Pravidlo tréninku 80/20: Tajemství rychlejšího běhu

What is the 80/20 Training Rule?

The 80/20 training rule states that runners should do approximately 80% of their training at low intensity (easy pace, Zone 1-2) and 20% at moderate to high intensity (Zone 3-5). This principle, backed by decades of research and practiced by elite runners worldwide, optimizes aerobic development while allowing recovery from hard efforts.

The 80/20 rule contradicts the instinct many runners have to run "comfortably hard" most days. Instead, it advocates polarizing training: run very easy most of the time, save true hard efforts for specific workouts.

The Science Behind 80/20 Training

Research Evidence

Dr. Stephen Seiler's groundbreaking research analyzing elite endurance athletes across multiple sports (running, cycling, cross-country skiing, rowing) found a consistent pattern: the best athletes in the world do 75-85% of training at low intensity.

Key research findings:

• Elite runners train 80-90% below lactate threshold (Zone 1-2)
• Recreational runners who adopt 80/20 improve more than those doing 50/50 or 70/30 splits
• High-volume, low-intensity training produces greater VO2max improvements than moderate-intensity training
• Injury rates decrease 30-40% when following 80/20 vs. higher intensity distributions

Physiological Adaptations

Easy running (Zone 2) creates specific adaptations that improve performance:

• Mitochondrial biogenesis: More "powerhouses" in muscle cells for energy production
• Capillary density: Enhanced oxygen delivery to working muscles
• Fat oxidation: Improved ability to burn fat, sparing glycogen for hard efforts
• Aerobic enzymes: Increased production of enzymes that support aerobic metabolism
• Stroke volume: Heart pumps more blood per beat (cardiac efficiency)
• Running economy: Better efficiency at all paces

These adaptations occur primarily during easy running. Moderate-intensity running (Zone 3) provides insufficient stimulus for maximal adaptation while accumulating too much fatigue.

The "Gray Zone" Problem

Most recreational runners violate 80/20 by running too much in Zone 3—the "gray zone" or "no man's land":

• Too hard: To maximize aerobic adaptations
• Too easy: To provide high-quality training stimulus
• High fatigue: Accumulates fatigue that compromises quality workouts
• Poor recovery: Doesn't allow proper recovery between hard sessions

The solution: polarize your training. Make easy days truly easy (conversational pace, Zone 2) and hard days truly hard (threshold runs, VO2max intervals, Zone 4-5).

How to Implement 80/20 Training

Step 1: Determine Your Training Zones

Accurate training zones are essential. Use one of these methods:

• Lab testing: Most accurate—provides precise heart rate and pace zones
• Field tests: 30-minute time trial for threshold pace/HR, then calculate zones
• Heart rate formulas: Less accurate but better than nothing
• Talk test: Easy pace = can speak full sentences comfortably

Run Analytics calculates personalized zones from your running data and Critical Running Speed analysis.

Step 2: Calculate Your 80/20 Distribution

Track training time (or distance) by zone:

Example: 50 miles per week

• 80% easy (Zone 1-2): 40 miles at conversational pace
• 20% moderate-hard (Zone 3-5): 10 miles at tempo or faster

Example weekly schedule:

• Monday: Rest
• Tuesday: 8 miles easy (Zone 2) = 8 easy miles
• Wednesday: 10 miles total with 6 miles tempo (Zone 4) = 4 easy + 6 hard
• Thursday: 6 miles easy (Zone 2) = 6 easy miles
• Friday: Rest or 4 miles easy = 4 easy miles
• Saturday: 8 miles easy (Zone 2) = 8 easy miles
• Sunday: 14 miles long run (Zone 2) = 14 easy miles

Total: 40 easy miles (80%) + 6 hard miles (12%) + rest = slightly conservative 80/20

Step 3: Adjust Intensity on Easy Days

The hardest part of 80/20 is running truly easy. Most runners need to slow down significantly:

• Common mistake: Easy pace feels too slow, so runners speed up
• Reality: Easy pace should feel almost boringly easy
• Guideline: Slow 30-90 seconds per mile from what feels "comfortable"
• Ego check: Your easy pace doesn't need to impress anyone

