Stretch Less for Growth

by Dean McKillop 2372 views Gain Muscle

Stretch Less for Growth

Static stretching is traditionally promoted for everyday mobility, joint function and overall health, which was then incorrectly transferred directly into sports performance without consideration for any implications. While joint mobility, muscular elasticity and general flexibility are beneficial for day-to-day health, it does not necessarily transfer directly into being equally as important in the acute stages of exercise.

What do I mean by acute?

Acute stretching refers to the direct approach of stretching in the immediate time prior to the act of performance, whereby the individual uses a stretching modality prior to exercise in ‘preparation’ for performance. All to often however, the implications that stretching may have on performance are forgotten in the wake of being an ‘over-cautious’ preparer for exercise.

What I mean by that is, while stretching has health promoting benefits, it may actually be detrimental to performance.

Currently the primary types of stretching include:
Static Holding a stretch in the same position for an extended period of time at a moderate intensity (how it feels).
Dynamic Using momentum to take a muscle through a full range of motion.
Proprioceptive Neuromuscular Facilitation Contracting the antagonist (opposite to the agonist) muscle while the agonist (the muscle being stretched) is in the stretched position.
Ballistic Using a bounce like motion through varying ranges of motion.

Traditionally the two primary styles of stretching used in exercise and more specifically hypertrophy training are static and dynamic, so for that reason, I will be focusing solely on these.

The Warm Up

stretching

The primary focus of a warm up should be based around minimising immobility or impairments, with the preference being submaximal aerobic style exercise followed by dynamic sports specific stretching (1). In essence, ‘the warm up’ should be designed to prime the body for exercise, placing it in an optimal state to ensure performance is also optimal. An individual requiring flexibility should focus on flexibility, whereas an individual that requires strength or power should focus on priming the body for exactly that.

Research currently suggests that dynamic stretching is more beneficial than static when looking at ensuring maximal power and strength is maintained (2). More specifically, the timing of static stretching appears to be of primary importance, whereby holding stretches for longer appears to have a dose response relationship with reduced performance in sprint, power and agility tests (3).  Individuals focusing on power and agility perform better with dynamic stretching when compared to static (4), but should you wish to utilise static stretching, it is recommended to hold a static stretch for no more than 15 seconds at a moderately uncomfortable length (3). Individuals who tend to stretch too much in a static sense, traditionally reduce strength, power and overall performance in dynamic sports.

Why does all this matter for hypertrophy?

Based on the research of Eric Helms and his team, it is currently recognised that the 4 primary exercise modalities that manipulate strength and hypertrophy the most are (5):

  1. Volume – Total work completed
  2. Intensity – Strength relative to your 1 rep maximum
  3. Frequency – How frequent the muscle is stimulated
  4. Progression – Improving on at least 1-2 of the above 3 factors

Knowing this, the primary importance for a warm up for an individual looking to maximise hypertrophy should be to prime the muscle for strength and power. The goal is not to improve flexibility but instead, ensure the muscles being worked are ready to perform maximally.

So while static stretches may ‘feel good’, research suggests they may be detrimental to performance and thus may indirectly affect your ability to progress on the 3 major training modalities responsible for muscle growth and strength.  In essence, stretch less in a static sense, but instead use a dynamic approach if you want to warm up prior to a weights session.

However, what about during exercise?

Inter-Set Stretching

As the name suggests, inter-set stretching utilises stretching in between the working sets of a weight training session with the thought process being that it may increase the total time the muscle is under tension as well as improve the activation of the working muscle. Currently, there is no specific research that can really determine a cause and effect of inter-set stretching and if it enhances muscle growth above the norm, however, there may be some indirect benefits seen via improved acute performance.

The good news is that there is currently no definitive research suggesting that inter-set stretching is detrimental to performance, provided that the stretch time is not too long.

In a study conducted in 2013, it was found that 30 second inter-set static stretching actually increased performance marginally in the lower limbs when compared to passive rest but it was not considered statistically significant (6), which means it didn’t performance notably better for it to be considered for clinical recommendation. Similarly, Mohamad et al found that 15 second static stretches, completed across multiple muscle groups, showed no negative effect on performance either (7).

