Performance · Recovery · Mental Edge · Functional Testing

What five functional tests reveal
for the serious athlete

Not "are you sick?" — but "why aren't you performing at the ceiling your training says you should be?" Every marker mapped to what it means in the gym, on the mat, and in the fight.

5Functional Tests
40+Performance Markers
33Training-Specific Insights
1Complete Picture

Standard blood tests were designed to catch disease. They were not designed to answer the questions that matter to a serious athlete — why recovery is slower than it should be, why strength isn't tracking with training volume, why aggression and focus in training are inconsistent, why the body composition isn't shifting despite the effort going in.

Functional testing asks a different set of questions entirely. It examines the hormonal environment that determines whether training produces adaptation or breakdown. It maps the nervous system state that determines whether you are anabolic or catabolic — building or burning. It assesses the digestive capacity that determines whether the protein you're eating is actually becoming muscle. And in the context of combat sports and martial arts specifically, it reveals the neurochemical patterns that govern focus, aggression, resilience under pressure, and the ability to stay sharp when the body is under maximum physiological stress.

What follows is every question the five-test panel answers — framed entirely around what it means for performance, recovery, and mental edge. Not illness. Not disease management. Training optimisation.

01
Test One · Blood Chemistry · 46 Markers · Optimal Range Interpretation
The Hormonal and Metabolic Foundation
Your blood chemistry is the most direct read of whether your body is in an anabolic or catabolic state — and whether the hormonal environment supports the muscle gains, aggression, recovery, and energy that your training demands.
WIN 01
Total Testosterone — Your Anabolic Ceiling
Total testosterone defines the ceiling for muscle protein synthesis, recovery speed, drive, and competitive aggression. Functional optimal for a male athlete is above 18–20 nmol/L. Below 15 nmol/L with significant training volume is a red flag regardless of what the reference range says.
Marker: Total Testosterone (nmol/L)
WIN 02
SHBG — How Much Testosterone Is Actually Available
Sex hormone binding globulin locks testosterone up and makes it biologically inactive. Total testosterone can look fine while free testosterone — the amount actually reaching muscle androgen receptors — is clinically low. High SHBG explains the athlete who trains hard, eats enough protein, and doesn't gain muscle at the rate their volume predicts.
Marker: SHBG (nmol/L) — calculate free testosterone from total T + SHBG
WIN 03
Cortisol:DHEA Ratio — Catabolic vs Anabolic Balance
DHEA is the counter-hormone to cortisol — anabolic where cortisol is catabolic. The ratio between them determines whether training stimulates growth or breakdown. An athlete with high cortisol and low DHEA is burning muscle for fuel regardless of dietary protein intake. Serum DHEA-S gives the first indication before DUTCH confirms the full picture.
Marker: DHEA-S (µmol/L)
WIN 04
Thyroid Function — Metabolic Rate and Recovery Speed
Subclinical hypothyroidism — TSH elevated but within reference range, Free T4 low-normal — produces slower recovery, reduced metabolic rate, impaired protein synthesis, and fatigue that doesn't resolve with rest. It also elevates SHBG, compounding the testosterone availability problem. A TSH above 2.5 in a training athlete warrants investigation.
Markers: TSH, Free T4
WIN 05
Iron and Ferritin — Oxygen Delivery to Working Muscle
Haemoglobin carries oxygen to muscle during exercise. Iron saturation determines how efficiently haemoglobin is loaded. A ferritin of 60 looks fine on a standard report but may represent functional iron deficiency in a high-training-volume athlete if saturation is below 45%. Low iron = impaired VO2, reduced endurance, slower recovery between rounds.
Markers: Ferritin, Iron Saturation, TIBC, Haemoglobin
WIN 06
Protein Status — Are You Actually Building?
Total protein and albumin on blood chemistry give a direct read of protein adequacy and liver synthetic function. Athletes on high training volume with insufficient dietary protein — or with impaired digestion reducing absorption — will show low-normal total protein despite high intake. The number tells you whether the protein is arriving.
Markers: Total Protein, Albumin (g/L)
