Week 13: Building Peak Endurance (September 13-19, 2025)
Welcome to Week 13! You’re now in the peak phase of your marathon training. This week features your longest run yet—18 miles—which will build both physical and mental endurance critical for marathon success. You’ve come a long way from those first run/walk intervals, and your body has adapted remarkably to handle these longer distances.
Week 13 Goals
- Complete your longest training run (18 miles)
- Perfect your fueling and hydration strategy for long efforts
- Focus on maintaining good form even when fatigued
- Build mental toughness for late-race scenarios
Daily Workout Schedule
Monday: Rest Day
Complete rest day after your previous week’s long run. Focus on recovery, hydration, and getting your nutrition back on track after that major effort. Consider a light stretching session or gentle foam rolling if you have persistent soreness.
Tuesday: Easy Run
Total Distance: 5 miles
- 5 minutes very easy jogging
- 5 minutes dynamic stretching:
- Walking lunges with rotation (10 each side)
- Leg swings (10 each leg, forward/back and side to side)
- Arm circles (10 forward, 10 backward)
- High knees and butt kicks (30 seconds each)
- Run at an easy, conversational pace for 5 miles
- Focus on relaxed, comfortable breathing
- Keep your effort level very controlled (perceived exertion 4-5 out of 10)
- This is a recovery run – resist the urge to push the pace
- Very easy walk for 2 minutes
- Static stretching for 3 minutes:
- Calf stretch (30 seconds each leg)
- Quadriceps stretch (30 seconds each leg)
- Hamstring stretch (30 seconds each leg)
- Hip flexor stretch (30 seconds each leg)
Wednesday: Cross-Training
Duration: 45-60 minutes
- 45-60 minutes moderate cycling with 3 x 5-minute tempo efforts
- Structure:
- 10 minutes easy warm-up
- 5 minutes moderate-hard effort
- 5 minutes easy recovery
- 5 minutes moderate-hard effort
- 5 minutes easy recovery
- 5 minutes moderate-hard effort
- 10-25 minutes easy cool-down
- 45-60 minutes swimming with intervals
- Structure:
- 10 minutes easy warm-up
- 5 x 100m at moderate-hard effort with 30-second rest
- 5 minutes easy recovery
- 5 x 50m at hard effort with 20-second rest
- 10 minutes easy cool-down
- 50-60 minutes focusing on marathon-specific strength:
- 3-4 sets of 12-15 bodyweight squats or goblet squats
- 3-4 sets of 10-12 walking lunges (each leg)
- 3-4 sets of 8-10 single-leg deadlifts (each leg)
- 3-4 sets of 30-45 second planks
- 3-4 sets of 10-12 glute bridges
- 3-4 sets of 8-10 step-ups (each leg)
- Core routine: dead bugs, side planks, bird dogs
- Rest 45-60 seconds between sets
Thursday: Tempo Run
Total Distance: 8 miles
- Very easy jogging for 1.5 miles
- Include dynamic stretches after the first mile
- Run 5 miles at tempo pace (comfortably hard pace you could maintain for an hour)
- This should feel challenging but sustainable
- Focus on maintaining even effort throughout
- Target effort level: 7-8 out of 10
- Very easy jogging/walking for 1.5 miles
- Complete with thorough static stretching
Friday: Rest Day
Complete rest day to prepare for your longest run yet. Focus on hydration and nutrition today. Begin carbohydrate loading by increasing your carb intake moderately. Aim for at least 8 hours of quality sleep tonight to prepare for tomorrow’s challenge.
Saturday: Long Run
Total Distance: 18 miles
- Eat a carbohydrate-rich meal 2-3 hours before
- Plan your route with water/aid stations or carry sufficient hydration
- Bring energy gels/chews (1 per 45 minutes)
- Apply anti-chafing products to potential hot spots
- 5 minutes easy walking
- 5-10 minutes very easy jogging
- Dynamic stretches
- Start at a very comfortable, conversational pace
- Run 1-2 minutes per mile slower than your goal marathon pace
- Take brief walking breaks (1-2 minutes) every 4-5 miles if needed
- Hydrate every 20 minutes (approx. 4-6 oz)
- Consume energy gel/chews every 45 minutes
- Focus on maintaining good form even when fatigued
- Practice positive self-talk through difficult sections
- Walk for 10-15 minutes
- Complete gentle stretching once you’re home
- Focus on rehydration and refueling within 30 minutes
- Consider an ice bath or contrast therapy for recovery
Sunday: Active Recovery
30-45 minutes very easy walking
30-40 minutes gentle yoga focusing on recovery
20-30 minutes light swimming or water walking
The goal today is to promote recovery without adding training stress. Focus on hydration, nutrition, and gentle movement to reduce soreness.
Tips for Week 13
Mental Strategies for Long Runs
Your 18-mile run will test your mental strength:
- Break the distance into smaller segments (6 x 3 miles)
- Create a mantra to repeat when things get tough
- Practice visualization techniques during challenging moments
- Focus only on the current mile, not the total distance
- Use the power of “just one more” (one more mile, one more minute)
- Dedicate miles to supportive people in your life
Recovery After Your Longest Run
Proper recovery after 18 miles is crucial:
- Consume carbs and protein within 30 minutes (3:1 ratio)
- Rehydrate with electrolytes (16-24oz for every pound lost)
- Take a cold/ice bath (10-15 minutes) if possible
- Elevate your legs for 10-15 minutes
- Use compression socks/sleeves for 1-3 hours
- Get extra sleep the night following your long run
- Monitor for any unusual pain that persists beyond normal soreness