The Annals of Internal Medicine, the American College of Physicians' internal medicine journal, published a study last year showing that participants who were instructed to use sun-protection factor 15+ sunscreen every day (reapplying after sweating, swimming, or spending a few hours in the sun) showed 24% less skin aging than a control group.
Use sunscreen if you spend any significant part of your day outside - which you should do if you can! If you're doing facial exercises but not taking care of your skin and overall health, you're not going to get the results you're looking for. It doesn't make sense to go have a smoke and a doughnut after doing yoga. Same thing here.
In addition to the face exercise program in The 15 Minute Fix: FACE, you'll find tons of other tips on how to take care of your face by improving your nutrition, changing the personal care products you use, and making smart decisions about your overall health. I hope you'll take a look....
Age well my friends!