Strength Training

Is Your Training Really Functional?

Ultimate Sandbag Josh Henkin, Master RKC, Creator of the DVRT System May 31, 2025

Josh Henkin, Master RKC and Creator of the DVRT system explains the importance of rotational power in a truly functional training program. Video drills and workout included. Read more

Becoming a Great Coach

Ultimate Sandbag Josh Henkin, Master RKC, Creator of the DVRT System May 31, 2025

Master RKC, Josh Henkin, Creator of the DVRT system describes the path to becoming a great coach, and the questions great coaches must ask to better help their athletes, students and clients. Read more

Better Mobility in Seconds

Ultimate Sandbag Josh Henkin, Master RKC May 31, 2025

Better mobility in seconds is a lofty promise. This isn’t an infomercial—it’s science! I can speak from personal experience, since I found this a methodology after recovering from four spinal surgerie… Read more

What Real Users of The IsoMax Have to Say

“Having been a Strength and Conditioning Coach for 40 years (33 years at the college level, 7 years at the high school level), I have seen a LOT of devices come and go. The IsoMax impresses me so much that I would definitely incorporate it into my program if I were starting all over again in my career. It'll defin… Read More

Rod Cole

Stephenville, TX

“Been working out since 1975. The Isomax has taken center stage. The combination of convenient, very effective isometrics and seeing the amount of force generated on each rep is phenomenal. Dragon Door's innovations are a godsend. I'm 70 and the strongest I have ever been.”

Bob Lorenz

Vernon, NY

“I have been able to gain more muscle mass and increased strength with the Isomax than with any free weights or weight machine. I am in my mid 40s and have been lifting weights since my late teenage years, but nothing I have tried compares to the Isomax!”

Mike Little

Lansing, NC

Excellent Isometric Trainer. Additional training technique to weights. Exercises your muscles differently than normal weights. For those people like me who have never trained isometrically they stimulate your muscles without risk of injury. Isometrics strengthens muscle strength / endurance in different ways to w… Read More

Tommy Cusack

London, England

I love my IsoMax. I am 55, I had the normal aches and pains you would expect for someone my age. Back, knee and tricep tendonitis. I have been using the IsoMax for 4 months, my aches and pains have faded to nothing. My blood pressure has also improved and i have effortlessly gained muscle. And i am only using it … Read More

Stu W.

Long Island, NY

Clear video

Clear video, but nothing new compared to the texbook

The Sequel is as good as the original!

This is a great book for getting and keeping yourself srong!This is my 'bible' for calisthenics training. Thanks Coach!

excellent

It was a good live review of the pushup chapter from the book

It was a good live review of the pushup chapter from the book. But it unintentionally (I think,) accented the importance of using a slow with the exercise. Gong down on a two second pace, pausing one second at the bottom, and then rising on a two count, ads tremendous value to the exercise. When I did the book course originally, I topped out before getting to the one handed push up. I suspect that, given recent gains, that should be able the master the one armed push up this time around while using this cadence.

Exceptional video

This is an outstanding video, very well produced and the explanations are clear. I highly recommend this, it’s inspirational.