. He thought the sharp pain in the groin could be a labral tear, so he ordered an MRI to rule it out. He brushed off the pain I described on the right side as 'sciatica' (I said it's at the base of my glute -- I should have said 'top of thigh' -- and NO, it's definitely NOT sciatica!), and later changed the MRI order to left side only without consulting me. When I went back for my results which show a partial tear of the left hamstring, I asked "what about the right? It hurts more on that side". His answer: There aren't any films of that side. The next day, I wrote to the doctor and requested an MRI of the right side, and it's scheduled for next Wednesday with a follow-up to get the results the following week.

Meanwhile, I'm catching up on knitting and reading, and doing my indoor core/upper-body exercises to build strength and stability.

Is there a lesson here? Apparently I have a very high pain tolerance, so I need to learn to listen to the pain and STOP the activity when it hurts, and begin treatment immediately. Weeks, almost a month, went by before I began any treatment (ice, heat, anything). During that time, I continued stretching and doing exercises that probably aggravated the hamstrings. In fact, a torn hamstring never came up in any discussions with either doctor -- and these are GOOD doctors.

Apparently, one of the risk factors of hamstring tears is weakness and imbalance of the hip/pelvic/core muscles. I wonder if I first tore the hamstrings, which in turn set in motion a chain of events leading to pain in other muscles that tried to compensate for a sudden lack of power and strength in the hamstrings.

Sorry this is so long.... I wanted to share all the details in case anyone is interested and might have additional insight.