Intensity vs. Effort

What is intensity vs. effort? The definition in 20 seconds

In strength training, intensity usually means load intensity: how heavy a weight is relative to your 1RM, given as a percentage. Effort means how hard the set is: how many clean reps would have been left at the end. You measure it with RIR or RPE. Together they decide how much stimulus for hypertrophy a set delivers.

• Intensity: a property of the load. 80 percent of your 1RM is 80 percent, whether you do 3 or 8 reps with it.
• Effort: a property of the set. The same load can be an easy set with plenty in reserve or a hard set just short of failure.
• For hardgainers this means: A heavy set is not automatically a hard set. And a hard set does not have to be heavy. You steer the two separately.

The anchors in the system: the Training Volume and Fatigue System, SFR for stimulus per fatigue and technical failure vs. muscular failure.

Intensity vs. effort compared

Two terms, two measures, two different statements. Lump them together and you plan past the stimulus.

An example from a study with young novices: at one rep in reserve, the deadlift load for sets of 3 was about 88 percent of 1RM, for sets of 8 about 79 percent. Same effort, different intensity.

The reverse holds too: at 80 percent with five reps in reserve, the set is heavy, but not hard.

What you control and what you don't

How much stimulus a set triggers in the end is not something you set exactly. What you can control is the load, how hard the set is and how many hard sets you can afford.

• Load by task: Heavy compound lifts more in the lower rep range, isolation work more in the middle and upper range. Which ranges do what is covered under rep ranges.
• Effort as a target: RIR 1 to 3 for most working sets. Hard enough for a clear stimulus, with enough in reserve that your technique holds.
• Autoregulation on weak days: After a short night the same load feels harder. Then you hit your target RIR and take some weight off instead of forcing the number.
• Volume within limits: Hard sets count, but only as many as you can recover from. The total per muscle group belongs between MEV and MRV.
• What you don't control: how accurate your estimate is on day one. RIR is a self-rating that gets better with practice and a log.

Practice: the 14-day check

• Day 0, set your base: Pick 3 to 4 main lifts and write down a target RIR for each. To calibrate, take one set on a machine to true failure and count how many reps came after your felt “RIR 2”.
• Log every session: Load, reps and estimated RIR for every working set. Add sleep and steps as your measure for NEAT, because both draw on your recovery. How much your steps burn is shown by the NEAT Calculator.
• Day 14, check the trend: More reps at the same RIR means: add load, that is progressive overload. High load, but almost always RIR 4 or more? Then your sets are heavy, but not hard. A 0 on nearly every set means you train harder than you can recover from.

Load shows how heavy. RIR shows how hard. Only both together in your log tell you whether a set did its job.

Common misconceptions

• “Intensity just means as heavy as possible.” No. Without enough effort, even a heavy set often brings little stimulus. A lighter set at RIR 1 to 2 can do more than a heavy one with lots in reserve.
• “RPE is pure feel, it is useless.” Without calibration the estimate is rough. With a fixed routine, though, it is quite reproducible: in one study with young novices, loads chosen by RIR were very stable from session to session.
• “I have to test my 1RM all the time.” As a hardgainer, an occasional test is enough. In between, you steer by reps and RIR. Maxing constantly eats your recovery.
• “The harder, the better.” Not in a straight line. In one meta-analysis, training to momentary muscular failure brought no advantage for muscle growth over training with reps in reserve. Take every set to the limit and you pile up junk volume fast.

Common questions