Barry Bassin - Certified Personal Trainer (ACE) - Personal Training  -  Health Coach  -  Corrective Exercise
Resistance Bands & Tubes
Dynamic Resistance
Strength training, muscular development, and  body toning and shaping is about subjecting your muscles to resistance. In simple terms, there are two types of resistance: static and dynamic.
Static resistance is when you apply force against an equal amount of resistance, thereby creating force without movement. This is called isometric resistance. An example of an isometric exercise would be pressing the palms of your hands against each other, applying equal force on both sides. The muscles will tense, but there will be no contraction, as there was no shortening or lengthening of a muscle. Using a biceps curl as an example, when you raise your palm toward your shoulder by bending your elbow, your biceps muscle will shorten during the motion, causing the muscle to contract, while the opposing muscle, the triceps, lengthens in response. With isometric (static) exercise, this does not occur.
Dynamic resistance occurs when there is movement of a muscle between two joints. Using the biceps curl as an example, as you raise your hand toward your shoulder, the two muscles that are between the shoulder and the elbow - the biceps and triceps - will create a movement, with the biceps shortening and the triceps lengthening as the hand goes up, and then the biceps lengthening and the triceps shortening as the hand goes down.
But there are two kinds of dynamic resistance: fixed and variable. And here's where it gets interesting.
Dynamic fixed resistance occurs when the source of the resistance has a specific amount of resistance, such as a 25 pound dumbbell; it weighs 25 lbs, regardless of where it is in the movement pattern of the exercise. Again, using the biceps curl as an example: the dumbbell weighs 25 lbs at the beginning of each repetition, when your arm is straight down, and it weighs the same at the mid-point of the repetition, when your lower arm is half way up, as it does at the top of the repetition, when your elbow is fully bent and your biceps is fully contracted. And ditto on the return motion, but in reverse order, when you lower the dumbbell.
Dynamic variable resistance occurs when the amount of resistance is not the same throughout the entire movement pattern, such as is the case with resistance bands and resistance tubes.
With variable dynamic resistance, you replicate the exact same movement patterns that you do with dumbbells, but with the maximum amount of resistance being applied at the "top" of the movement, where the muscles' contractions matter the most, and in exactly the same way.
What you don't get with variable resistance is the trauma to the joints, ligaments, and tendons that so often occurs with fixed resistance. This is because each exercise has a movement range for executing the repetitions which is shorter than the entire movement pattern, including the "mount" and "dismount."
Consider the biceps curl again. The starting position (mount) and the ending position (dismount) for the biceps curl is with the hands holding the dumbbells at the outside of the thighs, with the arms straight down and no bend at the elbow. However, the working range of motion for the biceps curl calls for going up from and returning down to a point which is less than all the way down, with a small amount of bend remaining in your elbows during the lowering portion of each repetition, and then ending with the dismount, when the arms are lowered once again to the original starting position.
It is almost always the starting and ending points of fixed resistance strength exercises that traumatizes the joints and their associated connective tissue. And yet, despite the trauma, the mounts and dismounts are not even part of the actual exercise - just how you get into position to do the exercise! This is how strength trainers using machines, dumbbells, and barbells injure their elbows, shoulders, and knees.
And it is why I love dynamic variable resistance.
Note: I use the biceps curl only as an example as it is the one exercise that everyone can visualize, but the principles discussed apply equally to all exercises.
My Favorite Equipment
To the uninitiated, the image of resistance tubes is one of rubber tubes with handles used by seniors and others with lower levels of strength and no need for higher resistance levels more appropriate to stronger people and well conditioned athletes. And resistance bands are either totally unknown or are thought of as those 1/2-inch-wide bands used for therapy.
In fact, resistance bands, which is what I use, all come in the same length but various widths, with each width corresponding to an amount of resistance. For instance, the set I use has five different bands:

  •   5-15 lbs
  • 15-35 lbs
  • 35-55 lbs
  • 50-75 lbs
  • 75-120 lbs

The 35-55 lbs, for instance, refers to the equivalent amount of resistance from the beginning of the stretch to the fully-stretched position. This means that doing a biceps curl with the 13/16 inch wide band is the equivalent of beginning the lift with 35 lbs and progressively increasing the resistance up to an equivalent of 55 lbs at the top of the movement, and digressively returning to the starting point.
Resistance Bands
I am a huge fan of resistance bands. Indeed, my own personal training program is now done almost entirely with 41" continuous loop bands. I love them, and I think you will, too. In fact, anything - and I really mean anything - that I could do with free weights during all those years I trained in the weightroom I now do with bands. My physique is as good as it has ever been, my functional movements are better, and I no longer have the shoulder, knee, and elbow pains I used to get following an intense weightlifting session.

Resistance band training allows for complete range of motion exercises in all three anatomical planes of motion, and not just up-and-down like with free weights and machines, and involve more muscle activation with most exercises as well, resulting in longer, more shapely muscles.