I've done a whole slew of exercises focused on remedying this. In the last post I focused on feet and calves; here I'll detail what I've found most effective and time-efficient for the muscles above the knee, as well as a few additional general exercises.
Glutes and Posterior Chain:
- Reverse planks -- These target the erector spinae, glutes, and hamstrings. Basically, you lie on your back, legs straight in front of you, then prop yourself up on your elbows, with your lower arms parallel to your torso. Then fire the glutes (don't forget to engage your abs) and lift your rear off of the ground, so that you have a straight line from shoulder to heel, with your only points of contact with the ground being the back of your heels and your lower arms (including elbows). Here's what it should look like (I hate "fit sugar", but the graphic is a good one).
Once you're in this position, you can either hold it for a set period of time, or do leg lifts, per the graphic linked above. When I was first out of the aircast, I worked my way up to holding it for 2 intervals of 50 seconds each. Right now, I consider myself to be more in "maintenance," so I limit myself to holding this position and doing 5 leg lifts with each leg each morning.
- Hamstring ball curls -- Lie on your back like you were going to do reverse planks, but with your feet on an exercise ball (I like to mix up different sizes, as each works slightly different muscles). Then fire your glutes, and lift your rear off the floor. The next step is to use your hamstrings to roll the ball in towards your rear, and back out (the abs will get a decent workout stabilizing). This is a good demonstration video (I do try to keep my pelvis higher than she does). I usually perform 1-3 sets of 20; I do skip this one the evening before a hard running workout.
- Stool dips -- These are a great exercise that target the glutes and quads, but also get the feet and lower legs. I place a balance pad on a 12 inch plyo box. I then balance on top of the box/pad on one leg, with the other leg held straight and extended in front of the box. Then, I bend the knee on my standing leg and perform a controlled single leg squat until the heel on the other leg gently touches the ground, then rise back up.
It's sort of like a pistol except a) I'm on top of the balance pad (making it harder) and b) my extended leg is pointed downwards and the range of motion less (making it easier). 10 on each side; 2-3 times a week at a minimum.
- Sliders -- another glute exercise. Find a wall with a smooth surface. Then remove your shoes (keep your socks on), and lie down on your side facing away from the wall, with both your hips and shoulders about a fist-width's away from the wall, and your legs straight and stacked on top of each other.
Take the heel of your top leg, and press back into the wall firmly (focus on firing your glute). Now slide your top foot up and down the wall by lifting and lowering the top leg, firing the glute the entire time to push your heel agaist the wall and give resistance. When I was in the aircast, I was religious about this one. Now? I should do this one every day; I usually only get to it 2-3 days a week.
- Headstand leg lift -- I picked this one up when I was playing Capoeira a few years back. This gets your lower back, and also your glutes and abs. To do this one, get into headstand position, then lower your feet to the floor, keeping your legs straight, and raise them back into full headstand. Better explanation here. It's a similar exercise to back extensions, but targets the back and abs more and the glutes less, doesn't require access to a gym, and is much more fun. I do these at least once a week.
- Balance on ball -- This is a fun one. Find an exercise ball (bigger is better here, and an under-inflated ball will make this significantly harder). Then balance on top of the ball on your knees while swinging light weights with your hands in a motion that simulates running.
This isn't so much a strengthening exercise as a balance and coordination exercise. Thus you want to keep the weights fairly light: just heavy enough that they disrupt your balance slightly when you swing them, and you have to focus to avoid falling.
It may sound intimidating at first, but it's really not that hard. I would start learning this one by simply getting comfortable balancing on hands and knees on top of an exercise ball. Then progress to balancing on your knees only, and then to balancing on your knees while swinging your arms. Then add in light weights.
I like this one because it forces the glutes and abs to work together to stabilize you in the same way they do when running -- I did this every day as soon as I came out of the aircast, and I think it helped with my return to running.
I do this one at least twice a week (3-5 sets of 20 arm swings). You can actually integrate this into a solid routine with the following sequence: a) balance on balls and swing weights; b) put the weights down and walk your upper body out, so that you're now in plank position with your feet on the ball; c) do a set of push ups; d) walk your body back in.
- Stretching -- As Katie noted in a comment to my previous post, the hip flexors get VERY tight when pool-running; and Beth noted something similar with regard to calves/feet. Yup, IMHO it is essential to stretch both hip flexors and calves on a daily basis if you're pool-running a ton. And getting some professional massage work done to release those muscles ain't a bad idea either.