you should be doing back or front squats?

Allow us to enlighten you: the Zercher 
is the variation you should actually be using. “It offers 
all the benefits of a back 
squat, without beating up 
your shoulders, wrists and hips,” explains former Soviet special forces instructor Pavel Tsatsouline. “And it works 
your core better than most abs-specific moves.” The weight is also easier to balance due to the lower centre of gravity, reducing injuries. 
And you can skip the bicep curls: the Zercher will hit 
them hard. Suddenly “legs day” doesn’t seem so bad.

Ensure your back is straight, not curved, and core tensed throughout.

Keep your fists close together or cup one hand inside the other.

Don’t wrap the bar with a towel: it’s lame, plus it can slide and hurt you.

Squat until your elbows touch your knees, thighs just parallel. Pause; drive up hard.

Shift the weight back onto your heels, feet slightly beyond shoulder-width apart.

Perform the Zercher twice a week: do 3 sets of 3 reps on one day and 3 of 5 on the other. “You will feel ready 
to walk through walls,” 
says Tsatsouline.