REF-317 · Kong PW, Chua YH, Kawabata M, Burns SF & Cai C, 2018 · Journal of Sports Science and Medicine, · PubMed · Free full text

Effect of Post-Exercise Massage on Passive Muscle Stiffness Measured Using Myotonometry

A Double-Blind Study — after 40 min downhill running in 18 male recreational runners, passive stiffness of four leg muscles rose at 24 h and stayed elevated for up to 96 h; a 16-min massage of one leg changed nothing versus sham ultrasound on the other

B+moderate evidenceMeasured on recreational to trained athletesWritten before October 2026, being re-checked

Participants

n=18 male recreational runners

Protocol

40 minutes of downhill running (eccentric-biased)
One leg received a 16-minute massage; the contralateral leg received a 16-minute sham ultrasound treatment (placebo)
Passive stiffness of rectus femoris, biceps femoris, tibialis anterior and gastrocnemius by myotonometry at baseline, immediately post-run, post-treatment, and 24, 48, 72 and 96 hours post-run
2 (treatment) × 7 (time) mixed ANOVA with a robust procedure per muscle

Key Results

Passive stiffness of all four muscles changed over time: it increased at 24 h post-run and remained elevated above baseline for up to 96 h
No treatment effect of massage versus sham in any muscle
A treatment × time interaction appeared only in the tibialis anterior, with no post-hoc differences identified
Authors' conclusion: unaccustomed eccentric exercise raised passive stiffness of major leg muscles for up to four days, and post-exercise massage had no beneficial effect on it compared with placebo

Mechanism

The stiffness rise is delayed (visible at 24 h, not immediately) and long (still there at 96 h) — the time course of exercise-induced muscle damage rather than of acute neural tension. Inference, not tested: a single massage acting on the surface and on perception has no purchase on a process that is developing inside the tissue over days; the study measured stiffness only, not soreness or perceived recovery.

Practical Application

In 18 recreational male runners, 40 min of downhill running raised the passive stiffness of the quadriceps, hamstrings, shin and calf from 24 h and kept it elevated for up to 4 days (96 h); a 16-min massage of one leg did not change this compared with sham on the other leg
Eccentric-biased running (descents) leaves a tissue stiffness footprint that outlasts the session by days — the 4-day window is the number to plan around after unaccustomed downhill work
Massage did not reduce objective tissue stiffness here; if it is used, use it for what it does for the athlete's comfort, not to "release" the muscle
Not from this paper; the base's own practice: after an unaccustomed hilly or descent-heavy session, keep the next eccentric-heavy or high-force session 3-4 days away regardless of how the legs feel; for cold-water or cryotherapy effects on the same time course see Wolska 2023 REF-323

Limitations

Downhill running — high eccentric bias, may not represent flat running or cycling
Male recreational runners only
Single massage session — repeated sessions not tested; no soreness or perception outcome in the abstract
How this entry was checked and changed
Why this level

regraded 2026-09-27 from A-: controlled within-subject crossover, n=18

Content correction 2026-09-27
Added the abstract's interaction result (treatment × time only in tibialis anterior, no post-hoc differences) and the sham-ultrasound placebo design.
"Massage does NOT reduce stiffness (despite subjective relief)" -> subjective relief was not measured in this study; removed. Gravel / CWI / nutrition advice relabelled as house practice.
Level A- -> B+ (controlled crossover, n=18); Tier 2 -> Tier 1-2 (recreational runners); Sport "trail-running, cycling, running" -> running; duplicate PMID line removed.