Effect of Exercise on Body Measurements

Body Weight / Height / Body Fat / Waist Circumference / Arm Span & Michael Phelps / Chest Circumference / Bicep Circumference / Thigh Circumference / Heart Rate

Body Weight
I measure body weight using a bathroom scale. Body weight measurements are done without clothes. Usually I weigh myself in the evening, but not always. Therefore I never rely on a single measurement. Instead, I find the average of all measurements taken in a given month. In August 2011, my average weight was 176 pounds.

Historical records are given below:
  • Spring 2001--------179 pounds at age 26
  • Spring 2002--------173 pounds at age 27
  • Fall 2002-----------175 pounds at age 28
These figures show that at times I weighed slightly more in my 20s than I do now. I think that may be a reflection of both higher fat and higher muscle mass. I was not working out back then, but my outdoor job kept me very fit. Around 2002 I remember my sister noticing I had fat accumulations around my belly--nothing serious of course. Well sis, that's nearly gone now!

Since starting my workouts my body weight has increased by a few pounds. This is good news. I believe I have lost fat and gained muscle. I have increased my protein intake considerably, and I have decreased my fat intake by looking at the nutrition labels on grocery items and cutting out the foods that have more grams of fat than protein. On the graph I notice that I have not gained much weight since September 2009. I attribute this to my swimming, as this exercise burns a huge amount of calories. I started swimming for the first time in that month. My weight lifting has also reduced in frequency and weight since March 2010, so perhaps I have not been gaining as much muscle. I can't explain the sudden drop in body weight at the end of 2010, but whatever was going on has stopped and my weight is back to summer 2010 levels.
My body weight increased after starting a workout program.

With shoes, I am definitely 6'4" (76 inches) tall. But without shoes, I come in below that mark. I'm a scientist and like to be exact, so when people ask how tall I am I give them this long explanation. But really they don't care that much and I should just say 6'4".

There is a little more to say on this topic because I used to be almost half an inch taller. As described briefly in the 'About' page, I broke my back in 1998 after falling 40 feet. One of my vertebra was partially crushed, and while it healed without complication, it was never restored to its original height. 

Body Fat
Estimating body fat using skin-fold calipers.
I started calculating body fat in March 2010, but it takes a little extra effort to do, so I don't do it often. For my measurements in 2010 I used skin calipers that I obtained from a school that no longer needed them. The booklet that came with the calipers dates to 1992 and it instructs me to take 11 different measurements at various places on my body. Given the imprecision of the technique, I used the average of 3 different measures for each of the 11 parameters. Then, using the provided equations based on age and gender, I estimated body fat as a percentage of body weight. My stats:
  • Mar 2010------11.9%
  • Jun 2010--------9.1%
Starting in 2011, I used a different set of calipers to do the body fat estimation. I will post a blog entry on this new equipment soon. Here are my stats using this new equipment:
  • Jan-Mar 2011------12.9%
  • Apr-Jun 2011------12.9%
  • Jul & Aug 2011------12.4%
There seem to be fairly big month-to-month variations, but when I calculate 3-month averages this random noise evens out. From month to month I may happen to select a different fold of skin ("an inch to the right of the belly button" could actually be 0.5 inches or 1.5 inches, depending on how I judge it on a given day). Given the different technique used for estimating fat in 2010 versus 2011, I can't say whether I increased in fat over that period. All I can say is that I do carefully monitor my fat intake. If a food item at the grocery store contains more fat than protein, I don't buy it. I like being lean and thin. I see older men with a large belly and it doesn't look comfortable or compatible with the kinds of activties I like to do. Fortunately, if I sense that the little "love handles" around my abdomen are getting a bit thick, I don't have to do much to shrink them down again. Just a day or two of limiting fat intake or ramped-up exercise gets rid of the excess. I cannot get rid of them entirely, however.

Waist Circumference
Starting in 2008 when my workouts began, I had a 34" waist. I don't remember when I changed pant sizes from 33 inches to 34 inches, but I never actually measured my waist. I just knew that my 33" pants felt a little small. In 2010 when I started this blog, I measured my waist and it was still 34 inches. However, almost none of my pants fit me anymore. All are too large and I have to use a belt to hold them up. Indeed, there are some pants that I wear to work that are so large that the folds of material at my belt buckle are obvious and embarassing. I really need to buy new pants for a new, thinner me. There is a delimma of what size to buy! I measure 34 inches but none of the 34-inch pants fit me, and the 33-inch pants are too large, too. Have clothes manufacturers increased the pant waistlines of clothes without telling us? I heard that that happens all the time in women's clothing, where a size 6 in 1990 is the same as a size 4 in 2010 (something like that). I guess it is true for men now, too. Americans really do have a problem with weight...except the author of this blog!

Arm Span & Michael Phelps
I never would have thought to measure arm span, except that American Olympic swimmer Michael Phelps is someone whom I admire. Phelps is 10 years younger than I, and I love swimming so much that I have to wonder what I could have been like if I had started swimming when Phelps started swimming at age 7. According to websites, Phelps' body is made for swimming, as he has an unusally large arm span (79.1 inches) as well as large hands and feet (US size 14). What about my arm span? It's 74.8 inches. My shoe size is US 13. We are the same height, but he's 190 pounds (or was in 2008). Alas, I am not quite like Michael Phelps.


