Is an alternative form of barbell used in gyms for weight lifting, power lifting, and so forth.
It is so called because whereas a standard bar is just a single contiguous and straight piece of metal that is held with a horizontal grip (pronated, supinated, or split), the hex bar has sleeves for plates on it at each end but then these are joined in a hexagonal shape (hence the name) forming a lacuna in which the user stands. Bridging each side of the hexagon is a further pair of metal pieces which form one or more handles of differing heights, which instead require the user to hold it with a neutral grip (i.e. fists oriented vertically). Then, it can be used for various exercises.
The advantage of the hex bar is that because the bar doesn't require the user to pitch forward slightly and roll it up and over their knees when performing a deadlift, the load is more in line with the centre line of the body. Therefore less strain is put on the lower back, but more is put on the knees. This makes it worthwhile for people who have back pain or similar as it allows them to deadlift without risking injuring themselves or hurting themselves quite so much. In addition, because one hexbar deadlifts predominantly pushing with the legs and using the lower back as more supplementary force rather than the "main" source of the force used to lift, it can substitute for a squat for people who have trouble with their knees (i.e. recovering hamcannons like me) who want to try to work out their thighs without risking damaging their joints in such a way. A hex bar can also be used to exercise the trapezius by loading it up then doing shrugs as one would with a pair of dumbbells; for this reason it's sometimes called a trap bar. Further, or in the alternative, one can load up a hex bar and then use it to perform a farmer's walk. Which for obvious reasons one cannot with a standard Olympic barbell as it would get in the way of your legs moving. It's also in theory possible to bench press or overhead a hex bar if one can get it up into a squat rack and then scoot the bench under it or have it on the rack at shoulder height and then push from there. But this requires getting it into position in the first place.
Which brings one to the main disadvantage of the hex bar. It's really awkward a piece of kit. It is not only heavier than a standard barbell - whereas a standard Olympic barbell weighs 20kg, hex bars are of necessity weighing more and in the one in my friendly local industrial unit gym is a 40kg big horse. It is also much bulkier. Whereas a standard barbell can be stored on a rack or put in an upright pipe type contraction, a hex bar would stick out in multiple directions to do that and so often it's just flung up against a wall where it takes up space. It's also much more awkward to load or unload especially if you're trying to lift heavy. Whereas with your ordinary straight bar you can use a jack or a stand to get it off the floor to shove your plates on the end, you can't with a hexbar because it would of necessity wobble about if put on a jack. So you have to jack up by the end of the sleeve, pull the plates forward, then move the jack to behind the plates and slide them off, then do the same for the other side. Also if you try to overhead it by getting it into a squat rack, loading it up, and overheading it from there, and forget to remove it afterward, the next user is likely to clonk their head on it which will be painful.
I prefer to deadlift with the hex bar myself, partly because the neutral grip doesn't quite hurt my elbows so much. Also I can as previously stated use it to substitute for squats if my knees are misbehaving as well they might given that I used to be a Big Lad.
(IN24/11)