Kipping pullups are to strict weighted pullups.
What box jumps are to barbell squats.
They're a completely different exercise.
If I have a day where I do barbell front squats, straight legged deadlifts, weighted dips and weighted pullups, that would be a strength day.
If I had a day where I was doing box jumps, clapping pushups, kipping pullups, and kettlebell swings - all in sets of 30, in circuits - you could call that a strength endurance day. Or "cardio".
Kipping Pullups and 300
Kipping pullups have been most recently made famous by Gym Jones, training the actors for the movie 300. The legendary "300 workout" is bracketed by two sets of 'em - 25 kipping pullups start the workout and 25 kipping pullups finish it.
Kipping pullups were one of the uncommon exercises that the 300 workout introduced people to. The other two exercises most people had never seen before were floor wipers and kettlebell clean and presses.
The 300 workout is a good context for the kind of workout that would use kipping pullups - a brutal full body circuit workout.
Kipping Pullups - How To Do 'Em:
A kipping pullup, done correctly, is more than just kicking your feet wildly and flopping around on your way up to the pullup bar. A correctly done kipping pullup is fluid and powerful.
While a kipping pullup is easier on your direct pulling muscles, it's much harder on your grip and it's much more cardiovascular. It's a full body movement where you generate power at your hips - a similar use of the legs and hips to a kettlebell swing or a barbell snatch - just the opposite direction.
A kipping pullup is a pullup with a variation on the gymnastics kip.
The pullup kip differs greatly from the gymnastics kip in that the pullup kip you lead with your shoulders as much as your hips, while you throw your feet behind you. The gymnastics kip leads with the hips and feet. Both have a piking motion where you throw your feet up and forward while snapping your hips back.
The bigggest mistake that most people make in the pullup kip is letting their legs swing forward with their hips. WHEN YOUR HIPS ARE FORWARD, YOUR FEET MUST BE BACK. Likewise, if your feet are forward, your hips must be back. This is the single biggest mistake people make when they are first learning the kip - they let their whole body - shoulders, hips, legs, arms - swing forward at the same time.
One way to think about it is that your hips and shoulders are always on the opposite side of the pullup bar from your feet. Your body should either be forward in like a half moon shape (feet and hands back), or your body should be in a half moon shape the other way - shoulder and hips back (feet and hands forward). I recommend spending a fair amount of time with your feet on a box and your hands on a pullup bar (like Eva's video below) just pushing your body back and forth and keeping your hands and feet in exactly the same place. It's how you will get a feeling for the movement. Every time you let something slip, come back to that drill.
All of these links come from CrossFit. CrossFit is an organization that, more than anyone else I can think of, truly championed the oft maligned kipping pullup. The first two links are absolutely essential for anyone interesting in doing kipping pullups with any amount of style, flow, and grace.
Eva T. Teaches Kipping
This link is a MUST if you want to learn the kipping pullup.
More Functional Movement -
Advanced Bodyweight Training: