Agreed that it's an awesome workout in a good time, but FYI guys: do not deadlift the way that he does. The main drive as you're getting off the ground comes from the hips. If you watch him deadlift, his legs are totally static and uninvolved in the lift and his feet are spread way too far apart to allow for his legs to help him drive the weight up. 135 lb deadlifts are really easy, so he can get away with simply pulling himself up in what is essentially a back extension. You try throwing more weight on there and do deadlifts like that and you WILL PULL YOUR BACK.
Think of the deadlift in three phases:
1) The bar is on the ground, you are gripping it shoulder width apart, and the bar is NO MORE THAN ONE INCH in front of your shins. Feet are shoulder width apart, with toes tracking out laterally slightly. (Through the entire movement the bar should move perfectly vertically, which means that you should not have the bar swinging away from you. This guy is just swinging away, and as he comes up he loses power b/c he swings the bar away from him. Watch him at the top of the movement....he has to lean back to compensate, which is yet another way that you will hurt your back). Feet are shoulder width apart, with toes tracking out laterally slightly.You're not in a full squat, but your legs are bent, knees tracking out, hips high but not higher than your chest. The first drive off the ground is all off your hips. As you stack on weight on a deadlift, you will not be able to get the weight off the ground if you are not driving your hips up, pushing through your heels, and letting your chest come up so that it always stays above the level where your hips are driving up, ensuring that you never lose a good back curve.
2) You've lifted the bar off the ground and are building momentum, which is the hardest part (lots of squat work, lunges and box jumps will make this part easier and easier). You're keeping the bar close to your body, not letting it swing away from you. As the bar approaches your knees, it should be so close to you that if you simply force it up the bar would scratch your knees. At this point, you will keep the momentum going but get out of the bar's way, which means you start straightening your knees so that they will be out of the bar's way. Engage the arms, keep them nice and straight and strong, engage the shoulder blades and pretend you're cradling an egg between them and it will fall if your shoulder blades move apart. If at any point in the deadlift your elbows bend or you use your shoulders to get the weight up, you are doing the deadlift incorrectly.
3) At this point, you are straightening your legs and your hips have driven up, so now it is all core strength to get it up the rest of the way. This guy feels that it's sexy or motivating to scream like an idiot while exercising, but if you are inhaling or exhaling on this phase, you are not fully engaging your core and you are actually weaker and begging to pull a back or abdominal muscle. If you need to take a breath, do so at the very top where you lock out, but the best way to ensure a tight, strong core is to take a big breath at the bottom of the movement, come up quickly and efficiently, come back down in a CONTROLLED manner, and exhale/take your next breath when the barbell touches the ground.
4) To reiterate the last sentence, YOU HAVE TO COME DOWN IN A CONTROLLED MANNER. This dude is doing his exhaling/screaming, forcing the bar up, swinging himself backwards at the top to compensate for wasted momentum, and he's basically letting the bar drop back down and letting it drag him down. You have to do the reverse on the way down, engaging all the relevant muscles, otherwise you are again setting yourself up for a nice little hernia or back spasm.
Following good form not only prevents injury, but it maximizes your efficiency and what you can do. One of my favorite workouts is 400m run, 10 deadlifts at 225lbs, 30 situps all x 5 rounds. On those last two rounds i feel like i'm gonna fuckin' die, but when i focus on my form i keep myself from wasting energy and i get through it, even though a torrent of curses emerges out of me when i put the bar down for the 10th time and move on to the next exercise in the set.
It would have to be yet another lengthy post, but he has the same problem on his kettlebell cleans. He has no hip drive, and is essentially pulling the weight up using his back. He will absolutely pull his back at some point doing it that way.