It still frustrates me how little most physios know about exercise, with many not knowing how to progress or regress it, or what parameters are more important to adjust and monitor. That’s if they bother to adjust and monitor anything at all.
In this blog, I want to discuss the two most important parameters of exercise; INTENSITY and VOLUME. I want to highlight why these are so important for physios to consider and monitor during their patient’s rehab.
The volume of an exercise gives you a way to quantify the amount of work done. In its simplest form volume can be worked out for resistance exercise as the load x sets x reps or time x distance for cardio exercise.
The intensity of an exercise is an individual’s internal subjective rating of how hard or effortful an exercise feels. This is usually done using rate of perceived exertion (RPE) scales such as the Borg Scale ranging from 6-20 to coincide with heart rate, or the more common modified Borg scale ranging from 1-10 with 10 being maximal effort.
An Example
So let’s say you’re doing a 10kg dumbbell shoulder press, for 3 sets, and you do 10 reps per set. This gives you a volume for this exercise of 300 (10kg x 3 sets x 10 reps). Now let’s say we found that hard an gave it a score of 8/10. This gives us a total volume for this exercise of 2400.
We can also add the volume of each exercise to others in a session to give us the total session volume. So let’s say we also did some lateral shoulder raises with 5kg dumbbells, for 3 sets, and did 8 reps each time and it was also hard at 8/10 RPE. This gives this exercise a volume of 960 (5kg x 3 set x 8 reps x 8 RPE). And a session volume of 3360
Unaware
However, not many physios measure or record the volume or intensity of rehab for patients, and as a consequence, many are unaware if they are progressing or regressing.
Usually, the most common way physios and patients gauge if they are progressing or not with rehab is if they feel less pain when doing an exercise or task. Now, of course, these are useful things to monitor and check, but in my experience, they are not always the most accurate or fastest occurring.
As for many things that hurt or have been injured, it takes time for pain and functional improvements to become apparent and noticeable. This can mean patients often become demoralised and disheartened, thinking their rehab isn’t helping or working when in fact it is.
If more were to record and monitor the volume of their rehab they would see the progress in their numbers a lot sooner than they feel improvements in their pain or function.
This can potentially help motivate more patients and help with rehab adherence. Personally I think the volume of work done during rehab can be a far more sensitive measure in the early stages of rehab, not to mention helping patients to focus less on pain.
Volume > Load
Many think that increasing the load of an exercise is a good sign and measure of its progress or success, and it can be. However, many tend to focus on the load of an exercise too much and try to progress it too fast and too soon at the expense of volume.
Let me explain using a very simple example.
Let’s say we have done that 10kg shoulder press as mentioned above doing 3 sets of 10 reps at an RPE of 8 giving me a volume of 2400. But in the next session, we want to progress so we go and grab the 12kg dumbbells.
However, as the load is heavier we find that we can only do 8 reps per set compared to the 10 reps before at the same level of RPE at 8. This gives our 2nd session a volume of 2304 (12kg x 3 sets x 8 reps x 8 RPE) which is actually lower than the previous session’s volume!
Ok, so it’s only a small difference of just 4%, which isn’t much in the grand scheme of things in this example. However, we would probably have been better to stick with our original 10kg weights and just added a few more reps or even an extra set. Both of these options would have increased the volume of the exercise, whereas increasing the load reduced it slightly.
This is a situation I commonly see in rehab and training, increasing the load too quickly and sacrificing the volume. This mistake is also made when we underestimate the effects of fatigue and try to do too many reps in one set.
Volume > Fatigue
Let me demonstrate this by using the same 10kg shoulder press as an example again. Let’s say we are fired up and feeling good at the start so we do 15 reps in the first set. Great, that’s progress, right?
Well, hold on, because when we come to do our 2nd set we are fatigued and so can now only do 6 reps, and only 3 reps on the 3rd set. This gives the total number of reps for this 10kg shoulder press now at 24 compared to 30 we did last time. This is a 20% drop in volume and a big deal. Had we just paced things a little better we could have got more work done.
Again most physios and most patients will not recognise this reduction of volume and think that because they have done more reps on one set, or are using heavier loads they are progressing when in fact they could be regressing.
The lesson here is don’t let your ego to progress the load or number of reps in one set come at the expense of the total volume of work done. Often pacing and spreading the effort more evenly over a session is beneficial.
Summary
I hope I have demonstrated how recording or monitoring the volume and RPE of exercise can be very helpful. This helps avoid sacrificing volume by increasing the load or number of reps in the first set too soon. Don’t let your ego or eagerness harm your exercise progression.
I urge more physios and patients to record their exercise volume and RPE during their rehab more as it can show progress before changes in pain, strength, or function are noticed. You can download and use my very simple old skool paper exercise log that I use to do this for many of my patients here.
As always thanks for reading, and remember to pump up that volume…
Adam
Hi Adam,
Great post!!! You have covered important points. Within the exercise world there has always been this “volume” against “intensity” of effort debate. On the one hand the intensity guys (people like Dr. Doug McDuff) believe that one hard set to failure is all that is necessary performed at a slower pace than normal. Take the chest fly machine as an example. He says that 4 to 6 reps done slowly with a cadence of 10/10 much more effective than pumping out endless reps. On the other hand bodybuilders often train in reps up to 25.
The Borg Rating Of Perceived Exercise is a another way to record exercise improvements.
Great article loved reading it. Thank you
Best
Cliff
Thanks Cliff and yes the Borg scale is very similar to RPE!
Great post Adam. I am a new graduate into the work force and this is was a huge misconception of mine that increasing load is basically the same as volume or might be worth sacrificing in the short term until they can work up to that higher rep count (eg. Heavier weight at 2 reps less). Gives a lot to think about in terms of monitoring and being more objective in assessing treatment responses.
It’s something that’s very underlooked in our training, at least here. Everyone tells you to use outcome measures but that’s where it stops. Things like questionnaires are usually taught while the simple and often more important things are often forgotten.
I think that you have said something important (that volume is something that can be monitored and measured and potentially used to guide exercise) I do think that the population you are dealing with is a huge factor. With inexperienced people, such as many patients, getting them to develop good exercise habits and better kinaesthetic sense seems really important. True strength changes (as in physical growth in the muscle in response to loading) take months and much of what a physio might see in the short time a patient attends a clinic might well just be neurological adaption rather than anything else. Volume is important in producing physical change but will this apply to typical patients?
We’ve just been looking at this in our clinic recently as the question of how much weight should i use is a frequent one..
i like using RPE as this auto-regulation for loading accommodates for fatigue levels and stresses of daily living but still allowing the patient to work at an appropriate level.We find we can use it along side the prescription of other variables of training, e.g rest times, sets ,etc etc, to good effect. I feel that patients like athletes “maximal effort or 1RM” on an exercise will fluctuate daily depending on accumulative effects of training, work and other stresses. Thus sometimes we have to adapt to these factors. Since we are usually dealing with a de-conditioned state anyway could it potentially be more susceptible to fluctuations and therefore require a bit of flexibility rather than rigidity in the programming ?
From an RPE perspective the scale we use is the OMNI resistance scale and for people further down the rehab continuum or for more experienced clients we are starting to look at reps in reserve type algorithm to see if that has an application
However i feel RPE relies heavily on honesty of recording and assessing the session within 30-60 mins of completion.
Getting them to buy into all this can be a bigger problem , never mind recording it
Nice blog – Always useful to amaze patients how strong they actually are.
Any references/reviewed evidence on clinical use?
Also any distinction in units used? Kg.m.RPE???