The campaign could make some people think they ought to be exercising rather than relaxing. In fact it probably has to, if it is going to be a successful public health campaign. This is not necessarily a good thing. People who are unable to relax are liable to do something stupid or unpleasant. Many even think that being unable to relax is unhealthy and pay others to teach them how to relax.
Meditation is particularly popular.
While there are a variety of ways to meditate, the most popular is to stop thinking. No chance of guilty thoughts stopping you from relaxing if you are no longer thinking. Others get help from psychiatrists. Another effect of public health campaigns is to stop the money they use from being spent on something else. If the something else is an environmental group, then this benefit ought to be considered when examining the campaign merits.