Monitoring low-frequency fatigue during return-to-play in elite football: physiological basis and a four-case series

Buchheit M, Barba Balda E, Lopez Sagarra A, Carruthers T, Ogden A, Marques J, Hader K, Millet GY. Monitoring low-frequency fatigue during return-to-play in elite football: physiological basis and a four-case series. Sport Performance & Science Reports, #289, Apr 2026.

📄 Read the full paper here

Strength ✅ Range of motion ✅ Pain-free ✅ GPS targets hit ✅

…But are they ready, or just capable?

We’ve just published new data on what happens after players tick all the traditional return-to-play boxes.
The gap? We know they completed the work. We don’t know if they can tolerate it.

Traditional discharge criteria tell us about capacity:
– Strength symmetry restored
– Full ROM achieved
– Pain-free through progressions
– GPS milestones reached (HSR, sprint volume, accelerations)

But they don’t tell us about tolerance:
– How does the injured limb respond to that work?
– What’s the neuromuscular cost of a high-intensity session?
– Can they back it up across consecutive days?

Are they ready, or just capable?

This is where low-frequency fatigue (LFF) monitoring with MYOCENE fills the void.

What we found across 4 elite football cases (ACL, rectus femoris, 2x hamstring):
🔹 Early rehab: Players completed pitch sessions successfully, but the injured limb showed disproportionate acute fatigue suppression vs. the healthy side. Capable? Yes. Tolerating it well? Not yet.
🔹 Mid-progression: Same player, bigger load, smaller acute response. Tolerance is building – but you’d never see this from a strength test or GPS completion.
🔹 Late-stage: Consecutive high-intensity days revealed who could genuinely back it up and who was still paying a disproportionate cost. Some players restored overnight. Others accumulated fatigue despite “passing” all traditional criteria.

Why MYOCENE works here:

✅ Passive – No maximal effort required, so no added fatigue or risk
✅ Daily feasible – Fits into arrival protocols without disrupting rehab schedules
✅ Mechanism-specific – Measures peripheral contractile function (excitation-contraction coupling), not just force output
✅ Acute + chronic signals – Tracks both session response AND multi-day tolerance

One case (hamstring, Case 3) reached 27.4 km/h peak speed and completed 16 sprints in a session – objectively cleared for discharge by traditional metrics. But LFF still showed persistent right-sided deficit and incomplete restoration after consecutive pitch exposures.

Capable of completing the work? Absolutely.
Ready to tolerate what’s coming next? The data said not quite.
That’s the difference.

We’re not replacing traditional criteria. We’re adding the piece that tells us whether players can handle the cumulative load demands of return to play – not just complete individual sessions in isolation.

Full case series published with Sport Performance & Science Reports

The question that keeps me up: where do you feel least confident in the discharge decision? Is it strength? Movement quality? Or is it this tolerance piece we can’t quite see?

#ReturnToPlay #SportsRehabilitation #FootballScience #LoadManagement #SportsPerformance #Myocene #SPSR