Weight rooms continue to add new machines and tools to allow exercisers to work out in a variety of ways. Most weight rooms have many different machines and exercises that can work the upper body. The bench press, works the pectoralis major, triceps barchii and anterior deltoid, with stabilization by the medial deltoid.  A variety of equipment and a large number of options such as a free weight bench press, seated chest press, or Smith Machine bench press can be used to perform a bench press exercise.

But how do these machines and exercises fare in regards to last week’s blog “Training on Unstable Surfaces: Superior to Traditional Strength Training?” Many experienced lifters accept the free-weight bench press as the ideal method for maximal upper body strength gain. The Smith Machine, such as the one in the picture above¹, offers a safer and more controlled means of training the same muscles for inexperienced lifters.

The Smith Machine is a weight lifting rack with fixed rails that the bar moves along. Most can be used for a variety of exercises by moving a bench into or out of the rack. In addition, many have catch points for the bar to stop at or rest on to increase safety.

But what happens to muscle activation during lifts on the Smith Machine versus the free weight bench press? A recent study² found that there were no significant differences in muscle activation of the pectoralis major or anterior deltoid for experienced and non-experienced lifters. The study looked at any a variety of loads (70% 1RM & 90% 1RM) for both groups. There was a significant difference in muscle activation by the medial deltoid. The free weight bench press required more activation of the medial deltoid. This muscle helps stabilize the shoulder joint during the resisted phase of the free weight bench press.

Since the Smith Machine bench press required less stabilization, you might think that this would allow for greater loads to be used. This was not found in the study. “It may be that the unnatural bar path of the smith machine forces the subjects to press in an unnatural linear path instead of the reverse ‘C’ observed during free weight bench press, subsequently hindering optimal force production.”

This confirms that both exercises are good options in the weight room, but depend on the goal of the exerciser. These results suggest that the free weight bench press may lead to increased requirement for stabilization about the shoulder joint from muscles such as the medial deltoid. Exercisers should determine if this is an area in need of development when choosing an exercise and working towards their training goal. 

Activities such as basketball, baseball, tennis, racquetball, hockey or volleyball require movement and stability by the glenohumeral joint. If preparing for these activities then the free weight bench press might be the best exercise. But as with any exercise, machine or tool in the weight room, it all goes back to the purpose or goal.

¹Photo permission from: Free Motion Fitness, www.freemotionfitness.com. 03/25/10.

²Schick, EE, Coburn, JW, Brown, LE, Judelson, DA, Khamoui, AV, Tran, TT, and Uribe, BP. A comparison of muscle activation between a Smith machine and free weight bench press. J Strength Cond Res 24(3): 779-784, 2010.

You probably saw the media coverage earlier this week about the study that has determined that super-sizing may have been going on a lot longer than we thought. 

For a millennium to be exact. 

Drs. Brian and Craig Wansink (they are brothers) studied over 50 paintings of the Last Supper that were painted between the years of 1000-2000 AD¹.  They picked the Last Supper because they said, “it is the most famously depicted dinner of all time.”  Using the size of Jesus Christ’s and the Apostles’ heads a size reference, the researchers used computer aided design  software to measure the sizes of the plates and food represented in the paintings.  They found that the plates and food sizes increased by over 65% over time.  While this finding doesn’t pardon us the excessive portions we eat today it does generate awareness about our distorted portions.  For more information on the study, click here.

In our earlier blog, “Picking the Right Dinner Plate,” we remarked about how plate sizes have expanded in modern times from 8 to 9 inches in the 50’s and 60’s to 12-inches or more in the last few decades.   So what?  Dr. Brian Wansink’s  research demonstrated that people are likely to eat more food (and therefore more calories) when they eat off arger sized plates.  Likewise, smaller plates means fewer calories.

I had a personal experience with this last week when I was visiting my brother.  In his cupboard are several sets of antique china.  All the plates ran 9 to 10 inches in diameter.   I found that indeed, I and the others around the table tended to choose less food because there was less surface area on the plate.  

