Here I provide you with a quick guide on how to perform relaxed stretching in order to make maximum gains in the side (box) split position.
1. Sit down and open your legs as wide as possible. Your toes should be pointing straight up to the ceiling.
2. Place your hands palm-down on the floor behind you and lift your butt off the floor.
3. Keep one foot anchored. Imagine a pin has been hammered through the ankle of that foot into the ground so it cannot move. For argument's sake, let's say the left ankle. That foot will not move - it stays where it is.
4. Push the other (right) foot sideways. It may help to imagine you are "pushing the walls apart" or "pulling your hip from its socket." Initiate the movement from your hip - look down at your pelvis and focus on increasing the angle between your thighs.
5. When you have pushed as far as you can, sit your butt back down on the floor and... wait.
6. There is no set time you should hold the stretch. Just sit there and wait for as long as it takes for the tension to disappear from you inner thighs, or adductor group (adductor magnus, adductor brevis, adductor longus, pectineus, and gracilis). This may take from 10 seconds to 10 minutes. Above all, do not count or time yourself in the stretch.
7. When the tension has disappeared, lift your butt off the floor again and increase the stretch. Then sit down and wait again. Continue this stretch/wait cycle until you cannot increase the stretch further.
8. Hold your final (maximum) position until you are close to getting spasms, then slowly come out of it.
Repeat the stretch for as many sets as it takes to reach your maximum limit (for that stage of training). Once you are not making further gains in that sitting, stop stretching.
Perform this routine once per day after all of your physical activities.
Remember - do not count yourself in the stretch. There is no complicated science or secret ingredient to successful stretching. All you have to do is wait. Tension in your muscles, like everything else in your body, gets tired after time. You just need the mental fortitude to wait it out.
Contrary to popular belief, you do not physically elongate the muscles in relaxed stretching. You simply wait for the tension to disappear (because your muscles get tired, or bored, or both, of tensing up) and then pick up the slack by moving into a greater range of motion.
Do not get eager and force the stretch further. This will produce zero gains and plenty of injuries.
You do not have to perform a warm up for this, or any other method of stretching. However, the paranoid types out there can warm up beforehand if they wish.
Do not perform this routine when you are stretched for time (excuse the pun). The best place and time to stretch is at home in front of the TV, when you feel less competitive and you are not in a rush.
Do not use this method for forward-bending stretches. If you do, then you will loosen the ligaments of your back and develop spinal deformities. You have been warned.
It may be useful to employ mental imagery to help you relax. Think of a hot towel and imagine it wrapped around your target muscles - the inner thighs - as heat helps muscles to relax. Or think of the most peaceful place you have ever visited. If you live in Baghdad or the Bronx, you're kinda screwed there.
Cease this stretch immediately if your muscles start to spasm.
REMEMBER - do not time yourself in the stretch. If you cannot sit still and wait out the tension, it may be pointless setting yourself any flexibility goals. If you don't have the patience for this method, you will have to resign yourself to the ranks of chronic inflexibility.
The final position should look something like this...
Please excuse the scary half-naked man with the kettleball above his head. At least he is wearing pants.
This stretch is not as difficult as it sounds. The level of mental fortitude required to perform this stretch successfully is relatively easy to develop. It is pretty much like anything else in life - the more you do it, the easier it becomes. Well, except maybe playing Tekken 5 on hard mode. That shit is crazy difficult.