If you’ve ever stayed up watching late night movies, you’ve probably seen commercials promising miracle total body makeovers.
You know the kind. “Just 30 minutes of exercise a day, three times a week, and you could have a totally ripped body in as little as six weeks.”
It sounds good, but the truth is, there’s no quick way to get fit.
“If a gym, trainer, or class promises to make all your dreams come true in six weeks, run — don't walk — in the other direction,” New York-based certified personal trainer Lisa Snow, president of On the Mend Customized Fitness and Massage, told Healthline.
Even “natural” exercisers won’t see fitness miracles any time soon.
“Some people seem to put on muscle at a much quicker pace than others — although nobody is going to look like Vin Diesel overnight,” said Justin Fauci, a certified personal trainer and co-founder of Lean Muscle Project.
If you doubt that six weeks isn’t enough time to get fit, take a look at a 2004 study by researchers at the University of Wisconsin, La Crosse, which was published in The Journal of Strength and Conditioning Research.
The researchers put a group of 25 sedentary men through a six-week exercise program — either three 20-minute cardiovascular sessions each week, or three 30-minute high-intensity, total-body strength training sessions.
Yes, it sounds a lot like those miracle fitness commercials.
A group of panelists rated the men’s appearance at the start and end of the study based on photos. After six weeks, the ratings were unchanged. Even the men’s ratings of their own appearances were pretty much the same after six weeks.
Also, objective signs of fitness — like percent body fat, number of pushups, and oxygen efficiency — didn’t improve over the course of the study.
So if six weeks isn’t enough time to get in shape, how long does it take?
Time depends on goals
The answer to this fitness question depends, in part, on what you mean by “in shape."
“How long it takes to see fitness results will vary depending on what your goals are,” Eliza Kingsford, director of Wellspring Camps, and author of “Brain-Powered Weight Loss,” told Healthline. “Are you looking to improve time? Get stronger? Lose weight? Lose body fat? The answer to how long it will take to get fit will vary for each one of those goals.”
A beginner wanting to run a 5K race will take less time to get in shape than someone training for their first marathon or triathlon. And they will need a different training program than someone getting ready for a weeklong backpacking trip.
In general, though, you will start to “feel” better long before you see major fitness results.
“For someone starting out, I notice that within two weeks they can start feeling the benefits of exercise,” Jamie Logie, a personal trainer who runs Wellness Regained, told Healthline.
This might mean being less out of breath when you climb stairs or run to catch the subway. Or being able to play with your grandchildren in the back yard without getting tired.
Although you might not have a “ripped body” yet, these small changes shouldn’t be dismissed.
“The mental benefits of getting active are even more important than the external changes we are all so concerned about seeing,” Samantha Clayton, senior director of Worldwide Fitness Education at Herbalife, told Healthline.
This includes increased motivation and confidence to keep coming back to your workout until you start seeing physical benefits.
“If you have been out of shape, or not working out for 10 years — or forever — it will generally take about two months of working out most days of the week to get to a moderate level,” New York-based Nikki Glor, creator of NikkiFitness videos, told Healthline.
And if you exercise regularly, over time you will gain even more fitness benefits.
“At six to eight weeks you can definitely notice some changes,” said Logie, “and in three to four months you can do a pretty good overhaul to your health and fitness.”
Strength-specific results take about the same amount of time.
“For a client who is already in good cardio shape but just wants to learn how to lift weights safely, three months is usually a reasonable timeframe,” said Snow.
So, how long until you are sporting a “ripped body”?
“If you're consistent about working out and dieting properly for a full year, and you weren't significantly overweight to begin with,” said Fauci, “then after one year you can expect to sport a lean, muscular physique with a visible six pack.”
Getting fit to compete
Not everyone likes getting fit just for the sake of getting fit.
For them, there are any number of outdoor races to choose from — 5K or 10K running races, marathons, half marathons, or 100-mile bicycle rides.
There are also triathlons, Tough Mudders, Super Spartans, and other obstacle races for people who like variety.
With this kind of specific fitness goal, it’s even more important to not rush getting in shape.
“If you are preparing for an event or race, please be over-prepared,” James Shapiro, a certified personal trainer with New York-based Primal Power, told Healthline. “If you plan to participate in an endurance event like the Spartan race and have never jogged five miles, it's time to start three to four months before. Our bodies do get stronger, but you want to run past the finish line, not crawl to get there.”
There are many training programs to help you get in shape for these races, but expect to spend at least two months on pre-race training, clocking miles three to six days each week.
That extra time will be worth it, especially for beginners.
In a 2007 study in the European Journal of Applied Physiology, researchers put a group of untrained adults through a nine-month half-length and full-length marathon training program.
By the end of the study, people in the program had increased their cardiovascular fitness — VO2 max — by 24 percent, and their running speed by 29 percent.
Even if you prefer noncompetitive outdoor activities like backpacking, kayaking, or mountain biking, expect to put in solid miles to get in shape.
“We find that it takes about four to five full days of backpacking to get into hiking shape,” Steve Silberberg, owner of Massachusetts-based Fitpacking Weight Loss Backpacking Adventure Vacations, told Healthline.
These are full eight-hour days, back-to-back, with a fully loaded pack. It may sound daunting, but lots of beginners have walked this path before.
“Many people can get right off the couch and start backpacking,” said Silberberg. “The second day is the toughest because the first day’s enthusiasm has waned and you already have sore feet and muscles.”
Factors that affect fitness
These, of course, are general guidelines.