I thought about turning my small plate dining experience into a book but Alex Bugosky beat me to it.  Drats!! His 9-inch Diet book describes how he happened upon the “small plate” idea and ways to incorporate portion management into daily living. 

At the heart of most weight management  programs is the premise that we are simply eating too much food.  So what is the right size?  WebMD has a great portion size tool that will help you learn how what a serving looks like for many different foods. 

Nobody knows what was the exact size of the plates used at the actual Last Supper.  The Wansinks believe the size of the plates depicted in the all the various Last Supper paintings is representative of the dinnerware used at the time of each respective painting.  If so, our modern portion distortion problems might be a just the latest phase in a growing trend. 

 

¹ Wansink B and Wansink CS. The largest last supper: Depictions of portion size and plate size increased over the millennium,” The International Journal of Obesity.   2010; March 23, e-published ahead of print.

  

Training on unstable surfaces such as stability balls and balance boards continues to gain popularity. Exercises on unstable surfaces are often promoted to improve balance and challenge core stability more than traditional resistance training using free weights and machines. However, scientific proof that training on unstable surfaces is superior to traditional resistance training performed on stable surfaces, such as a bench, is lacking. Given that most activities of daily living are performed on stable rather than unstable surfaces, it is important to determine whether exercising on unstable surfaces transfers to improvements in activities performed on stable surfaces.

One group of researchers designed a study to answer the following questions:

1. Can you lift more weight on stable surfaces compared to unstable surfaces?

2. Which requires more core stabilization – lifting on a stable or unstable surface?

3. What effect does lifting an unstable load (dumbbells vs a barbell) have on strength and core stabilization?

A study by Kohler and his associates1 measured the amount of resistance that could be lifted during an overhead press using stable vs unstable loads (barbell vs dumbbells) and stable vs unstable surfaces (weight bench vs stability ball). Thirty subjects with at least one year of resistance training experience volunteered to participate in the study. Each subject performed an overhead press under four conditions:

1.  Using a barbell seated on a bench (no back support) – stable load, stable surface

2.  Using dumbbells seated on a bench (no back support) – unstable load, stable surface

3.  Using a barbell seated on a Swiss ball – stable load, unstable surface

4.  Using dumbbells seated on a Swiss ball – unstable load, unstable surface
Researchers measured strength for each exercise during a 10 RM (Repetition Maximum) shoulder press exercise. The test measures the amount of resistance that could be lifted 10 times to failure during each exercise condition. This allowed researchers to determine if subjects were able to lift equal amounts of weight when using unstable loads and surfaces. Next researchers measured the activity of the core muscles while subjects performed 3 sets of each exercise.

Subjects lifted the most weight when using a barbell seated on a stable surface and the least when lifting dumbbells (unstable load) on a stability ball (unstable surface). This demonstrates that as the load and/or the surface becomes unstable that the maximum amount of weight lifted decreases. If an individual’s goal is to increase strength, the reduced ability to load an exercise when using unstable loads (dumbbells) or surfaces will limit strength gains.

Muscle activity in the abdominals was higher during exercises performed on stable surfaces. This suggests that the ability to lift more resistance on stable surfaces requires more abdominal musculature. For the back muscles, activity was signficantly higher when lifting stable loads (barbell) on both stable and unstable surfaces.    These findings may, however, be specific to the overhead press and may not reflect core muscle activity for other exercises like the bench press or rowing exercises.

TAKE HOME MESSAGE: The results of this study emphasize the need to include some traditional strength training exercises into your exercise program to maintain and improve muscular strength. Although this study did not measure balance or ability to perform activities of daily living, another study by Spennewyn2 reported that training on unstable surfaces can improve balance. Until more research is available regarding the effects of training on unstable surfaces, it is a good idea to incorporate a mix of traditional resistance training, in addition to exercises on unstable surfaces into your exercise program. This is especially important if the goal of the program is to improve muscular strength.