WIN 07
Vitamin D — Testosterone, Muscle, and Immune Function
Vitamin D receptors are found on every cell type, including muscle cells and Leydig cells (testosterone producers). Deficiency — which is endemic in the UK — is independently associated with reduced testosterone, impaired muscle protein synthesis, slower recovery from injury, and reduced immune tolerance. Athletes training hard with low D are fighting the physiology.
Marker: 25-OH Vitamin D3 (nmol/L) — functional optimal 100–150
WIN 08
Inflammation Markers — Training Stimulus vs Systemic Burden
CRP and white cell differential (particularly neutrophil:lymphocyte ratio) indicate systemic inflammatory burden. Training produces acute inflammation that drives adaptation. But chronic low-grade inflammation from gut dysbiosis, food sensitivities, or chronic stress competes with that signal, impairs recovery, and reduces anabolic response. The blood panel tells you whether the system is clean or burdened.
Markers: CRP, WBC differential, Neutrophil:Lymphocyte ratio
WIN 09
Fat Digestion — Triglycerides and Lipid Profile
Triglyceride:HDL ratio is a proxy for insulin sensitivity and fat metabolism efficiency. An athlete eating adequate fat but with elevated triglycerides is not clearing dietary fat effectively — often indicating insulin resistance, impaired bile production, or insufficient fat-digesting enzyme output. Cross-referenced with GI-MAP for confirmation.
Markers: Triglycerides, HDL, Triglyceride:HDL ratio
WIN 10
Liver Function — Supplement Clearance and Anabolic Steroid Monitoring
ALT and AST reveal hepatic stress from training load, supplement burden, or alcohol. Elevated liver enzymes in a high-training athlete can indicate that the liver is processing the anabolic-catabolic cycling of intense training — or that it is under additional load that is competing with recovery. Either way, the panel makes it visible.
Markers: ALT, AST, ALP, GGT
02
Test Two · DUTCH Plus · Dried Urine Hormone Assessment
The Full Hormonal Picture — Across 24 Hours
Blood testosterone is a snapshot. The DUTCH Plus is the film. It shows the full diurnal cortisol pattern, the anabolic:catabolic balance, how testosterone is being metabolised, oestrogen clearance, melatonin, and the neurotransmitter precursors that govern focus, aggression, and mental edge under pressure.
WIN 11
Cortisol Awakening Response — Morning Drive and Readiness
Cortisol should spike 50–160% within 30–45 minutes of waking. This morning surge drives motivation, physical readiness, and the competitive edge that makes early training sessions productive. A blunted CAR means sluggish mornings, poor training quality before noon, and a nervous system that isn't primed for output. This is measurable and correctable.
DUTCH marker: Cortisol Awakening Response (CAR)
WIN 12
Diurnal Cortisol Pattern — Training Timing and Recovery Windows
The full 24-hour cortisol curve determines when training should be scheduled for maximum output and when the body needs recovery. An inverted pattern — low morning, high evening — explains the athlete who trains well at night but struggles with morning sessions and can't wind down to sleep. Training against this pattern instead of with it is recoverable time and energy.
DUTCH markers: Morning, midday, evening, night cortisol
WIN 13
Total Cortisol Metabolites — Anabolic or Catabolic State
Total daily cortisol production determines the catabolic burden on the system. High total metabolites with high training volume = muscle breakdown exceeding repair. This is the overtraining marker that blood tests miss entirely. The DUTCH quantifies the actual cortisol load across a full day, not a single point in time.
DUTCH markers: eTHF + THE (total cortisol metabolites)
WIN 14
DHEA and DHEA-S — The Anabolic Counter to Cortisol
DHEA is the primary anabolic counterbalance to cortisol. High DHEA-S relative to cortisol = good anabolic environment, rapid recovery, maintained muscle mass. Low DHEA-S relative to cortisol = catabolic dominance regardless of training programme or protein intake. The DUTCH gives the full adrenal picture that blood DHEA-S alone cannot.
DUTCH markers: DHEA, DHEA-S, Cortisol:DHEA ratio
WIN 15
Testosterone Metabolism — DHT and 5α-Reductase Activity
Testosterone is converted to DHT (dihydrotestosterone) by 5α-reductase — DHT is 3–5x more potent at androgen receptors and drives strength, aggression, and body composition change more directly than testosterone itself. The DUTCH reveals how efficiently this conversion is occurring and whether testosterone is being channelled toward performance or diverted toward oestrogen.
