The Complications of the Minimum Effective Dose Principle

An interesting concept has crept into the fitness industry in recent years that seems to go against the traditional “Eat less, move more” dogma we’ve been ingrained with. That is the concept of the minimum effective dose (MED), which was popularized in Timothy Ferriss’ bestseller, The Four Hour Body.

The definition of the MED is the minimal dose that will produce the desired outcome or effect. This is easily illustrated in the pharmaceutical industry where the MED is the amount of drug needed to produce the desired effect in the body an more of the drug will not improve the effect or could even cause harm.

Another real life example is boiling water. Water boils at 100 degrees Celsius. Heating the water above that will not make the water boil more or faster. Heating it beyond that temperature will only be a waste of resources.

When it comes to fitness the question then becomes, “What is the least amount of activity needed to produce the desired outcome?” The answer, of course, is more complicated than it would seem and varies depending on what you’re trying to accomplish. Weight loss goals will be different than performance goals. Endurance goals will be different than muscle building goals.

Unfortunately this is not a question that many people ask. The “Eat less, move more” philosophy has trained us to just assume that we need to do more to get results. I’ve written extensively about why more is not better, but the question of the MED takes it to the other end of the spectrum.

What if we all asked “What is the type of activity and the amount of that activity needed to produce results?” When it comes to weight loss clients we start small.  Make the easy changes like daily walks, drink more water, and eat more green, leafy vegetables. There’s a does for each of those activities that is effective and a point at which doing more of each could have detrimental effects. Excessive walking could produce blisters for the untrained, and an excess water consumption could result in hyponatremia (a sodium imbalance in the body that can have serious health consequences). Eating too many vegetables is usually something we don’t need to worry about but it could, in theory cause digestive issues or prevent you from getting enough healthy fats in the diet if that’s all you ate.

As far as workouts go there is a lot of evidence for high intensity interval training being more effective than long slow cardio for weight loss. This approach can also keep you in pretty good cardiovascular shape. A couple of sprint sessions a week for me and I can still go out and run five miles without a problem. Much further than that though and I would be in trouble. That’s where the goal comes into play. The activity and dose necessary for getting in shape to run a marathon is much different than getting in shape to run a 10k.

Further complicating matters is that you may be following the most efficient workout program, but other factors can influence the outcome of that program.  Diet and sleep can have a huge impact on the effectiveness of any program. It’s tough to get results with a poor diet and lack of sleep can lead to poor recovery and hormonal issues.

The MED approach can be applied to diet as well. How few carbs can you get away with without sacrificing performance? How many carbs can you tolerate without slowing fat loss? How little food can you eat without feeling ravenous, gaining weight, or losing muscle mass?

Again, all of these situations are goal dependent and trial and error is usually necessary to dial in all of the variables. What’s worked in the past may need tweaking to get over plateaus. What works for one person may not work for another. Everything you do or change should have a purpose too, in order to get you closer to your goal.

The only exception I’ve found to that rule though is when it comes to the minimum effective dose for maintaining mental sanity. I used to run, bike, and swim absurdly large amounts every week because I truly enjoyed it and it made me happy. Once that was no longer the case I scaled back. Now I train with kettlebells five days a week and run a few times too.  It’s probably more than I need to do to keep my body composition where I want it, maintain my kettlebell skills, and stay in shape, but it keeps me happy and hasn’t been detrimental to my health thus far.

Like the medical example given earlier our lives are dependent on many different inputs, or “drugs.” They all interact with the others and finding the precise ones and dosages necessary for results can be a complicated process.  Me, I relish the complication.  It means I get to continually test, tweak, and change my routines and activities. For others it’s tedious and frustrating.

It’s all necessary though. There may be general principles and methods that prove effective for most people. Past that it is up to the individual to determine their minimum effective dose for a happy and healthy life.

Pullup, Lunge, Swing "Fun"isher
Bodyweight + Swing "Fun"isher

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