Will Strength Training increase or decrease flexibility?

Posted: February 19, 2015 in From my vantage point, Strength and Conditioning for Health and Fitness

Sometimes new trainees are apprehensive of starting a strength training program. Some of their fears come from remarks commonly heard from other people whose mouth is too fast for their own good. They usually say that “If you start weight training, you will become tight.” For some athletes, flexibility is very important. So it is normal that they will hesitate to do something which will affect their flexibility in a negative way. Flexibility is one fitness component that affects performance in sports or leisure and activities of daily living (ADL). And so is strength. Both should complement each other.


So does strength training make you less flexible? A quick answer is a big NO! To back up this answer, here are some facts about the relationship of Strength Training and Flexibility based on normal physiologic reactions, research, and observations from actual experiences:

1. Tightness associated with Strength Training is normal and temporary

When people first start training, they will always undergo the General Adaptation Syndrome (GAS). This is true even for athletes who have stopped training for a few weeks. And also for some of those who are training but are going to start a different type of training. The body’s initial reaction is called DOMS (Delayed Onset Muscle Soreness). The muscles are sore after 24 hours or more after starting with the new training routine. When you move a sore part of your body, you would feel the soreness or pain. Of course you would not want to move so much so as to avoid pain. And if you are reaching for something, like in stretching, this pain may increase. Pain inhibits movement and causes the muscles to tighten up a bit so as to protect the painful area. This is felt as tightness. So, initially, Strength Training can make you tight and this is normal and more importantly- TEMPORARY. Depending on the severity of discomfort, the training intensity and/or volume can be reduced or would just proceed as usual so as to ease through this process. The important thing is to continue training. This helps to resolve the soreness faster than not training at all. After a few days, the normal Range of Motion (ROM) will return as the soreness and stiffness abates.

2. Strength Training actually improves Range of Motion

Here is a summary of two studies involving Strength training conducted for 10 to 11 weeks. Sometime ago in 1987, there was a research to determine the effects of weight training on the Range of Motion (ROM) of the ankles, trunk, and shoulder joints. The subjects, male college students, underwent an 11 week weight training program which made them train three times a week. Range of Motion was measured was measured before they started training and after the 11 week program. Data showed that there was significant increase in the Range of Motion of the joints measured which leads to the conclusion that a weight training program aimed to develop muscular strength would not impair flexibility but might increase it. In a similar study conducted in 2008, sedentary middle aged women underwent a 10 week strength training program. Measurements of the ROM of major joints were done before and after the 10 week strength training program. Results showed that the ROM of their joints improved (flexibility improved).

From the above examples, one can infer that the effect of Strength Training on Flexibility is positive for both men and women as long as training is done consistently long enough (10-11 weeks).

3.  Compound movements, when done in sufficient ROM, improves flexibility of relatively tight individualsN.¼¤¿POª    1992 O¤YM¦IAKOI A¡¿NEª.BAPKE¤¿NH 92.¦YPPOª ¢HMAª.

Compound movements are movements that involve the major joints of the body- the shoulder girdle, the torso, the hip, knees, and ankles. Examples are the deadlift, squat,  and bench press. There are a lot more examples of compound lifts but these three are good to start with for someone who has not trained much. Athletes who are new to Strength Training may or may not have a good fitness foundation. Some are more skilled than fit, while some, depending on the nature of their sport, are already fit. But when they execute some of the compound lifts mentioned above, some exhibit deficiencies in their ROM. It can be due to tightness, lack of synchronization, or weakness. With properly guided progressive Strength Training, their ROM gradually improves. The same is true for non-athletes. They exhibit the same patterns, the difference is just in the degree of deficiency. Athletes and non-athletes  also respond similarly since they basically have similar anatomical and physiological features. The difference is in the degree of development.3090040526_cfef57f1c3

That is why Strength and Conditioning Coaches prefer to use compound lifts compared to isolated joint exercises or exercises involving only one joint, an example of which is the biceps curl. (Sorry gentlemen, big arms does not always impress, it is the ability to perform that matters, and by that I mean to perform in your respective sports or occupation). Compound lifts address a lot of training needs in one go therefore it saves time in a training session. But you have to invest some time practicing how to execute it in the most efficient way possible and the fastest way to do this is with an experienced Strength and Conditioning Coach who you can work well with.


So there you have it,  flexibility is actually enhanced by Strength Training, most specially in individuals with poor flexibility. For individuals who are already very flexible prior to starting, Strength Training may not improve their flexibility anymore  since it is highly developed already. Since the response (effects of training) depends on many factors, it would not and will not be exactly the same for each individual but it can be similar. Also, the type of training largely determines how fast is the improvement in flexibility and strength as well as which one of these fitness components, as well as the other components.

Click here to view some exercises for improving hip mobility.

  1. […] (Click here to read about the relationship of strength training and flexibility.) […]


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