Claim Check: "Stretching Prevents Injury"

Injury prevention: what the reviews found

• Meta-analysis of 25 trials (2014): 26,610 participants and 3,464 injuries. For stretching alone the authors found "no beneficial effect" (risk ratio 0.963, confidence interval 0.846 to 1.095, meaning the result could easily be no change). [1] Multi-part programs, balance (proprioception) training and strength training each showed reductions, and the authors reported that strength training reduced sports injuries to less than one third. [1] These were sports-injury trials, so they may not map directly to everyday yoga practice.
• Army recruits (pooled analysis): in two studies of 12 weeks of basic training with 2,630 recruits, stretching was linked to a 5% lower hazard of any lower-limb injury (hazard ratio 0.95), which was not statistically significant. [2] The reviewer concluded that stretching did not meaningfully reduce injury risk in that setting. [2]
• Stretching types (2016 systematic review): static stretching (holding a stretch) and PNF stretching had "no clear effect" on all-cause or overuse injuries, and no data were available for dynamic stretching (moving through a range). [3] The same review recommended stretching within a warm-up that includes dynamic activity afterward, for reducing muscle injuries and increasing joint range of motion. [3] So the picture for stretching as one part of a warm-up is mixed.
• Neuromuscular warm-ups: a review of nine studies found structured warm-up programs, which include stretching along with strengthening, balance, agility and landing techniques, can reduce lower-limb injuries in young amateur female athletes and in military recruits when applied consistently for more than three months. [4] The benefit belongs to the whole program, not to stretching alone.

Soreness after exercise

A Cochrane review of 12 studies found that stretching before, after, or before and after exercise does not produce clinically important reductions in delayed-onset muscle soreness (the ache that develops after exercise) in healthy adults. [5] The largest effect, in one trial with 2,377 people, was about four points on a 100-point scale, which the authors called very small. [5]

What stretching does do

A review of acute effects found that stretching types all increased range of motion, but typically for under 30 minutes. [3] It also found small to moderate changes in performance immediately after static stretching. [3] For what research shows more broadly, see Stretching: What Research Shows.

What this means for yoga

Yoga includes stretch-like positions, and some people begin it hoping to prevent injuries. We did not find a source showing that yoga prevents injuries in the way strength or multi-part programs do. Yoga also has its own injury risks. NCCIH says yoga is generally safe for healthy people when performed properly, that the most common injuries are sprains and strains, and that learning on your own without supervision has been associated with increased risk. [6] A 2013 systematic review of published yoga case reports found that about 36% of the 76 cases involved the musculoskeletal system, the largest group. [7] Case reports show that problems can happen, not how often.

Take care not to push into pain or force a stretch to reach a "target range." See Stretching and Movement Safety: Over-Stretching, Yoga for Flexibility Goals and Expectations and Mobility Training and Flexibility.

Practical, safe takeaways

• If you play sports or run, ask a coach or physical therapist about a warm-up and strength program supported by trials, not only stretches.
• Gentle stretching you enjoy is fine as part of being active. It is not a proven injury shield.
• The NHS lists yoga as one example of muscle-strengthening activity, and recommends at least 150 minutes of moderate activity a week for adults aged 19 to 64. [8]
• See a clinician for pain that is sharp, persistent, or follows an injury.