Smith machine

This is intended to make it safer for those who lift without a spotter, as one only needs to twist the wrist in order to lock the barbell in place in the event that the weight becomes too great.

Most models also incorporate blocks, pegs, or other devices which can be adjusted to automatically stop the barbell at a predetermined minimum height.

[1] Bench pressing while alone is dangerous in general, but even more so in a Smith machine; if one gets trapped under the bar, it cannot be rolled or tipped sideways off one's chest or neck, which has led to at least one fatality.

[2] Use of the Smith machine is frowned upon by many strength training devotees as it forces the user to adopt an unnatural straight-up-and-down "bar path".

[7][8] Many gyms cater to casual trainees and thus may provide Smith machines instead of power racks, which are a piece of equipment critical for safely performing squats and other barbell-based free weight exercises.

[11][12] Research published in December 2009 reported that free weights triggered 43% more activation of the muscles than a Smith machine when performing squats.