The Truth is in the Metabolic Armband

If you're like me, you've probably done some sort of physical activity and thought to yourself afterward "gee, that must've burned a whole bunch of calories!" But how many? For a class last semester I got to wear a metabolic armband for 24 hours that tracked my calorie output (as well as my sleep quality, how many minutes of moderate and vigorous activity I did, and the number of steps I took). How does it do this? By strapping the band onto your upper arm, it measures "galvanic skin response" to see how much you sweat in addition to skin temperature, the rate at which heat is being dissipated, and, via the accelerometer, how much you're moving. I was so excited to get to use the armband but I had a hard time deciding which physical activity I wanted to do on my one day; it ended up raining so an hour and a half of hot yoga won out over other options. Still, I was itching to try out other activities.

Last week I was able to borrow the armband for a whole week for just this purpose. I had a couple of activities I knew I wanted to try and then I talked with friends and followers to see what activities they've been wondering about. When I could, I compared my armband results from those that either the machine indicated, a website calculated, or the instructor of the class estimated to see how accurate these tools are compared with the armband (which claims to be the most accurate armband on the market).

Here's what the Body Media website that the armband syncs to knew about me going into it: my gender (female), my hand (right), my height (5'3"), my weight (~130), and whether or not I am a smoker (no). Here are my calculations, I hope you find them helpful!

Monday

• 3 mile walk to school (50 min): 228 cal  

Comparison: Shapefit.com estimates that a 130 lb person walking 4.0 miles per hour, which is a little faster than I was walking, can expect to burn 236 calories per hour.

• 1 hour basic yoga class at South Boston Yoga which focused that day on hip opening: 141 cal

Tuesday

• 3 mile walk to school: 223 cal

Comparison: Monday the same walk burned 5 more calories - maybe my backpack was heavier that day?

• Sitting in an hour and a half long lecture having walked to school: 92 cal

• 30 minutes on the treadmill, totaling 2.5 miles: 271 cal 

Comparison: The treadmill, knowing only my weight and age, told me I burned 294.4 cal.

Tuesday was the day I burned the most calories - by walking to school, running on the treadmill for 30 minutes during lunch, and walking to dinner and then the train later that night, I burned 2828 calories, took 22,513 steps, and had a total activity time of 276 minutes. Could it be because I had slept for 8 hours and 4 minutes the night before, with 94% sleep efficiency (time laying down versus time actually asleep) making it the best night of sleep I got all week? Perhaps!

Wednesday 

Day off! After awhile you don't really notice the armband during your daily routine and sleeping, but Wednesday I had ghost armband syndrome and kept thinking I was still wearing it.

Thursday

• Sitting in an hour and a half long lecture having driven to school: 85 cal

Comparison: Sitting in the same lecture on Tuesday burned 7 more calories having arrived from walking rather than arrived from driving.

• 1.5 hour boxing class at Boston Boxing and Fitness (mix of jumping rope, weights, sparing, step-ups, push-ups, lunges, etc): 434 cal

Comparison: Shapefit.com estimates 354 cal/hr of "boxing, punching bag" but that jumps to 531 if you're "boxing, sparring" and 708 cal/hr if you're "boxing, in ring, general." 

Friday

• Spin class at Sweat and Soul, 45 minutes long on Real Ryder bikes: 226 cal

Comparison: The instructor estimated 800 when I asked him how many calories one could expect to burn; a Body Media rep says via e-mail "When using certain gym equipment you may notice that your overall armband information may be lower than it should be. This is due to the fact that the abnormal and usually smooth motions throw off the accelerometers in the armband. Different equipment can affect the overall accuracy of the armband in many different ways." I think that the number is on the low side, but it was also only a 45 minute class and I wasn't panting, though I did sweat completely through all of my clothes so maybe a more accurate estimation would be around 300 calories.
 

Note: These Real Ryder spin bikes are pretty cool. They're supposed to mimic real riding on the road so they move to the left and right - and you really have to engage your core in order to turn them. See the above video for an example. 

Saturday

• Stair running at Harvard stadium (the little stairs that you use to enter the stadium, up one set and down the next around the entire stadium and back which took approx 25 minutes): 187 cal

Sunday

• Hour long Zumba class at ZYP Fitness Plus: 391 cal

Comparison: The ZYP website says participants can "dance away their worries & 500-700 calories." Before I went to the class I never would've guessed that I would get such a good workout but you literally move (or shake) your whole body the entire time - so don't underestimate this as a really good full body workout.

Special thanks to Rachel, Lea, Barrett, Dan, Chris, and Meredith who suggested workouts and then kept me company (or brought me along)!

I'm planning on borrowing the armband again in the spring so that I can track calories burned for fun outdoorsy activities like cycling, hiking, and running. Is there an activity that you've always wondered about? (Besides swimming since you cannot submerge the armband.) Let me know in the comments section and I'll write about it next time! Interested in learning more about Body Media, how it measures calories burned, or how it compares with other armbands out there? Check out their comprehensive website.