DUTCH markers: Androsterone, Etiocholanolone, 5α:5β ratio
WIN 16
Oestrogen Metabolism — Clearance and Pathway Dominance
Male athletes need oestrogen — it supports joint health, bone density, cardiovascular function, and libido. But oestrogen that isn't cleared efficiently accumulates and suppresses testosterone via negative feedback. The 2-OH:4-OH pathway ratio on DUTCH reveals how cleanly oestrogen is being processed — and whether methylation support is needed to open the clearance pathway.
DUTCH markers: 2-OH-E1, 4-OH-E1, 2-MeO-E1, 16-OH-E1
WIN 17
Dopamine Metabolites — Reward, Drive, and Motivation to Train
The DUTCH Plus includes dopamine metabolite markers (HVA — homovanillic acid) that reflect dopamine turnover. Dopamine is the reward and anticipation neurotransmitter — the one that makes training feel worth it, that produces the drive to compete, and that governs the experience of effort as meaningful rather than punishing. Low dopamine turnover = flat affect, reduced drive, difficulty finding motivation even when the goal matters.
DUTCH marker: HVA (dopamine metabolite)
WIN 18
Norepinephrine — Focus and Physiological Arousal in the Fight
Norepinephrine is the catecholamine of focused arousal — the neurotransmitter that narrows attention, sharpens threat response, and produces the controlled aggression that distinguishes a clean fighter from a panicked one. VMA (vanillylmandelic acid) on the DUTCH reflects norepinephrine turnover. Too low = flat response under pressure. Too high chronically = anxiety, sleep disruption, burnout.
DUTCH marker: VMA (norepinephrine metabolite)
WIN 19
Melatonin — Sleep Architecture and Overnight Recovery
Testosterone is produced during sleep — specifically during deep slow-wave sleep. Melatonin on the DUTCH reveals whether the circadian system is producing adequate sleep signal. Low melatonin in an athlete means compromised sleep architecture, reduced overnight testosterone production, impaired growth hormone pulsing, and slower recovery — regardless of how many hours they spend in bed.
DUTCH marker: 6-OHMS (melatonin metabolite)
WIN 20
Epinephrine (Adrenaline) Pattern — Stress Reactivity vs Resilience
Epinephrine drives the acute stress response. In combat sports, the pre-fight adrenaline surge is a performance tool — it mobilises glucose, sharpens senses, and prepares for physical output. But chronic low-grade epinephrine elevation between training sessions indicates that the system hasn't fully recovered from the last stress event. The DUTCH distinguishes acute reactivity from chronic burden.
DUTCH marker: Epinephrine (adrenaline) metabolites
The MMA-Specific Neurochemical Questions the DUTCH Answers
"Why do I freeze or gas out in sparring even when I'm fit enough not to?"
→ Cortisol pattern + norepinephrine + CAR
"Why is my training drive inconsistent — some weeks I'm on it, some weeks I can barely get to the gym?"
→ DHEA:cortisol ratio + dopamine metabolites
"Why am I aggressive outside training but flat inside it when I need the edge?"
→ DHT conversion + cortisol pattern + epinephrine
"I'm sleeping eight hours and still waking unrecovered — why?"
→ Melatonin + cortisol evening pattern
"My body composition won't shift despite the training and the diet being right."
→ Total cortisol metabolites + DHEA + testosterone:oestrogen balance
"I feel like my nervous system never fully resets between hard sessions."
→ Epinephrine + evening cortisol + melatonin suppression
03
Test Three · GI-MAP · Comprehensive Stool Analysis with Zonulin
Protein Absorption, Inflammation, and the Gut-Brain Axis
You can eat 200g of protein a day and absorb significantly less than half of it if the gut isn't working. You can have optimal testosterone and a leaky gut driving chronic systemic inflammation that suppresses the anabolic response at the tissue level. The GI-MAP tells you whether the digestive foundation is supporting or undermining everything else.
WIN 21
Protein Digestion Markers — Is the Protein Actually Getting In?
Elastase-1 on the GI-MAP measures pancreatic enzyme output — specifically the proteases needed to break dietary protein into absorbable amino acids. Low elastase means that a high-protein diet is producing largely undigested protein reaching the large intestine, feeding putrefactive bacteria rather than building muscle. This single marker explains many cases of high protein intake with poor muscle gain.