1. Kohler, J.M., Flanagan, S.P., & Whiting, W.C. (2010). Muscle Activation Patterns While Lifting Stable and Unstable Loads on Stable and Unstable Surfaces. Jour Stren & Cond Res, 24(2), 313-321.

2. Spennewyn, K.C. (2008). Strength Outcomes in Fixed Versus Free-Form Resistance Equipment. Jour Stren & Cond Res, 22(1), 75-81.

Last week we introduced you to the concept that changing the prices of foods via taxes or subsidies appears to change food purchasing habits and presumably, what people eat. We also touched on the fact that soda is being singled out for tax hikes in places like New York and Philadelphia.  The thinking is, “Tax it and people will drink less.  Less soda means fewer calories taken in.  Fewer calories means reduced body weight.  Reduced body weight means less obesity.  Less obesity means fewer health problems such as diabetes and heart disease.  Fewer diseases means savings in healthcare costs.”

Or the short version, “Taxing soda will save the (local or state) government money by reducing healthcare costs and, in fact, may be a source of funds to support public health initiatives.”

So that’s the thinking.  But why pick on soda?

For one thing, the obesity epidemic is a result of our population eating too many calories and not getting enough physical activity.  There have been some studies that have attributed most of the increase in calories to sweetened beverages.    We reported on one such study in our “Watch Out for Liquid Calories” blog.   Briefly, from 1965 to 2002 Americans increased overall calorie intake by nearly 200 calories.  More than 150 of those calories came from sweetened beverages.  So soda is a problem.

Second, a study published last week in the Archives of Internal Medicine¹, showed that between 1985 and 2006, soda prices actually decreased when inflation was taken into consideration whereas the price of milk increased.  The researchers calculated that if the soda price had increased by 10%, 7% less soda would have been consumed.  In a statistical model, a $1.00 increase in soda price was linked to lower calorie intake and lower body weight.  So taxing soda may help reduce the problem of excess calories.

Third, it is fairly easy to cut out soda.  There are plenty of other beverages – like water – to take it’s place.  So reducing soda intake is a simple dietary change. 

Finally, and top of the list for some people, is that sweetened beverages such as regular soda, fruit drinks, sweetened tea and coffee, and other sweetened beverages provide only calories – no nutrients.  For example, 8 ounces of soda contains about the same amount of calories (about 100 calories) as an 8-ounce glass of orange juice.  But the OJ has vitamin C, folate and other important nutrients.  The  soda has nada.  So there are much healthier alternatives to drinking soda.

There are a lot of good reasons to support a soda tax.  It just might be a good public health strategy because it may reduce soda – and calorie – consumption while at the same time raising money for the public health coffers. 

But we must ask, what gets taxed next?  Ice cream?  Candy?   There is no easy answer to this issue.  What are your thoughts?

¹ Duffy KJ, et al.  Food price and diet and health outcomes:  20 years of the CARDIA study.  Archives of Internal Medicine.   2010;170(5): 420-426.

Researchers are discovering that resistance training in overweight and obese children and adolescents is having multiple positive effects.  For starters it is increasing their time spent in physical activity.  It is lowering their body fat, improving their bone density, and increasing their sensitivity to insulin.¹ But, there is more. In a 16 weeks study in which youth participated in progressive resistance training, there was also a 96% adherence rate.² This is key because identifying activities that they like and can excel in is important for our youth to adopt a lifestyle of regular physical activity.

Also psychosocial wellbeing was improved.  Part of this is attributed to the growing confidence youth had because of their improved motor skill performance.  In other words, overweight and obese children and adolescents tend to have low motor abilities due to little participation in physical activities.³ This in turn negatively affects their confidence.  Without confidence there is less chance they will try other activities or even engage in physical activity.  But in resistance training programs, overweight and obese youth shine and even excel.  They tend to be the strongest students in the class, and they often receive positive feedback from their normal weight peers who are impressed with the amount of weight they can lift for the prescribed number of repetitions. 

Furthermore, these at risk youth tend to get bored with cardiovascular activity or it brings discomfort to them.  However, with resistance training which is characterized by short periods of physical activity followed by a brief rest period between sets and reps, the youth are enjoying it and sticking with it.

