Exercise and Research

Exercise enthusiasts have routinely been challenged by the best way to spend their time in the gym when the primary goal is fat loss. Historically clinical trials have supported aerobic exercise as having the greatest impact on total fat mass but with a consequent loss of lean mass in the process. Similar trials have supported the addition of resistance activities to cardiovascular exercise programs aimed at caloric expenditure and an improved body compositional outcome. Although both have demonstrated effectiveness at fat loss, practitioners are now concerned not only with fat loss but also where that fat is derived from. Obesity in the United States has reached an all-time high, jumping more than 10% in most States since just 1990. With the growth of the nation comes the increase of cardio-metabolic disease stemming from the high levels of visceral adiposity. Central fat storage is associated with inflammatory chemicals; a major contributor to disease. Although visceral adiposity is more metabolic the best way to reduce it has not been addressed. In a recent article published in the Journal of Sports Medicine and Physical Fitness (2010) researchers analyzed the affects of endurance training versus concurrent endurance/resistance training on measures of total and regional fatness in sedentary males. Following 16 weeks of treatment, subjects were measured for body fatness, body mass index, waist circumference, and waist to stature ratio. With changes to measures collectively reported, the endurance group as a whole reduced fat mass by 27% and body fat percentage 31%; the endurance/resistance group reduced fat measures by 32% and body fat percentage 30% respectively. When localized fat mass was reviewed the endurance/resistance group collectively reduced waist circumference by 3% and waist to stature 4%, whereas the endurance group reduced the waist circumference by 2% and the waist to stature ratio 2%. These findings suggest that although endurance training is effective for fat loss, utilizing resistance training as part of the regimen improves fat loss from central locations. Personal trainers can use this information to emphasize programs that address weight loss and central adiposity simultaneously.

New Heart Rate Max Formula Published (for women)
According to Dr. Martha Gulati M.D., assistant professor of medicine and preventive medicine and a cardiologist at Northwestern Medicine, women have been inaccurately attempting to calculate maximum or peak heart rate using the traditional (220-age) formula. As published in the Northwestern University Newsletter (June, 2010), "Women are not small men; there is a gender difference in the exercise capacity a woman can achieve. Different physiologic responses can occur." The data used for the new formula was based on the findings from the St. James Women Take Heart Project, a study of 5,437 healthy women, ages 35 and older which began in the Chicago area in 1992. The study was published in the journal Circulation (2010). According to Gulati, the new formula provides a more accurate estimate of the peak heart rate a healthy woman should attain during exercise. It also will more accurately predict the risk of heart-related death during a stress test. Due to the fact that the Heart Rate Max Formula is based on studies of men the newer formula better addresses the sex differences that affect the heart and circulation including heart size, blood volume, lean and total mass. The new formula for women, based on the new research, is 206 minus 88 percent of age. This suggests that a 45 year-old female would have a predicted max heart rate of 166 beats • min-1 using the new formula, compared to the original formula’s prediction of 175 beats• min-1. These finding may, in part explain the prediction error found in the original formula. These findings also suggest that females who were training at the high end of the previous 75-90% of max heart rate, or 60-80% of their predicted heart rate reserve were potentially over conditioning. A second question bears, does the published accuracy transfer to those females outside the ages in the study (under 35 years). Gulati is currently working on an iPhone application to make the calculation easier to use since the Heart Rate Max equation became a bit more difficult.