How to Build Unbreakable Cycling Endurance

The feeling is universally familiar to any cyclist who has pushed their limits: the gradual onset of fatigue, legs turning to lead, and the sudden, overwhelming sensation of fatigue - known as hitting the wall, ‘bonking’ or ‘the knock’.

This is not a personal failure, but a predictable physiological event. It’s your body's primary energy stores, muscle glycogen, running dangerously low, leaving you with little fuel for sustained effort¹.

While this moment often feels like an insurmountable wall, it is in fact a symptom of a broader, systemic challenge that can be overcome with a structured and scientific approach.

Cycling endurance is not an innate talent possessed only by a few. It's a trainable physiological capacity, built and refined through a strategy that integrates three core pillars: intelligent training, precise fuelling, and strategic recovery.

We spoke to Coach Joe Beer & Dr Thom Philips to explore training methods, fuelling strategies, recovery secrets, and how using objective data, like cycling blood tests, can help you truly personalise your journey and go beyond guesswork.

The Foundations of Endurance

Endurance, in a cycling context, is a multifaceted concept that extends beyond simply having the mental fortitude to keep pedalling. At its core, It’s about your body’s capacity to deliver oxygen to the working muscles and convert fuel into energy efficiently.

To truly understand how to improve, you must first understand the key physiological markers that dictate performance.

Two of the most widely referenced metrics are the aerobic capacity, or maximal oxygen uptake (VO2​Max), and the lactate (or anaerobic) threshold.

Aerobic Capacity

VO2​Max represents the maximum rate at which the body can consume and utilise oxygen during intense exercise.² It’s often described as the size of the body’s engine. A higher VO2​Max means a greater capacity for oxygen delivery, which is fundamental to aerobic energy production.

Lactate Threshold

The lactate threshold is the point at which lactate begins to accumulate in the bloodstream at a faster rate than the body can clear it². Crossing this threshold leads to a rapid build-up of metabolic by-products, causing that familiar burning sensation and forcing a reduction in effort.

Raising this threshold is a primary goal of endurance training, as it allows you to sustain a higher power output for a longer duration before succumbing to fatigue. Training at or near this threshold trains the body to manage lactate more effectively, pushing the “redline” of the engine to a higher, more sustainable level².

"Lactate threshold cannot be pushed higher and higher. After a good aerobic base and some interval work, it's then at a ceiling. There’s a lot more to be gained from smart equipment, pacing and fuelling than just thinking you can push your lactate up for ever more."

Coach Joe Beer

Physiological Transformations

Beyond these high-level metrics, the true adaptations occur at a microscopic level. Building endurance involves a series of complex physiological transformations within the muscles and cardiovascular system.

First, there is an increase in mitochondrial density. Mitochondria are responsible for converting fuel (fat and carbohydrates) into usable energy³. Endurance training stresses these cellular components, prompting the body to create more of them, resulting in a more efficient and powerful aerobic system with less lactate building up.

A second key adaptation is capillarisation, which refers to the growth of tiny blood vessels, or capillaries, within the muscle tissue⁵. An increased network of capillaries improves the delivery of oxygen and nutrients to the working muscles and, just as importantly, enhances the removal of metabolic waste. This adaptation directly supports a higher lactate threshold and better overall performance by ensuring the muscles are well-supplied and can clear by-products efficiently.

Muscle Fibres

Finally, a more nuanced but equally vital adaptation is the conversion of muscle fibres.

Human muscles contain a mix of different fibre types, including fast-twitch (Type II) fibres, which are powerful but fatigue quickly, and slow-twitch (Type I) fibres, which are built for endurance.

Through specific training (though the extent of conversion depends on factors like genetics and training variables), It’s possible to transform the least efficient fast-twitch fibres (Type IIX) into a more fatigue-resistant type (Type IIA)².

