Original episode & show notes | Raw transcript
In the world of cycling training, “Sweet Spot” is a popular intensity zone, but its purpose and application are often misunderstood. It is not a magical intensity that builds fitness without fatigue, nor is it the foundation of a complete training plan. As presented in the podcast, Sweet Spot is best understood as a valuable and versatile tool in a cyclist’s toolbox. It’s the “extra cake,” not the icing or the foundational ingredients. Its true value lies in its strategic application, tailored to an individual’s goals, training history, and physiological profile.
This guide will deconstruct the core concepts of Sweet Spot training, exploring its physiological basis, practical applications, benefits, and limitations, all through the experienced lens of the Empirical Cycling coaches.
At its core, Sweet Spot is a training intensity that sits in the upper end of the “Tempo” zone and just below an athlete’s Functional Threshold Power (FTP).
Definition: The hosts define Sweet Spot very simply and consistently as approximately 90% of FTP.
The “Gray Zone”: This intensity falls into a physiological gray zone. It’s significantly harder than traditional endurance riding but sustainably easier than riding at your threshold.
The Original Premise: The concept was popularized with the idea that it provides nearly the same adaptive benefits as threshold training but with substantially reduced acute fatigue. While there is truth to this, the hosts argue this view often “misses the forest for the trees.”
To truly compare different training intensities like Sweet Spot and Threshold, one must understand the concept of Time to Exhaustion (TTE).
TTE Defined: TTE is the maximum duration an athlete can sustain a given power output or intensity. While often used in the context of FTP (TTE at FTP), the concept applies to any intensity. You have a TTE at Sweet Spot, a TTE at VO2 max, and so on.
The Key to Equivalent Training Dose: The hosts argue that for two different interval sessions to be considered roughly equivalent in training stimulus, they must both be performed to near exhaustion. This is the cornerstone of their philosophy.
The duration an athlete can hold Sweet Spot is highly variable and serves as a key indicator of their muscular endurance and overall training status.
Untrained Athletes: Can typically hold Sweet Spot for 40-60 minutes. This is slightly longer than the 30-40 minutes they might hold their threshold power.
Well-Trained Athletes: The range expands dramatically with training. Most well-trained amateurs can hold it for 1.5 to 2 hours.
Elite & Ultra-Endurance Athletes: World Tour pros or elite ultra-racers might sustain 90% of their FTP for 3 hours or more in a single effort. Factors like genetic predisposition and, most importantly, high training volume contribute to this exceptional endurance.
The physiological adaptations from Sweet Spot training are largely identical to those from training at your threshold. They primarily target improving your muscular endurance. This includes:
Increased mitochondrial density and efficiency.
Enhanced lactate clearance and utilization.
Improved capillarization of muscle fibers.
The key difference is not what adaptations occur, but the cost-benefit ratio in terms of time, fatigue, and logistics. Early in a training season, for instance, Tempo, Sweet Spot, and Threshold work will all push an athlete’s fitness in a similar direction. The choice depends on the individual’s needs and constraints.
Lower Acute Fatigue: For a given duration, it is less stressful than threshold work. This makes it a great option for adding stimulus without accumulating excessive fatigue.
Accomplishable When Fatigued: It can be a productive intensity to hit mid-season between races or as a third “hard” day in a demanding training block when an athlete might be too tired for a full-on threshold session.
Psychologically Easier (Initially): The lower intensity can be more mentally manageable, especially for athletes returning from a break.
Effective for Over-Unders: It serves as an excellent “under” intensity for over-under intervals (e.g., alternating between 105% and 90% of FTP), as it’s challenging enough to prevent full recovery but manageable enough to allow for repeated “overs.”
A Safety Net for Incorrect FTP: If an athlete’s FTP is overestimated (a common issue with ramp tests), “Sweet Spot” training may inadvertently become true threshold training, making it a productive workout by accident.
