Many of us have ambitions to keep up a steady fitness program. Often we will begin one and be inspired by the fact we are doing something new, but then the novelty wears off and our enthusiasm drops off accordingly. Or we start off far too hard, trying to prove a point, and end up succumbing to injury. Here are a few tips to ensure that you can physically and mentally sustain a program for years to come.

- Make sure you're doing it for the right reasons. Sometimes we start a fitness program trying to keep up with others who might be a stage ahead in their fitness than we are, or to achieve a time in a race to boast about to others. Or perhaps we're trying to lose weight to please someone else. Such externally motivated goals tend to pull us off-centre, and make us less likely to succeed if there is an obstacle in the way. The most important reason for doing anything in life is that it gives you joy. If you're unhappy during or after your workout, then you need to look at changing things around.

- Create a constant sense of newness. When running, why not a different route each time and use the time as a chance to explore? Many people find it less mentally pressuring to run to time rather than distance - in other words, instead of saying you have to run a certain number of miles, just say instead you're going to run for a certain time.

- Have a sensible progression curve. Don't suddenly increase your program from zero to top gear. You might do it for a couple of times and say "oh, I can handle that", but it's not your cardiovascular system that's taking the strain, it's your body! As a rough rule of thumb, a 10% increase in capacity each week is enough to ensure your body still stays with you.

-Vary the intensity. Sometimes we feel that on a run or in the gym, we have to be pounding away every time; that certainly isn't the case. Perhaps you can have one set of exercises one day and another set another day. You could introduce an element of cross-training in your program by swimming or cycling one day a week. Whilst running, you can have a balance between high speed intervals once a week, a long run once a week, temp runs, fartlek runs - there are plenty of different things you can do to prevent mental burnout.

- A battle shared is a battle halved. Doing a fitness program in partnership with someone can really take the drudgery out of it. When running together, you can pull each other along, and chatting and laughing together helps take your mind off how long is left to the finish and other such annoying thoughts.