An important element in this process is the incorporation of heavy strength training. While it may seem counterintuitive for endurance athletes, evidence suggests that strength training can improve cycling economy and delay the onset of fatigue, even without significant changes in VO2​Max⁶.

The underlying mechanism is that strength training increases the maximal force of the Type I fibres and improves neuromuscular efficiency. This means that for a given power output, the muscle can generate the required force with less effort relative to its maximal capacity.

This reduces the reliance on less economical Type II fibres, which are a primary contributor to fatigue during prolonged efforts⁶. By delaying their activation, strength training effectively improves your body’s ability to exercise longer.

Summary: All this means that you need to take a nuanced approach to building cycling endurance. Consider where your fitness currently stands; if you’re used to sprints or short rides now and again, you may not have the base for endurance cycling. A long-term approach is needed to build an effective endurance engine. We’ll go into detail on how this works in a real-world context below.

Training to Build Cycling Endurance

A well-structured training plan is the cornerstone of building cycling endurance. The most effective programmes are not a simple collection of hard rides, but a strategic progression that builds a deep physiological foundation before adding intensity.

The Power of Base Training

This foundational period, often called the ‘Base Phase’, is non-negotiable for serious endurance development.³ Its purpose is to strengthen your aerobic energy system and prepare your body for the harder, more intense workouts or races to come.

The best approach, and backed by Coach Joe Beer, is the ‘Traditional Base’.

Traditional Base relies on the classic, low-intensity, high-volume approach, something Coach Joe Beer says is a “year-round bank account to keep depositing into”.

This involves long rides at a low-to-moderate intensity (Zones 1 and 2), with the primary goal of spending a significant amount of time in the saddle.

While time-consuming, this method is exceptionally effective at building a broad aerobic foundation, leading to the mitochondrial and capillary adaptations that underpin endurance.³

"I’ve seen it time and time again - athletes come to me looking for help improving their endurance and questioning why they are hitting a plateau, only to tell me they are spending the majority of their (often limited) training time in Zone 3 or above.

Training at this intensity is not an effective way of building lasting or meaningful endurance. Sure, you might get some PRs and the dopamine hit of kudos, but you’re prioritising short-term, superficial wins over long-term, sustainable gains.

Avoid ‘sweet spot’ training - it doesn’t work. You should be spending at least 80% of your training time in zone 1/2 and maybe 5-10% in zone 4/5. It’s not easy for everyone, and you may struggle to find time for regular 2 hour (or longer) rides, but the results speak for themselves. Runners will know this as LSD - long, slow, distance."

Coach Joe Beer

‘Sweet Spot’ training has been popularised recently, with many citing it as the goldilocks of fitness - not too much, not too little, just right. And it’s easy to see why many people jump at the promise of real progress in a fraction of the time.

In reality, it’s not going to provide the stimulation required to boost aerobic fitness and endurance. Beer recommends no more than 10-20% of your weekly training volume should fall within the ‘high intensity’ bracket (zone 4+).

“It’s especially important that you don’t push yourself too hard during winter, too. Intensity has its place, but I never prescribe my athletes high-intensity training during the autumn and winter. It’s just not the right time of the year to be pushing yourself – from both a physiological and psychological point of view.”
Joe Beer

Adding Intensity with Intervals

Once a solid aerobic foundation is established, interval training is used to build the capacity to perform at higher outputs.

High-Intensity Interval Training (HIIT) involves alternating short bursts of intense activity with periods of rest or lower-intensity work.11 This method is highly effective for improving VO2​Max, raising the anaerobic threshold, and enhancing muscle endurance².

When and how you add intensity to your training will depend on your available time and goals. There’s a delicate balance between intensity and endurance training that can be hard to master.

Too much intensity and you run the risk of dampening your endurance building, as well as overtraining, further impacting your performance.

If you’re ready to build intensity into your training, speak to someone with experience, like a seasoned cyclist or even better, a coach.

