Lactate Threshold Testing in Santa Cruz

Traditional lactate threshold testing requires multiple finger-prick blood samples every few minutes during exercise. We determine threshold through ventilatory analysis during VO₂ max testing-no blood draws required:

• Ventilatory Threshold 2 (VT2): As you exercise and we increase intensity every minute, we continuously analyze your breathing. VT2 occurs when ventilation increases disproportionately to oxygen consumption-this correlates extremely closely with lactate threshold (r = 0.95+ correlation)
• Respiratory Exchange Ratio (RER): The ratio of CO₂ produced to O₂ consumed. At threshold, RER reaches ~1.0 as CO₂ production spikes (buffering lactate)
• Breathing Frequency and Depth: Distinct break point in breathing pattern visible on breath-by-breath analysis
• Heart Rate at Threshold: Captured precisely at the moment VT2 occurs-this is YOUR threshold heart rate, not a formula
• Pace/Power at Threshold: Running pace or cycling watts at threshold moment gives you exact threshold training target

Accuracy: Ventilatory threshold determination has 95%+ accuracy compared to blood lactate testing, making it the gold standard for threshold identification without invasive procedures.

Your VO₂ max test actually reveals TWO critical thresholds:

• VT1 (First Ventilatory Threshold / Aerobic Threshold):
  • • Occurs at ~65 to 75% VO₂ max
  • • Marks transition from Zone 1 to Zone 2
  • • Below VT1: purely aerobic metabolism, fat burning dominant, can talk easily
  • • At VT1: lactate begins to rise slightly but clears easily
  • • Defines upper limit of "easy" training for base building
• VT2 (Second Ventilatory Threshold / Lactate Threshold / Anaerobic Threshold):
  • • Occurs at ~80 to 92% VO₂ max
  • • The classic "threshold" everyone talks about
  • • Above VT2: lactate accumulation, heavy breathing, unsustainable for long
  • • This is your tempo pace, FTP, threshold heart rate
  • • Most important zone for improving endurance performance

Our Testing Identifies Both: You leave knowing VT1 (easy/base training ceiling) and VT2 (threshold for tempo work), giving you complete picture of training zones.

Your lactate threshold determines your tempo pace-the cornerstone of marathon and distance running training:

• Tempo Pace Definition: The pace you can sustain for 40 to 60 minutes at "comfortably hard" effort. This is your threshold pace
• Typical Tempo Pace:
  • • 10 to 30 seconds per mile slower than 5K race pace
  • • 15 to 20 seconds per mile faster than half marathon pace
  • • 25 to 35 seconds per mile faster than marathon pace
  • • But these are generalizations-YOUR test reveals YOUR exact threshold pace
• Testing Protocol: Treadmill test with pace increasing every minute. We identify the exact pace where VT2 occurs. This becomes your tempo pace training target
• Example Tempo Paces by Level:
  • • Sub-3:00 marathoner: Tempo pace ~6:30 to 6:50/mile
  • • Sub-3:30 marathoner: Tempo pace ~7:15 to 7:35/mile
  • • Sub-4:00 marathoner: Tempo pace ~8:00 to 8:20/mile
  • • Sub-4:30 marathoner: Tempo pace ~8:45 to 9:05/mile
• Training Applications:
  • • Classic tempo runs: 20 to 40 minutes continuous at threshold pace
  • • Cruise intervals: 3 to 5 × 1 to 2 miles at tempo with 1 minute rest
  • • Marathon pace runs: Slightly below threshold (95 to 98% of tempo pace)
  • • Long runs with tempo finish: Last 3 to 6 miles at tempo

Your lactate threshold determines your FTP-the foundation of all cycling training zones:

• FTP Definition: Functional Threshold Power-the maximum average power (watts) you can sustain for approximately one hour. This is your threshold power
• Testing on Wahoo KICKR Bike: We test on our Wahoo KICKR Bike smart trainer with power measurement. Intensity (watts) increases every minute. We identify exact wattage where VT2 occurs-this is your FTP
• Why Lab-Tested FTP is Better Than Field Tests:
  • • Standard FTP test (20-minute all-out × 0.95) is brutal and relies on pacing perfection
  • • Ramp test (popular on Zwift) estimates FTP but is not actual threshold measurement
  • • Lab test identifies physiological threshold precisely without guesswork
  • • No need to "bury yourself" in maximal 20-minute effort
  • • Controlled environment eliminates weather, traffic, course variables
• Power Zones from FTP:
  • • Zone 1 (Active Recovery): Below 55% FTP
  • • Zone 2 (Endurance): 56 to 75% FTP
  • • Zone 3 (Tempo): 76 to 90% FTP
  • • Zone 4 (Threshold): 91 to 105% FTP-sweet spot is 88 to 93%
  • • Zone 5 (VO₂ Max): 106 to 120% FTP
  • • Zone 6 (Anaerobic): 121 to 150% FTP
  • • Zone 7 (Neuromuscular): 150%+ FTP
• Training with FTP:
  • • Sweet spot intervals: 88 to 93% FTP for 10 to 20 minutes
  • • Threshold intervals: 95 to 105% FTP for 8 to 12 minutes
  • • Over-unders: Alternate between 95% and 105% FTP
  • • Long climbs/time trials: Hold steady at 95 to 100% FTP

Why elite coaches emphasize threshold training above all other intensities:

• Highest Training Impact: Threshold work provides the greatest improvement in race performance per minute of training. More effective than easy running or VO₂ max intervals for most endurance events
• Raises the Ceiling: Improving threshold means you can sustain faster paces for longer. A runner with 40 VO₂ max but 90% threshold will beat runner with 50 VO₂ max but 75% threshold in marathon
• Highly Trainable: Threshold can improve 10 to 20% with focused training. VO₂ max only improves 5 to 10% and plateaus faster
• Physiological Adaptations from Threshold Training:
  • • Increased lactate clearance capacity (more MCT1/MCT4 transporters)
  • • Enhanced buffering capacity (resist pH drop)
  • • Greater mitochondrial density and enzyme activity
  • • Improved lactate shuttle (muscles use lactate as fuel)
  • • Increased capillary density for better oxygen delivery
  • • Cardiovascular adaptations (stroke volume, cardiac output)
• Optimal Training Frequency: 1 to 2 threshold sessions per week during build phase. More than this risks overtraining; less provides insufficient stimulus
• Time at Threshold Per Session: 20 to 40 minutes total time at threshold (can be continuous or broken into intervals with short rests)

The relationship between these two key metrics:

• VO₂ Max: Maximum oxygen consumption. Sets your absolute ceiling. Largely genetic (60 to 80% heritable). Improves with training but plateaus relatively quickly
• Lactate Threshold: Percentage of VO₂ max you can sustain. Determines race pace. Highly trainable. Continues improving for years with proper training
• Performance Equation: Endurance Performance = VO₂ max × Lactate Threshold % × Running/Cycling Economy
• Real-World Example:
  • • Athlete A: VO₂ max 60 mL/kg/min, Threshold at 75% = Race pace at 45 mL/kg/min
  • • Athlete B: VO₂ max 50 mL/kg/min, Threshold at 90% = Race pace at 45 mL/kg/min
  • • Result: Similar race performance despite 20% difference in VO₂ max!
• Training Focus: Beginners can improve both simultaneously. Advanced athletes with high VO₂ max focus more on threshold. Elite athletes spend 60 to 70% of quality training at or near threshold

Popular training methods built around threshold work:

• Pfitzinger Marathon Training: LT tempos are cornerstone workout. 5 to 8 miles with 3 to 5 miles at threshold pace. Testing provides exact LT pace for these critical sessions
• Jack Daniels "T Pace": Threshold pace is one of five key intensities. Typically 15 to 20 minute continuous runs or cruise intervals. Testing reveals YOUR true T pace
• Hanson's Marathon Method: Three quality days per week include threshold work. "Something of Substance" days often at LT. Precise threshold essential for cumulative fatigue approach
• Cycling Training: Sweet spot and threshold intervals dominate build phase. FTP from testing guides all power-based training
• FIRST Marathon Training (Run Less, Run Faster): Tempo runs at threshold are one of three weekly key runs. Exact pace critical for this low-volume, high-intensity approach

Threshold is the most trainable performance variable:

• Typical Improvements: Beginners can raise threshold 15 to 20% in 12 to 16 weeks. Intermediate athletes: 5 to 10%. Advanced: 2 to 5% (but from higher baseline)
• Best Training Methods:
  • • Continuous tempo runs: 20 to 40 minutes at threshold
  • • Cruise intervals: 3 to 5 × 1 to 2 miles (or 8 to 12 min) with 60 to 90 sec rest
  • • Sweet spot intervals (cycling): 2 to 3 × 10 to 20 min at 88 to 93% FTP
  • • Long runs with threshold finish: Last 20 to 30% of long run at threshold
  • • Threshold hill repeats: 6 to 10 min climbs at threshold effort
• Training Volume: 8 to 12 weeks of consistent threshold work (1 to 2 sessions per week) needed for measurable improvement. Then retest to update zones
• Aerobic Base Required: Must build solid Zone 2 base before adding threshold work. 8 to 12 weeks base building first
• Recovery Needs: Threshold work is demanding. Need 48 to 72 hours between threshold sessions. Keep other days easy (Zone 1 to 2)

What to expect based on training history:

• Beginners/Recreational (2 to 3 years training):
  • • Threshold typically 70 to 80% of VO₂ max
  • • Large room for improvement with threshold training
  • • May initially struggle to sustain threshold for 20 minutes
• Intermediate (3 to 7 years consistent training):
  • • Threshold 80 to 85% of VO₂ max
  • • Can sustain threshold 30 to 45 minutes
  • • Threshold work should be 15 to 20% of total training
• Advanced (7+ years, competitive):
  • • Threshold 85 to 92% of VO₂ max
  • • Can sustain threshold 50 to 60 minutes or longer
  • • Threshold work may be 20 to 25% of training
• Elite:
  • • Threshold often 90 to 95% of VO₂ max
  • • Can run entire marathon at or near threshold
  • • Threshold highly developed, focus shifts to maintaining while working VO₂ max and economy

Errors athletes make without proper threshold testing:

• Training Too Hard: Running tempo runs at 10K pace instead of threshold pace. This is VO₂ max work, not threshold. Cannot sustain proper duration, reduces training effect
• Training Too Easy: Tempo runs that are actually marathon pace or slower. Insufficient stimulus to raise threshold
• Using Generic Formulas: "220-age × 0.90" or similar formulas for threshold HR. Can be off by 15 to 20 beats per minute
• Inadequate Recovery: Threshold sessions too frequent (3+ per week). Leads to chronic fatigue, no adaptation
• Insufficient Duration: Threshold intervals too short (5 min or less). Need 8 to 20 minute efforts to drive adaptation
• Not Retesting: Using same threshold pace for years. As fitness improves, threshold shifts. Retest every 8 to 12 weeks during build

How threshold determines race strategy:

• 5K Race: Above threshold (102 to 108% of threshold pace). Can sustain 15 to 25 minutes before lactate forces slowdown
• 10K Race: Right at threshold (98 to 102%). Classic threshold race distance
• 15K to Half Marathon: Slightly below threshold (95 to 98%). Extended threshold effort
• Marathon: 85 to 90% of threshold pace. Should feel "comfortably moderate" not "comfortably hard"
• Ultramarathon: 70 to 80% of threshold pace. Well below threshold for multi-hour sustainability
• Time Trial (Cycling): 95 to 100% FTP for 40K TT. 90 to 95% FTP for longer events

VO₂ Max Test (includes threshold determination): $250

What's Included:

• • Complete VO₂ max assessment
• • VT1 (aerobic threshold) identification
• • VT2 (lactate threshold) identification
• • Threshold heart rate
• • Threshold pace (running) or FTP (cycling)
• • All five training zones based on your thresholds
• • Same-day results with detailed explanation
• • Training recommendations specific to threshold work

Retesting Schedule: Every 8 to 12 weeks during training build to update threshold as fitness improves. Annual testing minimum for recreational athletes.

VO₂ Max Test: $250

Complete lactate threshold testing with VT1, VT2, threshold heart rate, and all training zones.

Fit Evaluations
311 Soquel Ave
Santa Cruz, CA 95062

Behind Hindquarter restaurant (second entrance off Dakota St.)

Phone: 831-400-9227
Email: info@fitevals.com