40 20 intervals cycling refers to a high-intensity interval training (HIIT) workout where you alternate periods of high-intensity exercise with periods of lower intensity active recovery. Specifically:
- 40 refers to the duration (in seconds) of the high-intensity intervals. So you would workout at a high level of effort for 40 seconds at a time, typically 120% to 145% of your Functional Threshold Power (FTP).
- 20 refers to the duration (in seconds) of the lower intensity active recovery intervals in between. So after a 40 second high intensity burst, you would then have a 20 second period of lower intensity to recover before the next high intensity interval, typically around 35% of your FTP.
- This 40 second on, 20 second off pattern is repeated multiple times, forming ‘intervals’ of work and recovery. Doing a number of intervals in this manner makes up an interval training session.
- This type of workout is commonly done on a bike (either stationary or road bike), which is why it is referred to as interval ‘cycling’. But 40/20 intervals can also be done with other exercises like running or swimming.
The idea is that the high intensity intervals help boost fitness, endurance and calorie burn, while the recovery intervals allow you to put in more total interval time versus just working at a moderate steady pace the whole workout. The on/off pattern gets results very efficiently.
What If I Don’t Know My FTP?
Above we covered how to set the intensity targets for a 40/20 cycling workout. These rely on knowing your Functional Threshold Power (FTP).
But what if you do not know your FTP? Can you still benefit from interval training workouts?
While knowing your FTP (Functional Threshold Power) is highly beneficial for effective interval training in cycling, it’s not absolutely necessary for getting started. Here’s a breakdown of both sides:
Benefits of knowing your FTP:
- Precise targeting: FTP provides a quantifiable measure of your fitness, allowing you to design interval workouts at specific intensities targeted to boost your performance. You can set intervals at percentages of your FTP to push yourself in the right zones for optimal training (e.g., 120% FTP “on“, and 55% “off” in this workout).
- Improved efficiency: With an accurate FTP, you avoid over-training or under-training. You can track progress by retesting periodically and adjust your training plan accordingly.
- Structured guidance: Many training plans and platforms are based on FTP data. Having this number makes following plans or using apps much easier and more effective.
Alternatives when you don’t know your FTP:
- Perceived exertion: Use the RPE scale (Rate of Perceived Exertion), ranging from 1 (easy) to 10 (maximal effort), to gauge your intensity during intervals. Aim for intervals around 7-8 on the RPE scale.
- Heart rate (HR): Personally I really dislike training to heart rate. It is highly specific to the individual and I would not suggest using this as a sole metric when training.
- Time-based intervals: Choose interval durations based on your current fitness level and goals. In this example we are working to 40 seconds “on” and 20 seconds “off”, but you can change these numbers to suit your levels of fitness.
Ultimately, the decision depends on your goals and training experience:
- Beginners: Start with simpler RPE or time-based intervals and focus on building a base fitness before diving into structured FTP-based training.
- Intermediate/Advanced riders: Knowing your FTP unlocks significant benefits for maximising your training and tracking progress. Consider investing in an FTP test or using online calculators for an estimate.
Remember, consistency and effort are key in interval training, regardless of whether you know your FTP. Listen to your body, adjust intensity levels as needed, and enjoy the workout.
How To Warm Up For 40/20 Intervals
There are two ways that I would choose between when warming up for 40/20 intervals.
Choosing between the two, for me, depends on whether I am indoors or outdoors, and whether or not I have access to a cycling computer.
The Outdoor Warm Up
If I am outdoors, and following a fairly loose structure to the workout where I am tracking the intervals by counting the seconds in my head, I would warm up as follows:
First 5 minutes:
- Easy spinning: Start with 5 minutes of easy spinning at a comfortable pace. This gets your blood flowing and warms up your muscles gently. Aim for a cadence of around 90-100 rpm.
