Exercise for Neck Pain: What EIH Evidence Actually Shows

Exercise can reduce neck pain, but the most interesting question is not whether movement helps. It is whether exercise temporarily changes how the nervous system processes pain. The best neck-pain evidence says it can—but it does not yet identify a winning protocol, dose, or mechanism with much confidence.

This effect is called exercise-induced hypoalgesia (EIH): a rise in pain tolerance or threshold after exercise. In neck-pain research, investigators usually measure it with pressure pain thresholds (PPT), which test how much pressure someone tolerates before it becomes painful. PPT is an objective sensory measure, not the same thing as feeling better in daily life. That distinction matters throughout this literature.

The strongest clue comes from where pain sensitivity changes

A 2023 systematic review and meta-analysis by Senarath et al. pooled three randomized studies in people with chronic whiplash-associated disorder (WAD). It compared exercise types using PPT measured immediately after exercise, within roughly 30 minutes.

At the cervical pain site, isometric exercise had a borderline advantage over submaximal aerobic exercise: mean difference −0.21 kgf/cm², 95% confidence interval −0.43 to 0.00, p = 0.05. The result technically reaches conventional statistical significance, but only barely: the confidence interval touches zero. More troubling, heterogeneity was extreme (I² = 92%). The individual studies varied so much that the pooled average is a shaky basis for choosing one exercise over another.

At remote sites away from the neck, isometric and aerobic exercise were statistically indistinguishable: mean difference 0.01 kgf/cm², 95% CI −0.33 to 0.35, p = 0.95; I² = 0%. The studies agreed much more closely here. The review also reported a comparatively larger remote-than-local EIH effect after submaximal aerobic exercise.

This spatial pattern is biologically interesting. Isometric cervical exercise may have a stronger local effect, while aerobic exercise may engage pain modulation more broadly. Researchers often frame that possibility in terms of local or segmental versus higher-level nervous-system pathways. But that is a hypothesis, not a demonstrated mechanism in people with neck pain. The studies did not use pharmacological blockade, neuroimaging, or neck-pain-specific conditioned pain modulation experiments to prove which system caused the change.

The review rated certainty of evidence as low to very low. Its pooled data came only from chronic WAD, not from the broader population with chronic nonspecific neck pain. For nonspecific neck pain, the review could only summarize studies narratively: isometric and range-of-motion exercise showed EIH in some studies, while active stretching produced contradictory results. WAD often includes altered pain processing and central sensitization, so it would be a mistake to treat this as a universal neck-pain rule.

Feeling less pain does not prove EIH caused it

Several randomized trials support exercise as a reasonable treatment for self-reported neck pain and function. They do not establish EIH as the reason.

In a single-blind randomized trial of 60 people with chronic neck pain, Büyükturan et al. compared sternocleidomastoid (SCM)-specific stretching plus massage with non-SCM stretching plus massage. Both groups improved in visual analog scale pain and Neck Disability Index scores. The SCM-focused group did better on selected cervical range-of-motion measures at some time points, but it did not show consistent superiority for pain. The trial did not measure PPT or other quantitative sensory outcomes. It supports SCM work as one option for mobility, not as proof that this particular muscle produces superior analgesia.

A 2025 three-arm randomized trial by Thanasilungkoon et al. enrolled 80 Thai office workers with at least three months of neck and shoulder pain. Ruesi Dadton traditional Thai exercise, yoga, and conventional stretching all reduced self-reported pain, with no significant between-group differences at four weeks. Preference, access, and willingness to keep moving may therefore be sensible reasons to choose among these approaches. The trial offers no evidence that a traditional sequence or yoga beats ordinary stretching for pain relief. Its participants were recruited through Thai Traditional Medicine institutions and worked with licensed practitioners, which narrows how confidently the findings apply elsewhere.

Other trials point in the same practical direction without settling the mechanism. A 2024 randomized trial of cervical mobilization plus post-isometric relaxation found improvements in pain, range of motion, and functional limitations among people with mechanical neck pain and myofascial trigger points. In another randomized trial of 60 people with mechanical neck pain, Akgüller et al. found that all exercise, manipulation, and combined-treatment groups improved; the combined group had greater improvements on several outcomes, including resting pain, disability, and left-sided PPT. These studies support exercise within rehabilitation. They do not show that EIH alone explains longer-term pain or disability changes.

Why stretching helps some people and irritates others

Individual responses are probably not noise. In a mechanistic observational study, Støve et al. found that tolerance to stretch was linked with endogenous pain modulation capacity. The study was not a neck-pain treatment trial, so it cannot tell a person which neck routine to use. It does offer a plausible explanation for the inconsistent stretching results: people with better endogenous inhibitory function may get a different sensory response from stretching than people with impaired inhibition.

There is also a real counterexample to the idea that exercise automatically suppresses pain. An experimental study in healthy adults by Peterson et al. documented exercise-induced hyperalgesia, meaning increased pain sensitivity after exercise. The researchers also found that body composition did not predict conditioned pain modulation. Healthy participants are not chronic neck-pain patients, but the result makes one point clear: a bad response to exercise is biologically plausible, not a character flaw or proof that someone needs to grind harder.

What to do with this evidence

For localized chronic neck pain, isometric cervical exercise has the closest available evidence for short-term local hypoalgesia. Treat that as a tentative option, not a prescription carved into a foam roller: the key estimate barely met statistical significance, heterogeneity was high, and evidence certainty was low to very low.

Aerobic exercise is equally plausible when the goal is broader pain modulation, because its remote-site PPT effects matched isometrics in the meta-analysis and showed more consistent pooled results. No study here identifies the minimum effective intensity, contraction duration, weekly frequency, or force threshold. No included study establishes whether an acute PPT change lasts beyond about 30 minutes or accumulates across sessions.

SCM stretching, yoga, Ruesi Dadton, and conventional stretching remain reasonable additions when they improve mobility or make a program easier to sustain. None has shown superior analgesia over the comparators in these trials. Monitor the response over several weeks rather than assuming a fashionable exercise category has special neurological powers.

If exercise repeatedly increases pain instead of easing it, do not automatically increase intensity or volume. Persistent worsening deserves clinical assessment, especially when pain feels widespread, highly sensitive, or disproportionate to activity.

The evidence supports exercise for neck pain. It also supports humility about why it works, which version works best, and who will respond well. At present, the most defensible strategy is individualized, tolerable movement with attention to pain response—not a one-size-fits-all hunt for the perfect exercise.