Jack Blatherwick

Misuse of the word “power” has been a century-long distraction

By Jack Blatherwick

Let’s Play Hockey Columnist

Summary: for sports that prioritize quickness and agility, we’ve been told the appropriate term from physics is ‘power;’ and therefore our top training priority should be to maximize power.  However, scientists who use the word power correctly have been researching a different quality from quickness and agility, because our common colloquial use of ‘power’ is often incorrect. 

Quickness and Agility are most simply charcterized, not by vertical power, but by acceleration: horizontal acceleration of body weight using one leg at a time.  This is an important distinction.  In a century of research into short, explosive movement, the conclusions have been contradictory at best, except for one consistent finding: Specificity. Training is most effective if it looks and feels like the competitive movement.  Certainly much of the recommended ‘power training’ doesn’t look and feel like skating or sprinting.

Are various vertical two-legged strength exercises effective training tools?  Yes, some are.  But, in a century of dogma about training for power, we’ve reduced the role of some very good, old-fashioned training activities that enhance one-legged horizontal acceleration.


The Journal of Strength Conditioning Research published an important review article by Dr. Duane V. Knudson, correcting our longtime colloquial use of the word “power” to characterize short, explosive, accelerating movements (Sept., 2009). This is a significant step toward re-orienting the research and training for explosiveness.

From physics: ‘Power’ is the rate at which Work is done (or Energy expended).

Is colloquial misuse common? Stop for a second, and think of five ways you’ve heard the word ‘power’ or ‘powerful’ used for athletic events. There’s a good chance they are incorrect.Toss out the strength movements of ‘power-lifting competition,’ the dead lift, bench press and squats.They’re not powerful, because they’re slow. 

Question: Which movement by a sprinter requires more power: (a) accelerating out of the blocks to 5 miles per hour in the same time as (b) accelerating from 10 to 15 miles per hour? Answer: It’s (b) by a long shot, but quite often the word ‘power’ is used to characterize ‘explosiveness’ in the first few steps.

Hockey, like many sports, requires skills combined with speed, quickness and agility. These are quantified most simply by the kinematic terms velocity and acceleration. It is these qualities that determine the winner of each 1-on-1 race in a game. Rather than analyze research data in this simple form, it has been common to use regression estimates or mathematical calculations to analyze the kinetic terms ‘power’ or ‘force’ instead. This has led researchers to investigate and recommend training activities designed to improve power, not necessarily quickness and agility, the qualities we’d like to develop.

Note: Unlike ‘Power,’ the word ‘Force’ is used correctly in describing acceleration (F = ma), but by multiplying the original data by body mass, we can end up with correlations and comparisons between athletes that might be misleading. Consider this example: If player X jumps higher and sprints faster than player Y, but weighs less, we do not declare Y the winner of the jump and sprint contests, simply because his power and force are calculated to be greater.

Many researchers have multiplied (added or divided) original data by body mass, and produced relationships that reflect body mass more than anything else. This is a common mathematical mistake in the annals of pseudoscience (citations upon request).

To increase Force (or power) production, coaches have often recommended workouts using great mass (F = m*a) and minimized training with great acceleration (F = m*a).  But great acceleration was our original objective. Training with great mass is not wrong, of course, but neither is training with great acceleration of body weight or slightly more.

Research efforts to find the optimal training loads to maximize power may have minimized the investigation and incorporation of the most obvious and specific training activities involving one-legged horizontal acceleration. For example, in 30 years, we’ve tested more than 150 hockey teams (4,000 subjects) of various ages and abilities for both on-ice and off-ice acceleration.  In every case the correlations have been high (ranging from r=0.65 to r=0.90).

Furthermore, improvements in sprinting and skating acceleration were highly related. Sprint training for hockey is a little too obvious and simple to market for profit, compared to a weight room full of gimmicks. This has led to the de-emphasis of short quality sprints as a training tool for quickness and agility in North American hockey. Sprints are used extensively in Russia to develop acceleration capabilities.

In a century of research, many other activities could have been investigated that are specific to horizontal acceleration, but the emphasis on vertical power exercises might have precluded this. Knudson’s review of the word ‘power’ should stimulate appropriate research and encourage coaches to analyze the validity of their advice to athletes.

