CORE TRAINING - STRETCHING

PHYSICAL TRAINING IS OF SOME VALUE, BUT GODLINESS HAS VALUE FOR ALL THINGS, HOLDING PROMISE FOR BOTH THE PRESENT LIFE AND THE LIFE TO COME
- 1 TIMOTHY 4:8
Proper warm-up is the most important part of any exercise and is often under-estimated or overlooked entirely. I typically stretch before and after every workout. That said, there's a difference between light stretching and heavy stretching. Light stretching is good for a warm up as it loosens up muscles and gets them ready to perform. Heavy stretching is good after your workout to stretch out your muscles after heavy activity. Over time, your flexibility should increase.

I am certainly no expert when it comes to stretching. I played baseball from the time I was old enough to hold a bat and I competed in collegiate pole vault. I never stretched before or after any sort of exercise. Now I wish I had. Since taking up parkour, I've begun stretching daily as per the suggestions of my chiropractor and my massage therapist, and I've seen remarkable gains in my performance. It seems that every muscle pull I experience is due to improper warm-up.
Calf Stretch
Keep one leg straight while you lean into a stationary object, a wall, lamp post, etc. Keep your back heal on the ground while you stretch your calf. Repeat for other leg.
Heal Stretch
Use a similar position as the calf stretch. This time bend your back leg, yielding a stretch of your lower calf and Achilles tendon.
Squat Stretch
Lower your hips into a squat position. Your feet should be angled to each side allowing a comfortable crouch.

I use this stretch more than any other as I often battle with tightness in my lower back due to an injury from 1990.
Side Stretch
From a standing position, stretch each side of your core.

Recommendations:

ACT Wellness Center - Dr. Carmelo F. Caratozzolo DC

MayoClinic.com - Stretching: Focus on Flexibility

Stretching and Flexibility by Brad Appleton