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Hello

Today is most people’s first day back at work. All I can say is: yikes.

In December, our office was a sea of chocolate wrappers and mince pie crumbs. Now, with our waistbands a little tighter, the conversation has switched from whether we’ve got all our Christmas shopping done to whether we’re going to the gym after work.

A word of warning: the gym will be hectic today (and for the rest of the week). So think ahead to make the most of your time there. There’s nothing worse than having to queue to use the machines.

If you can go off-peak, we’d recommend it. Otherwise take a moment to plan out your week, whether that’s nailing a gym session (read our tips) or booking on to classes ahead of time.

If you’re signing up to a new gym today – high five! Don’t be intimidated by those around you, focus on yourself and your own goals.

Brogan Lifestyle Editor, HuffPost UK

HIIT

This stands for “high intensity interval training” and is not for the faint hearted. Typically a HIIT session involves short bursts of high-intensity exercise, followed by medium intensity or short rest periods.

There is no set duration for the bursts, but it could be 30 seconds on and 30 seconds off or 45 seconds on and 15 seconds off. It is usually so gruelling that classes are rarely longer than 30 minutes (and if they are, we feel for you).

It is usually so gruelling that classes are rarely longer than 30 minutes (and if they are, we feel for you). Be prepared to get SWEATY.