Skip to content
SPEND £40, GET A FREE PILLAR RECOVERY & IMMUNE SACHET PACK
FREE PILLAR SAMPLE PACK WITH £40+ ORDERS

Your Cart

Maximum order value is €150. View International / EU Shipping

Try BOLT Chews
Try BOLT Chews
Vegan & Gluten Free
€6,44
New from BIX
New from BIX
2 Gels for £3
€3,86
2 Gels for £3
2 Gels for £3
Whilst stocks last
€3,86
Try Active Root Gels
Try Active Root Gels
3 Gels for £3
€3,86
Clean Your Kit
Clean Your Kit
Eco-Friendly Laundry Sheets
€9,01

Your cart is empty.

Log into your XMiles account here and view your store credit.
Subtotal
Secure checkouts with / /

AMBITION 4.5L

Visit the Instinct store

Engineered for peak performance, the Instinct AMBITION 4.5L sets a new benchmark in trail running vests. Designed for minimalism without compromise, this vest delivers everything you need for ultra-distance training and racing in a lightweight, form-fitting design.

  • Lightweight and minimalist design
  • Secure, breathable fit with sternum straps and elastic side lacing
  • Secure, breathable fit with sternum straps and elastic side lacing
  • Honeycomb mesh promotes airflow and rapid moisture wicking
  • Five different pole-mounting options for varying needs
  • Designed for long-lasting use across rugged terrain and conditions

AMBITION 4.5L

Visit the Instinct store

€122,14
Mix & Match
member exclusive price
BBE
One-time purchase
Subscribe & save 10%
Free UK delivery
Pause or cancel anytime
Easy returns
Translation missing: en.general.icons.icon_check_circle icon 2 in stock, ready to be dispatched

Want it faster? Select fast shipping or DPD next day at checkout

Standard delivery is delivered via Royal Mail within 3–5 working days. Alternatively, select 24/7 InPost Lockers for a flexible pick-up option.

Description

Whether you're tackling a local 10km or grinding through a 70km ultra, the AMBITION 4.5L gives you unmatched freedom of movement and fast access to your kit.

Weighing in at just 190g, the vest offers a smart 4.5L capacity, strategically divided into front and rear pockets to ensure intuitive access on the move. Hydration, nutrition, emergency gear, and layers all have their place, thanks to the thoughtful layout and high-sitting fit. Every component is designed to minimise bounce and maximise comfort, so you can stay focused on the trail, not your gear.

Its breathable honeycomb mesh construction enhances airflow, keeping you cool even during hot, high-output sessions. The adjustable sternum straps and elastic side lacing system ensure a custom fit for all body types, while maintaining full freedom of breathing and motion. Multiple pole-carrying options let you adapt to race demands or terrain changes with ease.

Whether you're a seasoned ultra-runner or just building up to long days out, the AMBITION 4.5L delivers a balance of efficiency, reliability, and comfort. It's a vest built for athletes who demand performance, but won’t compromise on practicality.

How does it work

The Instinct AMBITION 4.5L works by combining precision fit with ergonomic storage. The custom lacing and strap system creates a stable, body-hugging fit that moves with you, eliminating bounce and preserving breathability. High-sitting design positions essentials like hydration bottles and nutrition close to hand, so you can refuel without breaking stride. Each pocket is placed for natural reach and maximum usability, whether you're mid-race or adjusting gear on a training run.

Its structure uses a lightweight but durable honeycomb mesh that promotes airflow, reducing sweat build-up during high-output efforts. With front bottle holders, rear storage for kit, and multiple ways to carry poles, the AMBITION adapts to your specific needs for distance, weather, and terrain. Every detail is designed to reduce faff and keep you focused on performance.

About Instinct

Born on the trails of the French Alps and race approved around the world.

Redefining a hydration pack comes from asking the right questions... introducing analytical observations & first hand experience in running the toughest conditions. At the heart of each revolutionary Instinct product is the desire to achieve a greater degree of function, accessibility and ergonomics; Total liberty of movement, zero obstruction and a second skin fit.