So while static stretching prior to exercise may be detrimental in its traditional sense, inter-set stretching does not appear to be an issue provided the time of stretching is maintained to 30 seconds or less.

Now here is the silver lining…

Most recently, research conducted by Miranda et al in 2015 found that inter-set static stretching focusing on the antagonist (opposing side) muscle as opposed to the agonist (working muscle) like discussed above, resulted in an increase in working muscle activity and more importantly, an increase in total repetition performance when training to failure (8). Essentially what this is telling us is, if you are training your chest muscles and want to perform better as well as activate more muscle fibres, stretch your back muscles for 40 seconds in between sets to increase pressing performance.

It is important to note, however, that these findings are in their infancy, so we can’t draw a direct conclusion on inter-set antagonist muscle stretching and our current understanding as to why this occurs is still inconclusive despite there being multiple theories.

The Final Stretch

flexibility

Mobility, agility and joint integrity are critically important factors for maintaining musculoskeletal health, of which stretching both statically and dynamically offer benefits for general day-to-day health. Athletes who require flexibility in their sports should focus on static stretching, while those who are more power, agility and strength dominant should focus on dynamic stretching for sports specificity.

If you are strength athlete who has mobility or flexibility issues and you would like to improve them, it is suggested that these be kept to times away from training, as this is when you will benefit most. In fact, participants who were subjected to 40min of stretching, regardless of the type, 3x a week for 8 weeks, not only improved flexibility but also improved their strength and power during performances thereafter (9).

Stretching is an important factor of health and should be equally considered alongside specified training for performance, however, the modality, length and time of stretching also needs to be specified.

In essence, you want to stretch smarter around training, while stretching more throughout the day.

Stretching is not a generalised exercise modality, but instead, like any type of exercise needs to be specified to the individual. 

Miranda, H., Maia, M., Paz, G. and Costa, P. (2015). Acute Effects of Antagonist Static Stretching in the Inter-Set Rest Period on Repetition Performance and Muscle Activation. Research in Sports Medicine, 23(1), pp.37-50.

Behm, D. and Kibele, A. (2007). Effects of differing intensities of static stretching on jump performance. European Journal of Applied Physiology, 101(5), pp.587-594.

Avloniti, A., Chatzinikolaou, A., Fatouros, I., Protopapa, M., Athanailidis, I., Avloniti, C., Leontsini, D., Mavropalias, G. and Jamurtas, A. (2015). The effects of static stretching on speed and agility: One or multiple repetition protocols?. European Journal of Sport Science, 16(4), pp.402-408.

McMillian, D., Moore, J., Hatler, B. and Taylor, D. (2006). Dynamic vs. Static-Stretching Warm Up: The Effect on Power and Agility Performance. J Strength Cond Res, 20(3), p.492.

http://muscleandstrengthpyramids.com/

Souza, A., Melibeu Bentes, C., Freitas de Salles, B., Machado Reis, V., Vilaça Alves, J., Miranda, H. and Silva Novaes, J. (2013). Influence of Inter-Set Stretching on Strength, Flexibility and Hormonal Adaptations. Journal of Human Kinetics, 36(1).

Mohamad, N.I., Nosaka, K., Cronin. (2014). Effect of stretching during the inter-set rest periods on the kinematics and kinetics of high and low velocity resistance loading schemes: Implications for hypertrophy. Journal of Sports Science and Physical Education Malaysia, 45-57. Web.

Miranda, H., Maia, M., Paz, G. and Costa, P. (2015). Acute Effects of Antagonist Static Stretching in the Inter-Set Rest Period on Repetition Performance and Muscle Activation. Research in Sports Medicine, 23(1), pp.37-50.

KOKKONEN, J., NELSON, A., ELDREDGE, C. and WINCHESTER, J. (2007). Chronic Static Stretching Improves Exercise Performance. Medicine & Science in Sports & Exercise, 39(10), pp.1825-1831.

 

Dean McKillop

Exercise Scientist

I completed my Exercise Science Degree at the University of QLD and have worked in the fitness industry for over 8 years, including a short stint at the Brisbane Broncos in 2010 as a student. I also hold my Level 2 Strength and Conditioning Coach accreditation (ASCA) and have competed in 1 bodybuilding season, placing 2nd at the IFBB u85kg Nationals.

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