This is the Guardian.

It's January, which for a lot of us, means it's time to brush away the chocolate wrappers, put down the glass of wine, drag ourselves off the sofa, and get fit.

But if you're starting out on your fitness journey this year, you might be wondering where to begin.

So today we're asking, what are the best ways to get active and make it stick? How should we be changing our exercise routines as we get older and can just three minutes a day make a difference.

I'm the Guardian Science editor Ian Sample and this is Science Weekly.

So I'm a committed exerciser.

I try to do something every day and I sort of go back and forth between cycling-based interval

training. I'm 55 with an osteoarthritic left knee and so I can't run anymore. So my go-to

cardio exercise is cycling.

And in between that I try to do strengthening exercise,

a lot of body weight style training,

simple functional movements, things like that.

That's Martin Gibala, an exercise physiologist and professor of kinesiology at McMaster University

in Canada.

Physical activity, including structured exercise, it's good for our hearts, our bodies, and our minds.

And so regular activity can prevent, help manage heart disease,

type 2 diabetes, cancer, and it can also reduce symptoms of depression, anxiety, enhance thinking, learning and just general overall well-being.

And in really high-level terms, how is exercise giving us those benefits? What's going on in our

bodies when we exercise that makes us healthier? So I'm a physiologist so I'll stick to that

side of it but generally regular physical activity exercise.

Overall, it makes our heart a better stronger pump. Our blood vessels become more elastic and that allows oxygen and nutrients to flow easier.

It helps to manage our blood pressure and our muscles get better at using the oxygen to produce

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