A Balanced Take on the Stretching Debate

Recently on Letsrun.com a poster started a thread claiming that “All Stretching Is A Waste Of Time.” Many posters agreed or partially agreed with this claim citing scientific research. Others disagreed with the claim and backed it up with stories of how stretching worked for them. I think we can learn from both sides to improve movement quality, reduce the risk of injury, and improve sports performance.

If you would like to read what science has to say about stretching for yourself you can read the 73 summaries of warm-up science posted here.

Types of Stretching

There are many types of stretching, but here is a list of the most commonly used techniques:

Static Stretching: Holding the stretch position for anywhere between 10 s and many minutes. Unless otherwise stated “stretching” will refer to static stretching throughout the rest of this piece.

Dynamic Stretching: “Controlled movement through the active range of motion” (Fletcher and Jones, 2004)

Active Isolated Stretching (AIS): Holding the stretch position for no more than 2 s while simultaneously contracting the muscle’s antagonist. Perform multiple repetitions. AIS can be thought of as a type of dynamic stretching.

Proprioceptive Neuromuscular Facilitation (PNF): Contract a muscle for several seconds while it’s in a stretched state, relax, move deeper into the stretch, and repeat

Stretching As Part of the Warm-Up

It seems that the initial negativity towards stretching comes from research showing that stretching during the warm-up led to decreased performance. Studies show a 3-30 % reduction in power output! Behm and colleagues (2004) showed that stretching led to a 9.2 % reduction in balance and a 5.8 % reduction in reaction time. Nelson and colleagues (2005) also showed that stretching impaired muscular endurance. Similar findings have been shown for PNF.

On the other hand dynamic stretching has routinely been shown to improve subsequent performance. According to Fundamentals of High School Strength and Conditioning 2^nd Ed. (Brooks and Colleagues, 2012) dynamic stretching has been shown to “improve performance in 20 m sprints, jumping tasks, and agility tests; increase dynamic range of motion; and reduce injury rates when compared with static stretching programs.” Therefore, it would appear that stretching should not appear during the warm-up.

Looking a little bit closer at the research reveals some issues with methodology. The methodology doesn’t follow the advice given by coaches. Firstly, the stretches are held for too long – up to 30 min per muscle group! Most coaches recommend 15-30 s stretches during the warm-up. Secondly, stretching is used as the sole method of warming up. However, when coaches employ stretching in the warm-up it may be preceded by 5-10min of aerobic work and followed by dynamic stretching; it’s always concluded with sports-specific drills.

Interestingly, there’s some research in the link I provided showing that stretching for 15-30 s improves flexibility to the same degree as 45-60 s stretches, but without the subsequent decrease in performance. The link also has research that shows that any decrease in performance from stretching can be reversed with a sports-specific warm-up.

Stretching for Injury Prevention

Contrary to popular belief stretching does not prevent injury … according to the research. However, stretching seems to be employed effectively by many individuals and physical therapists.

The problem with science as it pertains to this particular topic is that science reports averages and standards of deviation. What the science is reporting is that stretching does not prevent injuries for the majority of people using a generalized stretching protocol.

A good coach or physical therapist knows how to manipulate stretching for the needs of his clients/athletes. For example, an individual that’s hypermobile has too much range of motion and is unable to control her full range of motion. Stretching would thus make her more vulnerable to injury. She needs lots of stability work. Similarly, the low back often has adequate range of motion, so most people – including those with low back pain – would be better off to avoid stretching the low back and instead improve range of motion about the hips while working on core stability. Also, avoid stretching the neck as it’s a sensitive area. Leave the low back and neck to chiropractors and other health care professionals.

Your Beighton score determines hypermobility

Another example of a coach manipulating stretching for the needs of an individual is with myself. When I first began stretching my hip flexors my low back pain went away. If I don’t stretch my pectoral muscles before bed I wake up with pain in my upper back. On the other hand, stretching my hamstrings because they were always sore and I couldn’t touch my toes was a bad idea. My hamstrings were always sore because my glutes were weak and I couldn’t touch my toes because I was lacking stability elsewhere.

Gymnasts are incredibly flexible, but many lack the stability to perform a deep squat.

