CTS Performance Lab · Colorado Springs
Know Your
Numbers.
Then know what they mean.
Research-grade physiological testing for endurance athletes — and anyone who wants to understand how their body is actually performing. Measured, not estimated. Interpreted by an senior exercise physiologist, not an algorithm.
Research Grade Equipment
Senior Exercise Physiologist Interpretation
30+ Years testing endurance athletes
Metabolic Cart · Data
Breath by breath
58.4
mL/kg/min
VO₂max
2.1
mmol/L · LT1
Aerobic Thr.
186
bpm · peak
Max HR
Designed, Administered & Interpreted by Senior Exercise Physiologist
Renee Eastman,
MS, CSCS
Every test at the CTS Performance Lab is run by a senior exercise physiologist with 25+ years working with elite, professional, and masters athletes — including time at the USOPC Sports Science Lab and with USA Cycling.
She has analyzed over a thousand tests. At the CTS Performance Lab, that's who is reading your data — not a technician, not a graduate student.
Research-grade equipment
Parvo Medics TrueOne 2400 — the same metabolic cart used in university, clinical, and Olympic performance settings.
Expert interpretation
Your numbers reflect your physiology — your history, your baseline lactate, the shape of your individual curve — not a population average.
Continuity from test to training
The physiologist who runs your test interprets your data, writes your report, and delivers your consultation.
Five Tests
Choose Your Test
From a single VO₂max number to the most complete aerobic picture available in one session. Every test ends with a written report and a one-on-one consultation with your physiologist.
No Blood Draw
$199
VO₂max
Assessment
Assessment
Your maximum capacity to use oxygen — measured directly, breath by breath, with training zones built on your real thresholds.
View test →
Blood Lactate
$259
Lactate
Threshold Test
Threshold Test
LT1 and LT2 identified directly from blood, so your training zones reflect your physiology — not an average.
View test →
Lactate + Metabolic
$349
LT + Metabolic Profile
Thresholds plus how your body burns fat and carbohydrate at every intensity — including FatMax. Training and fueling, one session.
View test →
Most Complete
$475
Integrated Performance Assessment
Two protocols, one session: lactate, ventilatory thresholds, substrate use, and a true VO₂max ceiling — interpreted together.
View test →
$160
Sweat Test Add On
Hydration strategy built on your measured sweat sodium loss. Normally $200, $160 when added to any test above.
VO₂max Assessment · No Blood Draw
VO₂max Assessment
$199
Colorado Springs · 1–2 hrs
Know your number. Understand what it means.
VO₂max — your body's maximum capacity to use oxygen during exercise — is one of the strongest predictors of both athletic performance and long-term health. Your Garmin estimates it. This measures it directly, breath by breath, using a research-grade metabolic cart.
You'll leave with a lab-measured result, the physiological context to understand it, and personalized training zones based on your actual aerobic threshold — not age-predicted formulas or wearable algorithms.
Who this test is for
- Active adults who want an objective, accurate picture of their cardiovascular fitness
- Anyone motivated by longevity who wants to know where their aerobic health actually stands
- Athletes who train regularly but have never had their effort levels calibrated to their actual physiology
- Anyone curious about Zone 2 training who wants to know exactly where their Zone 2 is
What you'll receive
- Measured VO₂max in mL/kg/min with age and sex percentile ranking
- Measured peak heart rate — more accurate than 220-minus-age
- Aerobic threshold (VT1) and anaerobic threshold (VT2) identification
- Personalized three-zone heart rate training zones based on your thresholds
- Written report with your results and physiological context
- One-on-one consultation to walk through your results and what to do with the data
CTS coached athletes receive 10% off all lab testing.
Book VO₂max — $199 Blood Lactate
Lactate Threshold Test
$259
Colorado Springs · 1.5–2 hrs
Your zones are only as good as the data behind them.
Training zones built on age-predicted formulas or 20-min FTP tests are estimates. The Lactate Threshold Test identifies your LT1 and LT2 directly from blood — serial fingertip samples taken at each stage of a graded exercise test — so your zones reflect your physiology, not an average.
LT1 is the ceiling of your true aerobic zone. LT2 is the highest intensity you can sustain for an extended effort. Everything else — your training zones, race pacing, interval targets — is organized around these two anchors.