When I speak to groups around the country, I ask coaches to list the highest priorities for development of a young player. Besides skill, they invariably rate quickness and agility near, or at the top of the list. To spread Knudson’s word, the next time someone tells you, “This particular exercise is the best way to improve power,” you might say, “Thanks, but I’m interested in acceleration.”


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Exercise myth?

By Jack Blatherwick

Let’s Play Hockey Columnist

TIME magazine’s misleading cover (Aug. 17) featured a full-page photo/cartoon and bold headline, the kind usually reserved for important events like Michael Jackson’s overdue funeral. The headline read, “The Myth About Exercise,” and the article blatantly misrepresents scientific research regarding the relationship between exercise and obesity. I reached for my glasses and discovered the fine print, a byline which assured us that John Cloud, the author, still thinks exercise, “... is good. It just won’t make you lose weight.”

“Misleading” doesn’t begin to capture the potential damage done by a headline and cartoon in a population that prefers short, bumper-sticker slogans, rather than lengthy scientific articles. So let’s set the record straight about the relationship of exercise to obesity.

First, “overweight” is a poor description of our greatest national health problem. Across the entire population, the real issue is FAT, not WEIGHT. For example, many males don’t want to lose weight; they want to lose fat and gain muscle. Many females want greater muscle tone to improve body shape, even if they don’t lose weight. Exercise is essential in this endeavor, and body weight may increase, because muscle is heavier (more dense) than fat. 

The Body Mass Index (BMI) was used in this study to categorize 57 year-old female subjects as overweight, and the BMI is not a bad first approximation for an older population. However, because the BMI is based solely on height and weight, it is likely to attach the same “overweight” label to lean, muscular male athletes. This is absurd.

The original research by Church et al., (www.plosone.org/article/info:doi/10.1371/journal.pone.0004515) investigated sedentary, post-menopausal, overweight women (average age 57.2 years). The conclusions might well have been different if another segment of our population had been studied. Over 410 women were divided into four groups and assigned different levels of exercise each week for six months.

The raw data show that in six months the group which exercised most (a) increased their fitness level by eight percent, which was greater than groups who exercised less; (b) reduced abdominal girth by one inch, as did other groups; (c) lost 3.3 pounds (p<0.05), but this loss was less than a hypothetical “predicted weight loss” based on the number of extra calories expended.

Also, when statistical significance is based on comparisons to controls, and the controls mysteriously lose weight, the weight loss by the exercising groups is not statistically significant. This was reason enough for the authors to conclude that weight loss is not related to exercise; therefore it must be related to diet.

(A parenthetical question: If the controls are a random sample of sedentary, overweight women, are we to conclude that if this population does nothing different than what they’ve always done, they will lose weight? If that answer is “yes” it should provide for another anti-exercise headline by TIME. It is also a reason to challenge the conclusions of a study that was otherwise very well done.)

My purpose in writing is not to dispute methods or conclusions of the original research, but to offer better advice than TIME did in its cover page and accompanying article. Facts: (A) Young people who exercise are less likely to be obese or become obese later in life. (B) Participation in youth sports further reduces the risk of obesity and related diseases. (C) Research in the fields of nutrition and exercise should be considered as one small piece of a large difficult puzzle. Do not exaggerate the conclusions of any one study, because next month you might be apologizing — as TIME magazine should. 

Do not extrapolate the findings from a specific population to everyone on earth. This is not valid, but it is what TIME did, and because our population is so conditioned to accept advice from public figures — expert or not — any huckster can sell a diet or exercise program on the basis of what they call “scientific research.” Heck, they can sell war to a population that wants peace.

Do not be misled on this subject: American young people are overFAT, and failing to exercise enough is one of the causes, as are poor nutritional habits. Thousands of studies address this, so I forego the bibliography and leave it to the readers and Google. 

TIME obviously produced the most spectacular cover possible, so people passing the newsstand would buy their headline rather than the ones next to it — one of which read, “Walk Inches Off the belly.” The danger of trivializing health research in this way is that many people will act or spread rumors based on the headline, without reading the TIME article or the scientific research it represents — certainly not the volumes of research the reporter ignores or misrepresents.

The article itself was a disgraceful review of a significant health research project, because it included unwarranted and contradictory conclusions, exaggerations, and personal bias by a poorly informed reporter. Proving that a little knowledge is dangerous, Mr. Cloud extrapolates the conclusions to “you.” Presumably that means everyone. This is not warranted, of course, because the subjects of this study were all sedentary, overweight, post-menopausal women.