The following are some of the guidelines for resistance training for youth:⁴
• Provide qualified instruction and supervision
• Children as young as 7-8 years old may participate
• Begin each session with 5-10 minutes of warm up
• Start with 1 light to moderate set of 10-15 repetitions
• Progress to 2-3 sets of 6-15 reps
• Focus on the correct technique rather than the amount of weight lifted
• Train 2-3 times per week on non consecutive days
• In general, adolescents require 1-2 minutes recovery between sets; children as little as 1 minute recovery
• Keep the program fresh and challenging by systematically varying the training program
• Cool down with less intense activities and stretching

Finally, there was not one optimal number of set, reps, and weight.  Instead, the emphasis should be to create safe, progressive, programs with regular variations to keep sessions fresh and challenging.  Also, any variety or combination of exercise equipment like small apparatus or children’s’ resistance training machines can be used.  And of course positive support and close supervision will make the programs successful.

1Faigenbaum A. Resistance training for children and adolescents: Are there health outcomes? Am J Lifestyle Med. 2007;1:190-200.

2 Shaibi GQ, Cruz ML, Ball GD, Weigensberg MJ, Salem GJ, Crespo NC, Goran MI. Effects of resistance training on insulin sensitivity in overweight Latino adolescent males. Med Sci Sports Exerc.2006:38:1208-1215.

3 Stodden D, Goodway J, Langendorfer S, Robertson M, Rudisill M, Garcia C, Garcia L. A developmental perspective on the role of motor skill components in physical activity: An emergent relationship. Quest. 2008; 60:290-306.

4 Faigenbaum A, Westcott W. Youth Strength Training: Programs for Health, Fitness and Sport. Champaign, Il: Human Kinetics, 2009.    

There’s a big beverage brouhaha brewing in New York state.  It has nothing to do with coffee or beer.  A proposed tax on soda is at the center of this storm.

Local (e.g., Philadelphia) and state governments such as New York are looking to raise revenues and reduce waistlines by taxing sweetened beverages.  The proposed taxes range from 12 to 24 cents per 12-ounce container.  As expected, soda manufacturers are all afizz over this development.

We won’t opine about whether or not taxing soda is worthy public health idea.  We’ll save that for another blog on another day.   But there is recent research that suggests that manipulating the price of foods may change – in surprising ways – what people buy. 

Testing Effects of Food Prices

Scientists at the University of Buffalo used a very innovative research design to test how reducing the costs of healthy foods (i.e., subsidizing) or increasing the cost of less healthy foods (i.e., taxing)  would affect the types of foods moms selected for their families¹.  The researchers simulated a trip to the supermarket by setting up a room with photos of 68 foods and beverages.  One-half of the foods were healthy and the other one-half were less healthy.  The food photos also had the nutrition information and price for the respective food. 

Forty-two mothers with at least one child living at home each went “shopping” through the “store” five different times.  They were given a spending limit (the same amount for each time) based on the size of their family and they had to spend it all.  Each time a mom went shopping the prices were different.  During some trips the prices of healthy foods were lowered (i.e., they were subsidized).  On other trips, the food prices on less healthy foods went up (similar to being taxed).  After each trip through the simulated store, researchers calculated the nutrient composition of the foods a mom “bought.” 

Food Subsidies or Taxes – Which Works?

The results very clearly showed that taxing less healthy foods reduced the calories and fat and increased the protein in the mom’s shopping carts.  The moms purchased less of the less healthy foods AND surprisingly, increased their purchase of the healthier foods!  What did subsidizing the price of the healthier foods do?  The moms bought more of the healthy stuff as expected but they also used their “savings” on the healthier foods to purchase more of the less healthy foods!  This led to an actual INCREASE in total calories purchased.  The opposite of what most families today need to do. 

So maybe New York, Philadelphia, and other places are on to something with their budget proposals that call for taxes on sodas.  But should soda and other sweetened beverages be the only foods targeted?  Tune in next week for a continuing chapter in the soda tax saga.

