2 Barbell drag curl
The major difference between regular barbell curls and drag curls is that your elbows end up further behind the body.
As mentioned, when we do that we increase the stretch and tension placed on the long head of the bicep.
To perform this correctly, you’ll grab a loaded bar. I recommend taking a closer grip to target the long head better.
From that starting position, curl the bar up while gliding the bar along your body the whole time.
Imagine that you’re dragging the bar up across your body. Your elbows will naturally stay back in the right place.
Once you curl the bar up as high as you can (about chest level), slowly lower it back down and repeat for reps.
You’ll most likely need to use a much lighter weight than what you would normally lift for regular bicep curls.
That’s perfectly normal for these first two exercises.