If you've ever spent some time doodling with crayons or sculpting a lump of Play-Doh and emerged feeling refreshed and relaxed, science may have an explanation. Researchers found that levels of the stress hormone cortisol (which normally spikes during the fight-or-flight response) went down in a group of 39 volunteers who drew with markers, made collages, or played with clay for 45 minutes.

Although this study, published in Art Therapy, was done in healthy adults, it confirms what Lindsay Aaron sees all the time in cancer patients: "This is a very science-focused study but it's something you see on the outside of the individual, in body language, the emotional state, behavior," says Aaron, a healing arts therapist at Montefiore Health System in New York City. "We're being able to understand what goes on in the neurology."  

Much of the research thus far has been done in people suffering from different health conditions, and usually with much more defined tasks, such as painting a single tile. This study is the first to look at more freewheeling creative expression in healthy people.

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Researchers took saliva samples from 33 women and six men aged 18 to 59 before and after 45-minute sessions with an art therapist, who was present to provide any assistance needed.​ Levels of cortisol in the saliva tend to mirror those in the blood, so are a good measure of how stressed you are.  

The participants were given no specific instructions other than to make anything they wanted with paper, markers, modeling clay, and collage materials. Some made collages out of magazine pages, some made small clay sculptures, and some combined clay, scribbles, and words cut out of newspapers. About half of the participants had little experience making art.

Cortisol levels went down in 75% of participants over the course of a session. Surprisingly, the remaining 25% had higher levels of cortisol than when they started, something the researchers are still trying to understand. It could be that the art led to new learning or self awareness, which raised stress levels. When asked to write about the experience, participants who said they had learned about themselves during the exercise were slightly more likely to have elevated cortisol levels. 

The study included no control group, which means the researchers don't know if the changes in cortisol levels were due to making art or to some other factor, like hanging out with other people, says study lead author Girija Kaimal, assistant professor of creative arts therapies at Drexel University College of Nursing and Health Professions in Philadelphia. 

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It's possible that cortisol levels would decrease after an hour of watching TV as well, points out James W. Pennebaker, PhD, professor of psychology at the University of Texas at Austin…

Working out might keep the brain sharp, and according to a new study, exercising four hours after learning a task can improve memory.

In the new report, published Thursday in the journal Current Biology, researchers found that exercising four hours after a memory task increased brain patterns associated with memory, and helped people retain information better than people who exercised immediately after or people who did not work out.

Seventy two people partook in a picture-location memory task for about 40 minutes. Then, the people were either randomly assigned to 35 minutes of exercise right away, exercise four hours later, or no exercise at all. Two days later, the people came back to see how well they remembered what they had learned, and their brains were scanned. The people who exercised hours later had better recall and stronger and more clear activation in the areas of their brain associated with memory retrieval.

“There is good evidence from animal data that the release of certain neurotransmitters—dopamine and norepinephrine—leads to a biochemical cascade leading to the production of so called plasticity related proteins,” says study author Guillén Fernández, director of the Donders Institute for Brain, Cognition, and Behaviour at Radboud University Medical Center in an email to TIME. “These proteins help stabilize new memory traces, which would otherwise be lost. Physical exercise is at the start of this sequence, because it is accompanied by the release of dopamine and norepinephrine.”

The idea that regular exercise has an impact on brain health, including memory, has been reported in many studies and Fernández says the new report adds to the evidence by showing a single session of exercise can aid in memory retention.

The number of people in the study is small, so it’s hard to say whether people should start pacing workouts exactly four hours after learning something important. Still, the study authors argue that their study is a proof of principal that exercise should be considered as a strategy for long-term memory.

This post originally appeared on Time.com.