The new exercise and physical activity guidelines issued by the US federal government’s Office of Disease Prevention and Health Promotion are better tailored for age and ability. Importantly, they also now take into consideration the intensity of activity, and not just a blanket generalisation of "moderate activity". This is the biggest difference which will most change the potential impact of the new guidelines as compared to the old.

This move to recognise intensity is a very useful change. Previously the recommendations focused people on spending a certain amount of time exercising, including the caveat that spending less than 10 minutes at any one time was not worthwhile. The new guidelines base your dose of physical activity on relative intensity: how much effort a given exercise takes compared with your capacity for exercise. ​They also recognise that short bouts of exercise can be useful - "what really is important is the total amount of physical activity you accumulate during the day and the week".

It's that time of year again where new gym memberships soar, ambitions are high, and lofty fitness goals are set. As we all know, the New Year's fitness see-saw usually ends up with an unhappy ending, unfortunately. Here are my five suggestions to help you create the most sustainable start for your New Year's fitness program.

Trim your ambition and start with much less than you think you can accomplish.

For a start don’t plan an hours session at the gym every day of the week, and don't plan 5:30am classes if you normally don’t even get up until 6:30am. It's better to add more later than to start and then try to subtract. Most people don't end up subtracting successfully - they stop altogether. You only need start with 3 gym sessions a week, make one focused on cardio e.g. a spin class, one on strength e.g. a Bodypump class, and one on functional exercise e.g. Pilates or Body Balance.

​Classes are the easiest way to get a pattern established and you don’t have to think about what to do next.