Pop quiz: Should you always stretch before a workout? If your answer was “stretch,” you’re half right. You should never start exercising without stretching, because “muscles need to be warmed up in order to increase your heart rate, which translates to increased blood flow, and therefore oxygen, to the muscles,” explains Rebecca Kennedy, an AFAA- and NASM-certified trainer and the founder of A.C.C.E.S.S., an active recovery fitness class. “And you want more oxygen in your muscle cells to assist in the stress you’re about to place on them.” But the type of stretching you do matters, a lot.
Dynamic stretching, or moving stretches, should be your go-to before a workout. As far as static stretching goes (a.k.a. holding a position for 30 seconds or longer), you’d be better off skipping that warm-up, according to a study published in the Journal of Strength & Conditioning Research. “Static stretching prior to a workout reduces muscle strength, decreases muscle power, and impairs explosive muscle performance,” says physical therapist Christina Ciccione, C.S.C.S., the clinic director at Professional Physical Therapy. “Static stretching can ultimately damage your muscles or tendons when performed before the muscles are adequately warmed up.”
1. ELEVATED HAMSTRING STRETCH
This is when you place one foot on a surface slightly lower than your hip, like a bench, and flex your foot before hinging at the hips to bend toward your flexed foot. This stretch often leads to a deep burn in the back of the knee, which you might translate as a good stretch. “In reality, this sensation is only tension being applied to the sciatic nerve,” explains Ciccione. “The hamstring isn’t actually increasing in length or becoming more flexible.”
You know this one from yoga: You stand with your feet together, hinge at the hips, and bend forward to reach palms toward the floor. “The hamstrings are a huge muscle group assisting in squats, deadlifting, running, and lunging,” says Kennedy. “A static hold could make them less efficient during training and potentially lead to painful injuries like microtears, which could limit your movement.”
This is a classic stretch, where you start in a standing position and grab one foot with the same-side hand, keeping your thighs aligned. But “the standing quadriceps stretch is often performed incorrectly and puts too much stress on the knee joint, causing anterior knee pain,” says Ciccione. “Anterior knee pain can indicate patellofemoral joint issues”—like runner’s knee—“which you should try to avoid.”
In Figure 4, you’re either lying on your back with your legs bent, one ankle resting on the other thigh right above the knee, or standing on one bent leg with the other crossed over it, ankle resting on thigh. “This position requires hip flexion, abduction, and external rotation in order to get into the proper stretch position, but prior to your workout, when the muscles haven’t had an adequate warm-up, the hip doesn’t have the range of motion, and the muscles surrounding the hip joint don’t have the adequate flexibility to target the glute muscles you’re trying to stretch,” says Ciccione. “It’s a waste of time,” says Kennedy.
Ah, pigeon. The goal of this hip opener—with one leg bent and parallel to the top of a mat and the other extended straight behind you while your torso hinges over your front leg—is to stretch the piriformis muscle and the external rotators of the hip. But “forcing this position with a fixed object, the floor, can torque your knee or ankle,” says Kennedy. Plus, “getting into pigeon pose involves several other muscles in the pelvis, hip, and knee,” says Ciccione. “If those muscles are tight, the stretch is often uncomfortable and more detrimental than it is helpful.”