Training without zones is like cooking without a recipe—you might get lucky, but you're mostly guessing. Training zones give you a framework for hitting the right intensity every time, whether you're doing an easy recovery ride or a hard interval session.
This guide will walk you through setting up both heart rate and power zones, explaining what each zone means and when to use it.
Quick Answer
If you're new to structured training, use heart rate zones if that's the data you have, and use power zones if you ride with a power meter. Both are useful, but they answer slightly different questions:
- Heart rate shows how your body is responding
- Power shows the actual work you are producing
Who this is for: athletes who want reliable intensity targets for endurance, threshold, and interval work.
Key terms in this article: max heart rate, FTP, zone 2, threshold, VO2max, recovery.
Why Training Zones Matter
Your body adapts differently depending on how hard you work:
- Low intensity develops aerobic base, fat burning, and endurance
- Moderate intensity improves lactate threshold and sustained power
- High intensity builds VO2max and anaerobic capacity
Without zones, it's easy to fall into the "moderate intensity trap"—going too hard on easy days and too easy on hard days. This leads to:
- Accumulated fatigue without adequate recovery
- Missing the benefits of true easy training
- Not pushing hard enough on intense sessions
Zones solve this by giving you clear targets for each workout.
Heart Rate Zones Explained
Heart rate zones are based on percentages of your maximum heart rate or heart rate reserve. They're accessible to anyone with a heart rate monitor.
Finding Your Maximum Heart Rate
Option 1: Age-Based Formula (Least Accurate)
Max HR = 220 - Age
This formula has a large margin of error (±10-15 bpm) and should only be used as a starting point.
Option 2: Field Test (More Accurate)
Perform a maximal effort test:
1. Warm up for 15-20 minutes
2. Find a steep hill (4-6% grade)
3. Ride or run as hard as you can for 3-4 minutes
4. Sprint the final 30 seconds
5. Your peak heart rate is approximately your max HR
Option 3: Race Data (Most Accurate)
Your highest heart rate from an all-out race effort (30-60 minutes) typically represents your true max.
The Five Heart Rate Zones
| Zone | % of Max HR | Name | Description |
|---|---|---|---|
| Z1 | 50-60% | Recovery | Very easy; conversation flows naturally |
| Z2 | 60-70% | Endurance | Easy; can speak in full sentences |
| Z3 | 70-80% | Tempo | Moderate; conversation is choppy |
| Z4 | 80-90% | Threshold | Hard; only a few words at a time |
| Z5 | 90-100% | VO2max | Very hard; no talking |
Heart Rate Reserve Method (Karvonen Formula)
For more personalized zones, use heart rate reserve (HRR):
HRR = Max HR - Resting HR
Target HR = (HRR × Zone %) + Resting HR
Example: Max HR = 185, Resting HR = 55
- HRR = 185 - 55 = 130 bpm
- Zone 2 (60-70%): (130 × 0.60) + 55 to (130 × 0.70) + 55 = 133-146 bpm
Power Zones Explained
Power zones are based on your Functional Threshold Power (FTP)—the highest power you can sustain for approximately one hour.
Finding Your FTP
Option 1: 20-Minute Test
The most common field test:
1. Warm up thoroughly (20-30 minutes including some hard efforts)
2. Ride as hard as you can sustain for 20 minutes
3. Average power × 0.95 = FTP
Why 0.95? The 5% reduction accounts for the fact that you can typically sustain slightly higher power for 20 minutes than for a full hour.
Option 2: Ramp Test
Progressive increases in power until failure:
1. Start at an easy wattage
2. Increase by 20W every minute
3. Continue until you can no longer maintain the target
4. FTP ≈ 75% of your highest 1-minute power
Option 3: Race Data
Your average power from a 40-60 minute time trial or all-out race effort is a good approximation of FTP.
The Seven Power Zones
| Zone | % of FTP | Name | Duration | Purpose |
|---|---|---|---|---|
| Z1 | <55% | Active Recovery | N/A | Recovery between intervals |
| Z2 | 56-75% | Endurance | 2-6+ hours | Aerobic base building |
| Z3 | 76-90% | Tempo | 1-3 hours | Sustained aerobic work |
| Z4 | 91-105% | Threshold | 20-60 min | Lactate threshold improvement |
| Z5 | 106-120% | VO2max | 3-8 min | Aerobic capacity |
| Z6 | 121-150% | Anaerobic | 30s-3 min | Anaerobic capacity |
| Z7 | >150% | Neuromuscular | <30s | Sprint power |
Setting Your Power Zones
Example: FTP = 250W
| Zone | Watts |
|---|---|
| Z1 | <137W |
| Z2 | 140-187W |
| Z3 | 190-225W |
| Z4 | 227-262W |
| Z5 | 265-300W |
| Z6 | 302-375W |
| Z7 | >375W |
Heart Rate vs. Power: When to Use Each
For a deeper comparison of the two metrics, see Heart Rate vs Power. If you ride with power, pair this with FTP Demystified.
