Stretching the wrong muscles
Choosing the best stretches and warm-ups depends on what the main movers are in the activity you’re about to perform, says Dyan Tsiumis, head instructor at SWERVE Fitness. "Think to yourself, 'What muscles are involved?’ and then focus on stretching those," Tsiumis advises.
For example, after a run or cycling session, you’ll want to focus on your lower body, whereas after a long day at your desk job you should stretch to open your hip flexors.
Doing seated spinal twists
Most people attempt this stretch to alleviate lower-back pain, but if you aren’t careful, seated spinal twists can actually aggravate the muscles in your lower back, says Nikki Warren, co-founder of Kaia FIT. "This stretch should only be performed with excellent posture," Warren explains.
Since most people, uh, don’t possess great posture, Warren recommends trying child's pose instead. "This passive stretch allows your lower back to release with zero pressure," Warren says. "Simply spread your knees as wide as possible while keeping your big toes together. Relax your glutes to heels -- place a towel under your hamstrings if you struggle to reach your heels -- and drop your forehead to the earth while walking your hands forward."