Ponder for a second and take in some of the marvellous advances of the last 50 years. Sure the moon landing might have set the bar high, but we’ve had the contraceptive pill, the internet, amazingly lifelike prosthetics, mapping the human genome and Simon Cowell’s teeth. So why has personal training gone backwards?

Most people want to shed body fat and it seems the way to do it in 2011 is to go to Boot Camp (ahem, see circuit training). Countless scientific studies show that mixing cardio and strength sessions means you dilute the intensity and just don’t challenge your body’s systems. Lactic acid makes you feel you’re working hard but that’s all.

Keep the weights as weights sessions and the cardio as cardio sessions and you’ll work much harder. With purely cardio exercise you can keep your heart rate consistently much higher for longer, and this consistency is what strips the fat. The extra muscle burning more calories theory works in a test tube, but not in practice – only cardio and diet burn the fat!

So how do you do it? Simple. Keep your heart rate as close as possible to your anaerobic threshold for a maximum of 50 minutes.

0 to 8 minutes: very gentle intensity

8 to 15 minutes: steadily increase as you get your second wind (fat oxidation takes over)

15 to 50 minutes: put your foot down

For tools on how to gauge your anaerobic threshold point and also why 50 minutes is the maximum time, visit www.makeitworkout.co