Exercise Under Doctor's Orders (Part 2)

 As the title suggests, this is a follow-up to my previous blog which can be found HERE.  Give that a read if you'd like some additional context and set-up, though I'll give a brief primer here before leading into the meat of the post.

In the previous blog post, I mentioned that there are a number of guidelines and orders that you may receive from clinicians which might not make a lot of sense without further context.  Further, I mentioned three somewhat typical kinds of rules/restrictions that you might encounter, with the aim of unpacking them to look at some potential issues/ambiguities in them.  I got through the first, but the other two were untouched.  Items #2 and #3 will be addressed today.

BUT FIRST:

None of what follows constitutes medical advice.  I am not telling you to override the clinical professional(s) in charge of your care, and I am not a clinician myself as of this writing.  Even if I were a properly credentialed healthcare provider, I would need to evaluate you directly before being able to speak on your specific circumstances.  This piece is simply intended for the purposes of education and provoking thought about some of the variables involved in exercise modification.  Cool?  Cool.

Okay, so with that out of the way, let's look at those three items again:

Three common types of instructions you might encounter:

1. You can do bodyweight exercises ONLY.
2. Bands are okay, but free weights are not.
3. Lift absolutely no more than [X] pounds.

See the previous article for my exploration of #1 (complete with a somewhat lengthy explanation of why machines might actually be preferable to bodyweight exercise for certain goals).  It will also make some points more familiar as I sally forth into the other two items.  With that being said, let's check out #2.

Bands are okay, but free weights are not.

The purpose behind this guideline might seem to make sense, as bands and similar exercise tools may provide some cool training opportunities.

Resistance bands and other "elastomer-style" tools (I'll refrain from parsing out subtle differences for now; let me know if you actually care and I might write up something detailed) limit the effect of momentum on the exercise that you're performing, since instead of moving a heavy object through space, you're deforming an elastic material that has a (usually) negligible weight.  What this means in practical terms is that you can stretch/pull a band as hard and fast as you like, and assuming you aren't tearing the band, it won't continue moving in the direction you pulled the way a free weight would.  This might be of benefit if you're worried about being pulled in the direction of your effort.

 Note this example for my explanation that is to follow.  The force line here -- both in terms of magnitude and angle
of application -- is changing throughout the rep as you perform a curl, and that's important to consider.

Additionally, a resistance band has another property that is both a strength and a limitation, depending on the circumstances: it resists with increasing tension the more you stretch it.  While that probably isn't news to anyone reading this, it does carry implications that are worth considering.  You may, for instance, only experience a meaningful challenge for a small portion of the available range of motion for the exercise.  A preview of the complexity associated with this resistance conundrum follows:

Depending on the "strength curve" associated with the working musculature (determined by things like joint position, muscle attachment points, pennation angles, etc.) and the "resistance curve" associated with the tension the band generates (a product of the tension [obviously] as well as the point of application of the band to your body and the joint[s] about which that tension is creating resistance torque), you may find that the exercise feels too hard or too easy for much of the range you're moving through.  While this isn't a total deal breaker, it may require more modifications to your body position or more sets with relatively smaller ranges of motion than you might wish to use so that you hit that resistance "sweet spot" for as much of your available range as possible.

All of the above deserve their own discussion, and I've covered much of it in our CORE course, which is available for Premium members (see the link at the bottom of this post or click HERE to check out that offering).  One has to explore muscle architecture, associated physiology, and fundamental mechanics surrounding resistance and how it can change before really understanding this, and that's unfortunately beyond the scope of a thousand-word blog post.  Hopefully the basic notion comes across for now, and I may create future posts that explain some individual elements of this.

What *is* worth saying right here is that despite the training opportunities that bands provide, they are not automatically safer than a free weight.  The safety depends on the resistance forces/torques applied to the body, how those forces/torques change during the exercise, and the specific tissue(s) that we are applying the resistance(s) to. 

Concerning the resistance:

1) The actual tension provided by the band matters (obviously), and that is a factor of the properties of the band (including the stiffness, "weight" of the band, etc.) and how much the band is stretched.  Comparing one band to another can become tricky, as they are not all created equal, and even bands from the same exact manufacturer and carrying the same rating can change over time.  We'll leave further exploration of this point for another time, but just recognize that these factors absolutely matter.

2) The resistance torque is a product of the force coming from the band (i.e. the tension described in the previous point) and the moment arm of that force.  In the vast majority of cases, that moment arm is going to change as we move through a given range, since one end of the band will tend to be fixed in place (e.g. attached to the wall, pinned under your foot, etc.) while the other end is "attached" to some part of the body that is moving through space.  Visualize, for example, the image a few paragraphs back of a band curl exercise where one end of the band is under the foot.  The angle of the band (and thus the angle at which the force is applied to the body) will change as the arm moves through an arc.  How much will depend on the height of the individual, arm placement, foot placement (determining the anchor point for the band), etc.

What does this all mean?

Essentially, it means that with a band, your resistance will be changing in ways that may be harder to measure than with something like a dumbbell, given that the magnitude of the external force changes throughout the rep as well as (often) the angle at which that force is applied to your body.  The particulars will depend on the exercise, of course, but this is important to know.  Don't get me wrong; the resistance is almost always changing with a free weight as well!  However, there are cases when a band might increase resistance towards the end range (of the exercise if not of the joint itself) while a free weight will not, and if you're dealing with rehabilitating a tissue, this might be a very significant factor in deciding whether you want to perform that exercise!

(With that being said, bands do limit the momentum/inertia issue and certain aspects of the "wobble" or "instability" that you might notice with a free weight, and that can be quite valuable, but you are trading those issues/limitations for different ones, as no tool is perfect.  That's really the point here).

If this is all still difficult to visualize, note that some images to help are included in our course content, and more is on the way, including a specific lecture on bands that will hopefully shed more light on what is going on when we use exercise tools that introduce an element of elasticity.

So that is a BRIEF exploration of a few points to consider about resistance bands when you're given instructions to use them.  A side-by-side comparison of certain exercises using different tools may happen sometime in the future, but hopefully this gave a taste of some factors to keep in mind.  Ultimately, you're in charge of your own rehabilitation and progression when overcoming any injuries or surgery recoveries, and paying attention to the factors that impact the resistances that you're dealing with will put you in a better position to avoid unnecessary risk.  Understand the tools, make better decisions, and have better outcomes.

ALSO -- If you enjoyed this topic and want to explore things like it further, be sure to check out our membership options HERE.  We have weekly Q&A roundups, short special topic videos, full-length course lectures, and even a discussion forum where you and other members can talk about this stuff (or toss your questions directly at Alex and me!)

 - G