Winter is finally over and the warmer spring weather has finally arrived. When dusting off your lighter, spring clothing, it's fairly common to find that it may be feeling a little bit tight and uncomfortable. A few months of rich, heavy winter foods and too much time curled up on the sofa may mean that a few unwanted kilograms have crept on and you're not feeling as svelt as you did in the autumn. If you'd like to shed your winter padding quickly and tone up your muscles ready for the warmer weather, then here are three group exercise classes that will get you in shape fast.

1. Crossfit classes

Crossfit is a specialised exercise program that was originally developed to assist athletes in training. It uses a combination of techniques that focus on cardiovascular fitness, toning the whole body and developing lean muscle mass. Crossfit utilises a combination of gym equipment and non-equipment exercise to give you a varied, fast paced and highly effective workout.

Crossfit is a sociable and exciting way to get fit. No two classes are identical so you'll never get bored from repetitive and unchallenging routines. Crossfit classes also have a palpable sense of camaraderie and teamwork that will inspire and motivate you.

2. Spin classes

Spin classes have been operating out of gyms and health clubs for many years and they remain a hugely popular option today. These high-intensity classes are guaranteed to help you shed unwanted kilos, tone up your muscles and get fit fast.

Spin classes are performed on stationary exercise bikes and use a combination of sprinting and simulated hill climbs to push you to your limits. They are generally shorter than other exercise classes, with a 30-45 minute duration instead of the usual 1 to 1.5 hours of other classes. Don't be fooled by the shorter duration though. You'll work hard and fast and spin instructors won't let you slack off.

3. Boot camp classes

Boot camps are popping up all across the country and are often run at local parks or schools in an outdoor setting. They embrace a military style workout that uses traditional exercise moves such as push-ups, sit ups, burpees and sprinting to give you a challenging and fun workout.

Boot camps are often available as a program that includes multiple classes as well as a nutritional plan and the setting of weight loss goals. The accountability you'll feel towards your instructor and fellow boot campers will help you to achieve results that would be unlikely in a less sociable exercise regime.