Many things along the way can speed up or slow down your progress.
“How fit you are when you get started is one factor that I’ve personally seen affect people’s individual results timeline,” said Clayton.
The type of exercise you choose also matters and it will affect you differently if you are a beginner or coming off an illness or injury.
“If you’re not comfortable with exercise, or perhaps are being cautious because of an injury, you are going to get different results from walking for 90 minutes per day than someone who is already used to exercise and decided to try a HIIT [high intensity interval training] program,” said Kingsford.
Beginners, though, may progress faster simply because they are starting lower down the fitness ladder and require less exercise to challenge their body.
“Beginners see huge jumps in strength across the board every week with proper training,” said Fauci.
Of course, what you put into an exercise program also determines what you get out of it.
On a perceived exertion scale of one to 10, “if you only feel comfortable exercising at a level six, you are going to get different results than someone who is comfortable exercising at a level nine,” said Kingsford.
In a 2007 study in the Journal of the American Medical Association, researchers placed sedentary, overweight, or obese women into three groups — exercising at 50 percent, 100 percent, or 150 percent of the recommended energy expenditure level.
Women who worked out at the highest intensity level saw an 8 percent improvement in their cardiovascular fitness after six months. Those at the lowest intensity level saw a 4 percent increase in fitness.
An 8 percent increase in fitness doesn’t seem like a lot, but if you’ve been inactive for a long time, it can be huge.
If you crank up the intensity even more, you’ll get faster results.
“We see fitness results from our students within about two weeks,” Tina Angelotti, fitness director of Krav Maga Worldwide, told Healthline. “Our students work at very high levels of intensity in our Krav Maga self-defense, fitness, and fight classes.”
If you are a beginner, or new to higher-intensity workouts, you might need to work up to this level.
“If you work too hard too soon, you risk injury or quitting from the stress,” said Clayton. “But if you don’t work hard enough, you won’t see results. So find your balance and know that healthy and fit is not a race nor a destination.”
Getting out of shape
Once your exercise routine becomes a habit, you’ll probably find that it’s easier to stick with it.
But an injury, illness, or even life can easily derail your workouts.
“Life circumstances will always throw you off your plan at some point,” Rob Williams, performance coach and trainer for EAS Sports Nutrition, “but the more important thing is to get back to your program and be in it for the long run.”
Often, cardiovascular fitness is the first to go.
“If you're highly trained and decide to take a break from exercise, your cardio is going to be the first and fastest to decline. It will drop significantly after only a few weeks of inactivity,” Tyler Spraul, a certified strength and conditioning specialist and the head trainer at Exercise.com, told Healthline.
According to the American College of Sports Medicine, physiological changes — like blood lipoproteins, ability to use glucose for energy and body composition — can occur one or two weeks after you stop exercising.
A 1984 study in the Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology also found that when endurance athletes stopped training, their VO2 max dropped by 7 percent within the first 21 days of inactivity.
This stabilized after 56 days of no exercise. And after 84 days of inactivity, the athletes still had a higher VO2 max than people who had never trained.
Muscle strength may last longer during a break.
A 2000 study in Medicine and Science in Sports and Exercise found that young people lost just 8 percent of their strength after 31 weeks of inactivity. Older people lost 14 percent of their strength during that time.
Most of the loss of strength occurred between 12 and 31 weeks.
Even small breaks may not affect your overall strength progress.
In a 2011 study in Clinical Physiology and Functional Imaging, beginners who took a three-week break in the middle of a 15-week bench press program achieved similar results by the end of the study as beginners who worked out the entire way through.
So once you build a foundation of strength, it stays with you.
“When you undergo resistance training, you permanently change the physiology of your muscle cells — even if you stop training for long periods of time,” said Fauci. “This makes the process of regaining strength and size after a long break from the gym much quicker.”
This is just as true for overall fitness.
“Everyone is going to be different when it comes to seeing results after a break from working out,” said Williams, “But the longer and more consistent you’ve been working out and training, the less of an impact a break will have on you.”
Minimizing losses during breaks
The good news is you can minimize fitness losses during a break by continuing to exercise at some level, even if it’s less than what you were doing before.
According to the ACSM, you can maintain your current level of strength, performance, and health benefits with “as little as a single session per week of moderate- to hard-intensity exercise.”
What you choose to get you through a break depends on your circumstances.
If you stopped exercising because life got in the way, you might need to squeeze in physical activity wherever you can — do bodyweight resistance exercises throughout the day, take the stairs instead of the elevator, or bike to work.
If you are injured, you may have to modify your workouts significantly.
“I encourage students dealing with an injury — depending on the severity of the injury — to continue to come and train, but we obviously modify their workout around the injured body part,” said Angelotti. “For example, a student with a shoulder injury can still come and work out their lower body so that they don't get completely deconditioned.”
It’s also important to work with a doctor or physical therapist to develop a program that will keep you active, but still let your body heal.
People who are coming back from an injury also “need to learn to trust the injured joint again,” said Snow. “Favoring the uninjured side for months or years after graduating from therapy only increases the risk of a new injury somewhere else in the body.”
If you have been inactive for several weeks, it is often safest to start fresh — working with your current level of fitness and health, not where you were before the break.
And for that, you’ll need lots of patience, the kind that got you in shape in the first place.
“After giving birth to my first son it took me four months to get back to fit and after triplets it took me 18 months,” said Clayton. “It’s all about one step at a time and allowing your body to adapt slowly — this is often the best and most sustainable approach.”
By Shawn Radcliffe