Leg muscle tension and tightness comes in many forms. It can be pain that radiats down your buttocks, through your hamstrings in the back of your leg, down through your calf, and maybe even to your ankle through your foot. Or, maybe it's tightness around the knee, ankle, or hip from muscles being tight and you're unable to get them to release.
It's common even when you're consistent with stretching before and after workouts, especially if you're pushing trying to increase your mileage as a runner or bicyclist. Or, maybe, you're changing workouts to one that involves more jumping or hopping type motions, or even just adding more squats to your routine.
A sharp distinctive pain that comes on quickly during a workout and that doesn't go away after a few minutes, but instead gets sharper and starts hindering your full range of motion is likely a sign that you need to go ahead and stop what you're doing before actually injuring the muscle or tendon.
I've pulled my soleus muscle in my calf where it attaches to the tibia when trying to up my running miles and instead of stopping and resting my legs, I tried to continue to run on it for a week. So, what might've been a shorter injury instead put me out of commission for 6 weeks.
Just stop doing the motion that is causing you increasing sharp pain. Icing immediately with one of those gel icepacks will a lot of times alleviate the swelling and inflammation affecting that muscle or the muscles around a joint. And then rest for a few days until the pain stops.
Sometimes an injury can end up affecting the whole leg because it changes your gait as you're limping around. If you're unable to get the tightness of the seized muscle to release, then you might try alternating between those hot and cold packs that they sell at pharmacies.
Usually gentle stretching at this point doesn't really help when the whole leg is involved. If you're into foam rolling then that would be very useful, a professional massage is also a good option. What I like to do is use one of those electric massagers with the long handle and the two paddles on the head that alternate pounding at you, and massage the muscles of the whole leg myself, including the hip flexors, buttocks, and especially the calves. This way you can control how the massager is working around the sore muscle because you're trying to get the surrounding area to release as well. DO NOT massage an actual joint, instead massage the muscles that are tight.
Either way, you'll probably have to rest and not exercise for a while, or at least switch to a low impact workout that doesn't involve moving or flexing the injured area. And go to a doctor is you think it's a serious injury, but hopefully you didn't let it get to that point.
Things you can do to keep it from happening again, increase your workouts and workout intensity gradually, stretch before and after working out, and use an electric massager at the end of the day when your muscles are still feeling tight.
It's normal to be sore, a little achy, or have some muscle tightness, but sharp pain is something you want to take care of before it gets worse. If you have an injury that keeps occurring over and over, you might want to look at your body mechanics. Are your feet turned too inward or too outward, are your feet too far apart or too close together, is one leg a lot shorter than the other, so you might need insoles for that one foot? Just look at your form when you're exercising and see if there's anything you might need to fix.