Fuelling for Endurance Training

Proper nutrition is as critical as the training itself. The ultimate goal is to provide the body with a consistent supply of energy to support demanding training and racing, while also optimising recovery.

A successful fuelling strategy can be broken down into three phases: pre-ride, on-bike, and post-ride.

Pre-Ride Nutrition

The foundation for a long ride is laid days before the event. The goal is to maximise your glycogen stores, to ensure there is a ready supply of fuel from the very start.

You’ll need to carb load before a long ride. This allows your body to gradually stock up its energy reserves and use glycogen as fuel to keep your legs spinning.

Find out how to properly carb load with our blog by Coach Joe Beer: Carbohydrate Loading: When, how and why?

On-Bike Fuelling

The most common reason for mid-ride fatigue is a failure to fuel consistently. For any ride lasting longer than 60 minutes, a consistent fuelling strategy is essential to prevent hitting a wall or blood sugar dips and maintain performance¹.

The golden rule for on-bike nutrition is to consume between 60 to 90 grams of carbohydrates per hour¹. For long, moderate intensity efforts, some athletes can even train their gut to absorb upwards of 140 grams per hour by using specific ratios of glucose to fructose, which utilises different metabolic pathways for faster uptake⁴. Although fat adaptation is important, and people shout quite loudly about this, to truly perform at a high level, carbohydrates are the only fuel choice.

Consuming high levels of carbohydrate during exercise is not a skill that comes naturally; it must be practised. Although often discussed, this is an aspect of long distance training that is largely overlooked.

If we look back at how world-beating performances in endurance events have progressed over the last 2-3 decades, the biggest change from a physiological and training perspective is top level athlete’s ability to consume and process glucose whilst exercising.

"If you look at some of the stand-out performances at the Hawaii Ironman World Championships in the last 5 years, you will see that many fuel at 120-140g/h, some of the top athletes are now able to stomach in excess of 200g per hour, meaning they almost never deplete their muscular glycogen stores, allowing them to continue to exercise at a higher intensity."

Coach Joe Beer

Your body's ability to handle large volumes of carbohydrates at high intensity needs to be trained, just like your muscles. This involves repeatedly consuming different foods and drink mixes during training rides to find what works best and to avoid gastrointestinal discomfort on race day.¹⁴

Fluid intake is equally important. The aim is to consume an amount you know you will sweat per hour depending on the conditions, and to replenish electrolytes, especially in hot conditions.¹⁴

The choice between real food and packaged sports nutrition products has its own considerations. Real foods like rice cakes, mini sandwiches, or dried fruit can provide a sense of satiety and help prevent "food fatigue" or "food boredom" on very long rides.¹⁴

However, sports nutrition products like gels and energy chews are specifically engineered to provide easily digestible carbohydrates for quick energy, which is particularly useful during high-intensity efforts or in the final stages of a race.⁴

A combination of both is often the most effective approach, and trial and error might be the best way to find what works for you.

The following table provides a quick reference for common on-bike fuelling options to help a cyclist plan their nutrition strategy:

Food Source	Typical Carbohydrate Content (g)	Pros	Cons
Energy Gel	20-30	Fast-digesting, convenient, liquid-based for easy intake at high intensity	Can cause stomach distress, may lead to "food fatigue," highly processed
Energy Bar	20-50	Balanced macronutrients, convenient, solid food feel	Can be difficult to chew and digest at high intensity
Rice Cakes	30-40	Easy to make and customise, wholesome, provides a real food feel	Can be cumbersome to eat and carry, requires preparation
Energy Chews	20-60	Easy to chew and swallow, provides a quick energy boost	Can be high in simple sugars, may cause a sugar "crash"
Dried Fruit	20-30	Natural source of carbohydrates, easily portable	High in fibre, which can cause stomach issues on long rides
Sports Drink MixPer litre	40-160	Hydration and fuel in one, customisable carb concentration	Can be too sweet for some, may require multiple bottles

Post-Ride Recovery Nutrition

Recovery begins the moment the ride ends.