Both metrics have strengths and weaknesses:
Heart Rate Advantages
- Works for any sport (cycling, running, swimming)
- No expensive equipment needed
- Reflects overall physiological stress
- Good for gauging recovery and fatigue
Heart Rate Limitations
- Delayed response (cardiac lag of 30-60 seconds)
- Affected by caffeine, heat, stress, sleep
- "Cardiac drift" during long efforts
- Doesn't capture short, intense efforts well
Power Advantages
- Instant, objective feedback
- Not affected by external factors
- Precise pacing for intervals and races
- Best metric for tracking fitness changes
Power Limitations
- Requires a power meter (costly)
- Cycling-only (running power exists but is less established)
- Doesn't account for how you feel
- Same power output can feel different depending on fatigue
Practical Recommendation
Use power for:
- Interval sessions (precise intensity targets)
- Racing and pacing
- Tracking fitness over time
Use heart rate for:
- Easy/recovery rides (ensure you're actually easy)
- Long endurance sessions
- Days when you don't have power data
- Cross-referencing with power to monitor fatigue
How to Use Zones in Training
Zone 2 Training (The Foundation)
Most of your training time should be in Zone 2—about 70-80% of total volume for most athletes.
Zone 2 builds:
- Mitochondrial density
- Fat oxidation
- Aerobic base
- Recovery capacity
Common mistake: Going too hard. True Zone 2 feels easier than you think. If you can't hold a conversation, you're probably too hard.
Threshold Training (Zone 4)
Threshold work improves your FTP and lactate clearance. Examples:
- 2×20 minutes at FTP with 5-10 min recovery
- 3×15 minutes at 95-100% FTP
- 4×10 minutes at 100-105% FTP
VO2max Intervals (Zone 5)
Short, hard efforts that tax your aerobic system maximally:
- 5×4 minutes at 106-120% FTP with 4 min recovery
- 6×3 minutes at 110-120% FTP with 3 min recovery
- 8×2 minutes at 115-125% FTP with 2 min recovery
Recovery (Zone 1)
Don't underestimate easy days:
- Stay below 55% FTP / 60% max HR
- Short duration (30-60 minutes)
- Purpose is blood flow, not fitness
Testing and Updating Zones
When to Retest
Your fitness changes, so your zones should too. Retest:
- Every 6-8 weeks during a training block
- After a significant break from training
- When workouts feel consistently too easy or too hard
- At the start of a new training phase
Signs Your Zones Need Updating
Zones too easy:
- Threshold intervals feel manageable
- You can easily exceed targets
- Heart rate stays lower than expected
Zones too hard:
- Can't complete prescribed intervals
- Heart rate spikes quickly
- Excessive fatigue after workouts
Setting Up Zones in RideIQ
RideIQ allows you to customize your training zones for personalized workout analysis:
- Go to Settings → Training Zones
- Enter your max heart rate and/or FTP
- Choose standard zones or customize each boundary
- Your workouts will automatically be analyzed against your zones
Frequently Asked Questions
Should I use 5 or 7 power zones?
Either works. 5 zones are simpler and sufficient for most training. 7 zones provide more granularity for advanced athletes or specific interval work.
My heart rate seems high/low compared to others. Is that normal?
Yes. Max HR is highly individual and not related to fitness. Some fit athletes have low max HRs; some beginners have high ones. What matters is your personal zones.
Can I use the same zones for cycling and running?
Heart rate zones generally transfer between sports. Power zones do not—running power and cycling power aren't comparable.
How accurate are smart trainer power numbers?
Most quality smart trainers are within ±2-3% of dedicated power meters. Test in the same conditions you train in, and you'll be fine.
What if I can't finish an FTP test?
Start with a shorter test (8-minute) or use a ramp test. You can also estimate from race data or hard group ride efforts.
Key Takeaways
- Zones remove guesswork from training intensity
- Heart rate zones use percentages of max HR (5 zones typical)
- Power zones use percentages of FTP (5-7 zones typical)
- Use power for intervals, heart rate for easy/endurance work
- Zone 2 should be most of your training volume
- Retest every 6-8 weeks to keep zones current
- Set up your zones in RideIQ for personalized analysis
Next Steps
Now that you understand training zones, it's time to put them into practice. Start by establishing your baseline with an FTP test or max HR test, then configure your zones in RideIQ. Your workouts will transform from random efforts into purposeful training sessions, each serving a specific role in your fitness development. From there, your zone targets feed directly into training load metrics and better workout analysis.