Every July, before the crowds come back, the Liverpool first team runs a lactate test on the training pitch. Players complete timed laps, a physiologist takes a drop of blood from a fingertip after each one, and anyone whose blood lactate climbs past a set line is pulled from the drill. The club has done it since Jurgen Klopp arrived, and the analyser doing the reading is a point-of-care device, an EKF Biosen, the same category of instrument you would find in a hospital near-patient testing service.

Nobody at the training ground calls it point-of-care testing. But that is what it is: a laboratory measurement, taken next to the athlete, delivered in seconds, used to make a decision that afternoon. And once you start looking, elite football turns out to be full of it. This piece is about what the game actually measures, where the evidence is solid and where it is thin, what happens inside a World Cup medical room, and the one lesson elite sport hands every service that tests away from a central laboratory. I have tried to be as honest about the limits as about the promise, because a club doctor will spot the difference immediately.

57%of elite female footballers were iron deficient when screened before a World Cup
65 to 1,972the creatine kinase range (U/L) proposed for professional footballers, far above the general population
116 vs 7radiology versus laboratory patient contacts at the Qatar 2022 athlete polyclinic
20.6match injuries per 1,000 hours at Qatar 2022, the lowest of any World Cup on record

The training ground runs laboratory chemistry

Lactate is the oldest and best-evidenced example. It maps conditioning and threshold, and it has been a near-patient measurement in sport for decades. Beyond Liverpool, a 2025 study compared lactate-threshold methods in professional and youth players using capillary finger-prick sampling, the same drop-of-blood approach, at scale. Small sample, next to the athlete, answer in seconds. That is point-of-care testing by any definition, done on some of the fittest people alive.

Creatine kinase is the more revealing case. It is the enzyme that leaks from damaged muscle, so it is used to read how hard a match hit and how recovery is going. In professional footballers it runs far higher than in the general population. One study of 27 professional players proposed a football-specific reference interval of roughly 65 to 1,972 U/L, against a general-population median nearer 124. The detail that matters here is the method. A two-season study of a Premier League club took finger-prick capillary samples and read creatine kinase on a Roche Reflotron Plus, a bench point-of-care analyser, then used the result to help judge who was fit to start through congested fixtures. That is a laboratory analyte, produced at the training ground, feeding a real team-selection decision.

C-reactive protein has gone the same way. A 2025 case-series followed a Premier League squad through a season of point-of-care CRP testing and built individualised reference ranges around each player, so a rise was judged against that player's own baseline rather than a population range. The authors are careful to call it an early-warning tool, not a diagnostic, which is exactly the right caution. Taken together, the picture is consistent: elite football runs real chemistry, near the athlete, across the season.

MarkerWhat it flagsWhere it runsLactateConditioning and thresholdPOCTCreatine kinaseMuscle damage and recoveryLABPOCTC-reactive proteinInflammation, recovery flagPOCTFerritin and ironIron deficiency screenLABVitamin DBone, muscle and immunityLABHydration (USG)Fluid status at playPOCT
Figure 1. The markers elite football watches, and where each one actually runs. Lactate, CRP and hydration are genuine point-of-care measurements. Ferritin, iron studies and vitamin D remain central-laboratory work. Creatine kinase is done both ways depending on the club. The split is never as tidy as the marketing suggests.

The biomarkers elite football measures

The markers fall into two jobs. One group reads training load and recovery: lactate, creatine kinase, and increasingly inflammation markers like CRP. The other is a screening layer that catches problems a fit young athlete can still carry, chiefly iron status and vitamin D. Here is the working set, with what each is for and where it is usually run.

