No time? No worries. These speedy workouts will get you sculpted in minutes

Who hasn't cancelled a workout with the line "I don't have time!"? We've all been there - but there are so many different ways to get your exercise session done and dusted within half an hour these days that your favourite excuse just doesn't cut it anymore, no matter how hectic your diary is!

By making sure your workout is an effective one, you'll not only be working your body at the gym or in tha park, you'll also be working in the hours afterwards, when your metabolism is sky rocketing.

From group exercise classes to intense sessions that are shorter than your shower, there's a timely solution for everyone.

4 mins: Speedy sprints
Four fast minutes - that's all it takes. We know what you're thinking: where's the catch? There isn't one. Trainers Ruben Ares and Ozzie Çakir have devised a four-minute training technique that promises to torch fat for good, and it takes less than five minutes six times a week. That's only 24 minutes all up!

Although the workout lasts only the length of around one of your favourite songs, it does mean running - a lot. The program consists of 20 seconds of sprinting followed by 20 seconds of rest, then a further 20 seconds of sprinting followed by 15 seconds of rest, another 20 seconds of sprinting followed by 10 seconds of rest… and the whole thing repeated. According to Ruben and Ozzie, results are guaranteed within six weeks if you stick to the routine.

15 mins: Focused Training
If you've got time for a cup of tea, you've got time for a workout. Fifteen minutes is all you need - in fact, new studies show that more concentrated sessions in 15-minute bursts will actually yield faster results than slower-paced, longer ones.

Personal trainer AJ Perera is used to deling with time-poor clients. "By the time they change, I only have quarter of an hour to whip them into shape!" he says. The answer? "I focus on just one area of their body. In 15 minutes you can stay focused on one body part and keep your intensity levels high. Try to use compound exercises, such as leg presses, which work more than one muscle group at a time."

20 mins: Quick circuits
Circuits are perfect for controlling the length of workouts. Just make sure you increase the intensity as you decrease the time to ensure a serious kJ burn.

"Twenty minutes is all you need to reap the benefits," says personal trainer Chloe Bowler. "Many people actually spend far longer than necessary in the gym."

The key to making it work? Plan the routine beforehand, and vary your workouts to keep it interesting and challenging. A good plan means fewer rest periods so you'll be done quicker and cover your cardio as well as resistance in one session.

"All you need is an efficient workout planned before you hit the gym," agrees Chloe. "Circuit training is a total body workout and is amazing at fat burning thanks to its fast and hard pace. In fact, this type of high- intensity training has been found to increase your metabolic rate for up to 48 hours after your session."

 20 mins: Tabata training
Make the most of every minute, and guarantee those post-workout jelly legs, with high-intensity interval training (HIIT). A form of HIIT, Tabata sets last for four minutes but are usually completed back to back using different exercises for around 20 minutes, so you'll really be feeling the burn afterwards.

"Tabata training is a quick, high-intensity workout"' explains bootcamp drill sergeant Dean Barton. "Basic training lasts for four minutes which is made up of eight intervals of just 20 seconds each, followed by 10 seconds of rest in between."

Why does it work? During those 20 seconds, you're working to your absolute max."You might not burn that much during Tabata training," says Dean, "but afterwards, your system is burning much more throughout the day. This is called after-burn, and it's the key to fat loss and a healthy, fit body."

When using this method, make sure you use compound moves like squats and even plyometric moves like burpees, to work as many muscles as possible. That way, you're not wasting any time!

30 mins: Fast classes
Short on time but enjoy class settings with an instructor and group to motivate you? A lot of gyms now offer express classes, from agility and speed workouts to interval training. They usually last 30 minutes, making them a perfect lunchtime session or quick workout either side of your working day.

"The classes fit well into most people's busy schedules and are designed to burn more kJs in a shorter space of time," explains fitness specialist Tim Foster. "We know this form of workout increases both aerobic and anaerobic [short-burst] fitness, meaning that metabolism is increased, even when resting, giving better results long after the workout has finished."

3 ways to get more from your workout:

1. Be competitive
As well as gossiping with your BFF during workouts, compete against her and try to beat her time, reps or pop-culture knowledge.

2. Increase your weights
Still using your 2kg dumbbells from last year? Keep your muscles challenged by using heavier weights.

3. Add new equipment
If you're using the same tools, you (and your muscles) will get bored pretty quickly. Mix it up with medicine balls, resistance bands and kettle bells.

Related:

Get competitive to cane more kJs

What's your workout sweet spot?