Deload weeks
In my opinion when it comes to deload weeks they should rarely be planned. As long as you are consistently progressive overloading with no joint,ligament, or tendon issues then why stop? But as soon as you start to feel your joints,ligaments or tendons affecting your lifts and numbers then its time to take your foot off the gas peddle. If you do not then injuries are inevitable. Your muscles grow and recover at a higher rate than your joints, ligaments, tendons. This is because there is limited bloodflow to these areas thus decreasing recovery rate and they are overall weaker. So in your training cycle as long as your progressive overloading(adding a little more weight or one or two more reps to each exercise each session) there will be some point where your joints, ligaments, and tendons catch up. You can only burn the candle at both ends for so long. It is unrealistic to expect to continuously push the envelope and expect everything to hold up. So when this happens its time to take a deload week. A deload week consist of a week of high reps, lighter weight, low joint impacting movements, and moderate intensity giving your central nervous system and joint, ligaments, tendons a good rest. If you choose not to take time to deload then it is only a matter of time before you perform a exercise and the joint,ligament or tendon that is bothering you gives out and you get a tear or other related injury taking you out of the gym for a few months. Now not only will you have to suffer the time out of the gym which the muscle will slowly start to atrophy but then you have to work on getting your strength back to where it was before you got injured and then you can start to make progress again. So you looking at months of time to get things back to where they were vs a week of lower intensity, higher reps, lighter weight, and low joint impacting exercises. It might not be the all out training style that you want but for that one week its about health and recovery. Now i said they should be rarely be planned because the only time i would say its ok to plan a delaod week would be if your using PEDs and its at the end of a cruise before you go into your next cycle because you know you plan on pushing your limits in the next upcoming weeks and you want everything to be well healed and prepared. If you are natural i would stay more instinctive and go by how things are feeling. But both ways if you start to feel joint, ligament, or tendon pain/issues it is a sign from your body telling you it needs a break from the heavy loads. Just like when you injure a area and your body swells up limiting your movement, strength, and mobility in that area. It’s your bodies protection mechanism limiting external stress to that area forcing you to heal.