From Pavel's old books I remember that he was not a big fan of doing warm up.
Pavel's Warm Up Approach
No Pavel isn't a "Big fan of warm up"; nor I am.
Pavel's example in " Power To The People" was when a rabbit sees a wolf, the rabbit does not ask the wolf it he can Warm Up first before the chase begins.
Ae pet stated...
From a 'real world' standpoint, ... Catching the bus, or being forced to fight may be examples.
Before moving on, let's address...
Does a professional powerlifters/strongmen/weightlifters do a warm up?
There are no professional Powerlifters or Weightlifters.
There at time a top Powerlift at a meet may win some price money. However, it not enough money to make a living on.
The Olympic Training Center in Colorado Springs, houses and feed some of the top American Weightlifters. So, they might be considered professionals.
What do you think about doing warm-up before training ?
Not Much
One of the main issues with many lifters is they turn their Warm Up into a workout. In other word, by doing so many individual top set are less they should be or could.
The Warm Up Objective
The purpose of a Warm Up is to prepare you for your top set; which elicits the greatest training effect. In other word, you want save everything for your tops set.
One of the keys to ensuring that you optimize your top set, your Warm Up need to be kept to a minimum.
"Greasing The Groove"
The primary purpose of a Warm Up is to essentially "Grease The Grove" for your heaviest exercise set.
As per bluejeff...
Warmup should be brief enough that it doesn't pre-fatigue the muscles you are training that session, and it should be focused on the motor patterns you will be training...
This is accomplished with Lower Repetition Warm Up Sets, 1-5 Repetition Per Set
A Reverse Pyramid Squat Set Example
Let's say you are going to work up to a top Squat Set of 315 X 5 Repetitions.
Your Warms Up might look like this.
Set 1: 135 X 5
Set 2: 185 X 3
Set 3: 225 X 2
Set 4: 285 X 1
Set 5 : 315 X 5 Plus...
Body Temperature
As previously posted on this site, research shows that when you Body Temperature is elevated, you preform you best; physically, mentally and emotionally.
A couple of ways of passively increasing your Body Temperature is...
First thing in the morning after coffee
As per Benjamin, this is effective. It increases you Body Temperature and get you ready to go.
Another Passive Warm Up is taking a warm shower. The are some other method that work, as well.
The Mental Aspect of Warm Up
For some lifter, there's more a mental component. They have more of a mental need than physical need for gradually increasing the Warm Up Load with more sets prior to their top set.
“Baseball is 90 percent mental. The other half is physical.”/Yogi Berra
There is definitely a mental side to the game that come into play.
For individual like this, multiple sets with lower increases in loading is effective. However, their Warm Ups Repetition need to be 1 -2 per Warm Up Set.
This allows the lifter to gradually increase weight (get a feel for the heavier loads to come) and "Grease The Grove" for the top set. It ensure the muscle in the movement is fresh rather than fatigued; as bluejeff stated.
Summary
1) Minimal Warm Ups: Performing the minimal amount of Warm Ups Sets and Repetitions ensure you optimize you top training set.
2) "Grease The Grove": Warm Up are more about ensuring good technique for your top set.
When a heavy movement is performed with good technique, the movement feel like you are pushing it along on rails; it feels like it gliding up.