My commentary is presented to Let’s Play Hockey, whose readers are either young athletes of both sexes or their coaches and parents — or of course, referees. TIME’s shabby treatment of an important health issue is worth mentioning, because the research does not address your situation unless your age, lifestyle, hormonal milieu, sex, metabolism and exercise habits are similar to the study group. Please understand that in this case, as in many cases of pseudoscience, there are also many good points by the author.

The finding of the research stated simply is: 194 minutes of weekly exercise (without dieting) will cause 57-year-old sedentary women to lose weight, but not much more than a control group that loses weight by random chance. The TIME author and those of the original research extend a second opinion about prevention of obesity, which goes well beyond the scope of this research. They refer to the “gap” between calories consumed and calories spent, and they posit that this gap is not reduced by exercise. In other words, they believe exercise does not prevent obesity, and perhaps it does not among older adults.

Preventing obesity among children and young adults is a major health concern in our country, and many studies show that sports participation helps align appetite with metabolism — calories consumed equaling calories expended.

Here’s an anecdotal argument worth mentioning: I’ve tested body fat for dozens of teams (thousands of athletes, mostly male, but some female) between the ages of 13 and 39. Each team had an average body fat lower than the national average for their age. Furthermore: many of them ate voraciously; that is, they pigged out every chance they got — not always the healthiest of food, and I won’t mention their habits with respect to beverages.

Why were they less fat than non-athletes the same age? Sports participation — not diet — probably explains the difference — aligning their appetite with energy expenditure and anabolic growth of muscle. Of course, there could be a genetic (or other) predisposing difference, meaning they might have played sports because they were not fat. But with all due respect to these thousands of athletes, I’d have to say these were not all a bunch of genetic phenoms like Usain Bolt, Tiger Woods or Alex Ovechkin.

No, these were ordinary kids who participated in sports, and this helped them prevent the obesity that plagues millions of their couch potato peers.


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Hockey endurance…endure what?

By Jack Blatherwick

Let’s Play Hockey Columnist

Exercise scientists and fitness gurus have recommended endurance training that does not fit the demands of a hockey game, because words like ‘aerobic and anaerobic metabolism’ have not evolved to a useful place in team sports. Currently, these words are ivory tower distractions, limited to their elementary definitions in biochemistry textbooks. 

To plan for conditioning that actually works, it’s better to ask, “Endure what?” Before wasting a lot of time and energy, decide which physical qualities your conditioning program should try to maintain throughout a hockey game.

When I address a group of coaches, I ask them to list the physical attributes needed for a player (or team) to excel. As a coach, I certainly recognize that mental assets are most important, but since I’m asked to speak about physical qualities, the list is limited to these.

Invariably coaches agree that the most important physical assets are stick skills and skating speed, quickness and agility. Next, they add strength, coordination, balance and endurance. In other words, the priorities are skills and athleticism, and it’s the same list for every team sport. Therefore, ENDURANCE would correctly be defined as the ability to maintain quality skills and athleticism for an entire game. This wouldn’t look much like jogging around the lake — admirable, but dumb. Playing other sports is a much better choice.

Why have words like ‘aerobic’ and ‘anaerobic metabolism’ become distractions in planning a conditioning program? Because their misuse has led “outside experts” to recommend isolating the various aspects of metabolism into separate workouts — exactly the opposite from the way they are needed in games. Instead, we should focus on high speed intervals to improve skills, speed and acceleration in every direction — repetition after repetition, until we can do it for the length of a game.

Forget the words ‘aerobic’ and ‘anaerobic,’ and listen to players and coaches. They talk about  ‘game shape’ or ‘hockey shape.’ If at any point in a game a player cannot compete with speed, agility, quickness, strength and skill … that player is poorly conditioned for hockey.

It is counterproductive to isolate the “conditioning” process into separate pieces all the time: (a) long slow aerobic distances; (b) isolated anaerobic interval workouts for speed, or agility, or endurance; (c) limiting strength and power training to the weight room where movement typically isn’t specific to hockey and lacks speed, agility and quickness.

Separate workouts like these would correctly be called ‘compartmentalization,’ not preparation for hockey, because the game requires all of these qualities at the same time. The greatest athletes in team sports are not necessarily the very fastest, strongest or most skillful. They are usually the best combination of all of these.

