From a medical research standpoint, 2007 was the year of interval training. In January, The University of New South Wales released a study (note released not published) that showed that high-intensity interval training was more effective than continuous moderate exercise at reducing fat. The study showed the benefits using women exercising with alternating sprints and moderate speed on a stationary bike for 20 minutes versus continuous moderate biking for 40 minutes. Over 15 weeks, the interval group (sprints and moderate biking) lost three times as much fat as the traditional exercise group. That’s contrary to traditional exercise thinking since more fat was lost with half of the total exercise time. Due to their rapid news cycle, SELF magazine just now noticed .

In the peer-reviewed literature, the folks at Shinshu University Graduate School of Medicine got down and dirty with the statistical measurements . They found that by alternating high intensity walking and moderate intensity walking in three minute intervals caused more improvement in blood pressure, a greater increase in exercise capacity and a greater increase in leg strength than continuous moderate exercise.

Canadian researchers got down in the enzymes and metabolic change and showed definitively that interval training produces significant improvement in fat oxidation.

So what to do with this information? Ultimately any aerobic exercise is good. Interval training is faster and better. Runners and others have known this for a long time. I remember years ago that high school coaches had their athletes doing wind sprints . You can modify your existing routines a number of ways. Add super fast walking at intervals to a walking routine, bike sprints followed by moderate biking. That kind of thing. Some exercise machines even have these kinds of routines built into their programming. I’ve been using a LifeCycle for years that has a "hill" routine that is essentially interval training. For the workout video set, there’s 10 Minute Trainer from Beachbody. I’ve been using this routine for 3 weeks and frankly, as someone who is fairly fit have been surprised how much difference tightening up the routine into a highly engineered interval plan makes.

No matter the path you choose, interval training really needs to become part of the plan. It’s definitely easier to start with long moderate activity routines but the real benefits in fitness and time saved come with interval training.

There’s much pressure in the news lately on the “anti-aging industry” and doctors who “peddle growth hormone.” These accusations are not entirely without entirely without merit. In the above link you’ll note that Dr. Thomas Perls is at the center of the controversy. According to his bio, he is solidly part of the Ivory Tower of medical establishment. He’s also a highly recognized geriatrician and researcher. That does create certain biases on his part, though he is certainly an authority on aging. The problem is that he discounts legitimate growth hormone deficiency. He and his counterpart, S. Jay Olshansky, PhD, have written a commentary in this week’s Journal of the American Medical Association that paints all clinical use of hGH with a broad brush but ultimately issues the following somewhat loaded statement buried in the commentary:

Systematic reviews have found that hGH supplementation does not significantly increase muscle strength or aerobic exercise capacity in healthy individuals. Clinical evidence does support the therapeutic administration of hGH for children and adults with appropriate clinical indications. (unfortunately the full text isn’t available to the public)

JAMA has been a source of consternation for advocates of growth hormone therapies that are within the legitimate prescribing guidelines because of the kind of press coverage that JAMA commentaries receive, so much so that involved Universities pump the commentaries with press releases like this one. It’s hard for physicians practicing no matter how legitimately to overcome the media juggernaut that this creates.

I have specifically stated over and over that human growth hormone is not a panacea for all things that afflict the aging, though there is likely more legitimate growth hormone deficiency than is recognized by many physicians. Growth hormone replacement is a valid therapy when patients are deficient and requires regular monitoring often with repeated labs for patients that are on growth hormone. Any physician doing otherwise is doing so with at least a degree of wreckless abandon if not outright hazardous behavior.

Even the American Academy of Anti-Aging Medicine, a group that generates no small amount of controversy on their own, has taken a position of responsible management of growth hormone that does not involve unmonitored or unwarranted prescribing.

Why JAMA feels compelled to repeatedly come out and make blanket statements with commentaries like these that make it appear that there is no legitimate use for hGH to the casual reader is something that I have always been confused by. Are there doctors who prescribe illegitimately? Yes. Are there people who use hGH and other hormones for illegitimate or sporting uses? Yes. Are those people at risk for complications from their abuse? Yes. Can they get their drugs from non-US sources making at least some of the furor displaced? You bet, this guy did.

People often get into a lather about BMI. Body Mass Index is a measure of the relative ratio of weight to height (and yes, it’s metric). It’s the basic yardstick by which obesity is measured. It’s easy to calculate. Normal BMI is considered to be between 18 and 25. This can cause much consternation for people who consider themselves otherwise healthy, though if you are reading here you’re probably not looking to rationalize away a weight issue.

The realities are that these old measures stick and stick hard. In January, the International Journal of Obesity published a paper that showed beyond doubt that normal BMI is an important predictor of risk of death. The study was simple and the numbers were large (over 50,000 women). Using health records from the 1980s through 1997 with measured BMI, the risk of death at various levels was compared. Turns out they found some interesting things.

Being outside of normal BMI at all increased the overall risk of death over the next 10 years. Whether with or without chronic disease, underweight women were at less risk than overweight women though women with a BMI of 20-24 were at the lowest overall risk. Underweight gets away with less risk than overweight until breast cancer comes into play. Regardless of weight, BMI outside the normal range was associated with a roughly equal risk of death for women with breast cancer detected by screening.

The study goes on to correlate BMI at age 40 with overall life expectancy. The results are unsurprising. No matter how this numbers get diced up the results are the same. The human frame lives longest and healthiest within a certain range and we know what that range is.