After a CrossFit workout, a contact device of red/near-infrared light plus a static magnet on the legs (PBMT-sMF) did not differ from passive rest, compression boots or shockwave on the primary outcome, jump height 1 h later, in a crossover of 12 male CrossFit athletes with no sham and only the assessor blinded; on secondary outcomes jump height held better than with passive rest at 24 and 48 h and damage and oxidative-stress markers favoured the device; the senior author receives research support from the device maker
Main caveat: Funding and ties: funded by a CNPq grant to the senior author and a CAPES scholarship to the first author (Brazilian public agencies, no role in the trial).
Martins and colleagues compared four ways of recovering from a CrossFit workout.
Twelve non-professional male CrossFit athletes did the same 21-15-9 workout (air-bike calories, hang squat cleans, box jump-overs, for time) four times, a week apart, and after each lay down for one of four 30-min conditions starting 5 min after the workout: passive rest, pneumatic compression boots, shockwave therapy to the thigh and calf muscles, or 32 min of photobiomodulation with a static magnetic field from a Multi Radiance Medical probe pressed on eight spots of each leg.
Countermovement jump height (filmed and scored with a phone app) and blood markers of muscle damage (LDH), oxidative damage (TBARS, carbonylated proteins) and antioxidant enzymes (catalase, superoxide dismutase) were measured before and 1, 24 and 48 h after, with perceived exertion and, at 48 h, satisfaction.
Jump height at 1 h, the primary outcome, did not differ between conditions. Against passive rest, jump height after the device was higher at 24 h (p = 0.0431) and 48 h (p < 0.0001); against all three other conditions, LDH, TBARS and carbonylated proteins were lower and the antioxidant enzymes higher at 24 and 48 h. Satisfaction was highest with compression and shockwave.
The authors conclude the device may be an effective recovery strategy, perhaps through oxidative stress, and that compression and shockwave showed no clear benefit over rest.
Participants
12 healthy male non-professional CrossFit athletes, 18-35 years (mean 29.7 ± 3.2), 87 ± 11 kg, BMI 27.8 ± 2.3, training at least four times a week for at least one year (37 ± 21 months).
Recruited October-November 2024 in São José dos Campos, Brazil; all 12 completed every condition; no adverse events.
Protocol
Workout: 21-15-9 for time, no rest: Assault AirBike calories, hang squat clean, box jump-over (24-inch, 60.69 cm). Calorie targets and barbell load are not given. Completion times did not differ by week or by condition (PR 512, IPC 509, ESWT 547, PBMT-sMF 519 s; p > 0.05). No other exercise from 24 h before to 48 h after.
Conditions (all from 5 min after the workout): passive recovery, lying supine 30 min (the control); intermittent pneumatic compression, Recovery Pump boots, 80-90 mmHg in four chambers, 30 min; extracorporeal shockwave, BTL-6000, 2,000 pulses per region (6,000 per leg), 0.03 mJ/mm², 10 Hz, 1.5 bar, to quadriceps, hamstrings and calf of both legs.
What was applied (PBMT-sMF): a Multi Radiance Medical (Solon, Ohio, USA) cluster probe of 20 diodes plus a magnet: 4 lasers at 905 nm (50 W peak, 1.25 mW average, 250 Hz), 8 red LEDs at 633 nm (25 mW, 2 Hz), 8 infrared LEDs at 850 nm (40 mW, 250 Hz); magnetic field 110 mT; aperture 33 (unit not printed).Per leg, eight spots: four on the quadriceps (129 s, 67.68 J each; 270.72 J), three on the hamstrings (115 s, 60.76 J each; 182.28 J), one on the calf (60.76 J). Direct skin contact with slight pressure, both legs, 32 min. Light was not tested without the magnet.
Comparator and blinding: no sham device; the comparison is against rest and two other devices. Only the outcome assessor and the statistician were blinded.
Order: four fixed sequences, randomised 1:1:1:1 with sealed opaque envelopes; 7-day washout.
Outcomes: primary, change in countermovement jump height at 1 h (best of three, smartphone video, JumPo 2 app); secondary, jump height at 24 and 48 h, LDH, TBARS, carbonylated proteins, catalase and superoxide dismutase activity (venous blood), muscular and respiratory RPE (0-100), and satisfaction (5-point scale, split into satisfied or not) at 48 h.
Analysis: repeated-measures ANOVA with Bonferroni post hoc tests within each outcome (figure legends say mixed-design ANOVA, the table says ANOVA with baseline adjustment), on absolute values and on percentage change from baseline; Fisher's exact test for satisfaction. No correction across the many outcomes and time points. The sample size was calculated after the fact from the first session's jump data (effect size 1.31).
