At some point in your cycling journey, you may realize that to tackle longer rides, steeper climbs, or endurance events, you need more stamina. Whether you’re an endurance athlete training for a race or a recreational rider wanting to push past your limits, endurance is the foundation of long-distance cycling.
But endurance isn’t just about riding for longer. It’s about building aerobic fitness efficiently—allowing your cardiovascular system to sustain effort without exhaustion. With the right training methods, you can develop endurance without spending unlimited time in the saddle.
What is endurance?
From a scientific standpoint, endurance training refers to any physical activity where your body relies on oxygen (aerobic conditioning). Endurance capacity is primarily developed through training in heart rate Zones 1 and 2, which involve low to moderate-intensity efforts sustained over extended periods. Training in these zones enhances the body’s aerobic system, improving oxygen delivery and utilization in muscles, thereby building endurance. However, higher-intensity zones (Zones 3 and above) also contribute to endurance by increasing lactate threshold and cardiovascular efficiency, but they engage anaerobic energy systems to a greater extent and are typically sustained for shorter durations.
Practically, endurance is about how long you can sustain a given effort. Long-distance cycling relies on your ability to manage fatigue and efficiently use energy over time.
Building an endurance training plan
Developing cycling endurance requires a combination of 3 key strategies:
1. Prioritize long, low-intensity rides
Zone 2 training is the backbone of endurance cycling. This effort level—typically 57-75% of your Functional Threshold Power (FTP)—develops aerobic fitness, strengthens the cardiovascular system, and increases fat oxidation, allowing your body to burn fuel efficiently.
Training in Zone 2 elicits several key physiological adaptations that enhance endurance performance:
- Enhanced mitochondrial density: Zone 2 training stimulates the production of mitochondria within muscle cells, particularly in Type I (slow-twitch) fibers. This increase allows for more efficient aerobic energy production, enabling sustained physical activity over longer periods.
- Improved capillary density: Engaging in Zone 2 workouts promotes the development of additional capillaries in muscle tissue. This expansion enhances blood flow, facilitating greater delivery of oxygen and nutrients while aiding in the removal of metabolic byproducts like lactate, thereby delaying fatigue.
- Increased fat oxidation: Training at low to moderate intensities enhances the muscles’ ability to utilize fat as a primary energy source. This adaptation conserves glycogen stores and supports prolonged exercise durations.
- Cardiovascular improvements: Consistent Zone 2 training strengthens the heart muscle and increases stroke volume—the amount of blood pumped per heartbeat. These changes contribute to a more efficient cardiovascular system, supporting sustained endurance activities.
Collectively, these adaptations underscore the importance of Zone 2 training in building a robust aerobic base, which is fundamental for endurance athletes.
CAROL Bike’s Zone-Based Free Ride Workouts offer AI-personalized low-intensity endurance sessions:
- Zone-Based Free Ride: Keeps you automatically in a specific training zone.
- Target Power Free Ride: Allows you to select a target power as the bike automatically adjusts resistance to keep your power output at that level.
- Regular Free Ride: Lets you directly control resistance.
2. Introduce tempo intervals for fatigue resistance
Endurance rides lay the foundation for aerobic fitness, but to push your endurance further, higher-intensity efforts are essential. Incorporating structured intensity, such as Sweet Spot training (also known as Tempo intervals), strengthens the cardiovascular system, increases fatigue resistance, and enhances the body’s ability to sustain high power outputs over extended periods. It’s one of the most effective ways to improve endurance in a limited time.
Sweet Spot training consists of high-intensity intervals at 76-90% of your FTP—intense enough to create significant adaptations without excessive fatigue. To maximize endurance benefits, these intervals should last at least 10 minutes per effort, with structured progressions leading to 2×20-minute or 2×30-minute blocks as fitness improves. The goal is to progressively extend time at your Sweet Spot while maintaining power targets.
For beginners, experts recommend separating Tempo intervals from endurance rides to allow for adequate recovery and adaptation. A simple way to start is by adding 1x Sweet Spot session per week while maintaining low-intensity endurance rides on other days. Once adapted, these efforts can be integrated into longer rides to simulate the demands of real-world cycling, such as sustained climbs.
3. Increase your training volume
Progressively extending the duration and frequency of training sessions is crucial for developing endurance. A gradual increase in training volume allows the body to adapt without risking overtraining or injury.
Since Zone 2 training is low-intensity, it requires minimal recovery, allowing for frequent sessions—even daily. Experts suggest progressively increasing your total training time, aiming to double your usual ride duration. For example, if you typically cycle for an hour, extending sessions to 2–2.5 hours will provide the necessary stimulus for endurance adaptations. As fitness improves, 4–5 hour rides can further enhance stamina and prepare you for longer efforts.
CAROL offers a range of 24 science-backed workouts, including a Zone-Basd Free Ride that tailors power zones to your ability.
Polarized training for maximum efficiency
Polarized training is a highly effective endurance strategy that emphasizes training in the extremes—spending 80% of your time in low-intensity Zone 2 and 20% in high-intensity Zone 5, while minimizing time spent in moderate-intensity zones (Zones 3 and 4).
