Video: Week 4 of our full body circuits with Jessica Ennis-Hill

We've reached the final week of our four-week workout plan with Jessica Ennis-Hill and we have to say, we think the olympian has saved the hardest til last with a session that concentrates on the core muscles.

The 20 minute circuit is a little taste of the content that is on Jess' fitness exercise app  Jennis , which features pre-and postnatal workouts as well as general fitness, combining both cardio and strength, based on HIIT principles.

What's in the workout

As with week oneweek two  and week three , you do each exercise in the set for 25-30 seconds followed by a ten-second recovery with a 60-second rest between each circuit.

This week's circuit comprises of a plank reach (which can be modified to just a plank), squats (with or without weights), cross scissor kicks, twist sit ups, single leg sprints (a bit like mountain climbers), feet up crunches and bunny hops. You'll be wokring hard for 15 minutes, isolating the core muscles.

The key thing about Jennis workouts is that they're never more than 30 minutes and many require no equipment - meaning they are easier into your daily life. This was important to Jess when she became a mum (even more. so now with the challenge of home-schooling) and had to make best use of limited time to herself.

For more information on Jennis, Jessica Ennis-Hill’s fitness exercise app head to  jennisfitness.com  and follow Jennis Fitness  @WeAreJennis