The Smith Machine - Friend Or Foe?

My neighborhood New York Sports Club has gone heavy on the Smith Machines, while providing only 1 full power rack - something that quite honestly has peeved me off.

It's not that I'm entirely anti-Smith machine and admittedly, I do use it for inverted rows and sometimes for incline push-ups. Oh yeah, it's also a great place to hang my towel when I'm using the power rack.

Regardless, the Smith machines do get a fair amount of usage at the gym and just this past week I was watching one guy loading up the Smith Machine and using it for bench presses.

He really had a good amount of weight on the bar and seemed incredibly pleased when he was able to complete 6 reps. So much so that there was a good amount of gloating between him and his friend who was doing free weight bench presses across the gym.

While it certainly wasn't my place to burst this guys bubble, the reality of the situation is that using the Smith machine requires less strength and less muscle than free weights. Because the Smith machine balances the weight for you and the bar is within a fixed plane, stabilizing muscles are taken out of play and muscle imbalances often occur.

The Journal of Strength and Conditioning Research published in March of this year an article on The Comparison of Muscle Activation Between a Smith Machine and Free Weight Bench Press.

The purpose of the study was to compare muscle activation of the anterior deltoid, medial deltoid, and pectoralis major during a Smith machine and free weight bench press at lower (70% 1 repetition maximum [1RM]) and higher (90% 1RM) intensities.

Normalized electromyography amplitude values were used during the concentric phase of the bench press to compare muscle activity between a free weight and Smith machine bench press. Participants were classified as either experienced or inexperienced bench pressers. Two testing sessions were used, each of which entailed either all free weight or all Smith machine testing. In each testing session, each participant's 1RM was established followed by 2 repetitions at 70% of 1RM and 2 repetitions at 90% of 1RM.

Results indicated greater activation of the medial deltoid on the free weight bench press than on the Smith machine bench press. Also, there was greater muscle activation at the 90% 1RM load than at the 70% 1RM load. The results of this study suggest that strength coaches should consider choosing the free weight bench press over the Smith machine bench press because of its potential for greater upper-body muscular development.

As the authors of the study point out, there were no differences in muscle activation for anterior deltoid or pectoralis major between exercises, regardless of load or experience level. The authors speculated that this may be due to the greater stability of the fixed path of motion in the Smith machine. However, activation of the medial deltoid was significantly greater during the free weight bench press.

The results of this study support the findings on the 1994 study by Steven McCaw and Jeffrey Friday comparing muscle activity between a free weight and machine bench press. Interestingly, these appear to be the only two research studies conducted on this often contested topic.

From personal observation, with the exception of the individual undergoing rehab, many of those who gravitate towards the Smith Machine for bench press, squats and deadlifts are more focused on ego than functional strength gains.

Start light, learn proper form and reap real benefits from the time you put in at the gym.

Train hard; stay strong.

Peace.

Susan