The Valslide is a versatile piece of kit which I have been using with clients for several years.
It can be used for upper body exercises, some killer core exercises and a number of great leg exercises which are hard to duplicate with other types of equipment (unless you want to shell out for a decent slideboard)
The other advantage is with the aid of some covers, the Valslide can be used on a variety of surfaces - providing they are not abrasive.
In this particular exercise, I'm demonstrating an Eccentric only leg curl.
Eccentric refers to the lowering part of an exercise i.e if you were doing a bicep curl and you're lowering the weight down to the start position, that would be the eccentric portion.
I really like this exercise as it is a very safe, effective way to target the hamstring muscle (the muscles on the back of your upper legs).
With it being eccentric only, there is a lot less chance of straining a hamstring muscles compared to if you had to reverse the motion.
Whilst it does look pretty simple, it can take time to build up to the full straight leg version.
Start with the feet going halfway out before lowering the hips to the floor and from there, gradually progress the feet out further and further.
This is my, mostly, Personal Trainer musings and information which I hope you'll find helpful!