If you train harder, you get faster, right? It might seem logical, but increasing volume and intensity can overwhelm your ability to recover, and may even lead to burnout or injury. By incorporating the concept of minimum effective dose in your training, you can find a healthy balance and ensure consistent improvement over the long term. 

For more on minimum effective dose check out Ask A Cycling Coach Ep. 284

What is Minimum Effective Dose?

The minimum effective dose (or MED) is the smallest amount of an input required to achieve a desired outcome. While the concept comes from medicine, it can be applied to any situation in which a stimulus is applied to the body to elicit a response. In our case, that stimulus is training, the dose is volume and intensity, and the desired result is usually improving fitness. 

A related medical concept is the dose response curve. By increasing the dosage of a substance or stimulus, the body’s intended response also increases, but the relationship isn’t linear and the response gradually plateaus. More of a good thing is better, but only to a point.

In any context, minimum effective dose is always defined relative to a desired outcome. For instance, the MED of training needed to win a local crit is different than that required to win the Tour De France. To further complicate things, the minimum effective dose for the same goal varies from athlete to athlete, and will even vary for the same athlete at different times.

How Minimum Effective Dose Applies to Training

Training works by disrupting the body’s state of equilibrium- otherwise known as homeostasis. Workouts stress your body beyond its current capacity, and it overcompensates through recovery to become stronger. Crucially, each training session needs to be enough to stimulate a response, while still allowing for more training in the coming days and weeks. Train too little, and you won’t get faster; train too much or too hard, and you’ll outpace your ability to recover and need time off.

Using minimum effective dose to guide your training ensures the healthiest and most sustainable balance between stress and recovery. It enables steady, long-term improvement, and helps avoid burnout and injury. Ironically, a minimal dose is the most effective way to achieve maximal performance improvements, year after year.

Determining Minimum Effective Dose

Finding your MED is an iterative process, requiring long-term experimentation and careful trial and error. Start conservatively- for instance, try a low-volume plan and assess your body’s response before you add extra workouts or attempt high-volume training. Within your training plan itself, each workout should be challenging but achievable, and none should create so much fatigue as to impact the completion of upcoming workouts. As you get fitter, intensity and volume will inevitably need to increase for you to continue improving, but always pay close attention to your body. If the dose response curve levels off and fatigue outpaces recovery, you’ve gone too far. 

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Minimum Effective Dose and Goals

Since MED is defined in relation to outcome, you need to consider your goals when determining whether your training is working. For most athletes, the fundamental purpose of training is to improve fitness and performance. In this regard, it’s fairly easy to assess your training: if you’re improving, the dose is at least sufficient. However, there are a few times when the desired outcome of training is not a short-term improvement in fitness. In these cases, the minimum effective dose drops dramatically, and it’s important to be aware that you shouldn’t always be chasing gains.

Offseason recovery periods are one example. The MED of training during this time is an amount that maintains some aerobic fitness, without adding any real fatigue. This might be as little as one or two easy rides a week, or even no riding at all if you do some cross-training. In this case, the effective dose of training is truly minimal, as the desired outcome is recovery. 

Likewise, the MED of training during periods of injury or life stress is dramatically lower than normal. Your body doesn’t compartmentalize stress, and the fatigue of work or family challenges reduces what you can productively tolerate on the bike. This is known as allostatic load, and represents the cumulative effect of all the stress you experience. While this stress won’t make you faster, it will run you down, and like it or not it is part of the dose equation. Just because you can train more, doesn’t mean you should– especially when you’re resting, injured, or dealing with challenges off the bike. 

How TrainerRoad Plans Incorporate Minimum Effective Dose 

Every TrainerRoad training plan uses Minimum Effective Dose as a guiding principle. The Base/Build/Specialty progression is designed to steadily develop your fitness over time in a sustainable manner. FTP Assessments every 4-6 weeks ensure that intensity is calibrated to your ability, so your training dosage is always appropriately matched to your fitness. And most importantly, Adaptive Training ensures that every workout is directly tied to your needs, without outpacing your abilities.

Minimum Effective Dose also explains the nuance of how plans are designed. Contrary to a common misconception, a low-volume plan is not just ⅓ of a high-volume plan. Sweet Spot Base II is a prime example.

Sweet Spot Base II, Low-Volume: Week 3
Sweet Spot Base II, High-Volume: Week 3

During the third week of training, the low-volume plan includes 3 workouts, all of which incorporate intervals above FTP. This same week in the high-volume version consists entirely of Sweet Spot workouts and never goes above FTP.

Because the training dose in the high-volume plan is quite large, intensity is lower. On the other hand, the low-volume plan is necessarily more intense, but in a lower dosage. Both plans target the same end result, and seek to avoid overtraining along the way.

Adaptive Training

Minimum Effective Dose is also one of the guiding principles behind Adaptive Training‘s continual customization of your training, and a big part of how Adaptive Training makes you faster. By monitoring your abilities with Progression Levels, your plan adjusts each workout to be the right one for your abilities and needs—but this doesn’t mean making each workout as difficult as possible. In fact, minimum effective dose dictates that while some workouts do need to be very challenging to continue progressing your abilities, others should be easier, to prevent your body from overreaching. This is why Adaptive Training’s adjustments go both ways, with some workouts becoming tougher and others adapted to be less difficult as you progress in your training. With the right balance of productive days interspersed with easier, more achievable workouts, you get the minimum effective dose needed to sustainably reach your goals.