A 2014 study compared 4 common endurance training protocols—high-volume training, threshold training, HIIT, and polarized training—among 48 runners, cyclists, triathletes, and cross-country skiers. After 9 weeks, the polarized training group showed the greatest improvements in key endurance performance markers, including VO2max, peak velocity, and time to exhaustion. This evidence supports polarized training as the most effective way to improve endurance with limited training hours.
Many elite endurance athletes rely on this method to maximize aerobic adaptations while reducing overall training stress, making it an ideal approach for those looking to improve endurance without excessive time in the saddle.
How long does it take to build endurance?
Developing cycling endurance takes patience and consistency. Most endurance athletes see measurable improvements in 4-6 weeks.
After completing a 4-week endurance training plan, you can measure these 2 indicators to assess your progress:
- Your heart rate recovery: Calculate the difference between your peak heart rate during exercise and your heart rate 1 minute after your workout. Faster recovery indicates improved cardiovascular fitness.
- Your maximum aerobic power: Maintain steady output over 20 miles and compare average power to past rides.
Sample endurance cycling training plan
Gradually increasing your training volume each week is key to building endurance safely and effectively. A steady 10% weekly increase helps improve aerobic fitness while minimizing the risk of overtraining or injury. This progressive approach ensures sustainable gains without excessive strain.
A structured 4-week plan incorporating the above strategies may look as follows:
Week 1
Monday – 60-min Zone 2 ride
Tuesday – Active recovery or rest
Wednesday – 60-min Zone 2 ride
Thursday – 45-min Tempo ride with 2×10 min intervals
Friday – Complete rest
Saturday – 80-min Zone 2 ride
Sunday – Complete rest
Week 2
Monday – 66-min Zone 2 ride
Tuesday – Active recovery or rest
Wednesday – 66-min Zone 2 ride
Thursday – 45-min Tempo ride with 2×10 min intervals
Friday – Complete rest
Saturday – 88-min Zone 2 ride
Sunday – Complete rest
Week 3
Monday – 73-min Zone 2 ride
Tuesday – Active recovery or rest
Wednesday – 73-min Zone 2 ride
Thursday – 50-min Tempo ride with 3×10 min intervals
Friday – Complete rest
Saturday – 97-min Zone 2 ride
Sunday – Complete rest
Week 4
Monday – 80-min Zone 2 ride
Tuesday – Active recovery or rest
Wednesday – 80-min Zone 2 ride
Thursday – 55-min Tempo ride with 2×20-min intervals
Friday – Complete rest
Saturday – 107-min Zone 2 ride
Sunday – Complete rest
Sample polarized training plan on CAROL Bike
CAROL Bike supports the polarized training method, offering the low-intensity Zone 2 Free Ride workout and maximum-intensity Reduced Exertion HIIT (REHIT).
REHIT on CAROL Bike is scientifically proven to deliver superior fitness benefits in 90% less time than traditional cardio. By pushing your muscles to near-maximal effort, CAROL Bike’s AI-personalized sprints trigger key adaptations, including increased mitochondrial density, greater oxygen uptake, and a stronger heart.
Research shows that 8 weeks of REHIT training can increase VO2max by 12.3%, making it a powerful addition to any endurance plan.
Example polarized training plan on CAROL Bike:
Week 1
Monday – Recovery day
Tuesday – REHIT training
Wednesday – 60-min Zone 2 ride
Thursday – 60-min Zone 2 ride
Friday – REHIT training
Saturday – 45-min recovery ride
Sunday – 90-min Zone 2 ride
Week 2
Monday – Recovery day
Tuesday – REHIT training
Wednesday – 66-min Zone 2 ride
Thursday – 66-min Zone 2 ride
Friday – REHIT training
Saturday – 50-min recovery ride
Sunday – 100-min Zone 2 ride
Week 3
Monday – Recovery day
Tuesday – REHIT training
Wednesday – 73-min Zone 2 ride
Thursday – 73-min Zone 2 ride
Friday – REHIT training
Saturday – 55-min recovery ride
Sunday – 110-min Zone 2 ride
Week 4
Monday – Recovery day
Tuesday – REHIT training
Wednesday – 80-min Zone 2 ride
Thursday – 80-min Zone 2 ride
Friday – REHIT training
Saturday – 80-min recovery ride
Sunday – 120-min Zone 2 ride
The long-term benefits of endurance training
Endurance training requires dedication and consistency, with most athletes committing 4-10 hours per week. However, if you’re short on time, you can still build endurance with just 3 cycling sessions per week—a longer weekend ride, a shorter midweek endurance ride, and a high-intensity REHIT session for maximum efficiency.
Within a month, you’ll feel the difference—steep climbs will become easier, fatigue will fade, and your overall stamina will improve. Over time, the benefits extend beyond cycling: a stronger heart, lower resting heart rate, reduced risk of heart disease, increased energy, a more resilient immune system, and better sleep.
The more you ride, the more you’ll gain—so keep pedaling and enjoy the journey.
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