ULTRA RUNNING WATERPROOF JACKETS & TROUSERS

There is no single specification that covers every ultra. Organisers set their own mandatory-kit requirements, so always check the current rules for your particular race.

Requirements commonly include a hooded waterproof jacket with taped or sealed seams, and some events specify a minimum waterproof rating such as 10,000mm or 20,000mm HH. Some races also require waterproof trousers so that full waterproof body cover is available.

Events such as the South Downs Way 100, Lakeland 50/100, Arc of Attrition and West Highland Way Race have their own requirements appropriate to their routes and likely conditions. These can change from year to year, so the current organiser's kit list should always take priority.

A technically excellent waterproof is no use as mandatory kit if it does not satisfy the specification for your event.

Waterproof ratings are commonly expressed in millimetres of hydrostatic head, usually written as mm HH. In simple terms, the figure represents the water pressure the fabric can withstand before water penetrates it under the relevant test.

Manufacturers may describe the same type of measurement using terminology such as water entry pressure. For example, a garment specified with a 30,000mm water entry pressure can be presented as having a 30,000mm HH waterproof rating.

The number is useful when checking race requirements, but it should not be treated as a simple overall quality score.

No. Waterproofness matters, particularly where your race organiser specifies a minimum, but choosing the highest figure available does not automatically give you the best jacket for ultra running.

Waterproof protection has to be balanced with breathability, ventilation, heat management, fit and comfort. How much moisture you generate depends on temperature, conditions and how hard you are working. That does not necessarily mean how fast you are moving: a long steep climb at walking pace can generate considerable heat.

Once a garment meets the protection and mandatory-kit requirements you need, consider how it actually works for you rather than choosing by waterproof rating alone.

Not always. Different manufacturers may use different test methods and reporting systems. For example, some waterproofs in this category quote breathability as B-1, while others use g/m²/24hr MVTR.

Those figures should not be treated as directly equivalent simply because both contain a numerical breathability rating. They are useful within the context of the manufacturer's own testing, but the test method matters.

For practical ultra-running use, also consider ventilation, fabric feel, fit, temperature and how much heat and moisture you personally generate.

Getting wet inside a waterproof jacket does not necessarily mean rain has passed through it. A waterproof shell can only transfer moisture at a limited rate.

If you produce sweat faster than the clothing system and surrounding conditions allow it to escape, moisture and condensation accumulate inside. In prolonged rain you can therefore become very wet even though the waterproof membrane is still doing its job.

Ventilation can help. Depending on the jacket, this may include opening the main zip, using underarm or hood ventilation, or partly opening the front while retaining some protection. Some jackets also have a small clip or retainer that allows the main zip to remain open without the front of the jacket flapping apart.

A hood needs to do more than satisfy a kit-list requirement. It should provide useful coverage around the face, have enough adjustment to remain secure and move with you rather than repeatedly shifting or flapping in wind.

Peak design is also important, particularly if you wear glasses, because a well-positioned peak can help keep rain away from the face and lenses.

Cuffs, hem fit, zip construction and fabric feel also contribute to long-duration comfort. Stretch and a softer, more mouldable fabric may feel less restrictive and quieter than a stiff shell. These details are difficult to represent with a single specification but can become very noticeable after several hours in bad weather.

They are particularly important when the jacket may spend most or all of the race in your vest. Mandatory waterproofs often have to be carried for the duration of an event, including dry races where they are never worn.

A lighter and more compact shell leaves more room for nutrition, hydration, spare clothing and other equipment, but that does not mean the lightest jacket is automatically best. Protection, breathability, ventilation, fit, hood performance, comfort and durability still matter.

If prolonged cold or wet weather is realistic, using the complete waterproof system in training can also reveal problems with fit, layering, ventilation, hood adjustment or equipment access before race day.

It depends on the race. Some events require only a waterproof jacket, while others require waterproof trousers as part of full waterproof body cover. Always check the current kit list rather than assuming jacket-only protection is sufficient.

The same balance of waterproofness, breathability, weight, packed size and fit applies to trousers. Because they may spend most of the race in your pack, compact construction is useful, but they still need to work properly when conditions deteriorate.

Think particularly about how quickly you can put them on. Long leg openings or zips can make a significant difference if you need to pull waterproof trousers over running shoes without removing them. Waist adjustment and freedom of movement also matter once you are actually running or walking in them.