Who this test is for
- Endurance athletes who want training zones grounded in actual physiology
- Athletes using heart-rate zones based on age formulas who want to know if they're accurate
- Anyone preparing for a goal event who wants interval targets and power/pacing guidance built on real data
- Athletes who have done this test before and want to track changes in fitness over time
What you'll receive
- LT1 and LT2 identified from your individual blood lactate response
- Full lactate profile curve — every stage plotted
- Individualized zones with heart rate and pace (run) or power (bike)
- Race pacing guidance based on your threshold data
- Written report documenting profile, methodology, zones, and altitude context
- One-on-one consultation with a clear training direction
Sample Lactate Profile
Blood lactate (mmol/L) vs. intensity
Lactate response
LT1 · aerobic ceiling
LT2 · sustainable max
CTS coached athletes receive 10% off all lab testing.
Book Lactate Threshold — $259 Lactate Threshold + Metabolic Profile
LT + Metabolic Profile
$349
Colorado Springs · 2–2.5 hrs
Stop guessing at your training and your fueling.
Most endurance athletes have two questions they can't fully answer: how hard should I actually be training, and how much should I be eating during a race? This test answers both — in a single session, from the same data.
Real blood lactate draws identify your precise LT1 and LT2. A research-grade metabolic cart measures exactly how your body uses fat and carbohydrate across every intensity stage — including FatMax, the intensity where fat burning peaks — so your fueling strategy is grounded in what you're actually burning at race pace.
Sample Substrate Utilization
Fat vs. carbohydrate oxidation across intensity
Fat oxidation
Carb oxidation
Crossover point
Who this test is for
- Athletes who train by feel and want zones grounded in actual physiology
- Anyone working on race-day fueling who wants data behind their carbohydrate decisions
- Athletes who have experienced bonking, GI distress, or inconsistent energy in long events
- Anyone who wants to know their FatMax and how to train it
What you'll receive
- LT1 and LT2 from blood lactate — individually identified, not estimated
- Full lactate profile curve across all test stages
- Substrate utilization — fat and carb oxidation rates at each stage
- FatMax identification — your peak fat oxidation intensity and zone
- Metabolic crossover point — fat-to-carbohydrate shift
- Individualized training zones and fueling guidance, plus written report and consultation
CTS coached athletes receive 10% off all lab testing.
Book LT + Metabolic — $349 Flagship · The Most Complete Picture
Integrated Performance Assessment
$475
Colorado Springs · 2–3 hrs
The most complete aerobic picture available in one session — your strengths, your limiters, and exactly what to do about both.
The Integrated Performance Assessment runs two protocols in a single session — a lactate ramp that precisely maps your LT1 and LT2 from blood and captures your ventilatory thresholds (VT1 and VT2) and substrate utilization, followed by a VO₂max ramp that pushes you to max effort to establish your true aerobic ceiling.
That ceiling is what the other tests can't give you. Knowing where your thresholds sit relative to your aerobic ceiling tells you what kind of athlete you are — whether the gap between threshold and ceiling represents untapped potential, or whether threshold fitness is the limiter holding you back.
Who this test is for
- Competitive athletes who want to know not just where their thresholds are, but how they relate to their aerobic ceiling
- Anyone who has done a lactate or VO₂max test before and wants the full picture interpreted together
- Athletes who need to know whether to focus on building aerobic capacity or raising threshold fitness
- CTS coached athletes who want lab data integrated directly into their training program
What you'll receive
- LT1 and LT2 from serial blood lactate sampling
- VT1 and VT2 from breath-by-breath metabolic cart analysis
- Cross-validated threshold placement — lactate and ventilatory data together
- VO₂max — measured, not estimated
- Substrate utilization across the full intensity spectrum, plus FatMax and crossover
- Individualized zones, fueling strategy, written report, and one-on-one consultation
CTS coached athletes receive 10% off all lab testing.
Book Integrated Assessment — $475 Sweat Test · Standalone or Add-On
Sweat Test Add On
$160
$160 added to any test · 45 min
Hydration built on what your body actually loses — not what the label says to drink.
Sweat sodium concentration varies dramatically between individuals. Two athletes doing the same ride in the same heat can have vastly different sodium losses — and the one with higher losses who follows generic hydration guidelines may be progressively under-replacing electrolytes throughout a long effort, even if fluid intake is on target.
The Sweat Test measures your sweat sodium concentration directly, giving you the individual data you need to build a hydration strategy that actually fits your physiology.
Who this test is for
- Athletes who train or race in hot or humid conditions
- Anyone who has struggled with cramping and isn't sure whether it's a sodium, hydration, or fitness issue
- Athletes following a structured nutrition plan who want hydration grounded in actual sweat composition
- Anyone preparing for a heat event who wants to dial in electrolyte replacement in advance
What you'll receive
- Your individual sweat sodium concentration (mg/L)
- Classification of your loss rate — low, moderate, or high — with context
- Personalized sodium replacement recommendations, scaled by duration and conditions
- Guidance on integrating results with your existing nutrition and hydration plan
CTS coached athletes receive 10% off all lab testing.
