Endurance Rides

Endurance rides make up nearly 80% of the bulk of any endurance athlete’s training and a normal week may include 3-5 endurance rides. With that said, it is worth understanding what these rides accomplish and the value they have for an endurance performance.

An endurance ride is characterized by long duration and easy-intensity riding. Some of the primary adaptations from riding long and easy include an increase in mitochondrial biogenesis and a conversion of fast twitch (type IIa) fibers to develop the characteristics of more slow twitch (type I) fibers. Endurance riding also increases aerobic enzymes and the body’s ability to utilize oxygen and fats as a fuel which improves metabolic flexibility and how long your glycogen stores last you during training and racing.

Endurance rides are also key for executing appropriate intensity distribution across the week. High intensity training sessions are much more stressful to the body so they must be dosed sparingly throughout a given training week to avoid non-functional overreaching or overtraining (no pain, no gain?…no brain.). A normal week may include 1-3x high intensity sessions and it is important to space out high-intensity sessions with days of low intensity between to allow the body to adapt and get stronger. These low intensity sessions between hard days can be endurance rides (zone 1/2) or recovery rides (zone 1).

To maximize the benefits of endurance riding, it is necessary to ride at a continuous intensity that correlates with a blood lactate level below ~2.0mmol/L. A blood lactate below ~2.0mmol/L is associated with a low-stress state of aerobic energy production that is generated by burning a high proportion of fats. Riding below ~2.0mmol/L represents a state of lactate buffering that can be sustained for many hours without fatigue or accumulating excessive muscle acidity.

Since it is not simple to determine our blood lactate levels during training, we determine the intensity that would be below 2.0mmol/L using power or HR metrics such as 75% of FTP power, 75% of max HR, 85% of functional threshold heart rate, or the Maffetone method of 180 minus your age to determine the top of your endurance training zone that correlates with ~2.0mmol/L of lactate. This does not mean ride at the TOP of this range during endurance rides, rather this is the CEILING and all of the benefits come from staying BELOW it! As long as you are riding at a steady pace with pressure on the pedals but it doesn’t feel like you are “trying” to push harder, and can maintain a conversation, you are doing it right. Some of the best endurance rides can be done around an intensity of 47%-54% of FTP, 65%-75% of FTHR, or 60%-68% HRmax.

It is a good idea to start your easy rides in zone 1 and work your way up to zone 2. This will allow the body to warm up as it enters a sympathetic state which mobilizes fats, divers blood to working muscles, and activates aerobic enzymes. You’ll know if you are doing endurance rides correctly if you notice yourself having to hold back throughout the ride. You will not get additional benefits by riding harder than zone 2 when you do an endurance ride. The whole point of an endurance ride is to allow the muscles to spend time under contraction with low tension and low physical stress. This is the endurance ride recipe for mitochondrial biogenesis plus the ability to recover and come into your high intensity sessions more fresh. Pushing endurance rides harder than the zone 2 ceiling leads to unnecessary stress, delayed recovery time, and may lead to overtraining syndrome in the long term if you do so consistently.

Even though endurance rides are done at low intensity, roughly 40-50% of your energy is created by burning carbohydrates. This means that you still need to fuel your low-intensity endurance rides with carbohydrates to prevent bonking and lower the body’s cortisol response to exercise (carbohydrate intake during training lowers cortisol). The longer your ride, the more fuel you will need, and most endurance rides from 2h-5h+ should be fueled at a rate of 60-90g/h. Your fitness level and how much power you are producing will influence how much fuel you should take in too. However many calories you are burning per hour, you should be replacing roughly 30%-50% of them with carbohydrates on the bike.

For high-intensity racing, I see no place for low-carb training. If you attempt to do them, you should work with a nutrition professional to execute them properly. In my opinion, low carb training is only beneficial for athletes who race at an intensity entirely below the lactate threshold, such as ultrarunners and adventure athletes who need to rely mostly on fats for energy production during extremely long events 9+ hours. Low-carb training does not improve performance, but it does improve metabolic flexibility, which is the ability to switch between burning carbs and fats. The most appropriate time to execute low-carb training would be during the base season, 1-3x per week, only on easy/endurance days, but I don’t recommend it.

Below is a list of some of the main purposes of low-intensity riding, and how the body adapts to get fitter by doing them:

• Continuous muscle contraction for long periods increases CaMkII enzyme activity which communicates to PGC-1a to increase mitochondrial biogenesis (you make more mitochondria in muscle fibers which produce energy aerobically)

• Training at low intensity dampens the catecholamine response to exercise (lowers the body’s stress response at low intensity which allows you to ride more volume at low intensity)

• Endurance rides activate the aerobic energy system, improving the efficiency of oxidative phosphorylation, beta-oxidation, fat oxidation

• Athletes have a higher tolerance for increased volume when riding at appropriate low intensities

• Endurance riding improves lactate buffering via greater fat oxidation (lower reliance on CHO) and an increased mitochondrial reticulum

• Allows time for recovery from high-intensity sessions while still getting a training stimulus that increases mitochondrial biogenesis

• Improves respiratory quotient (burn a higher proportion of fats vs carbs at low intensity)

• Improved glycogen sparing via increased fat oxidation

• Improved neuromuscular efficiency due to high repetition of the pedal stroke

SUMMARY:

• Most of your training (~80%) should consist of lower intensity training (zone 2 and below)

• Endurance riding correlates to continuous riding at an intensity below 75% FTP, 75% max HR, 85% FTHR, or 180 minus your age

• The adaptive pathway of endurance riding is via CaMKII enzyme activation which upregulated PGC-1a expression, which increases mitochondrial biogenesis

• Endurance rides lower the catecholamine response to exercise (you experience less stress hormones the more you do these rides)

• Most endurance rides should not feel hard, and you should be riding at a conversational pace with steady pressure on the pedals and a smooth cadence

• Endurance riding increases the number and function of mitochondria in the muscle, which makes you better at creating energy and removing waste products (lactate).

• Endurance riding increases your body’s ability to use fats as a fuel. This adaptation primarily comes from riding for long durations and in a low glycogen state near the end of the ride

• Endurance riding is a stimulus for your type IIa fast twitch fibers to develop the characteristics of type I slow twitch fibers by increasing the type IIa mitochondrial and capillary content. This adaptation primarily comes from riding high endurance or near the end of long rides when your glycogen runs low and your type I fibers become fatigued

• Even though endurance riding is low intensity, you are still burning roughly 40%-50% carbohydrates, so fueling these long rides at a rate of 45-90 grams per hour (depending on duration and intensity) is crucial to lowering the amount of stress the body undergoes throughout the ride