Science Summary: Flexibility and Core Strength (Cardio or Weights Part 7)

This post is a continuation on my series through Alex Hutchinson’s Which Comes First, Cardio or Weights? All of the following questions are taken from this book and the answers are paraphrased from the authors words with my interpretations and thoughts added in.

Will stretching help me avoid injuries?

Short Answer: Stretching has not been proven to reduce injury rates in the general population.

Long Answer:  Most muscle injuries occur within the standard range of motion rather than at maximum extension or contraction.  Therefore increasing the range of motion does little to reduce injury rates.  In 2004, the CDC compiled over 350 studies and concluded that stretching is not associated with reduced injury rates.  That being said, increased flexibility has benefits unrelated to injury prevention.

Could stretching before exercise make me slower and weaker?

Short Answer:  Yes

Long Answer:  Numerous studies have found that static stretching, especially with “cold” muscles, reduces maximum output and significantly reduces performance.  There are several theories as to why this happens.  On belief is that stretching cause muscular damage which prevents peak performance.  Another suggests that muscles need to be tight to function optimally and stretching loosens muscles enough to prevent that.

Do flexible runners run more efficiently? (Does stretching reduce running efficiency?)

Short Answer:  More flexible runners have been shown to be less effecient at running than less flexible athletes.  Runners who static stretch are less effective at higher intensities over long distance.  Dynamic stretching however has not be associated with reduced performance.

Long Answer: Several studies have shown a correlation between stride economy and lower body flexibility in long distance runners.  A study of British long distance runners found that participants with higher sit and reach scores were less efficient runners than participant with lower scores.  A study done at Florida State University found that static stretching before a workout resulted in greater caloric burn at a set effort and also decreased maximum output.

How should I warm up before exercise?

Short Answer:  It should be dynamic and workout specific.

Long Answer:  U.S. Army researchers found that the greatest performance increase comes from a warm up that dynamically moves your body through the movements you will be using during your workout.  They found that static warm ups such as stretching did little to help performance.

Will stretching after exercise help me avoid next-day soreness?

Short Answer:  No

Long Answer:  The thought that stretching will reduce DOMs comes from an outdated theory that DOMs was caused by restricted blood flow.  This theory has since been proven wrong though the stretching advice still hangs around.

Where is my “core” and do I need to strengthen it?

Short Answer: It’s a wide range of muscles that include more than just your abs.  Your back and hips are in there as well as deeper muscles that are below the surface.

Long Answer:  There tends to be a lot of focus on the abs as core muscles, but balance issues in many people stem from other areas such as the hips.  Reed Felber, a professor at University of Calgary, recommends hip strengthening work as the most effective way to improve stability in the general population.

What are the benefits of yoga for physical fitness?

Short Answer:  Yoga offers some benefits for muscle strength, endurance, flexibility, and balance.

Long Answer:  Yoga as physical exercise is a relatively new trend.  Only in the past few years has it started to be seen as physical exercise.  A 2001 study by the University of California, Davis, found that 180 minutes of yoga per week resulted in significant increases in muscle strength, endurance, and flexibility.  A study done by Northern Illinois University found yoga offered no cardiovascular benefits though.

What are the benefits of yoga for overall wellness?

Short Answer:  Yoga provides some benefits to overall wellness, including mental health, but so does most physical activity.

Long Answer:  A Rutgers University study compared the health benefits of yoga against those of strength training an found that strength training resulted in improvements in a broader range of mental health aspects and these improvements lasted longer than those caused by yoga.