It’s all about intensity! Short, intense cardio workouts can give you some of the same benefits as longer workouts, such as improving fitness, burning calories and losing fat, while short, intense strength training workouts are great for sculpting muscle. If you focus your efforts and make the workouts count, all you need is 15 minutes.
Cardio intervals target your cardiovascular system and increase the rate at which you can consume oxygen by increasing the volume of blood your heart pumps with each beat (stroke volume) and the volume of blood your heart pumps each minute (cardiac output). This type of training raises your heart rate close to its maximum, which strengthens your heart and dramatically improves your fitness level and and burns lots of calories.RELATED: RECOMMENDED PLANS FOR YOU
Endurance Tempo Workouts
Tempo workouts are performed at the intensity corresponding to your lactate (anaerobic) threshold – this is an important physiological variable that demarcates the transition between exercise that generates energy almost purely aerobically and exercise that includes energy generated from both aerobic and oxygen-independent (anaerobic) metabolism.
Tempo workouts raise your lactate threshold to a higher percentage of your maximum heart rate and maximum oxygen consumption, which delays fatigue during aerobic exercise. Since tempo workouts are performed at the highest intensity you can maintain aerobically, these workouts are great for burning fat.
Although the percentage of calories from fat is small when exercising at or slightly lower than your lactate threshold intensity, the total number of calories burned per minute is much higher than at a lower intensity. Research has shown that exercising at or slightly below your lactate threshold intensity causes the highest rate of fat use.This workout during which you’re breathing hard but still able to speak a few words to a sentence at a time – keeps you at your lactate threshold the entire time.
“It’s all about intensity! Short, intense cardio workouts can give you some of the same benefits as longer workouts”
Sprint workouts increase your anaerobic power and capacity by calling on your anaerobic metabolic pathways that don’t use oxygen. Short, intense intervals also recruit fast-twitch (strength and power) muscle fibres, complementing your strength training workouts by adding to your muscle definition and size.
Strength training is a very efficient way to sculpt your muscles quickly. Put it in a circuit and you’ll burn lots of calories both during and after the workout. The trick is to keep moving during the circuit. I’ve designed a non-stop circuit that pairs a dumbbell exercise with an explosive plyometric (jumping) exercise using your own body weight – see 15-minute workouts panel.
If you want to improve your fitness and lose fat in the shortest possible time, try these supercharged workouts. Do each of these workouts once every seven to 10 days and those 15 minutes could be the most profitable fitness-wise that you’ll ever spend.
Select any piece of cardio kit. Warm up and cool down before and after each workout.
3 x 3min at 95% max heart rate with 2min active recovery.
Endurance Tempo Workout
15min at lactate threshold intensity (80 to 85% max heart rate).
2 sets of 30, 45, and 60sec sprints at nearly all-out effort with 2min active recovery.
Do each exercise for 30sec and move from one exercise to the next with no rest between. Do the circuit twice. For the dumbbell exercises, use a weight that will almost fully fatigue your muscles in 30sec.
“Sprint workouts increase your anaerobic power and capacity by calling on your anaerobic metabolic pathways that don’t use oxygen.”
Rotated Chest Press:
With one dumbbell gripped in each hand, lie on your back on a bench. Feet should touch the ground with knees bent at 90-degrees. Begin with elbows bent at 90-degrees and palms of hands facing toward you. In one curved motion, straighten arms and bring dumbbells in toward the midline of the chest while rotating hands so palms face away from you until the ends of the dumbbells meet. Elbows should remain slightly bent at the top of the movement. Lower the dumbbells back down to the starting position and repeat.
Get into a press-up position, with back straight and hands shoulder-width apart on the edge of bench. Lower yourself down until chest comes close to the bench. Straighten arms to push yourself up, letting go of the bench at the end of the movement. Catch yourself on the bench and repeat.
Stand in front of a bench with right leg bent and resting on the bench. Bend your left knee and lower yourself straight down to do a onelegged squat. Make sure your squatting leg does not rotate inward. Squat with each leg for 15sec.
Begin in a squat position with thighs parallel to ground and hands on hips. Jump up as high as you can. Land with soft knees and lower back into a squat position in one smooth motion to immediately jump up again.
Place dumbbells vertically on ground. Stand over dumbbells, with legs shoulder-width apart and bent at the waist. Grab dumbbells with palms facing each other. Do an alternating row, quickly pulling one dumbbell at a time toward your chest by bending elbows. Lower each arm back down and repeat.
Medicine Ball Throw:
Stand with feet shoulder-width apart. With knees slightly bent and abdominals tight, throw a 5kg (10lbs) medicine ball with two hands from your chest straight up into the air. Catch the medicine ball with outstretched arms, drawing arms into chest in one smooth movement and quickly throw it back up again.
Stand with legs shoulder-width apart. Turn right leg 90-degrees to your right and turn your body so you are facing to your right. Lunge right leg forward like a fencer, keeping back straight, chest out, and shoulders back. Keep back leg straight. Push off with right heel to starting position. Lunge with each leg for 15sec.
From a forward lunge position (a squat with one leg in front of the other), jump up while switching leg position in mid-air. Land with soft knees, lowering back down into a lunge position.