ATG Squats, otherwise known as “ass-to-grass” squats, have always been a staple of proper strength and conditioning.
It requires to check your ego at the gym entrance, since getting out of the hole is often a weak point, but the athletic transfer as well as the gains in muscle mass and functional strength are well worth it.
Plenty of stars from the Iron Game, from Paul Anderson to Arnold Schwarzenegger, have made full use of them. However, it is not as commonly done as it was a few decades ago. Over the last 36 years, ankle flexibility has been probably the main cause of abstinence from this exercise. Here what I recommend to athletes under my tutelage to solve that issue:
Stretch the calves with loads
Stretching is most often done as an after-thought, and with as much vigor as a snail on Valium. If you want to squat deeper, you have to attack the problem with more gusto. Find the seated calf raise machine in your gym, and use a load to eccentrically stretch your calves. That means you let your feet in the down position for a 15 seconds, using the weight to increase the tension of the stretch. Take a pause, during which you’ll add more weight to the machine and do the stretch two more times, each time with a weight increase. This should help with stiff soleus muscles.
Repeat the same process on the standing calf machine, and your knees will travel further forward allowing you greater depth of squatting.
Charles R Poliquin