Second 5 minutes:
- Progressive drills: Gradually increase your intensity with short bursts of effort. Try 30 seconds at moderate pace (70-80% FTP), followed by 30 seconds of easy spinning. Repeat this 3 times.
Tips:
- Listen to your body and adjust the intensity and duration of the warm-up as needed.
- Focus on maintaining good posture and pedaling technique throughout the warm-up.
- Hydrate by taking small sips of water throughout the warm-up.
The Indoor / Structured Warm Up
If I am indoors, and / or using a cycling computer or indoor training software like Zwift, MyWhoosh, or similar, I would use a more structured warm up. The reasoning for this is that the computer will be able to control the simulated level of resistance, giving me a more controlled build up.
Here’s a breakdown of each segment in your warm-up:
- 2 minutes @ 60% FTP:
- This serves as the starting point, allowing your body to ease into the workout.
- FTP stands for Functional Threshold Power, and training at 60% of it is a moderate intensity to get your muscles warmed up.
- 2 minutes @ 70% FTP:
- The intensity increases slightly, continuing to raise your heart rate and warm up your muscles further.
- 2 minutes @ 80% FTP:
- The intensity continues to climb, bringing you closer to the threshold of your aerobic capacity.
- 1 minute @ 90% FTP:
- This is a short burst at a high intensity, pushing your body to the upper limits of aerobic effort.
- It’s a brief but intense effort to fully activate your cardiovascular system.
- 2 minutes @ 55% FTP:
- This serves as a brief recovery period after the high-intensity burst, allowing your heart rate to come down slightly.
- 3 minutes @ 65% FTP:
- This segment maintains a moderate intensity, providing a balance between recovery and continued warm-up.
After this warm-up phase, you move on to the more structured interval training. The warm-up is crucial to prepare your cardiovascular and musculoskeletal systems for the challenges ahead, helping to prevent injury and optimise performance during the main part of your workout.
How Many Intervals Should I Complete?
The main set of this workout consists of repetitions of our 40/20 intervals with five minute breathers between each block.
You can adjust the workout in a number of ways if the initial structure looks to be too challenging. More on that below.
Phase 1
This is the bulk of today’s work.
- 12 sets of 40 seconds at 120% FTP:
- After the warm-up, you have 12 intervals of high-intensity efforts at 120% of your FTP, each lasting for 40 seconds.
- 20 seconds at 55% FTP between each high-intensity interval:
- Following each 40-second high-intensity interval, you have a 20-second active recovery period at 55% of your FTP.
- 5 minutes at 66% FTP:
- After completing the 12 high-intensity intervals with recovery, you have a 5-minute period at 66% of your FTP. This serves as a recovery period.
Phase 2
Did you enjoy phase 1?
What do you mean, no!?
Well, Phase 2 is a full repeat of Phase 1.
Phase 3
Phase 1 and Phase 2 were really tough.
Fortunately Phase 3 is shorter:
- 6 sets of 40 seconds @ 120% FTP
- 20 seconds at 55% FTP between each high-intensity interval
Brutal.
How Can I Adjust The 40/20 Workout To Make It Easier?
To make the workout easier, you can consider adjusting the intensity and duration of the intervals. Here are some suggestions:
- Reduce Intensity:
- Lower the percentage of FTP during the high-intensity intervals (40 seconds @ 120% FTP). For example, you can decrease it to 110% or even 100% FTP.
- Increase Rest Intervals:
- Extend the 20-second rest intervals between the high-intensity intervals. You can increase it to 30 seconds or more to allow for more recovery.
- Shorten Duration:
- Reduce the number of intervals in each set. Instead of doing 12 intervals, you can start with a smaller number, like 8, and gradually increase it as you get more comfortable.
- Decrease Overall Duration:
- Shorten the entire workout by removing one of the main sets. For example, you can do only one round of the main set instead of repeating it twice, or do two repeats of the shorter Phase 3 blocks.