Why are we stuck on compartmentalization? Because this is the way metabolism is taught in Biochemistry 101. Teachers must separate aerobic metabolism from the various anaerobic pathways in order to outline the chemical reactions of each. But it is important for coaches to understand that our body uses all aerobic and anaerobic pathways at once when we play hockey. All different types of metabolism occur simultaneously in separate muscle fibers and various organs in the body. Lactate produced in fast twitch fibers is incorrectly called a metabolic poison. In fact, it is an important fuel — not a poison — in other parts of the body.

Fitness gurus mislead us with amazing success. On the tube, I recently saw a genius explaining that as the intensity of exercise increases, there is a point where, “…we switch to anaerobic metabolism.” Actually, as the intensity of a game increases, and we need anaerobic power from fast twitch muscle fibers, we don’t switch off aerobic metabolism to let slow twitch fibers take a break.  The demand for energy is greater! No one gets a break, so anaerobic training can also be highly aerobic, because we are using oxygen to supply much of the energy. 

I’m not a word cop, and I don’t write to correct gurus who mis-speak. However, this is an incredibly important and almost universal misconception — the thought that exercise is either aerobic or anaerobic, but not both. Coaches and athletes should know that with appropriate anaerobic interval training, athletes can also improve aerobic fitness and cardiovascular efficiency, often to a greater extent than if they had spent the same time doing long, slow distances.

So...what does all this mean for hockey players and coaches? The bottom line is this: what we want to maintain for an entire game is high quality skills and skating speed, quickness, agility and strength. Effective endurance training for this purpose would therefore include practices and dryland training which involve superfast execution of skills…eventually lasting for the length of a game. This integrates (rather than separates) the various physical attributes needed for success.

Contrary to impressions from the movie “Miracle,” Herb Brooks’ conditioning philosophy for the 1980 Olympic Team called for high speed, full-ice team skills with lots of creative decision-making. Early in the season, quality execution lasted only about an hour. Later, the team was able to maintain quality for two hours or more, and this continued for six months. Training at slow speed has no role in this concept. 

And from the previous discussion you can see we are not neglecting aerobic fitness when we practice high speed anaerobic intervals for two hours. There is no need for young hockey players to join the middle-aged pot-bellies who ride bikes and climb stairmasters.

Brooks would advise any coach that nothing you can tell your team will be as meaningful as preparing them to execute skills and make decisions at high speed, without slowing down for the entire game.

When you combine the incredible skills and competitiveness of 20 motivated players, many of whom eventually played in the NHL, and the masterful execution of high speed, high quality interval practices by Herb Brooks, it’s easy to see why the “Miracle of Lake Placid” was not a miracle.


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Improved endurance performance by rinsing with a carbo drink? Wow.

By Jack Blatherwick

Let’s Play Hockey Columnist

Scientists from the United Kingdom, have recently shown that carbohydrate drinks during exhaustive exercise will enhance performance – even if you simply rinse the drink around your mouth and spit it out! (Ref. 1, 2 below)

This should not be as surprising as we might think at first. After all, it has been established that ingesting the right mixture of electrolytes and carb/energy drinks will increase endurance performance. Secondly, we’ve known for years that there are oral receptors for sweetness that alert the brain within seconds, when sugars are taken into the mouth.

When a person is not exercising, the oral sweetness receptors play the first role in a negative cycle that eventually leads to storage of fat. Now, it is clear that these or similar receptors can also play the first role in a positive cycle during exercise. The mere presence of sugar in the mouth leads to the release of insulin, which assists cells in absorbing sugar out of the bloodstream – into muscle cells during exercise, into fat cells during inactivity. 

This is why, when someone consumes a “highly glycemic” food or drink (“glycemic” means it is quickly converted to sugars), the person can actually become hypoglycemic (low blood sugar). This triggers a strong craving for more sugar, so the negative insulin cycle is one reason for the failure of many diets.

During intense exercise, however, insulin plays a positive role in assisting muscle cells to absorb sugar from the bloodstream, to be used as fuel. Therefore, it was believed that ingesting carbohydrate drinks during exercise improves endurance activities, because it reduces the need to use glycogen stored in the muscle. That was our overly simplistic explanation before these recent studies. Now we can see that the brain also plays a role in this enhancement of performance. This should be no surprise, because the brain plays a role in everything physiological. 

