I disagree with Mark Rippetoe on many things but one thing we agree on is that for teens, getting sixpack abs may not be the best goal. Your teenage years are when you are growing rapidly and an attempt to be ripped and vascular will probably interfere with your ability to gain muscle mass. The teenage body does not want to be vascular. Many teens do not yet have the core musculature to have visible abs at reasonable bodyfat levels. It’s unwise to drop down to crazy low bodyfat levels in an attempt to see these marathon-runner abs. A much better plan is to keep at healthy bodyfat levels, say 8-12%, and work on getting stronger overall with a well rounded workout plan for a few years. Thats not to say that its OK to be fat, its not! Being obese doesn’t help you gain muscle but Getting rid of a belly is a great goal but for a teen, getting vascular 8-pack abs like Jeff Seid is a poor goal.
honestly, i know and grew up with good friends of mine who are bigger and just as lean as jeff. they are obviously natural because i know them like brothers. shut the fuck up before you even open your mouth to debate me on "oh you don't know 100% for sure"... yes motherfucker, i know 100% for sure. their dad is an animal (they are all brothers) and their mom was a beast too. They have awesome genetics and if they just dieted and trained as hard as jeff, they would look like him. And like jeff, they have also been training since children. jeff doesn't look that crazy. If you have good genetics IT IS POSSIBLE. it's just that most of us do NOT have awesome genes