Before we begin, let's get a couple of things straight.
1) You cannot stretch your Achilles Tendon. Straight up. It's the strongest tendon in the body and can be loaded to upwards of 15x bodyweight. It doesn't stretch, period. (We can argue the more technical side of apophysis abruption, or speed of tendon loading some other time.) But suffice it to say, your heel cords are like steel cables.
2) Your grandma's crappy runner's stretch that they showed you in Team in Training, physical therapy, or your third grade gym class won't lengthen your calves either.
You know the stretch, where it looks like you are holding up a wall with your leg extended behind you. You may feel your calf go on tension, but no muscle lengthening is occurring, trust me.
3) Three muscles attach into that common heel tendon; the soleus, plantaris, and gastrocnemius. The gastroc and plantaris both cross the knee and the ankle, but you can forget about the plantaris from here on out.
4) A little 20 second loading (can't even call what most people do to their calves stretching) isn't going to change anything in the back of your leg. Your calves are double under, split jerking, box-jumping, fore-foot striking while running machines.
You really think some pinche load is going to change the length of those freaky strong bastards? NO.
5) You've gotta wind up the calves with big loading at end ranges and at peak tension for 5 seconds before releasing that tension and moving further into a bigger stretch for about 10 seconds. This should be repeated for 5-7 cycles. This is known as contract-relax stretching. We should technically call it muscle lengthening. Contract relax stretching is a small piece of a larger theory of movement facilitation called PNF.
6) If you have knee pain, plantar fascia issues, tight hamstrings, are an olympic lifter, runner, rower, or your heels come off the ground when you front squat or overhead squat---STRETCH YOUR CALVES.
7) Muscles are like obedient dogs. They always respond. Always. "I'm just tight" is a BS excuse. Think of stretching as a dog fight. You need some attitude to get the job done. Ps. It's not relaxing or fun. Two to three times a day should do it if your heel cords suck.
8) Hold your breath while you generate that peak force in the muscle. Let it out like a bursting balloon when you go to reclaim more range during the off cycle. The parasympathetic response from your exhale is important.
8) There's more I'm sure but let's get to it.
The Set Up
With shoes on to support your foot, get as much of the ball of your foot up on the wall as you can. Really wind the sucker up. Step back from the wall to make this happen if you need.
Now while keeping your leg straight, bring your hip to the wall. This position stretches the entire calf but will also bias the gastrocnemius. (remember the gastroc crosses the knee and ankle) Start your PNF cycles now; 5 second peak tension with a held breath, release 10 seconds into new range.
Same set up, but bend your knee as you load the calf. The knee bend puts the gastroc on slack and will bias the soleus. Repeat your 5-7 cycles again.
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