This vest has been put through its paces. It carried a full load of winter gear on the Hardmoors 55 mile ultra marathon in March, has been up Skiddaw in blistering heat, around Wast Water, across Moors, up and down Dales, through the Cairngorms and numerous other outings. I have warn it in hot, humid conditions through to freezing temperatures where we experienced -12C with wind chill so I’m pretty confident I have tested this vest to my limits, if not the vests. My conclusion after all of this, I need to take a break from running! This vest pack has been superb. Comfortable, practical and with no obvious flaws that I could find and that is pretty rare as when I’m exhausted I usually find it very easy to pick holes and criticise kit (along with everything else).

The storage options in the Mountain vest are so good. It has a total capacity of 13.27L and weighs in at 372g. With 10 pockets (not including the two bottle holders) on the shoulder/chest straps you are never short of places to store anything from hats and gloves to gels, snacks and your phone. You get a selection of stretch mesh drop pockets, secure zip and Velcro closure pockets too. Admittedly, some are just big enough for a gel or energy bar but in the others I have stored my phone, hat, Buff and gloves with space to spare. The two bottle holder pockets are great and have a drawcord to secure the soft flasks (which come included with the vest) no matter how empty they get. I love using these and will throw extra soft flasks in the main compartment for longer races where checkpoints or refuelling points are significant distances apart. If you prefer the hydration system then the bag can take this and the tube can run down either shoulder, freeing up more space on the shoulder straps if you’re dropping the soft flasks. I haven’t actually run with this system as I’m not a fan of it but I’ve set it up this way to check that it is an option.

The materials used on the vest look quite thin and delicate. There are two different types of stretch mesh, one of which is breathable, soft to touch and amazingly stretchy while the other provides 4 stretch with added strength. There is also a see-though micromono mesh which is super lightweight, breathable and doesn’t absorb moisture. The combination of these and the 30D ripstop actually make this a surprisingly durable and hardwearing pack for its overall weight and feel. I’m never the most caring and gentle with kit but even after the amount of use this pack has had it still looks as good as new, which I am amazed by!

One of the main concerns when first looking at this pack is the cinch system on the back. It is a hard plastic section that sits at the small of your back and looks like it will dig in and be uncomfortable. It doesn’t. I don’t know how UD have managed it but in the varied conditions (physically and weather wise) I used it in I can’t recall ever noticing that it was even there. Amazing really when you look at it but it has never caused me any discomfort at all. This system is so worthwhile too. On the previous model of this pack to tighten the pack you had to go into the small pockets around your sides, find the buckle and tighten it. It was near impossible to do without stopping and taking the pack off. This cinch system is an amazing upgrade with two thumb loops to pull on to tighten and simple buttons to press to release. It is easy to do on the run to keep it snug, comfortable and eliminate bounce when the contents of your pack changes through the event. The comfort factor from this vest pack cannot be underestimated. Through hot and humid conditions to freezing cold and everything in between this pack has been superb. Unless I need a much bigger pack for multiday runs with camping involved the Mountain Vest covers the rest.

Overall, I can safely say that this is the best running vest I have ever used. At a conservative estimate that covers at least seven running packs from five different brands in the past couple of years. The Mountain Vest 4.0 is lightweight, easily adjusted to give the best possible fit, surprisingly comfortable in all conditions and provides loads of versatile storage space. I really can’t think of many negatives - although it doesn't come in a women specific design unlike every other UD vest which is a bit strange. The only reason I wouldn’t recommend this vest is if you need a much smaller or much larger pack, otherwise this is the best out there.

Michael S