T Nation

Reg Parks 5x5 and Chins

Just a quick question really - I was doing a bit of wandering around the site and came across the article on Reg Parks 5x5. Phase 1 is the one that caught my attention:

"Phase One

45-degree back extension 3x10
Back squat 5x5
Bench press 5x5
Deadlift 5x5

Rest 3-5 minutes between the last 3 sets of each exercise.

Train three days per week for three months."

I was wondering if people thought I could include weighted chins in here:

Back squat 5x5
Bench press 5x5
Deadlift 5x5
Weighted chins 5x5

And at the end I could add in my assistance work (like the back extensions etc.).

Could I chin heavy like this 3x a week?

EDIT: Also for those who do energy systems work - sprints, tabattas, etc. - how could they fit into such a program?