The first 30 to 60 minutes after a workout is a critical window for replenishing depleted muscle glycogen stores and initiating muscle repair.¹¹

The ideal post-ride meal or shake should contain a combination of carbohydrates and protein in a 3:1 or 4:1 ratio.¹⁰

The carbohydrates are crucial for rebuilding glycogen stores, while the protein provides the building blocks for repairing the minor muscle damage incurred during a strenuous effort.¹²

“You have to hit at least 60-80 grams of carbs and 15-30grams of protein quickly after a challenging training session to recover fast“
Joe Beer

A simple, effective recovery drink is a glass of strawberry milk (for a 100g serving of Strawberry Yop, nutritional values are approximately 65 kcal, 0.8g fat, 10.6g carbohydrates, and 3.0g protein), while other options include protein shakes, or a meal of lean protein and rice.¹⁵

Although during exercise glucose is vitally important, most endurance athletes fail to meet their necessary protein requirements for a day. The ISSN has an excellent paper summarising their recommendations around protein intake and athletic performance. Anyone doing regular physical activity should be aiming for 1.4-2g/kg/day of protein intake, with athletes aiming for the higher end of this scale. To give you an idea the combined protein in 2 large eggs, 200g natural yogurt, 200g piece of tuna and 2 slices of peanut butter on toast is around 100g of lean protein, so for a 70kg athlete this would just scrape across the bottom end of the target range. The challenge of protein intake is also often exacerbated by the adoption of restrictive diets.

Recovery

Training hard is only one half of the equation; the other, and arguably more important, is recovering effectively.

It’s during recovery that the body adapts to the stress of training and gets stronger.¹³ Of all the recovery modalities available to an athlete, a number of scientific sources state that sleep is the most vital, representing the undisputed “king of recovery”.¹³

The physiological basis for this is found in the stages of sleep. During deep, non-REM sleep (Stage N3), the body engages in crucial restorative functions. This is the only time that your body releases human growth hormone (HGH), really hitting home the importance of those first 2-3 hours of sleep after getting into bed.

Without this HGH pulse your body’s tissues will not receive adequate signalling to facilitate muscle protein synthesis and repairing the tissue damage caused by intense cycling (or strength training) sessions.¹³

Without proper sleep, this process is inhibited, leading to a higher risk of injury and a reduction in training adaptations.

In addition to sleep, other recovery methods play a supporting role. These can be divided into active and passive approaches.

Active recovery involves performing low-intensity exercise on rest days, such as a short, easy ride in Zone 1, walking, or swimming.¹² The purpose of this is to increase blood flow to the muscles, which helps to clear metabolic waste products like lactate and deliver oxygen and nutrients to aid in the healing process. This form of recovery is often more beneficial than complete inactivity for reducing muscle soreness and stiffness.¹⁵

Passive recovery methods include techniques such as massage therapy, foam rolling, and compression gear.¹⁶ While these can be effective at reducing muscle tension, improving flexibility, and promoting circulation, a comprehensive analysis of various recovery techniques highlights that massage is rated as the most effective for reducing muscle soreness and fatigue after sleep and rest days.¹⁴ Other modalities like cryotherapy and ice baths may be helpful, but the scientific data on their effectiveness remains inconclusive.¹⁴ “The merits of hot bath for recovery and fitness increases have my vote more than the ‘Get Cold’ advocates” says Coach Joe. These methods should be seen as supplemental and not a replacement for the fundamental pillars of a training plan, proper nutrition, and quality sleep.¹⁴

When the balance between training stress and recovery is lost, you risk developing Overtraining Syndrome. This condition is a result of a prolonged imbalance where the body is pushed beyond its capacity to recover.¹⁷

The warning signs include chronic fatigue that persists even after rest, diminished performance, mood changes, increased susceptibility to illness or injury, and changes in resting heart rate.¹⁷

For data-savvy athletes, a consistently higher-than-normal resting heart rate in the morning can be a strong indicator of overreaching or under-recovery, signalling that a period of rest is needed to avoid a serious setback.¹⁸

Remove the Guesswork with Blood Tests

While training, nutrition, and recovery form the foundation of endurance improvement, they are still reliant on a degree of guesswork. You may be following a seemingly perfect plan but can still feel fatigued or find your progress has plateaued.

