What Is Critical Velocity?
Critical Velocity (CV) is the pace you could sustain all-out for approximately 30 minutes. Tom Schwartz, the coach behind the Tinman method, defines it as 90% of your VO₂max velocity. For most recreational runners, this lands somewhere between 5K and 10K race pace – faster than threshold work, but not as brutal as traditional VO₂max intervals.
The distinction matters. Threshold pace (often called lactate threshold or tempo pace) is the fastest speed you can maintain in a metabolically steady state – typically around one-hour race effort. CV sits just above this boundary. You’re no longer in a pure steady state, but you’re not accumulating fatigue as rapidly as you would at true VO₂max pace.
Schwartz describes CV workouts as “somewhat hard” – you’re working, but you shouldn’t feel destroyed afterward. Most runners find they can complete a CV session and feel surprisingly fresh the next day, which is part of the method’s appeal. You’re getting high-quality aerobic development without the recovery cost of harder interval sessions.
How the Tinman Method Differs from Traditional Training
Most training systems emphasize lactate threshold as the key workout intensity. Jack Daniels’ VDOT tables, for example, center around “T pace” – the speed you can maintain for about an hour. The Tinman approach doesn’t abandon threshold training, but it elevates CV work to primary importance.
The physiological rationale involves Type IIa muscle fibers. These intermediate fibers sit between slow-twitch (endurance) and fast-twitch (power) fibers. They’re highly adaptable – train them anaerobically, and they function more like fast-twitch fibers. Train them aerobically at CV pace, and they become efficient oxygen consumers while still generating meaningful power.
Schwartz argues this adaptation is what allows distance runners to sustain faster paces for longer. Rather than simply raising the lactate threshold, CV training improves the aerobic capacity of the fibers that contribute to sustained speed. The result: you can cruise at what used to feel like tempo pace.
In Practice: A runner whose threshold pace is 7:00/mile might have a CV pace around 6:40-6:50/mile. This feels noticeably quicker than tempo runs, but recovery is surprisingly manageable when the workout structure follows Tinman guidelines.
CV Workout Structure
The classic CV session involves repetitions of 3-5 minutes (roughly 1000-1200m for sub-35-minute 10K runners, shorter for slower athletes) with minimal recovery. Schwartz typically prescribes recovery of one-third the rep duration – so a 3-minute rep gets 1 minute of recovery, or about 200m of easy jogging.
Total volume at CV pace in a single session should stay around 20-25 minutes maximum. Beginners start lower – perhaps 4 repetitions of 3 minutes – and build from there. Unlike traditional interval training where you might push toward exhaustion on each rep, CV work should feel controlled throughout. If you’re struggling to complete the final reps at pace, you’ve either run too fast or attempted too much volume.
The short recovery is intentional. It prevents full recovery between reps, maintaining an elevated aerobic demand throughout the session. But because the pace isn’t maximal, you’re not accumulating the same metabolic byproducts that make traditional intervals so taxing.
Sample CV Progressions
4-5 × 3:00 at CV with 1:00 jog recovery. Focus on finding the right effort – “comfortably hard” but sustainable. Total CV time: 12-15 minutes.
6-7 × 1000m at CV with 200m jog. Or 5 × 4:00 with 80 seconds recovery. Total CV time building toward 20 minutes.
8 × 1000m at CV with 200m jog, or mixed sessions like 4 × (1000m CV + 200m at mile pace). Total quality work: 20-25 minutes.
Your Training Zones
The calculator above derives all training paces from your vVO₂max – the velocity at which your body reaches maximum oxygen consumption. This is estimated from your race performance using established physiological relationships between race duration and sustainable intensity.
Recovery pace exists for genuine recovery – the day after a hard workout or race, or during extended cooldowns. It should feel almost awkwardly slow. If you’re questioning whether you’re going slow enough, you probably are.
Easy pace is where most of your weekly mileage should occur. Conversational pace, aerobic base building, the bread and butter of distance training. Many runners chronically run their easy days too fast, compromising recovery and limiting the quality of hard sessions.
Steady state approximates marathon effort for most runners – comfortable but purposeful. Useful for progression long runs or moderate aerobic development sessions. Not recovery, but not quality work either.