How To Cool Down From 40/20 Intervals
Much like the warm-up, the cool down for the 40/20 workout depends on whether you are following a primarily structured or unstructured workout.
If outdoors or following an unstructured workout I would simply do light pedalling now for 10 minutes. You earned it!
The main thing is not to just stop.
The Outdoor Cool Down
While getting off the bike immediately after an intense cycling workout might seem like a tempting option, incorporating a structured cool-down has several benefits that can contribute to your overall fitness and well-being. Here are some reasons why it’s beneficial to include a cool-down instead of simply getting off the bike:
- Gradual Heart Rate Reduction:
- A structured cool down allows your heart rate to gradually decrease. Suddenly stopping intense exercise can lead to a rapid drop in heart rate, which may cause dizziness or discomfort.
- Metabolic Waste Removal:
- Continuing to pedal at a lower intensity helps to flush out metabolic byproducts (such as lactic acid) that accumulate during intense exercise. This can aid in reducing muscle soreness and stiffness.
- Cooling Down Muscles:
- A gradual cool down helps your muscles cool down more gradually, preventing the abrupt cessation of exercise, which can lead to muscle cramps.
- Injury Prevention:
- Cooling down can contribute to injury prevention by allowing your body to transition from a state of intense activity to a more relaxed state. This can reduce the risk of muscle strains or other injuries.
- Enhanced Flexibility:
- Performing gentle stretches during the cool down can help improve flexibility. Flexibility is important for overall joint health and can contribute to better cycling performance.
- Mental Transition:
- The cool down serves as a mental transition from the focused, high-intensity workout to the post-exercise recovery phase. It provides a few moments for reflection and mental relaxation.
In short, while it might be tempting to skip the cooldown and hop off the bike immediately, the additional few minutes invested in a structured cooldown can pay off in terms of both immediate comfort and long-term fitness gains. It’s a holistic approach that takes into account the physical and mental aspects of your well-being, contributing to a more balanced and effective training regimen.
The Indoor / Structured Cool Down
A more structured cool down can be achieved when indoors or using a cycling computer that controls the trainer resistance. This cool down involves reducing the intensity gradually over a 10-minute period, transitioning from 55% to 25% of your FTP (Functional Threshold Power).
Here’s a breakdown of how you might structure your cool down:
Cycling Cooldown: 10 minutes
- Minute 1-2: 55% FTP
- Begin by pedalling at a comfortable pace, maintaining a power output equivalent to 55% of your FTP.
- Focus on keeping a smooth and controlled cadence.
- Minute 3-4: 45% FTP
- Gradually reduce the intensity to 45% of your FTP.
- Continue to pedal smoothly, allowing your heart rate and breathing to gradually decrease.
- Minute 5-6: 35% FTP
- Further decrease the intensity to 35% of your FTP.
- Use this time to relax your muscles and mentally wind down from the more intense part of your workout.
- Minute 7-8: 25% FTP
- Continue the reduction in intensity, now targeting 25% of your FTP.
- Focus on maintaining good cycling form and use this time for gentle recovery.
- Minute 9-10: Active Recovery
- For the final two minutes, allow yourself to pedal very lightly, almost like a spinning motion.
- This active recovery helps flush out metabolic byproducts and aids in muscle recovery.
Culmination and Takeaways: Achieving Fitness Goals with 40/20 Intervals Cycling Workout
The 40/20 intervals cycling workout offers a time-efficient and adaptable HIIT regimen to build endurance and enhance fitness.
Its structured format of high-intensity 40-second efforts followed by 20-second active recovery intervals can be customised across ability levels. Supported by crucial warm-up and cool-down protocols, this workout provides a comprehensive approach to training.
While intensity levels should align with individual fitness, the flexibility to tailor exertion, rest periods, duration, and structure ensures an appropriate challenge.
Ultimately, the 40/20 intervals workout presents a dynamic, efficient and balanced training template with broad exercise applications to aid fitness development through consistency and effort.