A lot of people want to know if lat pulldowns are the same as pull-ups. I get asked this question frequently and it is a good question because the two exercises seem virtually identical. Both pull-ups and lat pulldowns work the major muscles of your back, including the latissimus dorsi, as well as your arms, so I can understand why people wonder if there are essentially the same exercise. Well, unfortunately, they are not.
Lat Pulldowns vs. Pull-ups
Pull-ups require much more stability than lat pulldowns. Right off the bat, that’s the major difference. When you do a pull-up, lots of muscles in your body, especially your core, have to act as stabilizers to aid you in going up and down, and to prevent you from swinging all over the place. Lat pulldowns, on the other hand, are a machine-assisted exercise, so you don’t have to engage as many muscles as stabilizers as you do when you do a pull-up.
Pull-ups are also what I like to call a “heavy-lift exercise.” You have to lift your entire bodyweight when you do a pull-up and you can’t cheat. That’s why so many people cannot even accomplish a single pull-up – you’re lifting a lot of weight. On a lat pulldown machine you can adjust the weight to any amount you like, so you’re not forced to lift heavy.
If You Can’t Do a Pull-up
If you cannot do a pull-up, I think lat pulldowns are great substitute. There are really only two reasons you might not be able to do a pull-up: you’re either not strong enough or you’re overweight. You could also be a little of both. Since lat pulldowns strength most of the big muscles you use to do pull-ups, they’re the perfect exercise for working your way up to being able to do a pull-up.
If You Can Do a Pull-up
If you can do a proper pull-up, get off the lat pulldown machine; you’re not doing yourself any favors. I know a lot of bodybuilders like to use the lat pulldown machine because they can load it up with more weight than they way, but if you can’t do at least 10 pull-ups in row, there’s really no reason you need to be trying to lift more than your own bodyweight in this position. If you can do more than 10 pull-ups in a row, you would benefit more from wearing a weight vest or holding a dumbbell between your legs while you do pull-ups.
Sources:
Using the Lat Pull Down Machine to Get Strong for Your First Pull-up
http://www.exrx.net/WeightExercises/LatissimusDorsi/CBFrontPulldown.html
http://www.acefitness.org/exerciselibrary/191/pull-ups