Poor Time Efficiency: This is the most significant drawback. As an athlete gets fitter, the duration required to reach TTE at Sweet Spot becomes very long. A 2-hour Sweet Spot workout is simply not feasible for a time-crunched athlete with only 60-90 minutes to train. In such cases, higher intensities (Threshold, VO2 max) are a more efficient use of limited time.
Can Become a “Crutch”: Because it’s a comfortable hard pace, athletes can get stuck doing only Sweet Spot, leading to a plateau. It cannot be the sole focus of a training plan; it must be integrated with easier endurance work and higher-intensity efforts.
May Not “Feel” Like Progress: Because it’s 10% below FTP, an athlete might not perceive their threshold power increasing, especially if they are psychologically attached to hitting certain numbers. Well-trained athletes with a good sense of RPE (Rate of Perceived Exertion) can auto-regulate and push the power up as they get fitter, but others may get stuck.
Risk of Accumulated Fatigue if Overused: While a single session is less fatiguing than threshold, doing long Sweet Spot workouts to exhaustion multiple times a week (e.g., 4-5 times) will lead to significant fatigue, potentially masking true fitness improvements.
The podcast repeatedly emphasizes that the decision to use Sweet Spot training should not be based on hype or a rigid training philosophy (e.g., “Sweet Spot vs. Polarized”), but on a careful analysis of the individual.
What is my goal?
Criterium Racer: A crit is an hour of surging. While some muscular endurance is vital, spending weeks pushing your Sweet Spot TTE from 2 to 3 hours is likely a poor use of time compared to working on VO2 max and anaerobic power.
Ultra-Endurance Racer: If your event involves many hours of steady, hard climbing, then extending your Sweet Spot TTE is highly specific and beneficial. It can be a time-efficient way to simulate the demands of long-duration events if you can’t do 10-hour rides regularly.
Hilly Gran Fondo: This is a prime application for Sweet Spot, as it mimics the demands of long, sustained climbs at a hard but sub-threshold pace.
How much time do I have to train?
Time-Crunched (e.g., <8 hours/week): Sweet Spot is generally a poor choice for weekday workouts. Higher intensities are more effective. It can, however, be used strategically on a longer weekend ride.
High Volume (>12 hours/week): Athletes with more time can more easily incorporate the long sessions required for effective Sweet Spot training.
What are my physiological limiters?
What is my training history and psychology?
If you’re coming back from a break, Sweet Spot is a great way to re-introduce intensity.
If you find long, steady-state efforts mentally rewarding and they make you “feel invincible,” that psychological boost is a valid reason to incorporate them. Motivation is a key component of consistent training.
Fueling is a critical, and often limiting, factor for long Sweet Spot sessions due to the high kilojoule expenditure.
Muscle Glycogen is King: What you eat the day before a hard workout is paramount. Arriving with fully stocked muscle glycogen stores is the primary determinant of how much work you can accomplish in the session.
Fueling on the Bike: Eating during the ride is crucial for two reasons:
Performance: It spares liver glycogen, preventing the “bonk” from low blood sugar and helping you sustain the effort longer.
Recovery: It kick-starts the recovery process, reduces the overall stress response, and prevents the need to “house down 5,000 calories” post-ride.
Practice for Race Day: Long Sweet Spot rides are an ideal opportunity to practice and dial in your race-day nutrition strategy.
The central message from the podcast is one of nuance and individuality. Sweet Spot training is neither overrated nor underrated; it’s a rated tool. Like any tool, its effectiveness depends entirely on whether it’s used for the right job, at the right time, by the right person.
Forget searching for a formula to predict your Sweet Spot duration from your FTP. The most effective approach is to go out and do the work. Listen to your body, track your progress (is your TTE increasing?), and, most importantly, measure the outcome where it matters: in your goal events. By abandoning dogma and embracing an individualized, goal-oriented approach, Sweet Spot can be a highly effective component of a well-rounded training program.