If you're a dedicated runner who's yet to incorporate strength training into workout routine, the Activ5 is perfect for you. Worth £127, the Activ5 is a handheld strength training device used by Olympic medal winning runners that helps you to focus on the muscle groups you need to strengthen to smash your PBs.

Dubbed ‘a tiny gym in your pocket’ Activ5 by ActivBody allows anyone with a smartphone or tablet to complete effective five-minute workouts from virtually anywhere.

The sleek and portable handheld device guides you through short burst isometric workouts, that allow you to hone in on strengthening specific muscle groups such as glutes, core and hip flexors, all while tracking results and progress on the companion Activ5 coaching app.  It features more than 100 unique workouts that are calibrated to your individual strength level and uses your own body as resistance so you don’t need any other equipment. Fast, fun, and measuring data such as strength, strength increases, precision and other personal metrics, Activ5 helps you to reach those all-important training goals.

With a durable design that registers more than 90kg of force, Activ5 can help you increase your strength by as much as 5 percent per week. You can work your whole body or focus on particular areas and muscle groups.