Common biomarkers in elite football, with a representative published figure for each.
MarkerWhy it is measuredUsual settingRepresentative figure
LactateConditioning and thresholdPoint of careMatch values around 5 to 6 mM
Creatine kinaseMuscle damage and recoveryBothProposed range 65 to 1,972 U/L
C-reactive proteinInflammation, recovery flagPoint of care or labIndividualised ranges in an EPL squad
Ferritin and ironIron deficiency screenCentral lab54% of athletes hypoferritinaemic (ferritin under 50)
Vitamin DBone, muscle and immunityCentral labUp to two thirds low in high-latitude winters
Hydration (USG)Fluid statusPoint of careSoccer among the highest body-mass losses in team sport

Iron is the standout on the screening side. A meta-analysis of 17,519 athletes found around 54 percent were hypoferritinaemic at a ferritin threshold under 50, and 23 percent had absolute iron deficiency under 20. The prevalence swings with the cut-off you choose, which is why the threshold always has to be stated, but even at the strict end it is high. In elite female footballers specifically, a study screening a national squad before a FIFA Women's World Cup found 57 percent iron deficient and 29 percent with outright iron-deficiency anaemia. Frank anaemia in elite men is uncommon, so the honest story is deficiency without anaemia rather than a dressing room full of anaemic players. Even so, it is exactly the kind of finding a screening programme exists to catch.

0255075100Percentage of athletes affectedElite female playersiron deficiency, pre World Cup57%College athleteshypoferritinaemia, meta-analysis54%Youth players, femalemild iron deficiency53%Youth players, malemild iron deficiency41%
Figure 2. Iron problems are common even among the fittest athletes, and the prevalence you report depends on the ferritin cut-off you choose. More than half of elite female footballers screened before a World Cup were iron deficient, and pooled athlete data show the same pattern. Sources: Landahl and colleagues 2005 (elite women); Thompson and colleagues 2025 meta-analysis (ferritin under 50); youth cohort data 2023.

How Premier League clubs monitor players

What clubs actually do is less uniform than the vendor stories suggest. A survey of 99 sports-science and sports-medicine staff across European elite clubs found that the monitoring done most often is external load, the GPS and accelerometer data from training and matches, and that how much a club measures tracks its belief in evidence-based practice and, bluntly, its budget. Routine blood testing was not something every club did or quantified. So the accurate way to describe elite blood monitoring is as a growing and uneven practice, strongest at the best-resourced clubs, rather than a universal standard.

Where blood monitoring does happen, the published examples share a shape. Testing is periodic rather than constant, often built around pre-season, a mid-season point and the season's end, with more frequent sampling for a flagged player. The markers are interpreted against the individual's own baseline, not a textbook range, which is the single most consistent recommendation in the sports-medicine literature. The Premier League CRP work and the finger-prick creatine kinase study are the clearest peer-reviewed windows into it, and both anonymise the club, which is normal for this kind of research.

The point of care devices used in elite sport

The hardware is more visible outside football, in sports that publish or partner more openly, but the devices are the same class you would deploy in any near-patient service.

Point-of-care and portable diagnostics with documented use in elite sport. Named-club evidence is scarce, so the strongest sources are studies, governing bodies and manufacturer or partnership announcements.
DeviceWhat it measuresWhere it appearsEvidence type
EKF BiosenLactateLiverpool pre-seasonManufacturer and club press
Roche Reflotron PlusCreatine kinase (finger-prick)Premier League clubPeer-reviewed, 2021
Siemens epocBlood gas, electrolytes, lactateParis 2024, World AthleticsPartnership and trade press
Abbott i-STAT TBIConcussion biomarkersMotoAmerica (first pro org)Manufacturer and FDA clearance
Blood glucose meterGlucose (hypoglycaemia)UEFA match medical roomUEFA Medical Regulations 2024

The pattern in the table is worth naming. The genuinely near-patient blood devices in elite sport handle lactate, blood gas and single markers like creatine kinase, glucose and CRP. The deeper panels, iron studies, vitamin D, hormones, still go to a central laboratory. Nobody has replaced the lab. They have added a fast lane in front of it.