Indicators you're running truly easy (Zone 2):

• Can speak full sentences comfortably
• Breathing is relaxed and rhythmic
• Could maintain pace for 2+ hours
• Heart rate stays in Zone 2 range (doesn't creep up)
• Recovery is quick—ready for next run within 24 hours

Step 4: Make Hard Days Truly Hard

The 20% hard running should be quality work:

• Threshold runs: 20-40 min at comfortably hard pace (Zone 4)
• VO2max intervals: 3-5 min repeats at 5K pace or faster (Zone 5)
• Tempo intervals: 8-10 min repeats at threshold pace with short recovery
• Long runs with fast finish: Last 20-30 min at marathon pace or faster

Schedule 2-3 quality sessions per week maximum. More hard sessions violate 80/20 and compromise recovery.

Step 5: Monitor and Adjust

Track your intensity distribution weekly:

• Use training log or app to calculate time/distance in each zone
• Aim for 75-85% easy (some flexibility week to week)
• If consistently above 30% hard, reduce intensity or frequency of workouts
• If below 10% hard, add one quality session per week

Training Stress Score (TSS) and CTL/ATL/TSB metrics help monitor training load and ensure proper balance.

Sample 80/20 Training Weeks

Beginner/Intermediate (30 miles per week)

Advanced (60 miles per week)

Key observations:

• Even in weeks with 3 quality sessions, easy mileage dominates (75-85%)
• Recovery runs are truly easy—no "moderate" effort runs
• Quality sessions are genuinely hard—threshold or faster
• Long runs mostly easy with optional fast finish

80/20 vs. Other Training Approaches

Why 80/20 Beats Other Approaches

• Research-backed: Decades of studies support 80/20 effectiveness
• Elite validation: World-class runners follow 80/20 or more extreme (85/15)
• Injury prevention: Significantly lower injury rates than threshold-heavy training
• Sustainable: Can maintain 80/20 for years without burnout
• Adaptable: Works across all distances from 5K to ultra-marathon

Common 80/20 Training Mistakes

1. Running Easy Days Too Hard

Problem: "Easy" runs at Zone 3 pace (gray zone)

Solution: Slow down 30-60 seconds per mile. Use heart rate monitor to stay accountable. Practice true conversational pace.

2. Not Running Hard Enough on Hard Days

Problem: Quality sessions at moderate effort, not true threshold or VO2max pace

Solution: Make hard days count. Threshold runs should feel "comfortably hard," VO2max intervals should hurt.

3. Too Many Hard Days

Problem: 4-5 quality sessions per week violates 80/20

Solution: Limit to 2-3 quality sessions per week maximum. More isn't better.

4. Ignoring Weekly Distribution

Problem: Not tracking time/distance in each zone

Solution: Log every run by zone. Calculate weekly percentage. Adjust if consistently outside 75-85% easy.

5. Inappropriate Intensity During Base Building

Problem: Adding too much intensity during aerobic base phase

Solution: During base building, aim for 85-90% easy with minimal hard work (strides only).

80/20 Across Training Phases

80/20 distribution varies slightly across periodization phases:

Overall training cycle should average 75-85% easy. Individual weeks may vary but shouldn't consistently exceed 30% hard.

Tracking Your 80/20 Compliance

Run Analytics automatically tracks time in each training zone, showing whether you're following 80/20 principles:

• Weekly zone distribution: See percentage of training in Zone 1-5
• Trend analysis: Track intensity distribution over months
• Training load metrics: CTL/ATL/TSB ensure proper progression
• Recovery monitoring: Identify overtraining before it becomes injury
• Privacy-first: All analysis on your device—no cloud uploads

Manual Tracking Method

If tracking manually, use this simple log:

Frequently Asked Questions About 80/20 Training

Related Resources

• Training Zones and Intensity Guide
• Base Building Phase Complete Guide
• Marathon Periodization Strategies
• Training Load Management
• Running Performance Metrics
• Privacy-First Analytics