Skipping stretching before a workout is unlikely to increase your injury risk or hurt your performance in most cases. The widespread belief that you need to stretch before exercise to prevent pulled muscles isn’t well supported by research. In fact, for strength and power activities, static stretching beforehand can temporarily reduce your force output. What actually matters before a workout is warming up, and warming up and stretching are not the same thing.
Stretching Doesn’t Prevent Most Injuries
The strongest evidence against pre-workout stretching comes from large studies on military trainees, where researchers could tightly control the variables. When data from over 2,600 subjects was pooled, the group that stretched before exercise had only a 5% lower injury rate than the group that didn’t, and that difference was not statistically significant. In practical terms, stretching before exercise does not meaningfully reduce your risk of lower-body injuries like strains or pulls.
There is one important exception. Sports that involve explosive bouncing, jumping, and rapid changes of direction (soccer, basketball, football) place extreme demands on your muscles and tendons. In these activities, your tendons need to be elastic enough to store and release energy during high-intensity movements. Research suggests stretching may play a protective role in these contexts. But for lower-intensity activities like jogging, cycling, or swimming, where your muscles primarily generate power through direct contraction rather than elastic recoil, there’s no evidence that stretching offers any injury protection.
Static Stretching Can Temporarily Weaken Muscles
If you hold a stretch for a long time before lifting weights or sprinting, you may actually perform worse. A major review of 125 studies found that holding a static stretch for 60 seconds or more per muscle group reduced strength and power by about 4.6%. Even a separate meta-analysis of 104 studies, where stretches averaged well over a minute per muscle, found strength dropped by 5.4% and power by about 2%.
Shorter stretches are less problematic. Holding a stretch for under 60 seconds per muscle group only causes about a 1 to 2% dip in performance, which is small enough to be practically irrelevant for most people. So if you enjoy a quick stretch before training, brief holds won’t sabotage your workout. The problems start when you spend several minutes holding deep stretches right before you need explosive output.
How Stretching Temporarily Changes Your Muscles
Static stretching works by reducing the stiffness of your muscle-tendon unit. When you hold a stretch, the muscle fibers, tendons, connective tissue, and even the nerves running through them all become more compliant. This is why you feel looser afterward. But that temporary looseness comes with a trade-off: a stiffer muscle-tendon unit transfers force more efficiently, which is exactly what you want when you’re trying to jump high or lift heavy.
There’s also a neurological component. Five minutes of static stretching causes a significant inhibition of spinal reflex pathways. One study found a 57.6% reduction in a specific spinal reflex immediately after stretching, with lingering suppression for up to five minutes afterward. The reflex returned to normal by the 10-minute mark. This means your nervous system’s ability to rapidly activate muscles is temporarily dampened, which helps explain the short-term power loss. Notably, brain-level motor signals were unaffected, so the issue is happening locally at the spinal cord level, not in your overall motor control.
What About Running and Cardio?
If your workout is a steady-state run or other moderate cardio, skipping pre-exercise stretching has essentially no downside. Research measuring oxygen cost and running economy during sub-threshold running found no difference between runners who stretched beforehand and those who didn’t. All three stretching routines tested increased flexibility, but none of them changed how efficiently the runners moved or how much oxygen they consumed. Your body doesn’t need extra tendon compliance to run at a comfortable pace.
The limited research on long-term stretching routines (done consistently over weeks, separate from workouts) also shows no significant effect on running efficiency, positive or negative. Only two studies have examined this question directly, and neither found meaningful changes. So whether you stretch chronically or skip it entirely, your aerobic performance is unlikely to shift.
Warming Up Is What Actually Matters
The confusion for most people comes from conflating stretching with warming up. A warm-up raises your muscle temperature through active movement, which increases blood flow, reduces internal resistance, and genuinely prepares your body for exercise. Stretching, particularly static stretching, doesn’t do this. Holding a hamstring stretch for 30 seconds doesn’t raise your heart rate or increase circulation to your working muscles. It’s closer to a relaxation technique than a preparation strategy.
Dynamic movements like leg swings, bodyweight squats, lunges, arm circles, or light jogging serve as both a warm-up and a way to move your joints through their full range of motion. This is why the American College of Sports Medicine recommends that any static stretching be preceded by an active warm-up, not used as a substitute for one. For athletes who need running or jumping performance, dynamic stretching before activity is generally the better choice. Static stretching fits better as part of a cooldown or as a standalone flexibility practice on rest days.
When Pre-Workout Stretching Is Worth Doing
For sports that demand extreme ranges of motion, like gymnastics, dance, martial arts, or figure skating, pre-workout stretching serves a functional purpose. You need that range of motion to perform the movements safely, and a brief static stretching routine (under 60 seconds per muscle) integrated into a full warm-up causes negligible performance loss. The key is combining it with aerobic activity and dynamic movements rather than using it as your only preparation.
If you have a specific area of tightness that limits your exercise form, such as tight hip flexors that prevent you from squatting to depth, targeted stretching before your workout can help you move better during that session. In this case, the small cost in raw force output is outweighed by the benefit of performing the movement correctly. Just keep the holds short, and follow them with some dynamic movement before your working sets.