Stretching Recommendations

1. Start with foam rolling to improve the outcome of your stretching

2. If you have time to stretch before exercise stretch problem areas for 20 s. If you haven’t been assessed         it’s a safe bet to stretch the pecs, lats, hip flexors, calves, quads, adductors, and hip external rotators. I        don’t include it in my warm-up process, but I don’t have an issue with anyone that does. I prefer active          isolated stretching instead.

      3. Perform optional aerobic warmup either before or after stretching

      4. Perform mobility (dynamic flexibility) and stability exercises. If you’ve gained range of motion you need to     be able to control that range of motion with stability exercises.

      5. Perform task-specific drills

      6. Train or compete

      7. Follow up with more foam rolling and stretching. I prefer to stretch right before bed as it helps me unwind.

In conclusion, stretching can be used to improve movement quality, reduce the risk of injury, and improve sports performance. Stretching is neither good nor bad; it depends on who’s using it, how he’s using it, and when he’s using it.

Stay fit,

Jonathan Pratt

Pratt's Pro Fitness

Altering the Autonomic Nervous System for Improved Health

Just before posting this piece I was looking at an exercise physiology textbook published in 2007. It only had two pages devoted to the discussion of the autonomic nervous system and it didn’t discuss the effects of exercise on it. That’s because most of the research is relatively new.

According to Fundamentals of Human Anatomy and Physiology 6^th Ed. (Martini, 2004) the autonomic nervous system (ANS) “coordinates cardiovascular, respiratory, digestive, urinary, and reproductive functions … and it does so without instructions or interference from the conscious mind.” When discussing the ANS a lot of complex terms are used, so bear with me as I get the definitions out of the way. Altering ANS output for improved health is a rather simple process.

The ANS can be divided into the sympathetic and parasympathetic divisions. In order to feel great and remain healthy we need to strike a balance between the two systems. Increased output from the sympathetic nervous system “stimulates tissue metabolism and increases alertness” (Martini, 2004). Maximum output from this system is known as the fight or flight mechanism, which is experienced during extreme duress. Increased output from the parasympathetic nervous system “conserves energy and promotes sedentary activities” (Martini, 2004).

Parasympathetic Nervous System (PNS)

Activities that increase PNS output include low intensity/long duration exercise such as walking and running, yoga, static stretching, massage, diaphragmatic breathing, and sleep. These activities are excellent for lowering stress.

Sympathetic Nervous System (SNS)

Activities that increase SNS output include high intensity interval training (HIIT), sprinting on flat ground and uphill, plyometrics, and weight training with moderate to heavy weights*. These activities improve energy levels and metabolism. I was at a presentation by Dr. Mark Swain from Inside Out Chiropractic and he referred to research on posture and the autonomic nervous system. If you’ve been sitting in a slumped posture all day you may start to feel tired due to increased PNS output. The trick is to sit up tall for a few minutes until your energy levels return.

*Warning: Sprinting and some plyometrics are higher risk activities and should only be used for advanced athletes.  

Putting It All Together

If you have a lot of stressors in your life include more PNS activities. When I was working a lot of midnight shifts in addition to running my business and volunteer coaching I would be short on sleep and would often miss several weeks of running. This led to an increase in resting and training heart rates among other things. While you can say that this occurred due to being out of shape a single 30min run would return my heart rate to normal for the next day. Aerobic fitness doesn’t return that quickly. Yoga and static stretching are excellent activities to perform before you go to bed but maybe not before a workout.

If you’re lethargic all the time or your exercise regimen is limited to PNS dominant activities, then include more SNS activities. I’ve found that if I run for several weeks at high volume without performing weight training or hill sprints that my legs feel very heavy. When I choose to accelerate my body doesn’t respond. After a few hill sprints my legs feel immediately fresher. Most people will need at least 48 hours rest after hard high intensity activities. Hill sprints may be too aggressive for you, but most people can learn to safely perform squat and deadlift variations with moderate to heavy weight.

While stress increases SNS output it doesn’t necessarily mean that one needs to avoid these activities. Short weight training sessions can be used a couple times a week, but HIIT training should probably be avoided.

In order to maximize our health we need to avoid focusing on one or two aspects of fitness and neglecting the others.

Stay fit,

Jonathan Pratt

Pratt's Pro Fitness 

Key Principles of Running

A couple months ago I gave a presentation on running titled In Defense of Running named after Michael Pollan’s book In Defense of Food. Pollan discusses how indigenous tribes thrive on vastly different diets, because there is one common theme: they eat real food. In comparison I discussed how there were many successful programs, but despite their differences there was also a common theme: there was a lot of running involved! I thought I’d share some of the ideas from that presentation.

