What is Dynamic Variable Resistance Training

Dynamic Variable Resistance Training (DVRT) gives you the versatility to train rehabilitation or performance with high metabolic demand. It is a both unique and innovative system that was developed by Josh Henkin from the ground up to fill a void in strength training. DVRT rewards mastery of foundational skills as layers of complexity can be added as competence is achieved. Watching a sandbag demonstration with Josh makes DVRT look effortless, that’s until you have a look at his watch that reads 735 calories burned in 23 minutes.

Sandbag Exercise

The Ultimate Sandbag has been refined by Josh for use with DVRT. Inside the Ultimate Sandbag are bladders that can be filled with varying substrates (we have used sand, rice, and water). Load is one variable, but often not the most important. The dimensions and stability of the implementation become key considerations when performing an exercise. The caloric expenditure of training with an unstable load is substantial.


Changing load position, body position, stability of the load, dimension of the implement, and weight of the load combine for an almost infinite amount of possibilities for exercise variation. Here’s an example that takes into consideration only body and load position:

1. Front Loaded Squat (stable load and body position)

2. Shoulder Squat (unstable load position, stable body position)

3. Front Loaded Staggered Squat (stable load position, unstable body position)

4. Contra Load Staggered Shoulder Squat (unstable load position, unstable body position)

5. Same Side Load Staggered Shoulder Squat (unstable load position, unstable body position)

There are five quick progressions! And that is only the tip of the iceberg, DVRT is versatile.

The Ultimate Sandbag provides a different training stimulus than a barbell, dumbbell, or kettlebell. For example, in the performance of power movements such as a clean, the load is distributed unequally on the very bottom of the implement and must be pulled higher to catch in the front-loaded position. You must create more power with less load than conventional equipment to achieve the same position. Decelerating the load is also experienced differently as the filler bags inside the sandbag and substrate inside the filler bag are all moving at different rates. A lighter sandbag can make for a more challenging exercise compared to a comparable load with a kettlebell, dumbbell, or barbell during a similar movement.


DVRT demands major recruitment of the core musculature. The stabilizing demands increase when the load placement is asymmetrical (such as on your shoulder) or during acceleration or deceleration. The result is a huge hit on the exercise’s metabolic demand, in other words, it’s really hard.

Here’s a DVRT workout I performed two and a half weeks from competing at the 2013 Boston Marathon while in Hawaii. All that is required is an Ultimate Sandbag and a kettlebell. For your benefit I have listed the workout below:

Circuit 1 (Power – 10 minutes):

  • 1. 1. Staggered Single Arm Kettlebell Swing
  • 2. 2. Cyclone
  • 3. 3. Clean and Press (progression: Rotational Clean and Press)
  • Each performed for 6 repetitions. Rest as much as needed between sets.

Circuit 2 (Strength – 15 minutes):

  • 1. 1. Staggered Squat with Contra Load (4-second eccentric pause)
  • 2. 2. Lateral Bag Drag
  • 3. 3. Alligator Push Ups (Single Arm Push Ups)
  • 4. 4. Deceleration Lunge with Offset Row

Each is performed for 6 repetitions. Rest as much as needed between sets.

Envision Fitness is proud to be hosting Josh Henkin for a Level I and II DVRT Certification on May 18th and 19th at our gym in Maple Ridge, BC.

You can register for DVRT Level I and II here (select Vancouver): http://www.dvrtcertification.com/dates-locations/

Steve Di Tomaso CSCS
Director of Envision Fitness
DVRT Master Instructor