Christmas is often the time of year when we over indulge most, with countless turkey-based dinners, lunches and, in extreme cases, breakfasts, finding their way into our stomach. More often than not, these will be closely followed by mince pies, Christmas puddings, sweets, chocolate and booze.
We know it's not good for us, but at least once a year we simply want to let our hair down and just have what we want without dwelling on the possible consequences.
Then, when January comes, the guilt sets in. The thought of all those extra meals and snacks we enjoyed starts nagging away at us, made worse by the knowledge that we did not a single ounce of exercise during the whole holiday, except for the workout one of our biceps received when helping to transport the food from the plate to our mouth.
Now we're not for a moment suggesting that come the new year you jump in a swimming pool and do 50 lengths - such an extreme reaction to Christmas guilt will more than likely result in cardiac arrest than any feeling of well-being. But how about gently easing yourself back into a physical routine by joining a guided walk around a part of London?
These walks are always fascinating affairs - and certainly far from strenuous. The guides are experts on the particular parts of London they take you around, and on most occasions deliver their spiel with both wit and passion.
It's a super way of getting back out into the fresh air, reintroducing the concept of 'exercise' to your body and learning more about one of the greatest cities on the planet.