Threshold is the fastest pace you can sustain in metabolic equilibrium – around one-hour race effort. Traditional tempo runs target this zone. Expect to be able to speak in short sentences but not hold extended conversations.
CV sits above threshold – the Tinman cornerstone. Thirty-minute race pace, 90% of vVO₂max. The pace that develops aerobic capacity in your intermediate muscle fibers without excessive recovery cost.
Aerobic Power targets intensities around 15-minute race pace – traditional VO₂max interval territory. Hard efforts with substantial recovery needs.
Rep/Speed covers mile pace and faster – neuromuscular work, running economy, and leg speed development. Short repetitions with full recovery.
Weekly Training Integration
Most runners benefit from one or two quality sessions per week featuring CV work. A typical structure might look like:
Easy run + strides
CV workout: 6 × 1000m with 200m jog
Easy run or cross-training
Moderate run or second easy day
Speed work: 8 × 200m with full recovery
Easy/recovery
Long run (easy to steady state)
The key insight from Tinman methodology is that you can train at high quality (CV) more frequently than at traditional VO₂max intensities because recovery demands are lower. Some athletes run CV sessions twice weekly with good results, though this requires attention to cumulative fatigue and adequate easy running between efforts.
When to Update Your Paces
Training paces should be based on current fitness, not goal times. If you’re coming back from injury or time off, use a recent conservative effort to set paces rather than optimistic projections. Running CV workouts too fast defeats the purpose – you’ll accumulate more fatigue and get less aerobic development.
Recalculate your training paces every 4-8 weeks during a build phase, or after any race performance that suggests fitness has shifted. A successful training block should show gradual improvement in race times, allowing modest pace adjustments. If paces feel harder than expected, the input race time may have been too optimistic.
Environmental conditions matter significantly. Hot, humid days, altitude, and strong winds all affect pace sustainability. On challenging days, prioritize the effort level over hitting exact splits. CV should feel “comfortably hard” regardless of what the watch says.
Common Mistakes
Running CV too fast. If your CV sessions leave you as tired as traditional VO₂max workouts, you’re defeating the purpose. The pace should feel like you could go faster if racing, but you’re deliberately holding back. Schwartz uses the phrase “optimal training, not hard training.”
Too much recovery between reps. Long recoveries turn CV work into something resembling traditional intervals. Keep recoveries short – around one-third of rep time or 200m jog – to maintain the intended training stimulus.
Ignoring easy days. CV’s lower recovery cost makes it tempting to add intensity throughout the week. Resist this. The easy days allow adaptation to occur. Running them too fast compromises the quality of your CV sessions and increases injury risk.
Excessive CV volume. More isn’t always better. Keeping total CV time under 25 minutes per session prevents the workout from drifting into excessive fatigue. Quality matters more than quantity at this intensity.
Who Benefits from Tinman Training
The method works across ability levels, from recreational runners to elite athletes. Drew Hunter, one of America’s top distance runners, trained under Schwartz using CV-focused workouts. High school runners under Tinman’s guidance have posted nationally competitive times.
Runners who struggle with the recovery demands of traditional interval training often find CV work more sustainable. The lower per-session fatigue allows more consistent training quality across weeks and months. This consistency – rather than occasional heroic workouts – tends to produce long-term improvement.
CV training particularly benefits 5K through half marathon racers. These events demand the exact physiological qualities that CV work develops: sustained speed above threshold with manageable fatigue. Marathon runners may use CV less frequently, but it still has a place in developing pace control and race-specific fitness during shorter phases of training.
Calculator Accuracy Notes
This calculator estimates vVO₂max from race performance using established exercise physiology relationships. The accuracy depends on how representative your input race was of current fitness. A 5K time trial under good conditions provides a reliable baseline. A marathon PR from two years ago may not reflect where you are now.
Race equivalents are estimates based on typical endurance-to-speed ratios. Individual variation exists – some runners have exceptional speed relative to their endurance, others the reverse. If your calculated paces feel significantly off, trust perceived effort over calculated splits, and consider using a different race distance as your input.
For best results, use a race or time trial from the past 4-8 weeks run under conditions where you could genuinely compete. Training runs, even hard ones, typically underestimate fitness because they lack the race-day adrenaline and focus that produces peak performances.