What One Study Shows
In an interesting study carried out at the University of Massachusetts, researchers asked male participants to wear an elevated sole on their right foot and to use crutches to get around so only their right foot touched the ground when they walked. Their left leg, although free to move, didn’t touch the ground or bear weight and over the course of the two-day study. At the end of 48 hours, they did muscle biopsies and looked at genetic markers that might indicate atrophy in the left leg that didn’t bear weight for two days.
The results were surprising. Even after two days, the leg that didn’t contract against resistance or bear weight showed gene and protein changes consistent with early muscle atrophy. Even more surprising was the leg that didn’t work for two days didn’t return to normal quickly from a muscle protein standpoint after it started bearing weight and actively contracting again.
Does Sitting All Day Cause Muscle Breakdown?
This suggests that muscles may show early signs of atrophy after only short periods of inactivity and disuse. How short? According to this study, two days or less. This raises another question. Does sitting all day in a chair at the office without moving around trigger breakdown of lean body tissue, especially if you haven’t done significant weight-bearing exercise or resistance training for a few days? It’s an intriguing thought.
We already know that too much sitting isn’t good. Research suggests that staying glued to your chair too long during the day increases the risk of health problems like heart disease, type 2 diabetes and is linked with an increased risk of mortality. But can sitting around all day in a chair make it harder to build lean body mass too? If so, that’s another reason to get up and move around during the day – go up and down the stairs and do squats and lunges in your office at intervals. This isn’t the first study to show that muscle atrophy happens quickly when muscles aren’t actively contracted. According to a study published in Massage Today, some muscle wasting occurs in as little as three days of disuse.
What about Strength?
Another study in the Journal of Applied Physiology showed that strength drops off quickly too when a muscle doesn’t actively contract. Resistance training improves the ability of your brain to communicate with your muscles so you can recruit more muscle fibers to lift a load even before your muscles start to hypertrophy. That’s why you develop greater strength early in a training program before your muscles have had enough time to adapt and grow. When muscles aren’t contracted for a few days, some of this improvement in neuromuscular function appears to be lost.
What Does This Mean?
With any training program, consistency is important. Research suggests that loss of lean body mass and strength gains begin early at the molecular level. It’s also possible that sitting in a chair eight hours a day has some impact on muscle fibers at the cellular level and might make it harder to build lean body mass. Certainly, more research is needed to prove this, but it’s a good reason to move around more during the day and to be consistent with strength training. That doesn’t mean you shouldn’t take time off, but even on those “off” days, stay active in some capacity to keep your muscles moving.
References:
Journal of Applied Physiology November 1, 2010 vol. 109 no. 5 1404-1415.
Massage Today. “Understanding Disuse Atrophy”
Journal of Applied Physiology 1987; 62:2168-2173.
Related Articles By Cathe:
When You Lose Weight, How Much is Fat & How Much is Muscle Loss?
Can Cortisol Sabotage Your Muscle Growth?
How Do You Know if You’re Gaining Muscle When You Strength Train?
Building Lean Body Mass: 6 Things That Sabotage Muscle Growth
I hate to read this right now; I had a hysterectomy for a 14-15cm fibroid tumor a few days ago and even a little bit of walking makes my abdomen swell quickly. I really can’t do anything right now. I am hating this article!
Hi Laura,
Last November I got a severe case of the shingles that ran from my left buttock to my knee. It took me 8 weeks before I could work out again. I was left with a very weak leg. I took me about 2 months after that to get my leg back to normal.
I was angry and about to go nuts without my workouts. But I did get better and my strength and muscle tone losses quickly responded after working through this setback which was, the worst setback I’ve ever had in my fitness history. I was devastated.
Don’t feel bad – just give your body time to heal and as Cathe says, “Honor and Respect your Body”. It will get better I promise. You are just now out of surgery! Don’t beat yourself up!
I hope my story gives you hope that you can get back into shape but you must let your body heal 🙂
HATE to hear this… Does this mean that rest between wt training days can actually cause you to loose the muscle gain??? WORRIED!! see I workout VERY Hard every other day with weight training and tend to do one cardio day inbetween but then take one day off in between so every other 2 days i do A HUGE Total body weight training for 2 hours… does this mean I am just not gonna go anywhere in my gains??? Can u clarify this PLEASE!! Thanks!!
Jen
Great info to remind me to stay active even on a off day which is every Sunday for me, I have to have oral surgery in a few days, will work out before my appt. and rest the next day afterwards, but day 3 I will be back at it again!!
I am a Cathlete!!!
So what is your recommendation for those of us who do have a desk job? I alternate between my treadmill and a total trainer with an occasional day off. Very much struggle to loose the 20ish pounds that I would like to loose.
Can I gain my muscle strength back? I used to b muscular not as bad as a Guy just enough were you can see them. I was told when I was pregnant that my cervix was weak to hold my son in it was either get him aborted or stay in bed throughout my pregnancy as much as I hated both I chose to stay in bed. I feel weak I have no muscles and I strain my back and shoulders while picking my son up and putting him down.
Work in standing position most of the time combined with little sitting and you ll feel so energised and healthy.
I am recovering from Guillain-Barre Syndrome And became paralyzed from the neck down. I couldn’t move my legs for over a month before the GBS started to reverse and I lost so much muscle mass. It took a month of physical therapy to start walking and several months of Therapy before I was walking without a cane. It is amazing how much muscle you can loose in a fairly short time.
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