There’s a lot that we can learn from studying the science of running, but it’s not necessary to have a strong science background in order to develop an effective program. We have more than one hundred years of trial-and-error evidence by thousands of coaches and millions of runners that’s easily available to anyone. From these individuals we find that although methods vary there are several common principles:

Consistency is the key: Long term success in running is not determined by some amazing workout or training week but through months and years of good and even average workouts. The best workout you can do takes too long to recover from and can lead to injury. These should be done sparingly.

Individualized training is great, but so is training in a group: If we take many runners preparing for the same event they will all have different backgrounds and different needs even if they run the same time for that event. Thus, these runners should have some individualization to their training. Having said that, group training has tremendous benefits psychologically which transfers into physical improvements. The goal then is to individualize training within the group.

All the elements of a program are important: It’s not all about the long run or interval workout or high mileage.

You need to run … a lot: Yearly increases in running duration and frequency are necessary for continued improvements for both middle and long distance events. Training at lower intensities allows one to recover more quickly from race specific intensities both during and after interval training sessions.

Paula Radcliffe won World Jr XC on only 25-30mi/week, but it took 120-160mi/week to become one of the best ever.

Research by Seiler and Tonnessen (2009) reveals that elite runners spend about 80% of their training at below 75% maximum heart rate. While this has worked very well for elites Esteve-Lanao wanted to know if it was applicable to recreational runners. He found that these runners tended to run too fast on their easy days and were therefore unable to achieve the necessary intensity on their hard days. When Esteve-Lanao (2007) made another group strictly adhere to running below 75% MHR on easy days they outperformed a group following a higher intensity protocol over 10km. While some elites “hammer” their easy runs they’re still running moderately high volumes and rarely exceeding their marathon race pace.

Easy runs at less than 75% maximum heart rate allow one to develop the cardiovascular system and aerobic energy pathway, but at an intensity low enough that it spares carbohydrate stores for race specific work. These runs also develop fat burning capability for events over 60min. The use of a designated long run is optional for events shorter than 60min.

Don’t forget interval training: While general conditioning improves the capacity of your engine interval training improves your engine’s power. This gives you a higher work rate.

For race pace training I use race pace +/- one event. Using the 10km as an example I use 5km to half marathon pace. For speed work I run up to two events faster i.e. up to 3km pace for the 10km.

There are many examples of runners that reached a world class level without interval training. These runners will often feel that they got slower from regular interval training. For example, Ron Clarke significantly lowered the 10 000 m world record just by running high volume and running hard on some of those runs. However, Clarke could never win major championships, because his engine wasn’t powerful enough to change pace quickly. He needed interval training, but he needed to use it sparingly to avoid breakdown.

Include some form of training to develop the stride: This type of work improves performance by increasing stride length, increasing stride rate (through decreased ground contact time), and lowering energy consumption at any particular pace (i.e. it improves running economy). The methods used vary dramatically from program to program but may include any or all of the following: form drills, plyometrics, weight training, hill running, and sprinting.

Stay fit,

Jonathan Pratt

Pratt's Pro Fitness

History of Running Training

A month ago I found a 500 page PhD thesis paper Fast Science: A History of Training Theory and Methods for Elite Runners Through 1975 by Nicholas David Bourne. Bourne takes the reader all the way back to the beginning of the Olympics in Ancient Greece and describes how runners trained during this time all the way up to 1975. Bourne has an incredible background in this field making him the perfect choice for writing such a piece: he's very thorough. While he attributes some of Peter Snell's accomplishments to Herb Elliott, this is one of the best edited pieces I've ever read. I thought the first 200 pages were lacking in detail, but Bourne more than makes up for this in the second half. This was an excellent piece!

Fast Science: A History of Training Theory and Methods for Elite Runners Through 1975


Stay fit,

Jonathan Pratt
Pratt's Pro Fitness

Good Calories, Bad Calories (Part 3)

This is the final segment I'm writing on Good Calories, Bad Calories by Gary Taubes. In Part 1 I discussed the role of refined carbohydrates with respect to heart disease. In Part 2 I discussed the role of refined carbohydrates with respect to increased body fat. This section will pertain to the limitations of the research Taubes used to write his book.

Mmmmmm, refined carbohydates!