Me in 2011

Me in 1998

Michael Phelps in 2008









Weight (pounds)




Arm Span




Shoe Size (US)




100-yard freestyle (sc)

72.55 sec


41.93 sec

Years Training




Olympic Medals




Chest & Biceps Circumferences
I measure biceps circumference on my left (non-dominant) arm using a flexible plastic measuring tape. On any given day I measure a couple times to find the largest value, and then I average all days together to find a monthly average. I should note that even though I call this "biceps circumference," the bulk of a person's upper arm thickness is due to the size of the triceps. The biceps is a comparatively smaller muscle.

I measure chest circumference using the same plastic measuring tape. I sit up straight, inhale and then exhale in a relaxed manner, and pull the tape under my armpits and above my nipples.

Historical data from before I started working out are below:

Date-----------Biceps (inches)----------Chest (inches)
May 2001------10.9-------------------38.8 at age 26
Jun 2001-------11.5-------------------39.5
Apr 2002------11.4-------------------38.6 at age 27
Dec 2002------10.9-------------------38.8

These figures show that my chest size in my mid 20s was not appreciably different from when I started working out in 2008 at the age of 34. My biceps circumference was also fairly consistent between 2001 and 2008 when I started working out, though there is a little more variation in monthly averages. I should point out that if a measurement is taken after a workout, my arm circumference is at least a quarter-inch larger due to a larger volume of blood circulating in the muscle, so differences of 0.25 to 0.50 inches should not be considered significant.

Since starting my workouts, both my chest and arm circumferences have increased. My chest size has increased from 39.5 inches to more than 42 inches. My biceps measurement has increased from 10.8 to 11.8 inches. These increases really are not noticible in the mirror, but I feel different. I have also noticed that there is more pectoral muscle anchored to my sternum. If I didn't have so much chest hair, I might be able to see a groove down my front between the two pectoralis muscles. I can feel it in places, but at this point it wouldn't not be obvious enough for anyone else to notice. That's OK. Just looking at the charts below gives me great satisfaction that my workouts are making a difference. If I am beginning to see changes on the outside of my body, I know there are big changes going on inside as well. I am in excellent shape.

On the graph I notice that my chest and arm size increases have plateauted since Apr 2010. Given that my weight lifting was reduced in frequency and weight in 2010 compared with the previous year, this is a rather obvious indication that weight-lifing has been causing my muscles to increase.  
Both biceps and chest circumferences have increased since I started my fitness program.
Thigh Circumference

I measure the circumference of my right thigh above 5 inches below my crotch. This is the thickest point on my leg and I have a mole there, so it is easy to take consistent measurements at that spot. I stand in a relaxed position to take the measurement. Multiple measurements made during a month are averaged together. Historical data below show that my thigh circumference has decreased about an inch from my mid 20s to my mid 30s. I believe this is correlated with the decrease I've seen in body weight during this time. Back in my 20s I did a lot of walking and hiking as part of my job and I think my leg musculature was higher then because of that. I also didn't watch my diet as much, so I might have had a greater fat load. 

Historical data:
  • May 2001-------22.6 inches at age 26
  • Jun 2001---------23.0 inches
  • Apr 2002--------22.1 inches at age 27
  • Dec 2002--------22.6 inches
Thigh circumference since working out has increased over time, but not to the same degree as my chest circumference. The reason for this is obvious; I am not doing any weight-lifing exercises that target the lower body. Only the swimming, running, cycling, and hiking that I am doing with increased frequency will lead to stronger and larger leg muscles. The large drop in body mass I observed in December 2010 is also reflected in the thigh circumference data.

Thigh circumference seems to correlate with overall body weight.

Heart Rate
I watched an interview with Michael Phelps one time and he was asked what his resting heart rate was. He said "I have no idea." For as much as I consider him a role model in my swimming workouts, he has disappointed me a few times, and this was one of those times. He doesn't know what his resting heart rate is? Come on. It's easy to measure and I'm sure he knows what it is. But maybe this was just his way of dodging a personal question. My resting heart rate (taken when I awaken in the morning) ranges from 48-58 beats per minute. I like to measure it because a lower resting heart rate correlates with the strength of the heart muscle. Maybe it is not a metric that is comparable from person to person (everyone's heart and body is different, so 52 bpm for me may be better or worse than your 52 bpm), but within a person I think this is worth monitoring over time. However, I really don't see any pattern in my heart rate data. Some months I do more cardiovascular exercise than others, yet my resting heart rate is sometimes 48 and sometimes 58 bpm, regardless. I think there should be a pattern but it is obscured by the fact that resting heart rate can change from day to day, and my monthly averages of cardio exercise duration and intensity are longer-term measurements.

Anyway, it is worth discussing maximum heart rate here, and how I try to get my heart rate during exercise into training range. I know there are advanced methods for calculating one's maximum heart rate but I've never tried. I just use the equation 220-age(36) = 184 bpm. To increase cardiovascular fitness, experts suggest a person push their heart rate above the 70% of maximum threshold, which in my case is 148 bpm. Actually, I use 185*0.70*1.15 to get 148bpm because I read that was better. I'll have to find the source for that. If during the course of a swimming, running, cycling, or any other cardio workout my heart rate reaches 148bpm then I judge the intensity of my workout as a 3 on a scale of 1-4. A rating of 4 would be >170 bpm and a rating of 2 would be any exercise that results in a heart rate below 148 bpm but above 127 bpm. It's not hard to get a 2 score, and I strive for a 4. I keep track of my intensity rating to ensure I am working my heart as much as possible during exercise. The more efficient my heart is, the slower my body is to fatigue.

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