¹ Epstein LH et al.  The influence of taxes and subsidies on energy purchased in an experimental purchasing study.  Psychological Science.  Published online 5 February 2010.  DOI 10.1177/0956797610361446.

You may be aware that March is Colon Cancer Awareness Month. Among cancers that affect both men and women, colorectal cancer is the third most common diagnosed cancer and the second leading cause of cancer-related deaths in the United States. According to the American Cancer Society, almost 150,000 new cases of colorectal cancer were diagnosed and approximately 50,000 people died from the disease last year. Despite these statistics, unlike some cancers, colorectal cancer is highly preventable and can be detected early through proper screening. And what do you think one of the most important prevention tools is? That’s right—physical activity.

In 2009, a review published in the British Journal of Cancer combined the data from 52 published studies on physical activity and colon cancer1. It was determined that the most physically active participants were 24% less likely than the least active to develop colon cancer. And the good news is this pattern held true for both lifestyle and structured physical activity.

This may not be surprising to some as regular physical activity has been shown to reduce the risk of many chronic diseases. But what many may not realize is that for those diagnosed with colon cancer, regular physical activity may decrease the risk of cancer recurrence and death2,3. In the long running Nurse’s Health Study, women who engaged in moderate physical activity (i.e. brisk walking) six days per week for about an hour per day reduced their risk of colon cancer-related death by 61% and 57% for all causes of mortality, when compared with women who rarely exercised2. And maybe even more remarkable was that even if the women began exercising after their diagnosis, they reduced their risk of colon cancer-related death by 52%. So the expression “it’s never too late to start” definitely applies here. Another study, this time with both men and women who had been diagnosed with stage III colon cancer, showed similar results3. With about six hours per week of walking, just like the previous study, there was a 49% decrease in the risk of getting colon cancer again.

So once again, the evidence shows the amazing power of physical activity. The American Cancer Society recommends that adults get at least 30 minutes of moderate or vigorous physical activity on 5 or more days of the week. Moderate or vigorous activity for at least 45 minutes on 5 or more days of the week may lower your risk for colorectal cancer even more. And as a reminder, screening is the most powerful tool for preventing colon cancer.

To learn more about colon cancer visit the American Cancer Society.

1KY Wolin et al. Physical activity and colon cancer prevention: a meta-analysis. British Journal of Cancer. 2009; 100(4): 611-616.

2Meyerhardt JA, Giovannucci EL, Holmes MD, et al. Physical activity and survival after colorectal cancer diagnosis. Journal of Clinical Oncology. 2006; 24(22):3527–3534.

3Meyerhardt JA, Heseltine D, Niedzwiecki D, et al. Impact of physical activity on cancer recurrence and survival in patients with stage III colon cancer: findings from CALGB 89803. Journal of Clinical Oncology. 2006 Aug 1; 24(22): 3517-8.

Eating on the run. Dashboard dining.  Surfing and snarfing.  Viewing and chewing.  These are all ways to describe our modern eating patterns.  Especially our snacking habits.  Research suggests we are doing a lot more of that today than 30 years ago.  I know, it doesn’t surprise you given our hectic lives.  But do you know just how much we snack?  Read on.

Studying Snacking

Researchers at the University of North Carolina-Chapel Hill compiled data from four very large national nutrition surveys done between 1977 and 2006¹.  I won’t go into the complicated methodology but suffice it to say the scientists took great pains to sort through the food intake of nearly 45,000 adults over the age of 18.  In so doing, they were very careful to define snacks as eating occasions separate from meals.  Thus, foods commonly thought of as “snack” foods (e.g., potato chips) that were eaten as part of a meal were counted in the meal calculations.  The end result was a data set that had information on the three main meals (breakfast, lunch, dinner) and snacks.

