Michael delves into the science of cold water immersion, revealing how just a little bit of physical stress might go a long way to improve your heart health, boost your mood and help keep colds and flu at bay. To find out more, he speaks to Professor Mike Tipton from Portsmouth University who’s been researching exactly what happens in your body when you’re doused with cold water, and why it might have a positive impact on your body and brain, with lasting effects.

In this episode, Michael speaks to expert Kirsten Berding Harold, University College Cork, for all the latest science on all things good bacteria. Our willing human guinea pig Clare has a go making her own kefir at home and Michael has a go at cultivating some healthy bacteria in the form of sauerkraut - which he claims is far simpler to make at home than you might think!

Michael explores the secret power of early-morning light, revealing the surprising ways it can affect your brain to boost your mood and help get a better night’s sleep. But it’s not just when you go that’s important… He speaks to Marie Murphy, Professor of Exercise and Health at Ulster University, who’s shown how a simple change to the way you walk could cut your risk of heart disease by 20-50%.

If time is tight, what’s the one thing that you should be doing to improve your health and wellbeing? Michael Mosley introduces his new series in which he reveals surprisingly simple tips that are scientifically proven to change your life.