This is where objective, data-driven insights from blood testing become an invaluable tool for taking training from a general programme to a truly personalised, scientific endeavour.¹⁹

A sports blood test provides a snapshot of your internal health, revealing potential deficiencies or imbalances that can directly impact performance, recovery, and overall well-being.

"Chronically low levels of Testosterone in men and Oestradiol in women, are sometimes an indication of over training especially in endurance athletes. Other markers we variously monitor in athletes include, Cortisol (recovery marker, and non-exercise related stress indicator) and CK (muscle breakdown markers). You may want to personalise your blood test to include prolactin, thyroid markers and hs-CRP for a more comprehensive report.

From a nutritional perspective I recommend all athletes have a minimum 3-4 monthly blood screen to monitor their micronutrient levels too (Ferritin, Vitamin D, Active B12, Folate). I’ve lost count of the number of times we’ve caught an early stage iron deficiency that could’ve led to performance degradation if it wasn’t picked up and addressed early."

Dr Thom Philips

Chief Medical Officer

It's the feedback loop that closes the system, revealing why a body might not be responding to a training stimulus as expected.¹⁹

Here are seven key biomarkers you can check with our blood tests for cyclists and why they matter:

Biomarker	Physiological Function	Relevance to Cycling Performance	What a Blood Test Reveals
Ferritin	Stored iron, essential for oxygen transport	Low levels can lead to fatigue, impaired oxygen delivery, and reduced performance.	Indicates a potential iron deficiency before it becomes clinically anaemic.
Vitamin D	Bone health, immunity, muscle function	Deficiency can increase injury risk, hinder muscle recovery, and make an athlete more susceptible to illness.	A deficiency that may be hindering recovery and performance, particularly in winter.
HbA1c	Average blood glucose over 90 days	Reflects how efficiently the body manages carbohydrates, which is key for endurance fuelling.	Reveals issues with glucose control that can lead to fatigue and impaired performance.
Testosterone	Muscle repair, red blood cell production, mood	Low levels can impair recovery, reduce muscle mass, and cause persistent fatigue.	Potential hormonal imbalance impacting recovery and long-term performance.
Oestrogen	Bone health, cardiovascular repair, inflammation control	Vital for female cyclists for bone strength and managing training-induced inflammation.	Potential imbalance impacting bone density and overall health.
Cortisol	The stress hormone	Chronically elevated levels indicate overtraining, suppressing the immune system and recovery.	A hormonal stress response that shows you may be pushing too hard without enough recovery.
Creatine Kinase (CK)	An enzyme indicating muscle damage	High levels are normal after intense exercise, but consistently high levels may signal overtraining.	Indicates the degree of muscle damage from training and the need for adequate recovery.

Crafting Your Endurance Plan

Building a training plan is an exercise in strategic scheduling. It involves applying the core principles of periodisation and progressive overload to a consistent weekly structure.

Periodisation involves dividing the training season into specific blocks, each with a different focus.

Progressive overload is the gradual increase of training stress over time, ensuring the body is consistently challenged to adapt without being pushed into overtraining.

A successful plan is a flexible template, not a rigid prescription. The best approach is to adapt a proven structure to your lifestyle and goals.

