Use these techniques to train like an ancient Mongol soldier and achieve warrior fitness.

Genghis Khan’s soldiers didn’t worry about how much they could bench press. Their focus was real-world strength and speed. Here’s how to follow their lead in just 15 minutes a day. Okay, so we don’t live like Mongols and we don’t have the baseline cardiovascular fitness that a Mongol does. We are adapted to endurance as well as interval-type training and we need both for heart health. When you have time, cardiovascular exercise is vital due to our current general inactivity. But the following routine can be used when you lack the time to exercise. Here’s a week-long plan to get you fighting fit.

DAY 1 STRENGTH CIRCUIT

Think of each circuit as one continuous set. Perform eight to 10 reps of each exercise, resting for two minutes only after you’ve completed the entire circuit. Repeat each circuit three times. True fitness is measured in workout density, how much you can do in as short a time as possible, says Craig Friedman, a performance specialist. Single-leg exercises are also key. We live life on one leg at a time, and by training on one leg, you’ll get stronger faster.

Circuit A: push-ups; front planks; single-leg squats

Circuit B: chin-ups; side planks; single-leg dead lifts

DAY 2 INTERVALS

Find a rugby field and, after warming up by jogging the perimeter twice, begin running the length of the field (go for 70 percent of your maximum sprint speed) and jogging the width. Stop after you’ve circled the field five times. If you don’t have a field nearby, find a road with telephone poles, advises Boyle. Run the distance between three poles, jog to the fourth and repeat 10 times. The entire workout shouldn’t take longer than 12 minutes, but that’s all the cardio you need, says Boyle. In a recent study of cyclists at McMaster University in Canada, researchers found that those who exercised intensely for just 18 minutes a day (four 30-second bursts of all-out cycling separated by four minutes of rest) experienced the same gains in performance as cyclists who pedalled continuously for two hours a day. Have you ever seen a fat sprinter? Probably not, says Boyle. But I bet you’ve seen a lot of fat joggers. Intensity will always win over duration. Always.

DAY 3 STRENGTH TRAINING

Follow the same strategy as outlined in Day 1. The idea here is variation without change, explains Boyle. You’re going to perform the same basic movements; pushing, pressing, pulling and squatting but, by switching the exercises, you’re going to hit different muscle fibres in different patterns. As a result, your muscles won’t adapt to a routine and performance won’t plateau. Body weight is also an important element of any functional exercise plan says Friedman. You don’t carry around dumbbells in real life, so why overload your workout with them?

Circuit A: T push-ups; bicycle crunches; elevated split squats

Circuit B: inverted rows; back extensions; one-leg Romanian dead lifts

DAY 4 HILLS

Hill training represents a near-perfect combination of aerobic and anaerobic conditioning says Boyle. On the one hand, you’re getting your heart rate up and working your cardiovascular system. On the other, the hill’s incline provides resistance for building leg strength. Find a hill with a 20 to 30 percent grade (roughly equivalent to an intermediate ski slope), then run 50m uphill at 80 percent of your sprint speed. Walk down and repeat 10 times. Distance runs on flat ground are the scenic route.

DAY 5 SPORT

Thus far, you’ve focused on strengthening various muscles and bodily systems through a series of functional workouts. Today, you’re going to put everything together into one compound exercise: basketball. No other sport gives you as much bang for your fitness buck, says Boyle. It strengthens and reinforces every conceivable movement pattern: accelerating, decelerating, jumping, sprinting, upper-body coordination and rapid changes in direction. Everything is rolled into this game. And you only need one opponent to reap the benefits. If basketball isn’t your sport, try tennis, soccer or rugby.