Key Results
| Outcome | Finding |
|---|---|
| Jump height at 1 h (primary) | no significant difference between the four conditions |
| Jump height at 24 h | PBMT-sMF above passive recovery, p = 0.0431 (percentage change); not reported as different from compression or shockwave |
| Jump height at 48 h | PBMT-sMF above passive recovery, p < 0.0001 (percentage change); not reported as different from compression or shockwave |
| LDH, 24 h | lower with PBMT-sMF than passive (p = 0.0131), shockwave (p = 0.0057) and compression (p = 0.0003) |
| LDH, 48 h | lower than passive (p = 0.0007), shockwave (p = 0.0006) and compression (p < 0.0001) |
| TBARS, 24 and 48 h | lower than all three, p < 0.0001 |
| Carbonylated proteins | lower than all three at 24 h (p = 0.001 to 0.0127) and 48 h (p < 0.0001 to 0.0307) |
| Catalase, superoxide dismutase | higher than passive at 1 h (p = 0.0187, p = 0.0038); higher than all three at 24 and 48 h (p < 0.0001) |
| RPE, muscular and respiratory | no between-condition difference reported |
| Satisfied at 48 h | passive 42%, compression 83%, shockwave 83%, PBMT-sMF 67%; compression (p = 0.0195) and shockwave (p = 0.0125) above passive |
Absolute means, baseline → 1 h → 24 h → 48 h (Table 2):
| Measure | Passive | Compression | Shockwave | PBMT-sMF |
|---|---|---|---|---|
| Jump height (no unit printed) | 43.10 → 40.80 → 40.40 → 38.86 | 42.32 → 40.76 → 40.81 → 40.24 | 42.61 → 40.36 → 41.11 → 40.50 | 41.60 → 41.71 → 41.46 → 41.79 |
| LDH, U/L | 180.3 → 241.9 → 306.1 → 469.2 | 167.5 → 243.6 → 303.2 → 454.3 | 179.4 → 237.0 → 300.8 → 456.5 | 197.8 → 223.3 → 250.8 → 412.9 |
The jump result comes from percentage change; in absolute values the table marks no significant jump difference, and the device condition started from the lowest baseline jump. The same holds for LDH: the table marks no absolute difference, and the device condition started highest (197.8 U/L); TBARS, carbonylated proteins, catalase and superoxide dismutase are marked in absolute values as well.
In the first session alone, used for the sample-size calculation, jump height at 1 h was 102.12% of baseline with the device against 94.12-95.98% with the others.
Mean differences and 95% confidence intervals are said to be in a supplementary table that was not read; the main text gives P values only.
Practical Application
On the trial's main test, jump height 1 h after a CrossFit workout, a contact light-plus-magnet device on the legs was no better than lying down, compression boots or shockwave (12 athletes); it held jump height better than lying down at 24-48 h and moved blood markers of damage and oxidative stress, secondary results without a sham, from a trial whose senior author receives research support from the device maker.
To "should I use red light after a hard gym session?": say one small crossover, with only the assessor blinded, found no difference on its primary outcome and some secondary differences; with no sham, an expectation effect on the jump cannot be excluded. Recovery in the base rests on food, sleep and easy days first, and no physical modality beat passive recovery on performance in endurance athletes (SYNTH-70, REF-1090).
Lower LDH and oxidative-stress values are markers (PHYS-44): they do not by themselves show a better next session.
Compression and shockwave did not beat lying down on any outcome except satisfaction, in line with SYNTH-83's recovery-tools row: they may feel better without a shown performance benefit.
Inference, not tested here: the result belongs to this dosed device on the legs after one workout; it says nothing about a light bed, a panel or regular use through a block.
Limitations
Funding and ties: funded by a CNPq grant to the senior author and a CAPES scholarship to the first author (Brazilian public agencies, no role in the trial). The senior author (Leal-Junior) receives research support from Multi Radiance Medical, which makes the device tested; the corresponding author (Tomazoni) has a personal relationship with him, and both list ELJ Consultancy, Scientific Consultants as an affiliation.
The authors' own: men only; only assessors blinded; no placebo or sham, so expectation effects cannot be separated; phone-based jump measurement less precise than a force plate; limited power for secondary outcomes.
12 athletes; the sample size was calculated after the fact from the trial's own first session; the primary outcome was null, and the positive results come from many secondary outcomes and time points with Bonferroni correction only within each outcome.
The device condition started with the lowest jump height and the highest LDH, and the reported differences are in percentage change from baseline.
Light and a 110 mT magnet were given together; no light-only condition. The device session lasted 32 min against 30 for the others.
One application after one workout per condition; workout loads and calorie targets are not given.
How this entry was checked and changed
Why this level
a crossover of 12 (B) one step lower: the primary outcome was null, and the positive findings rest mostly on blood markers, with the one performance result secondary and against passive rest only