Intensity and volume are two of the most often discussed subjects in bodybuilding and working out. Some people argue for high volume training, others for high intensity workouts with low volume. The truth is in the middle.
Defining Intensity And Volume
Intensity is the amount of your power you have to use to complete a repetition of an exercise. The highest intensity possible is often called the “one rep max” (or “1RM”) – a weight you can handle just once when doing the movement of an exercise. At the 1RM you are using 100% of your available power output.
Volume on the other hand is how often you do the movement of an exercise. While intensity in the 1RM has an upper limit, volume can practically go on endlessly. If, for example, your 1RM doing a biceps curl is 45 lbs (~20 kg) you can do exactly one curl with those 45 lbs. But if you pick up a dumbbell with just 5 lbs, you can do the curling motion very often.
Intensity Vs. Volume
The relationship between the two is that the higher volume, the lower the intensity and vice versa. When the intensity gets too low – or the volume too high – you fall below the threshold where hypertropy happens, as hypertrophy requires you to work against sufficient resistance.
Always High Intensity?
Does that mean you should always go for high or very high intensities? No. While you need to work with enough intensity, always doing high (rep ranges of 3 – 8 ) or very high intensities (1 – 4 reps) is not recommendable either. If you do, two things can happen:
- You place a lot of stress on your musculoskeletal system, which takes its toll on joints and tendons, making injuries more likely
- Your body may get used to working against these resistances, limiting your muscle growth
It is therefore much more advisable to vary what you do: Fluctuate between high, very high and medium intensities, with the last being the rep range between 6 – 12. This will keep your body engaged in your workouts and make injuries more unlikely.
The Total Picture
Keep in mind that intensity and volume is more than what you do during a single workout, but rather how you work out in total before doing rest periods where your body can fully recuperate.
As a simple example, let’s say you do a 3-day-split and work your chest and triceps on Mondays, back and biceps on Wednesdays, and shoulders and legs on Fridays, with Tuesdays and Thursdays being your cardio days and the weekends your rest period.
On those Mondays you do three sets of push-ups and on Wednesdays three sets of pullovers. The chest muscles are the main ones involved doing the push-ups, but your chest also does quite a bit of working along doing pullovers, although they are most often classified as a back exercise.
In other words: Keep the complete picture of your weekly workout schedule in mind when assessing the total volume you subject a muscle to. If you count the sets of exercises together where a muscle is the main one being worked or substantially involved, and you arrive at more than 15 – 20, you may give that muscle too much stress. At the end of the week it may still feel like it is being worked with intensity, but in reality its power is spent and it works far below its possibilities.
Here is the video discussing the concept:
Picture courtesy of Antonio Esponda.