Book Sweat Test — $200 Side by Side
Compare the Tests
Every test includes a written report and a one-on-one consultation with your physiologist. Here's what separates them.
VO₂max Assessment $199 | Lactate Threshold $259 | LT + Metabolic Profile $349 | Integrated Assessment $475 | Sweat Test Add On $160 | |
|---|---|---|---|---|---|
| Measured VO₂max | ✓ | — | — | ✓ | — |
| Ventilatory thresholds (VT1 / VT2) | ✓ | — | — | ✓ | — |
| Blood lactate thresholds (LT1 / LT2) | — | ✓ | ✓ | ✓ | — |
| Full lactate profile curve | — | ✓ | ✓ | ✓ | — |
| Substrate utilization · FatMax | — | — | ✓ | ✓ | — |
| Fueling strategy | — | — | ✓ | ✓ | — |
| Sweat sodium concentration | — | — | — | — | ✓ |
| Personalized training zones | ✓ | ✓ | ✓ | ✓ | — |
| Written report + consultation | ✓ | ✓ | ✓ | ✓ | ✓ |
| Blood draw required | No | Yes | Yes | Yes | No |
| Approx. session time | 1–2 hrs | 1.5–2 hrs | 2–2.5 hrs | 2–3 hrs | 45 min |
Why the CTS Performance Lab
Few Labs Do All Three
What sets the lab apart is not equipment alone — it's the integration of testing, interpretation, and coaching that few university labs or standalone testing services can offer.
01
Research-Grade Equipment
The Parvo Medics TrueOne 2400 metabolic cart — the same system used in university physiology labs, clinical settings, and Olympic performance environments.
Breath-by-breath resolution is required for accurate ventilatory threshold identification. There is no shortcut to that data.
02
Expert Interpretation
Scientific protocols provide a framework, but they can't account for you specifically: your training history, your baseline lactate, your response to altitude, the shape of your individual curve.
That's where experience matters. Your numbers reflect your physiology, not a population average.
03
Continuity, Test to Training
The physiologist who runs your test is the same person who interprets your data, writes your report, and delivers your consultation.
For CTS coached athletes, lab data connects directly to your training program — your results don't sit in a folder, they shape how you train.
Frequently Asked Questions
Before You Book
QTreadmill or bike?
Both are available. Choose the modality that matches your primary sport — treadmill for runners (most applicable zones), bike for cyclists (sport-specific economy and pacing). No clear preference? Choose whichever you're most comfortable with.
QHow long does each test take?
VO₂max Assessment: ~1–2 hours. Lactate Threshold: 1.5–2 hours. LT + Metabolic Profile: 2–2.5 hours. Integrated Performance Assessment: 2–3 hours. Sweat Test: ~45 minutes.
QWhen do I get my results?
Reports are typically delivered within a day or two of testing, followed by a video consultation to walk through everything together.
QDo I need to prepare?
Yes — you'll receive a pre-test protocol after scheduling. Arrive well-rested, avoid hard training in the 48 hours before, eat normally, and bring your training device if you want to calibrate zones in real time.
QVO₂max Assessment vs. Lactate Threshold Test?
The VO₂max Assessment uses a metabolic cart to measure oxygen consumption and identify ventilatory thresholds — no blood drawn. The Lactate Threshold Test uses serial blood sampling to identify metabolic thresholds directly. The methods are complementary; for both, consider the Integrated Performance Assessment.
QLT + Metabolic vs. Integrated Assessment?
Both identify lactate thresholds and provide substrate analysis. The Integrated Assessment adds measured VO₂max and ventilatory thresholds — letting the physiologist assess whether your limiter is aerobic capacity or threshold fitness. That distinction drives fundamentally different training directions.
QI'm a CTS coached athlete — how do I get my discount?
Active CTS coached athletes receive 10% off all lab testing. Mention your coaching relationship when you book and the discount will be applied to your session.
QWhere is the lab?
The CTS Performance Lab is based in Colorado Springs, Colorado — at altitude, which your physiologist accounts for when interpreting your results and building your zones. 1319 W Colorado Ave Colorado Springs, Colorado 80904
Colorado Springs · By Appointment
Book Your
Test Today.
Tell us your sport and your goal event and we'll get you on the calendar. CTS coached athletes — mention your coaching relationship for 10% off.
CTS Performance Lab
1319 W Colorado Ave
Colorado Springs, CO 80904