Is It Possible to Get Fit Fast?

Everybody wants to get that beach body right now or to run that 10k next month, but can you really get fit fast?

Brock Armstrong
6-minute read
Episode #448

Everybody wants to get fit fast ... but should you?

In my early coaching career, I specialized in marathon and triathalon coaching. I eventually branched out and worked with everyone from fitness models to previously sedentary seniors. But consistently, throughout my career, people would email or call and ask seemingly innocent questions like: How long will I need to train to complete a marathon? 

My answer generally alternated between either “as long as possible” or “it depends.” Obviously, neither of these were the answer people wanted to hear.

For someone going from the couch to a marathon, I would recommend 10-12 months of training. If you have a solid running background (three or more years of consistent running), or you want to simply improve your finishing time, 16-20 weeks could do the trick.

But keep in mind that training for a marathon isn't the same as training for overall fitness. This equation changes when the question is “How long do I need to train to get fit?”

What is Getting Fit?

The illusive condition of “being fit” is something I have written about numerous times, and I still feel like the definition of fitness is open to discussion. But for sake of this conversation, I am going to define fitness as: “Activities relating to keeping healthy and strong, especially through movement.”

There are a couple reasons why I like this definition.

  1. It doesn’t contain the (loaded) word “exercise”

  2. It implies that fitness is a continuum, not a finish line 

Before we get into why I think those are important points to make, let’s look at some science.

Six Weeks to Fitness?

First, let’s look at a short duration study that reminds me of something you would see advertised in your social media feed with a title like “The Six Week Body Transformation.”

In a 2004 study published in The Journal of Strength and Conditioning Research, researchers put 25 previously sedentary men through a pretty standard six-week exercise program. The men either performed three 20-minute cardiovascular sessions per week or three 30-minute high-intensity, full-body strength sessions.

Even the study participants themselves agreed that their own appearances were pretty much the same after six weeks.

For the study, a group of panellists were asked to rate each man's appearance before beginning the program. After the six weeks of training, they were once again asked to rate photos of the men. Can you guess what the panelists said?

Yup, at the end of the six weeks, their ratings were unchanged. Even the study participants themselves agreed that their own appearances were pretty much the same after six weeks. And to top it off, even the more objective signs of fitness (body fat percentage, oxygen efficiency, and some physical fitness tests) did not improve over the course of the study.

Nine Months to Fitness?

On the other end of the spectrum, a 2007 study in the European Journal of Applied Physiology, put a group of untrained adults through a nine-month marathon training program. At the conclusion of the study, the participants had increased their cardiovascular fitness (VO2 max) by 24 percent, improved their running speed by 29 percent, and reduced their Apo B  (a predictor of heart disease) by 18 percent. 

So, at this point, we know that somewhere between six weeks and nine months is how long it takes to get fit ... at least by some measures. That is a pretty wide window, and it's about to become even wider. 

At this point, you may be thinking, “OK Brock, both of those studies involved some pretty simple-sounding workout programs. If hit the gym super hard, can I get fit faster?”

Does Intensity Make You Fit Faster?

A 2007 study in the Journal of the American Medical Association assigned 360 sedentary, overweight, or obese women to one of three groups: one exercising at 50 percent, 100 percent, or 150 percent of the recommended energy expenditure level.

After six months, not all that surprisingly, the women who worked out at the highest intensity level improved the most in their cardiovascular fitness (8 percent) while the women who exercised at the lowest intensity level saw the smallest increase in fitness (4 percent).

So, yes. If you workout harder, you will see faster results, to a certain extent.

But remember the law of diminishing returns. The Australian College of Physical Education explains it very well:

“When someone unfit begins a training regime, fitness levels improve rapidly, but as they become fitter, the returns diminish. That is, as you become fitter, the amount of improvement is less as you approach your genetic limits.” 

When someone unfit begins a training regime, fitness levels improve rapidly, but as they become fitter, the returns diminish.

