Flexibility is important and any good health and fitness program should improve or at least maintain your existing level of flexibility. Poor flexibility causes numerous problems including pain and injury, so it is crucial to avoid losing flexibility.
Lifting weights is a common form of physical activity that can benefit anyone, but some people have concerns that lifting weights decreases flexibility. There is a fair amount of confusion surrounding this issue, probably because there are a lot of people who do lift weights and lose flexibility as a result.
However, instead of stating that lifting weights decreases flexibility, it is more accurate to say that lifting weights can decrease flexibility, but it doesn’t have to. It is certainly possible to lift heavy weights as your primary form of exercise and increase flexibility at the same time.
There are a number of factors that determine if lifting weights decreases flexibility or not, but the most significant one is stretching. If you lift weights and consistently follow a good stretching routine, then you should not have any problems with losing flexibility.
The act of lifting weights does result in temporarily shortened muscles, but this happens during most other type of exercise as well. When your muscles contract, they end up being a little shorter than before the contraction started, especially when you contract your muscles very strongly, such as when lifting heavy weights. This shortening is only temporary as long as your muscles are stretched back to their normal length after the workout.
If you lift weights or contract your muscles during other activities and do not stretch at all, then your muscles will stay in a partially shortened position. The amount of muscle shortening after each workout is so small that you will not notice anything after one workout, but it becomes significant over time.
After exercising without stretching for an extended period of time, you can lose flexibility and probably have an increase in stiffness or pain as well. To keep things in perspective, this muscle shortening also happens with people who don’t exercise at all, so decreases in flexibility can’t only be blamed on exercise.
One of the most common reasons for muscle shortening and flexibility loss is sitting for extended periods of time. If you sit all day, your hip flexors and other muscles lose flexibility, because a muscle kept in a shortened position tends to stay in a shortened position, even if it is not being actively contracted.
On a side note, muscle shortening and flexibility losses from sitting are also major causes of low back stiffness and pain. Again, this shortening can be prevented or minimized by stretching or even just getting up and moving around at regular intervals.
Muscles kept in a shortened position and muscular contractions can both lead to a loss of flexibility but they are not the only problems. With regards to lifting weights, another factor that affects flexibility is the range of motion of exercises. Specifically, when people consistently lift weights using short ranges of motion, it makes it more likely for decreases in flexibility to occur.
Performing exercises through only a portion of the full range of motion simultaneously keeps the muscle contracted and in a shortened position. Performing a lot of short range of motion exercise and not stretching is a definite recipe for losing flexibility. In addition, constantly exercising a muscle through only a partial range of motion promotes muscle imbalances and/or weakness in the non-exercised range of motion.
On the other hand, lifting weights through a full range of motion can actually improve flexibility, especially if you currently have poor flexibility. Moving or exercising your muscles in ranges of motion that are greater than what your muscles usually experience, but still within normal limits, encourages muscle lengthening and flexibility increases.
When looking at all of this information as a whole, the issue of whether or not lifting weights decreases flexibility becomes clear. From a practical standpoint lifting weights does not decrease flexibility, as long as you perform exercises with correct form through their entire range of motion. Finally, regardless of whether you lift weights, do other types of exercise, or don’t exercise at all, stretching is essential for maintaining and improving flexibility.
14 years of experience and education in health and fitness