Improve Your Cardio with 'The Gauntlet' – a Hills and Intervals Challenge to Benchmark Your Fitness

If most of your cardio consists of running the same route at roughly the same pace, eventually you're going to need a different stimulus to keep improving.

That's where threshold training comes in. Sitting somewhere between an easy run and an all-out effort, threshold work challenges you to sustain a hard but controlled pace, helping improve your aerobic fitness and your ability to hold faster speeds for longer.

But that doesn't mean grinding out endless intervals on the same stretch of pavement.

This workout – dubbed 'the Gauntlet' – combines hard uphill efforts with faster running on the flat, giving you a serious conditioning session while adding some much-needed variety to your weekly mileage.

The hills force you to work hard without relying on pace, recruiting more muscle as you fight the gradient. You'll then move onto faster intervals on flat ground, where the same effort should suddenly feel considerably quicker.

Together, you're challenging your aerobic engine across different gradients and terrain while training your body to continue producing a strong effort after fatigue has already accumulated.

Heading off-road for the hill reps brings some additional benefits, too. Uneven terrain challenges your ankles and lower-leg muscles, while softer surfaces can reduce impact forces. And, let's face it, the view from the top of a trail probably beats another lap of your local housing estate.

This is a demanding session, so give yourself plenty of time to warm up before getting into the hard work.

• 15-20-minute easy warm-up, ideally on trails
• 4 x one mile uphill, ideally on trails, at threshold effort – around 7-8 out of 10 rather than chasing a specific pace
• Recover with an easy jog back down the hill after each rep
• 4 x 3 minutes on flat roads or paths at the same threshold effort. You'll naturally be moving considerably faster without the gradient
• Take 2 minutes of static recovery between each flat rep

The key is controlling your effort. Threshold training should feel hard, but you shouldn't be sprinting or completely emptying the tank during the opening intervals. Aim for a pace you could sustain for an extended period if you absolutely had to.

Unless you're already accustomed to high-volume interval sessions, there's no need to jump straight into the full workout.

A more manageable introduction is:

• Easy 10-15-minute warm-up
• 2 x 1km uphill at a 7-8 out of 10 effort, jogging back down between reps
• 2 x 2 minutes on the flat at the same effort
• 2 minutes of recovery between flat intervals

As your fitness improves, gradually add reps or extend the duration of the intervals rather than trying to run every effort faster.

Whether you're trying to improve your 5k, build better general cardio fitness or simply make your weekly runs a little less predictable, the combination of hills and threshold work will give your lungs – and legs – a very different challenge from another steady lap around the park.