How to Reach 4 W/kg FTP
4 W/kg has become a milestone in the cycling community – a marker of “serious” fitness that opens up new terrain and group ride possibilities. But is it realistic for someone with a job, family, and limited training time?
The answer is yes – with the right approach. This guide is based on current sports science, including research from Stephen Seiler on polarized training and the importance of low-intensity volume. For a deeper dive, see Polarized vs Pyramidal vs Sweet Spot.
KEY INSIGHT
Research shows that 80% of elite endurance athletes' training is done at low intensity (Zone 1-2). Recreational cyclists often do the opposite – too much medium intensity, not enough easy or hard. Fixing this distribution is often the fastest path to improvement.
🔢 What does 4 W/kg mean in practice?
Your power-to-weight ratio is simply FTP ÷ body weight:
| Weight | FTP needed for 4 W/kg |
|---|---|
| 60 kg | 240 W |
| 70 kg | 280 W |
| 75 kg | 300 W |
| 80 kg | 320 W |
| 85 kg | 340 W |
Use our FTP Calculator to see your current W/kg and training zones. If you want to explore the full toolkit, see all calculators.
PERSPECTIVE
4 W/kg puts you in approximately the top 10-15% of recreational cyclists. It's achievable for most healthy adults with 1-3 years of consistent training, but genetics, age, and training history all play a role.
📊 The science of training distribution
Research by Seiler (2010) and others has shown that elite endurance athletes typically follow a polarized training distribution. If you want to compare models, read Polarized vs Pyramidal vs Sweet Spot:
The 80/20 principle:
- ~80% low intensity (Zone 1-2, easy conversation possible)
- ~20% high intensity (Zone 4-5, hard to very hard)
- Minimize Zone 3 (“grey zone” – too hard to recover from, too easy to stimulate adaptation)
IMPORTANT CONTEXT
The polarized training research was conducted on athletes training 15-25+ hours per week. At high volumes, Zone 3 work accumulates excessive fatigue without proportional benefit. But for recreational cyclists training 5-10 hours per week, the equation is different.
When does polarized (80/20) make sense?
| Weekly volume | Recommended approach |
|---|---|
| 12+ hours | Polarized (80/20) works well – plenty of Z2 volume to build base |
| 8-12 hours | Hybrid approach – mostly polarized with some sweet spot |
| 5-8 hours | Sweet spot emphasis – maximizes limited training time |
| Under 5 hours | Focus on consistency; any structured training helps |
The case for sweet spot at lower volumes
When you can only train 5-8 hours per week:
- You can’t accumulate enough Z2 volume to fully develop your aerobic base
- Sweet spot (88-94% FTP) provides strong aerobic stimulus in less time
- Recovery cost is manageable with 48+ hours between hard sessions
- The “grey zone” problem is less relevant because total training load is lower
Bottom line: If you’re training 10+ hours weekly, lean toward polarized. Under 8 hours, sweet spot becomes your friend. See our Sweet Spot Training Guide for a complete program.
💡 The four key principles
1. Build your aerobic base first
Zone 2 training develops:
- Mitochondrial density – more cellular powerhouses
- Capillarization – better oxygen delivery to muscles
- Fat oxidation – improved fuel efficiency
- Cardiac output – stronger, more efficient heart
For time-crunched athletes, aim for 4-6 hours per week of Zone 2. More is better, but consistency matters more than volume.
2. Make hard days hard, easy days easy
The biggest mistake recreational cyclists make is riding at “medium” intensity too often. This:
- Creates too much fatigue to recover properly
- Isn’t hard enough to drive significant adaptation
- Erodes your aerobic base over time
Solution: Keep easy rides truly easy (Zone 1-2, able to hold a conversation), and make quality sessions properly challenging.
3. 1-2 high-intensity sessions per week is optimal
Research shows diminishing returns beyond 2 high-intensity sessions per week for most athletes. Quality over quantity.