Sample Weekly Training Plan

Day	Example Plan
Monday	Rest Day
Tuesday	Indoor ride - 4 x 4mins High-Tension Intervals (1 hr)
Wednesday	Endurance Ride (1-1.25h hr), fuelling carbs at least 1g/kg/hr
Thursday	Indoor ride - 4 x 4mins High-Intensity above threshold Intervals (1 hr)
Friday	Rest Day
Saturday	Endurance Ride (1h), fuelling carbs at least 1g/kg/hr
Sunday	Endurance Ride (2-3 hrs), fuelling carbs at least 1g/kg/hr

This structure ensures that the highest-priority, high-intensity workouts are scheduled after a rest day, when the body is fresh and ready to absorb the training stress.²⁰

The endurance rides build the critical aerobic foundation.

Consistency is the most important component of any plan; six one-hour rides in a week will not generate the same fitness gains as one three-hour ride and three one-hour rides, even though the total training time is the same.

Concentrating the workload into fewer, longer sessions amplifies the physiological effect on fitness.²⁰

Your Journey

Building unbreakable cycling endurance is a journey that requires a comprehensive, disciplined, and data-driven approach. “Its got to be fun to set the challenge, enjoy the sessions and see progress happening over time” says Coach Joe

It’s an intricate process that begins with understanding the fundamental physiological adaptations that make the body more efficient and robust.

From there, it requires a commitment to a structured training plan that combines a solid base with targeted intensity, a disciplined fuelling strategy that ensures a consistent energy supply, and a dedication to the often-overlooked art of recovery, with sleep as the cornerstone.

However, even the most meticulous plan can fall short without the right data. Objective monitoring through blood tests provides the crucial final piece of the puzzle, revealing the hidden physiological issues that no amount of training or perfect diet can overcome. By providing a precise snapshot of internal health, blood testing transforms a cyclist’s journey from a series of educated guesses into a personalised, evidence-based science.

To truly unlock your full potential and achieve unbreakable endurance, it’s essential to combine these pillars. The journey begins with a single step: understanding your body from the inside out with our blood tests for cyclists.

Frequently Asked Questions

What is cycling endurance?

Cycling endurance is the body’s ability to sustain a prolonged effort without a significant decrease in performance. It’s a trainable quality that depends on a number of physiological adaptations, including the body’s capacity to transport and utilise oxygen (VO2​Max), its ability to manage metabolic by-products (lactate threshold), and the efficiency of its energy systems.

How do I create a training plan for long-distance cycling?

A training plan for long-distance cycling should be built around a strong foundation of base training (long, low-intensity rides). The plan should then progressively add higher-intensity interval workouts to raise the lactate threshold and improve power output. It’s crucial to integrate rest days and recovery periods to allow the body to adapt and grow stronger. The most effective plans are periodised, with a clear focus on building volume before adding intensity.

What should I eat on a long bike ride?

For any ride lasting longer than 60 minutes, It’s essential to fuel consistently with carbohydrates. The general recommendation is to consume 60 to 90 grams of carbohydrates per hour, with a combination of real food (e.g., rice cakes, mini sandwiches) and sports nutrition products (e.g., gels, chews).1 It’s also critical to stay hydrated by drinking to thirst and your known sweat rate which may be approximately 500-1200 ml of fluid per hour, with added electrolytes.

How much sleep do cyclists need?

Most athletes should aim for a minimum of 7 to 8 hours of quality sleep per night, with more being beneficial during periods of intense training.

Can strength training improve my cycling endurance?

Yes, strength training is highly effective for improving cycling endurance. Heavy strength training has been shown to improve cycling economy and delay the activation of less-efficient, fast-twitch muscle fibres. This means that the body becomes more efficient at producing power, allowing a cyclist to maintain a higher power output for a longer duration before succumbing to fatigue.

How do blood tests help cyclists?

Blood tests provide objective data on a cyclist’s internal health, revealing deficiencies that may be hindering performance. By monitoring key biomarkers like iron, Vitamin D, and HbA1c, a cyclist can identify and address issues that might be causing fatigue or inhibiting recovery. Blood tests transform training from a guessing game into a precise, data-driven science, allowing a rider to tailor their nutrition and recovery to their body’s specific needs.