All scientific studies are limited in some way. The gold standard in research is the randomized control trial where neither the researcher nor the test subject knows which treatment they’re being given (i.e. a double blind study). Nutritional studies can’t be double blind studies as the test subjects can see that their diet is changed enabling the chance of developing a placebo effect. Another problem is that lowering a specific calorie containing nutrient (e.g. carbohydrates) changes the caloric content of the diet. Were the results tied to lowering the calorie containing nutrient or rather to lowering total calories? As well, most of the research subjects were overweight and obese, which is more common among those with an endomorphic body type. Is the low carb diet as effective in ectomorphs and mesomorphs? Moreover, much of the research was conducted by clinicians working with obese patients rather than as randomized control trials. While the RCT is the pinnacle of scientific research the research necessary to back up some of the claims in Good Calories, Bad Calories would cost hundreds of millions of dollars and is not currently being investigated.

In addition to the nutritional limitations, Taubes didn’t touch on the research outside of nutrition. There have been many environment links to poor health and obesity. He also didn’t discuss the hypothesis that obesity may be caused by the imbalance of omega-6 to omega-3 fatty acids that is present in the diets of many countries. Finally, he didn’t clarify if the high nutrient content of a mostly animal diet of the Inuit was solely from muscle meat or whether it was necessary to consume the other organs as well. 

In conclusion, the ideas presented by Gary Taubes in Good Calories, Bad Calories are compelling. While further research is necessary and some of the claims will either be refuted or modified I believe Taubes in on the right track. The consumption of a diet high in refined carbohydrates leads to many health related problems.

Note: For more information watch Sugar: The Bitter Truth by Robert Lustig. If your main interest is fat loss Taubes has also written a book called Why We Get Fat, which I hear is a shorter and easier read than Good Calories, Bad Calories.

Stay fit,

Jonathan Pratt

Pratt's Pro Fitness

Good Calories, Bad Calories (Part 2)

In Part 1 I discussed how the overconsumption of refined carbohydrates may be a leading cause in heart disease rather than the consumption of cholesterol and saturated fat. In Part 2 I'll discuss how overconsumption of refined carbohydrates may be the leading cause of obesity and overweight. I must admit that I don't think I've done this section justice. If this information interests you then I recommend that you read Good Calories, Bad Calories or Taubes other book Why We Get Fat.

When Taubes makes his case for the high carbohydrate diet being the cause of obesity rather than the high fat diet he discusses a number of interesting case studies. The Sioux and Inuit for instance ate almost exclusively meat, which is high protein/high fat/low carb. Even though fruits and vegetables were basically non-existent in their diets these populations were very healthy. It was only with the introduction of the foods of European settlers that these tribes experienced diabetes, obesity, and heart disease.

The typical treatment for obesity is calorie reduction and more exercise. However, most of the studies that drastically reduced calories by reducing fat intake led to ravenous hunger and lethargy. Not only were results abysmal but in one study the subjects became so hungry that when they were finally allowed to eat as desired they ate 8,000 calories a day. This led them to gain 5 percent more weight than when they had started the study and have 50 percent more body fat. Another study showed that an 18 month marathon training program led to an average loss of 5 pounds of body fat for men and no change for women.

Many of us are familiar with the phrase “a calorie is a calorie.” This means that whether you’re eating a calorie of protein, fat, or carbohydrate you’re getting the same amount of energy. Thus, in order to lose body fat it shouldn’t matter what you eat as long as calories are reduced. However, Taubes points out that different nutrients have vastly different effects on metabolism and hormone secretion. Insulin secretion for instance is dramatically increased by the consumption of refined carbohydrates. Insulin is the only hormone capable of shuttling fatty acids and glucose into fat cells where it stores them as fat.

The main argument against the research Taubes discusses is that it seems to defy the laws of physics; according to Jane Brody, “Eat more calories than your body uses and you will gain weight. Eat fewer calories and you will lose weight. The body … knows no other arithmetic.” In defense Taubes discusses an interesting hypothesis. Instead of overeating and lack of exercise being the cause of weight gain, what if we “eat more, move less, and have less energy to expend because we are metabolically or hormonally driven to get fat?” The body gets so good at fat storage that it creates an “internal starvation” for the other tissues causing you to consume more calories and be lethargic. Since insulin is “the primary regulator of fat storage” it would appear high levels of insulin due to overconsumption of refined carbohydrates is the problem.

