The next time you're lifting at the gym, take a minute to focus on your breathing or lack thereof. Unknowingly many of us, myself included, have the tendency to hold our breath and tense up during the hard part of an exercise. It's time to break the habit.
It may sound strange to remind you to breathe, but try to avoid holding our breath during the strenuous part of a lift. The problem is that breathing improperly while lifting can increase blood pressure potentially leading to light headedness, dizziness, nausea, hernia, heart attack or even stroke. Holding one's breath can be especially problematic for someone who is pregnant or for someone with hypertension. To avoid this, inhale with eccentric (the easy part) and exhale with each concentric phase (the hard part - when the muscle you are working is shortening) of a repetition.