Diets A-Z: Diet and fitness trends for 2005

Interval training

The theory: Most people use a continuous form of exercise at the same level and speed for the whole session. By combining high- and low-intensity exercise you can perform longer total periods of high-intensity work, which will improve fitness and help burn more calories as it raises your heart rate. Plus lower intensity periods allow for recovery while the body keeps working.

Expert's opinion: 'It allows you to adapt your routines and keep your body working at progressively greater workloads,' says Kristoph Thompson, a highly qualified personal trainer who swears by this method. (www.kristoph.co.uk)

Core training

The theory: Concerned with developing strength from the inside out, this applies to any exercise which works the deep abdominal muscle, which is often neglected, but is crucial to stabilising the spinal column and pelvic area.

Expert's opinion: 'There's no doubt that core training is crucial as part of every routine but not as important as it's been made out to be in the last few years,' says Matt Roberts. 'As part of an overall workout it's great because it provides a good base to work from. But you shouldn't devote more than your work out time to pure core strength work. In itself, it does not make you lose weight.'

New classes Nicki Waterman recommends taking part in a whole range of activities, such as some of the exercise classes new to our shores. 'I think anything that is fun and that you enjoy is great. In the case of exercise, variety really is the spice of life,' says Nicki. (www.nickiwaterman.com)

Here's a selection of the new classes on offer:

Baby boot camp: Group cardio, where you take your little one with you, and even lets you use the buggy as a prop during the class.

Gyro tonics and now gyro kinesis: This involves series of machine-based moves and looks set to explode. Known as yoga in motion, it's loved by Gwyneth Paltrow.

Yoqua: The latest therapy from the US, basically yoga in a swimming pool.

Top tip: Fitbug If you have an active lifestyle and find it hard to schedule trips to the gym, then hope may still be at hand. Fitbug is a matchbox-sized gadget that tracks your activity levels via your PC and the Web. It measures how far you're walking, and when connected to your computer, it develops a tailor-made health-and-fitness plan based on your personal goals. If you have a busy lifestyle, this helps you make the most of it. Priced #9.95 a month.