What happens inside a World Cup medical room

The best public window into elite tournament medicine is the account of the medical services at the FIFA World Cup Qatar 2022, published in the British Journal of Sports Medicine. It covers 832 athletes across 32 teams, run through a 24-hour medical command centre that logged 262 requests, and an athlete polyclinic based at the Aspetar hospital that recorded 438 encounters. What those athletes actually needed is the interesting part.

Diagnostics at the World Cup were dominated by imaging, not blood. Of 129 athletes seen in the polyclinic, 91 underwent imaging, and MRI was the single most requested service. The central laboratory, by contrast, was used by just seven patients across the whole tournament. That is not because elite footballers do not get blood tested. It is because, in the authors' own words, some teams had travelled with their own diagnostic ultrasound machines and point-of-care laboratory testing devices. The teams that wanted near-patient bloods brought them in a kit bag and did not need the central lab.

0306090120Radiology (imaging)116Podiatry23Pharmacy21Emergency medicine15Sports medicine12Dentistry12Surgery9Cardiology8Laboratory7Patient contacts by department, Qatar 2022 athlete polyclinic
Figure 3. Where athletes actually went at the Qatar 2022 polyclinic. Radiology recorded 116 patient contacts and the central laboratory only 7. The gap is the story: at a modern World Cup, musculoskeletal imaging dominates central demand, and the blood testing that does happen has largely moved into the teams' own hands. Data: Grant and colleagues, British Journal of Sports Medicine, 2024.
Elite teams have started bringing the laboratory to the athlete, instead of sending the athlete to the laboratory. A World Cup is where you can see it happen.

The rest of a World Cup medical operation is built for emergencies, not diagnostics. At Qatar 2022 each field-of-play team was an emergency physician and three advanced-life-support paramedics carrying an automated external defibrillator, part of an operation that trained thousands of medical staff across more than a hundred clinics. That is the priority pitch-side: recognise and treat a collapse, not run a blood panel.

What FIFA and UEFA actually require

Given how much testing happens, the striking thing is how little the sport's rulebooks say about it. FIFA's Pre-Competition Medical Assessment, compulsory across FIFA competitions and built after the cardiac death of Marc-Vivien Foe on the pitch in 2003, is centred on cardiac safety: history, examination, a 12-lead ECG and echocardiography. It does include a blood panel, but a fasting venous laboratory panel, not point-of-care, with no blood gas and no lactate. FIFA's pitch-side doctrine is the medical emergency bag and the eleven steps to prevent sudden cardiac death, an AED-led kit with no blood analyser in it.

UEFA is the same. Its 2024 medical regulations require a venous pre-competition screening panel done as scheduled health work, not at the venue. The only point-of-care blood-analysis device specified in the match medical-room equipment list is a blood glucose meter, there to manage a hypoglycaemic emergency, not to monitor performance. So the near-patient testing that clubs clearly value sits almost entirely in the space the governing bodies leave open. That is not a scandal. It is the familiar pattern of practice moving faster than the standards that describe it, and anyone who works in point-of-care testing will recognise it at once.

Match injuries per 1,000 match hours (time loss)02040200250.7200645.9201040.1201429.3201841.2202220.6lowest everMen's FIFA World Cup
Figure 4. Time-loss match injuries per 1,000 match hours at men's World Cups. The rate has fallen substantially since 2002, with Qatar 2022 the lowest on record at 20.6, alongside an interruption to the trend in 2018. Data: FIFA injury surveillance, Junge and Dvorak and colleagues; Qatar 2022 figure from Serner and colleagues, Science and Medicine in Football, 2025.

The uncomfortable truth about biomarkers

Here is where an honest article has to slow down. It is tempting to imply that all this testing predicts and prevents injury. The evidence does not support that, and the best sports physicians know it. A four-season study of professional players found that creatine kinase measured two days after a match had essentially no ability to predict a subsequent muscle injury, with a sensitivity of 56 percent, a specificity of 55 percent and an area under the curve of 0.557, which is close to a coin toss. The major sports-medicine consensus on blood biomarkers reaches the same conclusion: established markers reflect muscle-damage load and recovery, not future injury risk, and they are undermined by large individual variation and the absence of standard reference values.