This latest research shows that spitting the drink out before swallowing will also enhance endurance performance. MRI’s (magnetic resonance imaging) showed that the signal from oral sweetness receptors alerted three areas of the (cortical) brain known to be active in muscle control and reward.

When subjects swished and spit out a placebo drink containing artificial sweetener, their endurance performance was not enhanced and there was no extra activity in the same areas of the brain. The results are an eye opener, but the authors might also be guilty of over-simplification, attributing enhanced endurance performance entirely to a central nervous system phenomenon, not a metabolic one. The reality is that positive effects of carbohydrate supplementation (swallowed or not) are most likely due to an interaction between the brain and the biochemistry within the muscle.

Is this the final word, and should we jump on the bandwagon, trusting the research? No and yes. Future research will certainly uncover more, but these studies were published in highly respected journals. The MRI results are stunning. Meanwhile, before the verdict is finalized, you should act. If you don’t like to take in extra calories during games or workouts, it may be very effective to rinse and spit out the drink without swallowing.



1) Chambers ES, Bridge MW, Jones DA.  J. Physiology, 2009.  April, P.1779-1794.

2) Carter JM, Jeukendrup AE, Jones, DA. Med Sci Sports, Exer, 2004.  Dec, P. 2107-2111.


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Don’t underestimate the simple things

By Jack Blatherwick

Let’s Play Hockey Columnist

In planning your summer training, it’s easy to be fooled into thinking that the most expensive options are the best.  After all, that’s what marketing is all about.

Certainly, there are many valuable ‘pay-for-play’ options: stickhandling, shooting or skating instruction lead the way. You can also skate on treadmills, plug your muscles into a machine that stimulates them, lift weights and compete in summer hockey leagues. All good stuff really, but each represents only a single piece of the puzzle.

Watch closely as the Red Wings and Penguins battle over the Stanley Cup.  You’ll see the two teams who best represent the future direction of hockey — the type of players to copy if you’re serious about getting better. They play faster and with more skill than the rest of the NHL.

Faster. More skillful. Don’t forget these qualities this summer. The scouts certainly won’t. Their preoccupation a few years ago with size has been replaced with a search for skillful speedsters, and the league will continue to evolve in that direction as each team tries to catch the top two.

Skill and speed – plus quickness, agility, coordination and explosive strong legs – are athletic qualities that require repetition after repetition after repetition – not money. Instruction might help some players, but improving stick skills, athleticism and skating speed are projects for those willing to put in quality practice time. 

The one off-ice activity that is most likely to improve skating acceleration is short, explosive sprinting. It’s free; therefore no one is marketing it. In testing 500 teams, we have consistently found a high correlation between short sprints on-ice and off – a higher correlation than any other variable: strength, vertical jump or power measured on a bike or in any other way. The shorter the sprints the higher the correlation. 

At every age, off-ice sprints are a high priority. It’s too obvious and simple; therefore sprinting for quickness is unduly left out of the development process. Sprints are suggested for endurance training, but generally these sprints are too long and the rest intervals too short to improve speed and quickness. 

This is often the case when planning skating drills. Somehow “skating” equates to “drudgery,” meaning endless stops-and-starts or tough drills that are counterproductive for improving quickness and skill. Don’t make this mistake in the summer. Keep your on-ice and off-ice sprints short, and allow enough recovery to ensure that speed and quality technique are the highest priorities.

Another good choice is participation in explosive sports that involve quickness and agility – sports like basketball, soccer, football, lacrosse, tennis, racquetball and squash. One drawback however: in team sports it is easy to put it on cruise control and play without speed. Therefore, my recommendation is to try “BASELINE TENNIS,” a training game used by elite tennis players.

This is tennis without serves, so points last longer and are filled with incredible athleticism. There’s no way to hide, as in a team sport. You must sprint to each shot and immediately back to the middle to prepare for the next one. It includes dynamic training of core muscles, as you lunge and twist for forehands and backhands; plus, it duplicates the explosive interval nature of endurance in a hockey game.

Don’t fall for a sales pitch that the more money you spend, the better development you’re getting. Sprinting, stickhandling, shooting pucks and baseline tennis are free. Skating practice can be inexpensive at the right time of day. All these require no instruction – nothing but a commitment, and the rewards are not easily matched at any cost.


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