Session: Threshold intervals (3×10 min)
- Warm-up: 15-20 min progressive
- Work: 3×10 min at 95-105% FTP
- Recovery: 5 min easy spinning between intervals
- Cool-down: 10 min easy
- Goal: Steady power, controlled breathing, finish feeling like you could do one more
Session: VO₂max intervals (5×4 min)
- Warm-up: 15-20 min with 2-3 short openers
- Work: 5×4 min at 106-120% FTP
- Recovery: 4 min easy spinning between intervals
- Cool-down: 10 min easy
- Goal: Breathing hard but controlled. RPE 8-9/10. Should feel difficult but completable.
4. Prioritize recovery and consistency
Adaptations happen during recovery, not during training. Sleep, nutrition, and stress management are as important as the training itself.
WARNING SIGNS OF OVERTRAINING
Elevated resting heart rate, poor sleep, persistent fatigue, decreased motivation, getting sick frequently, declining performance despite training. If you notice these, take extra rest days.
📅 Sample Training Weeks
Here are two practical weekly structures based on available training time. Choose the one that fits your life.
Option A: Time-Crunched (5-7 hours/week) – Sweet Spot Focus
Best for riders who can only train 5-7 hours. Maximizes adaptation with limited time.
| Day | Session | Duration | Intensity |
|---|---|---|---|
| Monday | Rest | - | - |
| Tuesday | Sweet Spot (2×20 min) | 60-75 min | 88-94% FTP |
| Wednesday | Easy spin or rest | 0-45 min | Z1-Z2 |
| Thursday | VO₂max intervals (4×4 min) | 60 min | 106-120% FTP |
| Friday | Rest | - | - |
| Saturday | Long endurance ride | 2-2.5 hours | Z2 |
| Sunday | Easy recovery or rest | 0-45 min | Z1 |
Weekly totals: ~5-7 hours, 2 quality sessions
WHY SWEET SPOT HERE?
At this volume, you can't accumulate enough Z2 time to fully develop your aerobic base. Sweet spot gives you more training stimulus per hour, making it ideal for time-crunched schedules.
Option B: More Available Time (8-12 hours/week) – Polarized Focus
Best for riders who can train 8+ hours. Follows the 80/20 polarized distribution.
| Day | Session | Duration | Intensity |
|---|---|---|---|
| Monday | Rest or easy spin | 0-45 min | Z1 |
| Tuesday | Threshold intervals (3×10 min) | 75 min | 95-105% FTP |
| Wednesday | Easy endurance | 75-90 min | Z2 |
| Thursday | VO₂max intervals (5×4 min) | 60-75 min | 106-120% FTP |
| Friday | Rest | - | - |
| Saturday | Long ride | 3-4 hours | Z2 |
| Sunday | Easy endurance | 60-90 min | Z1-Z2 |
Weekly totals: ~8-12 hours, 2 quality sessions, ~80% low intensity
THE 80/20 ADVANTAGE
With more volume, you can build a proper aerobic base through Z2 riding. The two hard sessions provide the high-intensity stimulus, while easy volume does the heavy lifting for mitochondrial development.
Key principles for both approaches
- Never do hard sessions on consecutive days – minimum 48 hours between intensity
- Easy means easy – Z1/Z2, conversation pace, don’t let ego push you harder
- Be flexible – swap days as needed, but protect your quality sessions
- Listen to fatigue – if you’re exhausted, convert a hard day to easy
⚙️ Use the tools on this site
- FTP Calculator – Get your zones dialed in correctly
- Climb Time Calculator – See how W/kg improvements translate to faster climbs
- Nutrition Calculator – Fuel your training properly
📈 What to expect over time
With consistent training following these principles:
| Timeline | Expected changes |
|---|---|
| 4-6 weeks | Lower heart rate at same power, better recovery between sessions |
| 8-12 weeks | Measurable FTP increase (typically 3-8%), improved endurance |
| 6 months | Significant fitness gains, approaching or reaching goal |
| 1-2 years | Full potential realization with continued consistency |
🔬 References
- Seiler, S. (2010). What is best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance
- Stöggl, T. & Sperlich, B. (2014). Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training. Frontiers in Physiology
- Munoz, I. et al. (2014). Does polarized training improve performance in recreational runners? International Journal of Sports Physiology and Performance