So how much do we snack? According to this study, a lot. Nearly all (97%) American adults eat snacks in a two-day period.  That’s up from 71% in 1977.  Daily snackers increased in the same period from 42% to 78%.  Also, we have nearly doubled the number of snacks per day (1.3 in 1977 to 2.2 in 2006).  But here is the kicker.  Each snack has increased from 144 to 226 calories and our total daily snacking calories have increased from 357 to a whopping 579 calories.  That’s a 64% increase! Today, snacking accounts for 24% of our total daily calorie intake. 

Are you ready for more bad news?  Our top 5 sources of snack calories are desserts, salty snacks, other snacks, sweetened beverages, and juices/fruit.  Low- and high-fat snacks increased the most since 1977 with, unfortunately, milk/dairy and juices/fruit dropping over the same time period.

So where did all those extra snack calories go?  Likely right to our waistlines because we have not increased our physical activity in the last 30 years to balance out the extra calories. 

Make Snacking Work

We are not likely to change our grab and go, fast-paced lives.  So you need to make snacking work to your advantage.  For example, most people don’t eat enough fruit, vegetables, and/or dairy products.  So instead of reaching for a Snickers bar, choose:

• Fresh, frozen, or dried fruit or fruit canned in fruit juices
• Fresh vegetables such as carrot sticks, cucumbers, grape tomatoes, mushrooms, etc.
• Low-fat or nonfat yogurt and cheese

You’ll satisfy your need for a snack plus boost your nutrient intake with these nutritious options.  Also, check out our earlier blog on 100 calories food portions.  Eating two to three of these 100 calorie options a day is a vast improvement over the nearly 600 calories we are currently snarfing down. 

¹ Piernas C and Popkin BM.  Snacking increased among U.S. Adults between 1977-2006.  Journal of Nutrition.  2010;140:325-332.

The 2010 Winter Olympics, in Vancouver, British Columbia, Canada ended yesterday. There were fifteen sports and 85 medal events. These events were split up into three categories of ice sports, alpine skiing/snowboarding and Nordic events.

Here at The Cooper Institute in Dallas, Texas I felt a little bit more connected to the games this year...  Most due to the actual winter blasts we’ve had. During the games we had colder than normal temperatures and it even snowed.  We set a new 24 hour snowfall record at over 12.5”.

With a winter wonderland in Dallas and the winter Olympics it was impossible not to want to participate in my own winter games. I couldn’t build my own Luge track but some of the cars I saw sliding around on the highway made it look like I did. I did go sledding, shoveled snow and built a snowman.

During this fun I was a bit curious if I was getting any caloric expenditure.   Also, I wondered how much energy is burned in an event that sometimes lasts only a few seconds and looks to be just using gravity to go downhill.

You might be a bit surprised to see the expenditures:¹

• Vigorous Downhill Skiing at race pace – 8.0 METS
• Bobsledding and Luge – 7.0 METS
• Cross Country Skiing at more than 8mph (racing) – 14.0 METS
• Cross Country Skiing uphill at race pace – 16.5 METS
• Speed Skating – 15.0 METS
• Curling – 4.0 METS
• Ice Hockey – 8.0 METS
• Shoveling snow by hand – 6.0 METS

Remember a MET is a way of describing the amount of energy (calories) the body is burning relative to energy burned at complete rest. One MET is equal to 1 kcal/kg/hour or the same as rest or sitting quietly, two METs means the body is burning calories at twice the rate of rest, three METs is three times, and so on. So if you are shoveling snow by hand, you are burning six times as much energy as you would be just sitting at rest.

To meet the current recommendations for adults one should do at least 150 minutes per week of moderate-intensity physical activity or 75 minutes of vigorous-intensity physical activity per week (or some combo of the two). As was discussed in the past blog “Moderate Means What,” 3.0-5.9 METS equals moderate intensity.

So I was doing pretty well when shoving my sidewalks!

¹Ainsworth BE. (2002, January) The Compendium of Physical Activities Tracking Guide. Prevention Research Center, Norman J. Arnold School of Public Health, University of South Carolina. Retrieved [02/25/10] from the World Wide Web. http://prevention.sph.sc.edu/tools/docs/documents_compendium.pdf