In the end Taubes suggests a compromise with the saturated fat/cholesterol hypothesis into a diet that “might do us good and probably won’t do harm.” “The current conception of a healthy diet is one that minimizes salt content and maximizes fiber; has plenty of good fats (monounsaturated and omega-three polyunsaturated fats) and minimal bad fats (saturated and trans fats); has plenty of olive oil and fish, and little red meat, butter, lard, and dairy products. When meat is consumed, it’s lean … Dairy is low-fat or no-fat. The diet has plenty of nuts and legumes and good carbohydrates … (vegetables, fruits, and unrefined grains), but few bad carbohydrates ... (highly refined carbohydrates and sugars).” 

In Part 3 I'll discuss the limitations to the research.

Stay fit,

Jonathan Pratt
Pratt's Pro Fitness

Good Calories, Bad Calories (Part 1)

Wow! It's been nearly four months since I've posted a blog. A lot has happened since then. I coached track again at West Ferris with Graham Hansel taking the bronze medal at OFSAA in the 2000m steeplechase. In May I moved Pratt's Pro Fitness out of my home and into Inside Out Chiropractic. The increase in size from 200 sq ft to 700 sq ft and connections with the chiropractors has allowed me to gain a lot of new clients. Most importantly, three weeks ago I married the lovely Courtenay Robidas. The wedding was perfect!

Good Calories, Bad Calories

A few months ago I finished reading Good Calorie, Bad Calories by Gary Taubes. It had a lot of great information although some of the chapters were science-laden and made for slow reading. I really enjoyed Taubes’s thoroughness and his desire to challenge “the conventional wisdom on diet, weight control, and disease.” This post is particularly long, so I decided to break it into three parts: the effects of refined carbohydrates on heart disease; the effects of refined carbohydrates on obesity; and limitations to the research presented in this book.

The basis for the book is the chronic negative effects of the high carbohydrate diet – particularly a diet high in refined carbohydrates such as sugar, high fructose corn syrup, and refined flour. There is evidence that a diet high in refined carbohydrates may increase the risk of developing hypertension (i.e. high blood pressure), diabetes, various cancers, and dementia, as well as speed up the aging process. The majority of the book however was on the effect of diets high in refined carbohydrates on heart disease and obesity.

Effect on Heart Disease

It was once widely believed that the cause of heart disease was due to high cholesterol, and high cholesterol was caused by a high cholesterol/high saturated fat diet. While many still recommend a low cholesterol diet, evidence continues to show that a high cholesterol diet is not linked to high blood cholesterol. According to Taubes, “Dietary cholesterol … has an insignificant effect on blood cholesterol … Decreasing cholesterol consumption from four hundred milligrams a day … to the three hundred milligrams a day recommended by the National Cholesterol Education Program would be expected to reduce cholesterol levels by … perhaps 1 percent.”

Ancel Keys – the main proponent for the cholesterol-heart disease link – suggested that it was the consumption of saturated fats that raised blood cholesterol, and this in turn led to heart disease. However, the Masai of Kenya had “blood cholesterol levels among the lowest ever measured” despite a diet of “three thousand calories a day of mostly saturated fat.” Also, the researcher Krauss was also able to show that high saturated fat consumption led to an increase in the size of LDL particles (i.e. the so-called bad cholesterol) rather than increasing the number of LDL particles: this seems to be a beneficial effect.

Interestingly, total cholesterol levels may have little to do with heart disease. According to the MRFIT data, “If we were to stick rigorously to a cholesterol-lowering diet for thirty years – say, from age forty to seventy, at which point high cholesterol is no longer associated with an increased risk of heart disease – we would reduce our risk of dying of a heart attack by 1 percent.”

Taubes goes on to say that the cause of heart disease could be high blood triglycerides. Pete Ahrens showed that a high carbohydrate diet caused high blood triglycerides in the 1950s. Thirty years earlier Joslin had shown the same effect in diabetics. According to research by Albrink, Man, and Meigs “only 5 percent of healthy young men had elevated triglycerides, compared with … 82 percent of coronary patients.” A diet high in refined carbohydrates stimulates a high production of insulin. Insulin in turn causes the liver to release triglycerides into the blood.

In part 2 I'll discuss the effects of refined carbohydrates on obesity and weight gain.

Stay fit,

Jonathan Pratt

Pratt's Pro Fitness