The team at Project Fit want to keep your cardio sessions interesting with these treadmill workouts.

5-minute blitz
Add this speedy interval session to your regular workout or alternate 5 minutes of this with a 5 to 10 minute body-weight or weights circuit.

Start at a comfortable pace, then every 10 seconds, over 60 seconds, go up one number in speed. (If you start at 10kph, after 10 seconds your speed needs to go up to 11, after 20 seconds it goes up to 12, after 30 seconds it goes up to 13 and so on. Return to your starting speed after 60 seconds and repeat). Repeat this sequence five times over.

10 minute incline challenge
This tough hill challenge will really give your legs a going-over! Add it to a circuit workout or mix in with a rowing and spin bike session.

Start at a reasonably comfortable speed with the incline at 2. Run like this for 2 minutes to warm up. Then, for one minute, reduce your speed by one number and increase your incline to 8. After another minute, take your incline back down to 2 and increase your speed by three numbers for 30 seconds. Come on! Then take your speed up one more number for another 30 seconds.

Repeat this cycle until you hit the 10-minute mark.

15-minute speed blast
This speed session is a real killer! Add to a lighter workout sesh or do as a stand alone workout.

Do a 4-minute warm up at a comfortable speed. After 4 minutes put the speed up for a 30 second sprint at full throttle. Now back down to a walk for 30 seconds as recovery. Repeat this seven more times followed by a three minute cool-down.

Job done!