You have probably heard that exercise improves mental health and can even help treat mental health disorders like depression and anxiety. But the question is always the amount of exercise we need to have an effect. Happily, a new study suggests that it may not be that much.

Over 400 healthy middle-aged participants wore accelerometers to track their activity for four days. They filled out detailed questionnaires about their mental and physical well-being, which included information about their depression levels, pain symptoms, happiness level and so on.

Good news for people who aren’t active at the moment and who are daunted by the prospect of beginning an exercise routine.

People who reported being active at any level were generally happier than those who were sedentary, a confirmation of previous findings. Exercise intensity had some effect on the other measures: For instance, those who engaged in vigorous activity had a greater sense of well-being and less depression. And those who engaged in moderate activity reported greater well-being and less pain than those who were inactive.

But even light exercise made people feel better than not being active at all. “The ‘more is better’ mindset may not be true when it comes to physical activity intensity and subjective well-being,” said study author and Hartford Hospital, Connecticut staffer, Gregory Panza, in a news release. “In fact, an ‘anything is better’ attitude may be more appropriate if your goal is a higher level of subjective well-being.”

This is very good news for people who aren’t active at the moment and who are daunted by the prospect of beginning an exercise routine. You can take it slow, and, as other research has shown when it comes to physical health, even light activity may have a measurable effect.

“…[S]imply going from doing no physical activity to performing some physical activity can improve their subjective well-being,” said Panza. “What is even more promising for the physically inactive person is that they do not need to exercise vigorously to see these improvements. Instead, our results indicate you will get the best ‘bang for your buck’ with light or moderate intensity physical activity.”

So (with your doctor’s blessing if you’re just beginning), make an effort to get a little activity into your day. If you start with light activity, you can always work up to more over time. But the good news is that light to moderate exercise may well be enough, when it comes to both our physical and mental health.

The study is published in the Journal of Health Psychology.