Most functional trainers feature dual weight stacks, and that is the optimal setup. However, single weight stack functional trainers can be more affordable. Weight stacks are stacks of weighted plates that allows you to select how much load you’ll use for a specific movement.

You can see that most functional trainers have a 150 lbs. or 160 lbs. weight stack. Many manufacturers have an option to upgrade the weight stack with 50 lbs. to 200 or 210 lbs. One thing to look out for is if a machine has one or two stacks. The majority has two separate stacks.