A good warm up for heavy lifting should include some activation drills for key muscle groups. These are my two favourite glute activation drills.
The reason I've chosen these two is that they encourage activation of the glutes in two different positions, the terminal (or end point) positions of the hinge movement. One emphasises glute contraction when the hip is extended and the other when the hip is flexed.
This is important because in a loaded hinge movement, the glutes should play a dominant role; they are the most powerful muscle group in the human body after all and the deadlift (or kettlebell swing) is an expression of this power.
Many people set up for the deadlift and initiate the first pull without the glutes firing properly straight away. They might then kick in properly part way through the movement or occasionally not fully at all.
Similarly, when the hip is extended, some people struggle to contract the glutes hard to achieve lockout properly.
When the glutes don't fire properly in the deadlift, you see a number of compensation patterns, some of which are more worrying than others. Watching someone lift with an arched back, reminiscent of a stretching cat makes my back hurt in sympathy!
On the other end of the spectrum is a lockout achieved by hyper-extending the back instead of contracting the glutes. Over time, your back becomes very unhappy with this amount of extension under load.
Whilst glute activation drills like these aren't hard to do - in fact one can often question whether they're doing anything at the time you're doing them - their effectiveness becomes clear when you head to that heavy bar or kettlebell for your first set.
They're worth every one of the 5 minutes it takes to do them and you might even hit a personal best as a result.