February 4th, 2013
06:32 PM ET
Semen quality is a much-discussed subject among scientists these days. Data suggests sperm concentration has been declining in Western countries over the past couple of decades - and reasons for the decline are debatable.
The lead author of a new study on the subject, Audrey Gaskins, has been studying the effects of diet and exercise on semen for several years as a doctoral candidate at the Harvard School of Public Health. Her latest research shows a lack of physical activity – and too much time in front of the television - may impact sperm count and concentration.
Previous studies have shown a link between physical activity and decreased levels of oxidative stress, Gaskins says. “Oxidative stress” is stress placed on the body as it tries to get rid of free radicals or repair the damage caused by them. Exercise may protect certain male cells from oxidative damage, Gaskins says, leading to increased sperm concentration.
Those findings led Gaskins to complete an observational study on young men’s exercise and TV habits as they relate to semen quality. The results were published online Monday in the British Journal of Sports Medicine.
December 17th, 2012
12:33 PM ET
If you want to burn fat and lose weight, aerobic exercise may be your best workout option, according to a study in the Journal of Applied Physiology.
It was more effective than a weight-lifting routine, and about as beneficial as workouts combining cardio and strength training, researchers found.
"If a person is going to give me three hours of exercise a week,the most effective way to lose fat is to spend that time doing aerobic training," says lead study author Leslie Willis, an exercise physiologist at Duke University Medical Center in Durham, North Carolina.
If you lift weights, this doesn't mean you should stop, but if your time is limited and your main goal from exercise is to lose weight, cardio may be better than weight training, according to Willis. FULL POST
November 6th, 2012
05:02 PM ET
Add this to the list of reasons why exercise is good for you: A new study says 150 minutes a week of moderate-intensity, leisure time exercise is associated with roughly 3.4 years added to a person's life.
Researchers from the National Cancer Institute, Harvard Medical School, and other organizations analyzed six different prospective cohort studies of more than 632,000 people ages 40 and older. The studies had a median follow-up period of 10 years, with roughly 82,000 reported deaths. Regular, moderate intensity exercise was associated with an increased life expectancy, even when the person exercising had an unhealthy Body Mass Index (BMI).
Dr. I-Min Lee, a professor of medicine at Harvard Medical School and the senior author of the study, says that not exercising but having a healthy weight was associated with 3.1 fewer years of life, compared to obese people who were active. Conversely, people who exercised 150 minutes a week and had a healthy BMI gained an extra 7.2 years of life. FULL POST
October 30th, 2012
12:02 AM ET
During spinning class, I often find myself wishing I was in a pool. For one, water would make the sweat dripping down my back less noticeable. Two, it has to be easier to sneak a break when the instructor can’t see your legs below the surface.
The study analyzed cardiovascular data from 33 young, healthy participants who performed the same workout on a dry land stationary bike and on a water stationary bike.
Also called hydro-riders or aqua bikes, water stationary bicycles are anchored to the bottom of a pool so that cyclists are submerged up to their shoulders. Resistance can be added by changing the pedal size or, in some bikes, the angle of plates in the wheels.
Researchers found that participants’ oxygen consumption and average heart rates were lower while riding in the water. In other words, their cardiovascular systems were working more efficiently to do the same amount of exercise.
September 4th, 2012
07:01 PM ET
"I'm in shape," a friend of mine repeatedly quips at the gym. "Round is a shape."
It's an old joke, but there may be some truth to it. A new study published this week in the European Heart Journal shows it is possible to be both obese and healthy.
"It is well known that obesity is linked to a large number of chronic diseases such as cardiovascular problems and cancer," lead study author Dr. Francisco Ortega said in a statement. "However, there appears to be a sub-set of obese people who seem to be protected from obesity-related metabolic complications."
July 23rd, 2012
07:00 AM ET
Less than a week from the opening ceremonies, allergists are warning that some Olympic athletes may suffer breathing problems due to air pollution in London.
The amount of nitrogen dioxide in London is comparable to the level of nitrogen dioxide in Beijing before Beijing banned half of the cars in preparation for the Games, and London has done little to control traffic, says Dr. William Silvers, an allergy specialist and a member of the American Academy of Allergy, Asthma & Immunology (AAAAI).
Demanding workouts in the polluted air could spell trouble particularly for those athletes that already have conditions such as asthma or exercise-induced bronchoconstriction (EIB), a narrowing of the airways that makes it hard to move air out of the lungs, according to AAAAI.
July 16th, 2012
11:10 AM ET
Active teens are healthy teens, but some kinds of activities may be better than others.
New research published Monday in the journal Pediatrics suggests that team sports may be better at keeping kids' weight down than biking or walking to school.
Study authors from Dartmouth College looked at the influence sports, physical education and commuting to school had on adolescents and their weight.
Investigators surveyed more than 1,700 high school students by phone and asked them how much they participated in team sports, what other forms of physical activity they were involved in and their height and weight.
July 16th, 2012
07:45 AM ET
It’s well-known that exercising to maintain a healthy heart also helps create a healthy mind. But several new studies suggest that when it comes to preventing dementia, not all forms of exercise are created equal.
Studies presented at this year’s Alzheimer’s Association International Conference found that resistance training was particularly beneficial for improving the cognitive abilities of older adults.
While the studies were small, all including 150 participants or less, they did seemed to indicate that resistance training – such as weight lifting or using resistance bands – could possibly be an intervention for dementia in older adults.
July 6th, 2012
01:29 PM ET
After completing more than 150 marathons, running coach Jeff Horowitz got sick of running himself ragged with 70 to 100-mile weeks during training.
In order to avoid injury and burnout, he designed a less-is-more, quality over quantity philosophy in his book "Smart Marathon Training." Adapt some of his principles into your triathlon training program.
1. Ditch the junk miles.
Only add workouts that have a purpose.
June 22nd, 2012
09:34 AM ET
Knowing how to ride a bike is one thing, but having the ability to comfortably and safely share the road with other cyclists requires another level of skill.
These basic handling techniques will help you enjoy the transition from bike rider to full-blown cyclist, and, as an added bonus, can help save a little time on race day.
Hold a straight line
Whether riding on an open road or in a race, always look over your shoulder before swinging from one side of the road to the other. Before carving through a corner, always check your blind spot, especially in a race since the noise created by fellow cyclists isn’t always enough to alert you of their presence.
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.