The intensity of weight training is categorized in two general ways:
Qualitative and traditional intensity
The quantitative intensity and advanced
In qualitative and traditional intensity, we determine the intensity based on the rate of perceived exertion to the athlete and his opinion and the opinion of the coach. Of course, this method has many mistakes, but it has many uses, especially for people with some cardio risk background, pregnant women, and injured people. Of course, part of the professional and semi-professional programs are also determined today all over the world with this traditional method. Borg's rate of prcived exertion (RPE) system is also based on this qualitative method.
In quantitative and advanced intensity, we often and not always deal with numbers, and it is more accurate than the previous method. The methods of determining qualitative intensity are different and are chosen based on the need. Examples include:
weight weight
speed of movement (Velocity based)
Based on the training system (for example, the Superset system differs in intensity from the pyramid method, even in the same exercise with equal weights)
Based on the device (for example, the same exercise with the same weight as the cable machine, if it is performed, it may have a different intensity in the same exercise with the same weight but with a barbell)
Of course, there are other methods to adjust and determine intensity in resistance exercises, which are recommended and used based on needs.