Have you ever felt fear or panic before heading to a new workout because you were worried it was going to be really hard and really hurt? You might have even thought of an excuse or two to skip it altogether? Well, according to a new study, the stress of uncertainty of the unknown could actually be worse than the actual pain we experience.

The research published in Nature Communications observed 45 volunteers who played a computer game in which they had to turn over rocks that may or may not have a snake hiding under them. If there was a snake then they would receive a mild electric shock in their hand. Over time, the subjects were able to learn which rocks most likely hid snakes but the odds changed throughout the experiment.

Participants’ uncertainty that any individual rock would have a snake under it was estimated from their guesses using a sophisticated computational model of learning. The participants then reported on their stress levels, which was also tracked using measurements of pupil dilation and perspiration.

Lead author of the study Archy de Berker spoke about the effects of uncertainty in a release. “Using our model we could predict how stressed our subjects would be not just from whether they got shocks but how much uncertainty they had about those shocks,” he explained. “Our experiment allows us to draw conclusions about the effect of uncertainty on stress. It turns out that it’s much worse not knowing you are going to get a shock than knowing you definitely will or won’t. We saw exactly the same effects in our physiological measures – people sweat more and their pupils get bigger when they are more uncertain.”

The study linked uncertainty with higher levels of stress but it also found there could be a potential benefit. Participants who had the greatest spikes in stress responses during periods of uncertainty were actually found to use better judgement when it came to deciding whether or not individual rocks would have snakes under them.

While many of us crave control and certainty in life, trying something new and potentially having your stress levels spike isn’t necessarily a bad thing. You may find that the stress works to your benefit and you perform better, make smarter choices and even enjoy yourself.