The short version

A handheld is simple, light and fine for an hour or two, and it occupies a hand for the whole run. A vest carries far more water plus food, a jacket and mandatory kit, which is what anything ultra-distance actually requires. Use a handheld for short trail runs; use a vest as soon as aid stations are far apart or a race requires mandatory kit.

Common questions

How much water do I need per hour?

It varies enormously with heat, effort and individual sweat rate, so the honest answer is that you have to work out your own. Weigh yourself before and after a long run in typical conditions to estimate loss, and drink to thirst rather than to a fixed schedule.

What is hyponatremia and should I worry?

It is dangerously low blood sodium, and in endurance events it is more often caused by drinking too much plain water than by drinking too little. It is a genuine medical emergency. Take electrolytes on long efforts and do not force fluid beyond thirst.

How should a vest fit?

Tight enough that it does not move when you run with full flasks, loose enough to breathe deeply. Try it loaded rather than empty, because an unloaded vest tells you almost nothing about how it will sit at mile 20.

Best for long distance

Salomon Advance Skin 12 Vest

~$185

Check price on Amazon
Best for short runs

Nathan ExoDraw 2.0 Handheld

~$35

Check price on Amazon

At a glance

Salomon Advance Skin 12 VestNathan ExoDraw 2.0 Handheld
Water capacity 1.5 to 2 litres plus flasks About 500 ml
Carries food and kit Yes, substantial A gel or two
Hands free Yes No
Mandatory kit for races Yes No
Bounce when loaded Depends on fit None
Cost High Low

Choose the Salomon Advance Skin 12 Vest if…

You are running longer than about two hours, on trails with distant water, or entering races with mandatory kit lists. A vest is the piece of equipment that makes long days possible, and fit matters more than brand: it should be snug enough not to bounce with full flasks.

Check Salomon Advance Skin 12 Vest on Amazon

Choose the Nathan ExoDraw 2.0 Handheld if…

You are out for an hour on familiar trails. A handheld is cheap, weighs almost nothing and needs no fitting, and for short efforts the occupied hand is a minor annoyance rather than a problem.

Check Nathan ExoDraw 2.0 Handheld on Amazon

Full reviews of the vests

If the answer is a vest, the two we would put on a hundred mile start line are covered in the Salomon Adv Skin 12 review and the Osprey Duro 15L review.

Related

Comparison based on published manufacturer specifications and the general consensus of owner reports. We have not tested these products side by side. Confirm current specifications and prices before buying. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.