For quad growth
For quad growth, belt squat and Smith machine squat score the same.
Belt squat is easier on the joints; Smith machine squat is easier to progress.
Both are good choices that train the quads the same way, so they swap freely. Rotating between them every few weeks is an easy way to vary your training.
The research score comes from these, scored by hand from the studies. Lifter scores appear once an exercise has 10 ratings. How scores work
Belt Squat. Loads the legs from the hips, so the quads work hard with no weight on the spine.
Smith Machine Squat. A squat on rails, so you can place your feet forward and push the quads hard without balancing a bar.
For quad growth, belt squat and Smith machine squat score the same. Belt squat is easier on the joints; Smith machine squat is easier to progress. Both are good choices that train the quads the same way, so they swap freely. Rotating between them every few weeks is an easy way to vary your training.
About the same: both are easy to learn.
Belt squat needs a machine, so for most people it’s a gym exercise. Smith machine squat needs a Smith machine, so for most people it’s a gym exercise.
Belt squat: it rates Excellent for joint and recovery cost in our research rubric, against Strong for Smith machine squat.