MOVING IS! chosing the stairs instead of the lift, taking regular breaks from your chair at work, cycling, walking, playing football with the kids, cleaning and gardening are all activities which prevent us from suffering the devastating effects inactivity has on our health.
Sedentarity is fast becoming the number one cause of degenerative and chronic diseases. It is associated with metabolic illnesses like diabetes and 
osteoporosis; it is a known cause of depression, muscle waisting and premature aging.
Our Physiology and skeletal structure heavily depend on movement and interaction with gravity. Without movement our lymphatic system stagnates, our digestion slows down, our bowels become congested and our arteries glogged up. Our bodies need us to move no matter how very tempting that sofa might look.
Research suggest that to counter-act the negative side-effects assocated with sitting we need to get up every 20 minutes and move for 30 seconds. Interestingly the same research seem to conclud that office workers who rarely got off their chair suffered with the metabolic dysfunctions associated with sendentarity even if they also engage in a sport once to three times per week.
This said exercise is extreemly useful and will largely contribute to a younger, stronger, leaner healthier body if done properly and regularly.
Most exercisers skip a workout occasionally, traveling, falling ill, or heavy work deadline can keep even the most dedicated exerciser from the gym.
Sometimes lack the motivation to workout sets in as a result of too many skiped sessions but skipping workouts is not the same thing as spacing workouts appropriately.
If skipping workouts becomes a habit, your body and your fitness level will suffer, with negative changes occurring faster than you might think.
How Long Does It Take to Get Out of Shape?
There's no hard and fast rule about how long it takes to lose your fitness edge. Generally speaking, if you're very fit to begin with, your body will remain in a fitter state longer than someone who's not fit, even as your workouts cease.
That being said, a study in the Journal of Applied Physiology suggested that skipping workouts for just two weeks can significantly reduce your cardiovascular fitness, lean muscle mass, and insulin sensitivity.
Two months to lose all of your fitness gains is fast enough... but there are varying opinions on the matter. Many experts agree that about two weeks is a pretty standard number after which your body will start to fall out of shape with no exercise.
Cardiovascular Fitness Typically Fades Faster Than Muscle Strength
When you skip too many workouts, the strength of your heart and lungs will fade first. One study found that after just 12 days without exercise, VO2 max, ameasure of cardiovascular endurance, dropped by 7 percent, while blood enzymes associated with endurance performance dropped by 50 percent.4
Likewise, four weeks of inactivity among endurance cyclists resulted in a 20 percent decrease in VO2 max.5,6 Keep in mind this is among trained athletes... among those new to exercise, gains in VO2 max completely disappeared after four weeks of inactivity.
The opposite holds true for strength loss among newbies, with studies showing newly made gains in strength tend to hold on even after months of inactivity. For instance, among previously untrained men who engaged in a 15-week strength-training program, taking a three-week break in the middle had no impact on strength levels at the end of the study.
As for muscle strength among athletes, it appears to hold steady even after a month of inactivity – but there are significant differences among certain types of muscle fibers. Your body has three types of muscle fibers: slow, fast, and super-fast twitch muscles.
Slow-twitch muscles are the red muscles, which are activated by traditional strength training and cardio exercises. The latter two (fast and super-fast) are white muscle fibers, and these are only activated during high-intensity interval exercises or sprints. As reported by Greatist:
"Medicine and Science in Sports and Exercise published a review of several studies on the subject that looked at runners, rowers, and power athletes.For all of these groups, muscular strength fibers appear not to change, even after a month of inactivity.
But here's the kicker: While general strength doesn't change much in that period, specialized, sport-specific muscle fibers start to change in as little as two weeks without a workout.
For example, endurance athletes lose a significant amount of the extra slow-twitch muscle fibers that they worked so hard to accumulate, and the same thing happens for the power athletes and their hard-earned fast-twitch muscle fibers."
Long-Time Exercisers Have an Easier Time Bouncing Back
If you've taken a long hiatus from the gym, you might be nervous about returning to your workouts. You should ease back in gradually to avoid injury, but if you're a life-long exerciser, you'll have an easier time getting back into shape than someone who only recently started.
Your age also plays a role. The older you get, the faster your muscles atrophy if you're not regularly engaging in appropriate exercise. In addition, it will take you longer to gain it back. When comparing 20- to 30-year-olds with 65- to 75-year-olds, the older group lost strength nearly twice as fast during six months of inactivity.
That being said, if you're past your 30s, please don't let that discourage you. Older adults can gain a two- to three-fold increase in strength after just three or four months of weight training.
Are You Skipping Your Workouts Because They Take Too Long?
If time is the factor leading you to skip workouts, here's a simple hack you can use: cut down on the duration of your workout while increasing the intensity. Exercise experts are quickly abandoning the old exercise advice – the recommendations that suggest you need 30 or 60 minutes of moderate-intensity activity to best stay in shape.
Study after study is showing that this is not the best way to exercise, both in terms of its health benefits and its duration. You can actually reap much greater benefits by exercising in short, high-intensity bursts known as intervals than you can exercising for longer periods at a slower steady pace.
High-intensity interval training research presented at the Integrative Biology of Exercise VI meeting in Colorado, for instance, demonstrated that high-intensity interval training (HIIT) burns more calories in less time – a mere 2.5 minutes, divided into five 30-second sprint intervals at maximum exertion, each followed by four minutes of light pedaling to recuperate, can burn as many as 220 calories.
Another study published in the Journal of Obesity reported that 12 weeks of HIIT not only can result in significant reductions in total abdominal, trunk, and visceral fat, but also can give you significant increases in fat-free mass and aerobic power.13 Other research published in the journal Cell Metabolism showed that when healthy but inactive people exercise intensely, even if the exercise is brief, it produces an immediate measurable change in their DNA.
Several of the genes affected by an acute bout of exercise are genes involved in fat metabolism. Specifically, the study suggested that when you exercise your body almost immediately experiences genetic activation that increases the production of fat-busting (lipolytic) enzymes.
Yet another study found that unfit but otherwise healthy middle-aged adults were able to improve their insulin sensitivity and blood sugar regulation after just two weeks of interval training (three sessions per week). A follow-up study also found that interval training positively impacted insulin sensitivity.
In fact, the study involved people with full-blown type 2 diabetes, and just ONE interval training session was able to improve blood sugar regulation for the next 24 hours!
The HIIT approach I personally use and recommend is the Peak Fitness method, which consists of 30 seconds of maximum effort followed by 90 seconds of recuperation, for a total of eight repetitions.