The detrimental effects of a sedentary lifestyle
I do get it! A lazy evening with some comfort food on the couch and Netflix is super relaxing after a long day when you just want to unwind. However, balance is the key here. If you come from the office and go straight to your couch and TV every day and possibly on the weekend then we do have a slight problem.
We currently have unprecedented high levels of inactivity, primarily driven by increasing time in front of screens. Many jobs reward employees for being sedentary, and the longer you sit in front of the screen the greater the reward. Unfortunately, this lifestyle has been shown to contribute to both physical and mental issues. Lack of movement leads to decreased blood circulation, prolonged compression, sustained tension, and unbalanced musculoskeletal systems throughout the body leading to dysfunction and pain.
One of my favourite chiropractic saying is: ‘Move it or lose it’ and what you lose is function, strength, and/or balance. Most of us take for granted how we move, even the simplest of movements like taking a sip of water involves quite intricate human biomechanics. The fingers, wrist, elbow, and shoulder have to all work in a coordinated fashion to accomplish the task. The human body was made to move, when done properly and in the right amount it can help our body thrive. However, if done improperly or excessively it can lead to injury and/or debilitating pain. Here are a few key parameters of movement that will decide which end of the spectrum you will fall into, they are: time, type of muscle contraction, form, and load.
1. Time
There are a few variables to time that affect whether a movement is beneficial or detrimental to our body and function. The first variable is called time under tension, which means how long a muscle is actively contracted for during a specific movement. Time under tension is interesting because for some conditions such as tendinopathy (tendinitis) placing a muscle under a long tension time may cause or aggravate the problem. When I had knee tendinopathy (runner’s knee) a few years ago, I would go for a jog and the movement of my IT band at the knee was slow which resulted in it becoming degenerated and painful. However, when I sprinted, I could run without knee pain, this is because the IT band was under load for a shorter time - one second when I jogged compared to half a second when I sprinted. Jogging was doubling the time under tension of my IT band which ultimately lead to pain in my lateral knee. So, I stopped jogging and started to do more sprint work, which stopped irritating my knee and effectively resolved the problem.
2. Type of muscle contraction
There are several types of muscle contraction, but to keep it simple let’s focus on three.
Eccentric Contraction
This occurs when a muscle is placed under load and the muscle is lengthened. Picture your biceps when you take a weight in your hand and lower the weight from your chest to your waist level. This is an important movement because research into sports science has shown that many injuries that occur in sports are due to an athlete’s inability to handle eccentric loads. Nowadays, most professional sports teams incorporate eccentric exercises into their weekly training in an effort to reduce injuries.
Concentric Contraction
This is when a muscle shortens under load. Again, picture your biceps shortening when you lift something up like an apple off a counter to bring it to your mouth for a bite. This is the most common type of contraction, and it is what most people do when they lift weights at the gym.
Isometric Contraction
This is actually not a movement. It is when the muscle neither lengthens nor shortens, the weight is simply held in the same position. These are great exercises for when people are in this first stage of rehabilitation, or they have significant pain with movement. Some specific injuries do not respond well to repetitive movements, in fact an injury such as tendinopathy (tendinitis) is directly caused by repetitive movements, hence why they can be referred to as repetitive strain injuries. So, in the case of a tendinopathy, isometric contractions have been shown to effectively load and strengthen a muscle and tendon without irritating it with movement.
3. Form
As we all know form is very important, if you have the wrong form when you hit a golf ball it won’t go where you want it to go, if you have the wrong form when you throw a baseball, it won’t travel nearly as fast as it potentially could. However, what we want to focus on is that poor form when bending, twisting and lifting will eventually lead to pain or injury. It is not so much a factor of if you will get a problem, it’s more about when will you get a problem. Most people are aware of their lifting form when they pick up something heavy, they think: “bend with the knees, keep your back straight, engage your core and lift with your legs.” These are all great queues for good lifting form; however, these queues are rarely adhered to when people pick-up something arbitrary (light) off the ground. So, make sure you do watch your form even if you’re just picking up after your kids.
4. Load
There are many different types of loads (forces) that can be applied to the body. Movement of the body occurs when internal and external forces act on it. The two main types of loads are: external load which are external forces that act on the body such as a barbell with 100kg on it. The second type of load are internal loads which are loads generated inside the body. For example, when one of your muscle’s contracts, it applies an internal pulling force on a bone, which causes movement.
There are many ways we can place an external mechanical load on the body such as body weight movements, weights, bands. The first phase of most rehab programs involves body weight movements, this is because they are the easier and safest (you must only resist gravity) of the external loads. If you are injured or have just had surgery, rehab generally starts with these exercises.
In the second phase of rehab patient are often given some form of light resistance training like resistance bands. Resistance bands have some great advantages because they are not heavy, they can be done anywhere, are inexpensive, and they are versatile. The cons are that they commonly break, and they are somewhat limited in their ability to greatly increase strength.
The third phase of rehab generally involves some form of resistance training with weights such as dumbbells, barbells, kettlebells, sleds – you name it. The great advantage of weights is that they are versatile, can be increased or decreased easily, and they are the best thing to increase your muscle size (hypertrophy) and strength. The cons of weights are they are a bit dangerous (try dropping one on your foot or doing a deadlift with bad form), they are expensive (especially if you buy your own, otherwise you need a gym membership), and the exercises can be difficult to perform correctly (good form). You may need to do some research or pay a coach or trainer to show you how to use weights properly and how to design a proper training schedule.
So let’s get moving!
Adam