So, those same women who saw the eight percent increase in fitness after six months will not see 16 percent after 12 months and 24 percent after 18 months. Basically, by the time they cease being categorized as “sedentary, overweight, or obese,” no matter how hard they continue to work out, they will see diminishing results. 

There is also the problem of potential injuries at these higher intensities. I have written about the problem of “too much, too soon” a few times. No example is better than CrossFit. That's not because CrossFit is inherently dangerous or poorly designed. It's simply due to its focus on high intensity and competition style (or what is called “for time”) workouts. 

According to a study called The nature and prevalence of injury during CrossFit training, 73.5 percent of people sustained an injury during their CrossFit training. So yes, training with this type of intensity will get you “fit fast,” but only if you are in the lucky (or is it smart?) 26.5 percent of people who don’t end up injured. 

Fitness in a Different Light

Now let’s go back to the definition of fitness that I stated at the beginning of this article. Here's why I think we need to look at the answer to this question of “how fast can I get fit?” in a different light. 

Fitness: activities relating to keeping healthy and strong, especially through movement.

To me, the word "movement" is key. For most of us, the word "exercise" conjures a notion of dedicated time set aside specifically to perform a routine of one type or another (a workout). Our workouts usually take place in a specific set of clothes (workout gear) and in a specific environment (like a gym).

But fitness doesn’t come solely from workouts, which take up a small portion of our time. It's also dependent on all the movement we perform on a regular and consistent basis througout the day. In fact, not including regular movement in our day could actually be making those exercise periods less effective.

In a 2019 study published in the Journal of Applied Physiology, researchers showed that four days of prolonged sitting actually caused a state they dubbed “exercise resistance.”

The researchers took ten participants and had them sit around for more than 13 hours a day (taking fewer than 4,000 steps per day) for four days. At the end of the four-day sit-fest, they were asked to do a difficult hour long treadmill workout. A workout like that would normally result in some healthful metabolic benefits that last about 24 hours. But after all the sitting, the workout no longer resulted in the benefits we associate with a solid bout of exercise.

Not including regular movement in our day could actually be making our workouts less effective.

The researchers concluded that “It seems that something inherent to inactivity and/or prolonged sitting makes the body resistant to the [one hour] of exercise preventing the normally derived metabolic improvements following exercise.”

There is No Finish Line

This brings me to the other important part of my “what is fitness” definition: “activities relating to keeping healthy and strong.” That part of the definition implies that there is no finish line in fitness—this is an ongoing process. Fitness is not something you achieve and then rub your hands together and say “OK, great! Now I'm fit.” I think people who are interested only in quick fitness and weight loss forget that fitness is a lifestyle and not an end game. 

I think people who are interested only in quick fitness and weight loss forget that fitness is a lifestyle and not an end game.

In weight loss, the lack of meaningful lifestyle and dietary changes often means regaining the lost weight, or perhaps more. (That's the main reason I co-created the Weighless program). In fitness, it usually results in the never-ending cycle of dragging yourself off to the gym, boot camp, or boosts of quick-fix activity that are treated more like taking medicine than celebrating your body and all its achievements. 

I encourage you to look at your fitness journey as a long-term commitment, not something to rush through. 

Instead of thinking about how quickly you can get in shape, think about how long you want to be able to move your body through the world in the ways that bring you joy. Instead of focussing on how little time you can get away with dedicating to your fitness improvement, focus on how much you enjoy moving your body in new and exciting ways. 

In short, as corny as it sounds, focus on enjoying the journey not on crossing the finish line. Honestly, if you want your fitness to last, there is no finish line. We’re in it for the long haul, so make it sustainable, meaningful, and fun.

All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.

About the Author

Brock Armstrong Get-Fit Guy

Brock Armstrong was the host of the Get-Fit Guy podcast between 2017 and 2021. He is a certified AFLCA Group Fitness Leader with a designation in Portable Equipment, NCCP and CAC Triathlon Coach, and a TnT certified run coach. He is also on the board of advisors for the Primal Health Coach Institute and a guest faculty member of the Human Potential Institute.