Cardio upgrade with a few simple tweaks can turn a humble cardio machine into a real test of your manhood.

As well as being, well, a bit boring, treadmills and stationary bikes aren’t very manly. Rocky Balboa knew this. That’s why he preferred dragging a sled through a frozen field to get his cardio.

However, you don’t need to live in a cabin in Siberia to get a real man’s workout. Try these tips from US trainer Cameron McGarr for a cardio routine that will kick your arse.

Military Run

Hold a light barbell overhead, keeping your elbows locked out while you run.

Unpowered Treadmill Run

Set a treadmill to a low incline, then shut off the power. Move the belt with your own power, “pawing” at it with your feet.

Weighted Step Mill

Strap on a weight vest or grab a pair of dumbbells and take to a step mill (or a set of real stairs) and get climbing.

Kettlebell Intervals

Alternate between 10 heavy kettlebell swings and running 400 metres.

Bear Crawl Intervals

Place your feet behind the treadmill and put your hands on the belt. Crawl with your hands for 60 seconds, then run for 60 seconds.