ZFOsports vs RUNFast: the weighted vest argument is about increments, not pounds

The one spec that separates them

Adjustable pocket vests all work the same way: a nylon shell with pockets front and back, and removable weight bags you pull out to lighten the vest. The interesting number is not the maximum weight. It is the size of one bag, because that is the smallest change you can ever make to the load.

ZFOsports publishes 3 lb packets across a 3 to 40 lb range. RUNFast's vests take weight out in 2.5 lb steps across a line that runs from 12 lb to 140 lb depending on which version you buy. Half a pound sounds like nothing until you are the person adding weight to a pull-up, where the difference between a 3 lb jump and a 2.5 lb jump is roughly the difference between a set that moves and a set that stalls.

It also decides which specific loads you can hit. If you need exactly 20 lb for a CrossFit workout, the ZFOsports gives you 18 or 21 and the RUNFast gives you 20 on the nose. If you need 14 lb, the ZFOsports gives you 12 or 15 and the RUNFast gives you 12.5 or 15. Neither is wrong; they just land in different places.

Head to head

Which one for weighted pull-ups

This is what most people are actually buying for, and the answer depends on where you are. If you can do eight to twelve strict pull-ups and you are adding weight for the first time, the ZFOsports is the better vest: it starts at 3 lb, it climbs in 3 lb steps, and 40 lb is more load than the overwhelming majority of home lifters will ever hang off themselves. The padded shoulders are a real benefit on long hanging sets, where an unpadded strap digs in.

If you are already strong — fifteen-plus strict pull-ups, or you are a heavier lifter — the RUNFast line is the one with headroom. The 60 lb and heavier versions exist precisely for that, and the 2.5 lb bags make the climb finer. The honest caveat is that at those weights a vest becomes a poor tool: the load sits high and bulky, and a dip belt carries it better and cheaper. That trade is set out in full on the weighted vest vs dip belt page.

Which one for walking and rucking

Here the answer flips, and it flips on fit rather than increment. The RUNFast adjusts to a chest between 28 and 48 inches with quick-release buckles, which is a real sizing range; the ZFOsports is one size with adjustable straps, which fits most people well and the extremes poorly. For a walk, where the vest is on for an hour and shifting is the whole problem, the better fit wins.

That said, both are pocket vests, and both bounce more than a thin steel-weight vest does. If walking is the main use rather than an occasional one, the walking vest roundup covers a category built for it. If you are loading a pack rather than a vest, the vest versus rucking comparison is the one to read.

Where the CAP 20 lb fits in

A sizeable share of people comparing these two vests want neither. They want 20 lb, they want it cheap, and they want it to breathe. The CAP Barbell 20 lb is a mesh vest with roughly 0.75 lb packets, which is by some distance the finest increment of the three, and it costs less than either of the others. Its ceiling is the catch: 20 lb and no further, forever.

The decision rule is simple. If you will never go past 20 lb, buy the CAP and spend the difference on something else. If 40 lb is plausibly in your future, buy the ZFOsports. If you already know 40 lb will not be enough, buy the RUNFast in the class you need.

What neither vest does well

Running is the obvious one. Both are thick, both have weight standing off the torso rather than lying flat against it, and the maker of the RUNFast says outright that its heavier versions bounce. A vest you can genuinely run in is a different product built around thin steel plates and a compression fit.

Push-ups are the quiet one. A loaded pocket vest bunches between your chest and the floor, which shortens the rep without you noticing. And neither vest is subtle: these are gym objects, not something you wear under a jacket to the shops.