GI-MAP marker: Elastase-1 (pancreatic sufficiency)
WIN 22
Fat Digestion — Steatocrit and Bile Sufficiency
Steatocrit measures fat in stool — elevated levels indicate fat malabsorption. Fat is essential for testosterone production (cholesterol is the precursor), fat-soluble vitamin absorption (D, K2, A, E), and sustained energy during training. An athlete not absorbing dietary fat is not producing optimal testosterone or absorbing the fat-soluble nutrients that support performance regardless of intake.
GI-MAP marker: Steatocrit
WIN 23
Gut Permeability — Zonulin and Systemic Inflammation
Zonulin is the primary regulator of tight junction integrity in the intestinal wall. Elevated zonulin indicates increased gut permeability — "leaky gut" — allowing bacterial endotoxins (LPS) to cross into circulation. LPS drives systemic inflammation that competes directly with the anabolic response to training, impairs testosterone signalling, and produces chronic inflammatory load that the body cannot exercise its way out of.
GI-MAP marker: Zonulin (add-on, included in TDG GI-MAP Entry)
WIN 24
Gut Microbiome and Neurotransmitter Production
Approximately 90% of serotonin is produced in the gut by enterochromaffin cells — a process dependent on the presence of specific microbial species and adequate tryptophan availability. Gut dysbiosis disrupts serotonin production, directly affecting mood stability, stress tolerance, sleep quality, and the ability to maintain composure under competitive pressure. The GI-MAP reveals the microbial environment driving or disrupting this pathway.
GI-MAP markers: Microbiome diversity, Lactobacillus, Bifidobacterium
WIN 25
Pathogenic Load — Hidden Infections Draining Performance
Subclinical gut infections — H. pylori, parasites, pathogenic bacteria — produce chronic immune activation that consumes energy, suppresses anabolic signalling, and drives inflammatory cytokines that directly antagonise testosterone production. An athlete with an unidentified gut pathogen is fighting a two-front war. The GI-MAP identifies the pathogen. Treatment removes the hidden drain.
GI-MAP markers: H. pylori, parasites, pathobionts, opportunists
WIN 26
Mucosal Immunity — Secretory IgA and Training Immune Suppression
High training volume transiently suppresses secretory IgA — the frontline immune defence of the gut and respiratory tract. Low sIgA on the GI-MAP indicates that the immune system is already under strain from training before any additional stressor is applied. This explains the athlete who catches everything that's going around and loses weeks of training to repeated upper respiratory infections at high volume phases.
GI-MAP marker: Secretory IgA
04
Test Four · Organic Acids Test · Mitochondrial and Neurotransmitter Function
Energy Production at the Cellular Level
Every rep, every round, every recovery process is ultimately powered by mitochondria. The OAT shows whether the cellular energy machinery is running efficiently, where the bottlenecks are, and what the neurotransmitter picture looks like from the metabolite level — often more accurately than any symptom questionnaire.
WIN 27
Krebs Cycle Efficiency — Where Energy Production Bottlenecks
The Krebs cycle intermediates on the OAT reveal exactly where cellular energy production is running inefficiently. Elevated citrate with depressed downstream markers indicates a B-vitamin or magnesium bottleneck early in the cycle. This produces fatigue that is entirely out of proportion to training load — the engine is misfiring, not underfuelled. Targeted cofactor support can meaningfully improve output within weeks.
OAT markers: Citrate, Isocitrate, α-ketoglutarate, Succinate, Fumarate, Malate
WIN 28
B12 Functional Status — Energy, Recovery, and Neural Repair
Methylmalonic acid (MMA) on the OAT is the most sensitive functional marker of B12 sufficiency — far more accurate than serum B12 which can appear normal while intracellular B12 is functionally depleted. B12 is essential for myelin repair, red blood cell production, DNA synthesis for muscle cell replication, and the methylation reactions that govern neurotransmitter production. An athlete with elevated MMA is B12-insufficient regardless of what their blood level says.
OAT marker: Methylmalonic acid (MMA)
WIN 29
Serotonin and Dopamine Metabolites — The Neurotransmitter Baseline
