Contrary to popular opinion, scrunching your face when lifting weights does not make you stronger. Straining your face when you're working your body just makes you unnecessarily engage muscles in your neck, chest, and shoulders. I am always telling Pilates clients and yoga students to relax their faces when enduring physical challenges, but new evidence leads me to believe I should tell them to smile.
The face is a barometer of our emotions, but research shows that it is a two-way street. Your facial expressions can affect how you feel. Moving your face toward a smile makes it easier for you to laugh. Plus, facial expressions lead to physiological responses associated with emotions — meaning the face leads and the body follows. Rather than grimacing during your next one-minute elbow plank, try a smile instead. Your upturned mouth may make you feel lighter from the inside out.