The honest limit

Blood biomarkers in football are recovery and load-monitoring tools, interpreted against a player's own baseline. They are not injury-prediction tools. Any claim that a routine blood test forecasts the next hamstring tear runs ahead of the evidence.

That matters because injury is the real prize. Hamstring injuries now make up 24 percent of all injuries in men's professional football and a fifth of all days lost, and they have been rising for two decades, according to the UEFA Elite Club Injury Study. If a simple blood test could flag them, every club would already run it. What the biomarkers genuinely offer is quieter: a read on how a player is recovering, judged against their own history, so that training load can be adjusted with more information than a coach's eye alone. Useful, but not prophetic.

A creatine kinase value tells you a muscle was damaged. It does not tell you the next one is coming. Sell it as recovery monitoring, not a crystal ball.
Creatine kinase, relative to resting level0h24h48h72hHours after matchresting rangepeak around 24h
Figure 5. Creatine kinase rises to a peak around 24 hours after a match and settles over roughly three days. A systematic review makes an important point that the figure cannot: physical performance, jump height and sprint speed, often recovers before the biochemistry normalises, so the blood marker and the player can disagree. Kinetics per Doeven and colleagues, BMJ Open Sport and Exercise Medicine, 2018. Curve is illustrative of the published time course.

The lesson for every point of care service

Strip away the glamour and elite football is a working demonstration of testing outside the laboratory, with the same strengths and the same failure points as a community clinic or a pharmacy bench. Go back to that creatine kinase value on the Reflotron. It is a laboratory result. It carries the same pre-analytical failure modes, a fingertip squeezed too hard, a sample taken too soon, a strip stored wrong. It needs the same quality control, the same competency behind the operator, and the same connectivity, so the number reaches the record attributed to the right person, with its context intact, instead of dying on a device screen.

The market is betting on this. The blood-based biomarker segment for sports medicine was valued at about 778 million US dollars in 2024 and is forecast to pass 1.2 billion by 2030. But a forecast is not a quality system, and a device is not a result you can trust. A few things the football evidence makes plain for anyone testing away from a central lab.

  • A point-of-care result is a laboratory result. The moment a device produces a number a clinician acts on, it inherits every obligation a laboratory result carries. The training ground gets no exemption, and neither does the clinic.
  • Interpret against the individual. The strongest evidence-based theme in this whole field is that individualised baselines beat population reference ranges. A number only means something next to that person's own history.
  • The device is rarely the weak point. Modern analysers are good. The risk sits in sample technique, the operator, the quality control skipped on a busy day, and the result that never leaves the screen.
  • Do not oversell it. Recovery monitoring is real and useful. Injury prediction is not there yet. Claiming more than the evidence supports is how a good idea loses the room.

Elite football has built, almost by accident, one of the great real-world tests of near-patient diagnostics: intensive, high-stakes, and largely invisible to the people who write the rules. It shows how much testing near the person can offer, and it shows just as clearly that the offer only pays off when quality, connectivity and honest interpretation travel with the device. The finger-prick at the side of the pitch and the finger-prick on a pharmacy bench are closer cousins than either setting realises. Both are point-of-care testing, and both deserve to be done properly.

Sources and notes

This article draws on peer-reviewed literature, official FIFA and UEFA medical publications and named manufacturer sources. Where a device is attributed to a specific club, that comes from the cited source; many elite clubs keep their exact diagnostics confidential, and several studies below anonymise the club by design. Some cited physiology cohorts are professional rather than top-tier elite, and this is noted where it matters. Prevalence figures for iron are threshold-dependent, so the ferritin cut-off is stated. Market figures are single-firm estimates and are revised over time. The creatine kinase recovery curve in Figure 5 is illustrative of the published time course rather than a single dataset.

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