Guest Post! Getting the Most Out of Your Warm-Ups

Today's guest blog post about stretching comes from personal trainer Chris Chapman, a friend who suffered through Organic Chemistry with me this past spring. Chris will be guest blogging more in the future, so feel free to leave questions for him in the comments section...

Are you getting the most out of your warm-ups?

Before beginning a workout, whether it is a 3-mile trail run or an upper body strength day, you need prepare your body for the specific demands of that workout.  Done are the days where before we start exercising we do some arm circles, maybe a toe touch, and of course, the standing heel-to-butt quad stretch.

The best way to prepare the body for exercising is to use dynamic stretching (a.k.a. mobility drills).  Dynamic stretching is a sport-specific movement that prepares the body for exercise by actively moving a joint through range of motion used in your sport or activity.  Contrary to static stretching (holding a stretch for 15-30 seconds to lengthen a single muscle), dynamic stretching forces muscles to work together while raising your body temperature and increasing blood flow to the muscles. 

You are wasting your time by walking on the treadmill for 10 minutes or running a couple of laps to “warm-up” the body and then picking a couple of stretches to hold for 15 seconds.  A proper warm-up should take 10-15 minutes, and most of that will come from dynamic stretches (remember these will increase your body temperature and blood flow).

Over the next couple of weeks I will tell you which dynamic stretches you should be using that will increase your mobility (the quality of your joint’s movement), reduce the chance of injury in your exercise, and best yet, improve your performance in your activity! 

ANKLE MOBILITY

One source of knee pain is poor ankle mobility.  If you do not have quality movement in your ankles, your knee becomes less stable and this increase in force on your knee can lead to pain.  Luckily there are drills you can do before you exercise that can decrease the stiffness in those ankles!  My two favorites are the Wall Ankle Mobilization Drill and the Rocking Ankle Mobilization.  Alternate which days you use each drill and perform 12 repetitions on each ankle.

Wall Ankle Mobilization

Eric Cressey does a great job of explaining this drill. 

Rocking Ankle Mobilization

In this drill it you want to rock back onto your heel as far as you can, and curl your toes up off the ground, then you will point your toes as straight as you can.

Check back soon to see my dynamic stretching recommendations for your hamstrings!

-Chris

Chris works at the YMCA of Central Massachusetts as a personal trainer where he helps clients with goals ranging from weight loss to athletic performance.  He graduated from the University of Massachusetts-Amherst in May 2010 with a BS in Kinesiology.  Chris is a Certified Strength & Conditioning Specialist (CSCS) through the National Strength and Conditioning Association (NSCA).  In the fall of 2010, he completed his internship in the Rehabilitative Services department at the Fallon Clinic in Worcester, MA.  During his senior year, Chris worked as a Manager and Personal Trainer at the University of Massachusetts-Amherst Residential Wellness Centers.

Active Fun in the Sun

Summertime is here (finally. seriously.) so being active is starting to become a way of life - something that I want to do rather than something that I tell myself to get through in order to deserve the hot shower. I talk a lot in this blog about eating healthy and being active, but there is something else very important to me that everyone should remember when being active and that is: use protection. Whether you are the fairest of the fair or the darkest of the dark, if you're out in the sun being active, you need to use sunscreen. Worried about not getting enough vitamin D? (Had to bring it back to nutrition for a moment) Don't be - even if you put your sunscreen on 15 minutes before you go outside, your skin will still be able to synthesis enough vitamin D during your time in the sun.

Ok back to sunscreen. There are a lot of sunscreens out there, so how can you know if the $4 bottle will do the same thing as the $16 bottle? Chances are that as long as you are getting a high enough SPF, you'll be fine with the cheaper version, although it might not be as gentle on your skin or might not smell as nice. One thing that I always look for is the Skin Cancer Foundation's seal of recommendation. They're in the process of changing over to a new seal, but it should look something like this:



You can find a list of products including sunscreen, sunglasses, clothing, and umbrellas that have received this recommendation here. A few things I recently learned about sunscreen that you may find interesting: The FDA has mandated that they can no longer claim to be water or sweat "proof" just resistant. Sunscreen with an SPF of lower than 15 cannot claim to help prevent skin cancer. Sunscreen cannot claim to be effective for more than two hours without reapplication.

That last one may be especially surprising to those of you who think that you can put it on in the morning and then be good to go all day. Remember the importance of reapplying though - even if it still feels like you're wearing sunscreen, the effectiveness might have worn off. I find this to be a good time to use the spray sunscreen (being the fairest of the fair, I don't tend to trust the spray to cover every fair bit of me during initial application). I'll keep spray sunscreen in transition during a longer triathlon and reapply between events. It's easy, it takes 5 seconds, and your skin will thank you years down the line. I also recommend keeping a bottle of SPF 30 (or higher if you are related to me) in your car or backpack or purse. You never know when you might be outside for longer than expected and prevention is key for skin cancer. Be smart and protect yourself this summer.

(For more on skin cancer prevention as well as warning signs of melanoma, visit The Skin Cancer Foundation website)