1. Rest less

Weights can improve your cardio: in one review of studies, young and old subjects alike saw VO2 max improvements from resistance training alone. Short rests are key – reduce the weight slightly, and aim for 45 seconds or under.

2. Think EDT

Escalating Density Training (EDT) is the best way to pack in a lot of work in not much time. Pick moves that work opposing muscles – pull-ups and press-ups are classic – and do as many as you can in 15 minutes. Next time, beat your score.

3. Go complex

A dumbbell/kettlebell/barbell complex is anything but complicated – you use one weight and one bit of space. Simple is best: grab a bar, do five deadlifts, five cleans, five presses and five squats, rest for 90 seconds and repeat for four sets.

4. Make it HIRT

One study comparing high-intensity resistance training with traditional lifting saw HIRT lifters hit four times the post-workout calorie burn in half the gym time. Do three sets of six, then take ten breaths, go to failure – and repeat.