The OAT measures 5-HIAA (serotonin metabolite) and HVA (dopamine metabolite) — giving an independent confirmation of the neurotransmitter picture that the DUTCH begins to reveal. Low 5-HIAA correlates with poor stress tolerance, impulsive aggression, and disrupted sleep. Low HVA correlates with poor motivation, reward insensitivity, and difficulty sustaining effort when the emotional driver is absent.
OAT markers: 5-HIAA, HVA, Quinolinic acid, Kynurenic acid
WIN 30
Oxidative Stress Burden — Training Recovery vs Damage
8-OHdG on the OAT measures oxidative DNA damage — the cumulative oxidative stress burden. High-intensity training produces significant reactive oxygen species, and the body's antioxidant capacity determines whether this drives adaptation or damage. An athlete with high 8-OHdG and high training volume is running an oxidative deficit — the damage is outpacing the repair. Glutathione status markers confirm this picture.
OAT markers: 8-OHdG, Pyroglutamic acid (glutathione demand)
WIN 31
Carbohydrate Need — Is the Current Intake Right for This Athlete?
Pyruvate and lactate patterns on the OAT reveal how efficiently the body is handling carbohydrate load and whether glycolytic capacity is adequate for the training demand. An athlete eating too little carbohydrate for their training intensity will show elevated markers of gluconeogenesis — the body cannibalising protein and muscle for glucose. The OAT makes the macronutrient case from the cellular level up, not from theoretical protocols down.
OAT markers: Pyruvate, Lactate, β-hydroxybutyrate
WIN 32
Fatty Acid Oxidation — Fat as Fuel Efficiency
Adipate and suberate on the OAT indicate impaired mitochondrial fatty acid oxidation — the ability to use fat as fuel. An athlete with elevated adipate and suberate cannot efficiently access fat stores for energy, is more carbohydrate-dependent, and fatigues faster when glycogen depletes. This also explains poor body composition response despite training: fat is being stored rather than oxidised because the mitochondrial machinery isn't running cleanly.
OAT markers: Adipate, Suberate, Ethylmalonate
05
Test Five · Food Sensitivity Panel · IgG Reactivity Assessment
The Hidden Inflammatory Load in the Training Diet
Food sensitivities are not allergies — they don't produce an immediate, obvious reaction. They produce delayed, low-grade inflammation that accumulates over days of repeated exposure. For an athlete eating the same high-protein training diet repeatedly, a sensitivity to a staple food is a constant, invisible inflammatory burden running alongside training-induced inflammation.
WIN 33
Removing the Hidden Inflammatory Burden from the Training Diet
An athlete with IgG reactivity to whey protein, eggs, or another dietary staple is producing a low-grade immune response every time they eat their standard recovery meal. This inflammatory signal competes with the training adaptation signal, slows recovery, and maintains a chronic inflammatory baseline that impairs testosterone signalling, disrupts sleep, and contributes to the gut permeability picture confirmed on the GI-MAP. Remove the reactive food, and the system cleans up. Recovery improves. Inflammation markers drop. The training stimulus gets a cleaner response.
Panel: 96–200 foods tested by IgG reactivity. Cross-reference with GI-MAP inflammation markers.

"An athlete can be doing everything right in the gym and in the kitchen and still be training against their own biology. These tests find the hidden variables — the ones that don't show up on a standard blood test and don't respond to more training or more protein."

33 Performance Insights
From 5 Tests

Every insight is a potential lever for performance

Not every marker will be suboptimal in every athlete. But in an athlete who is training consistently and not performing at the ceiling their volume predicts — experiencing inconsistent recovery, plateaued strength or body composition, variable focus and drive, or the gut and mood issues that compound under training stress — the probability that several of these 33 levers are suboptimal is high. Finding them is the work. The corrections are often targeted, specific, and effective within weeks rather than months.

This is not guesswork. This is the test, don't guess principle applied to performance.

Ready to find your specific levers?

The TDG Five-Test Programme includes all five tests, full practitioner interpretation of every marker in the context of your training, and a written protocol covering nutrition, supplementation, and lifestyle interventions targeted to your results. One investment. A complete picture.

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