By Dr. Mercola
According to novel research, obese women can exercise longer if they cool the palms of their hands.
Fat tissue is a very effective insulator, causing many who are obese to get too hot while exercising.
To investigate whether cooling the hands might help overweight women overcome fatigue and overheating while exercising, researchers at Stanford University School of Medicine tested a hand-cooling device already in use by some professional athletes.
According to MSN Health i:
"[Researchers] assigned the women to one of two groups: both held the cooling device in their palms, but only one group had cool water (60.8 degrees Fahrenheit) running through the device...
The cooling group shaved more than five minutes off their time for the 1.5 mile treadmill test...
Their exercising heart rate went up, too, 136 beats per minute to 154 beats per minute -- a good thing.
The cooling group also took more than two inches off their waist by end of the 12-week study.
... Their blood pressure also went down, from 139/84 to 124/70. (Below 120/80 is the goal.)
In contrast, the comparison group didn't show any substantial differences in any of the measures..."
The Connection Between Cooling and Increased Metabolism
While such results may sound too good to be true—after all, it's hard to believe that simply cooling your hands could boost fat loss and increase performance. However, there may be more than meets the eye here. I recently wrote about other research that, at least in part, explains why metabolism increases when you're exposed to cold. It has to do with brown fat.
Research suggests that calorie combustion in brown fat may be of significance for your metabolism, and brown fat is effectively activated by cold temperatures. In one recent study, men burned more calories when cooled, and lost white fat, the kind that causes obesityii. This supported findings from previous research, which also found that cold temperatures can increase activity in your brown fat regionsiii. In fact, cold-induced glucose uptake was increased by a factor of 15!
Interestingly, part of the explanation for why the activation of brown fat can help boost metabolism is because it actually behaves more like muscle than fat.
Bruce Spiegelman, PhD, with Harvard University's Dana-Farber Cancer Institute has published at least five studiesiv on the topic of brown fat over the past five years. In one, his team identified a sort of master switch that promotes the production of brown fat. This molecular switch, known as PRDM16, regulates whether immature cells will turn into brown fat or into muscle cells. In an interview with WebMD, Spiegelman saidv:
"We showed that brown fat and white fat have completely different origins. Brown fat is derived from muscle. That was a huge surprise."
While scientists are eager to develop medical interventions to boost brown fat production to capitalize on its fat reducing potential, the non-invasive way to accomplish this might be plain exercise. This was successfully demonstrated in a mouse study, in which the animals converted white fat into brown fat simply by exercising. According to Time Magazinevi:
"During exercise, the animals' muscles released a newly discovered enzyme called irisin, which triggered the conversion. It's not clear whether the same phenomenon is true in people, though humans do have the same protein."
Ice Therapy: a Viable Strategy?
Tim Ferriss, author of The Four-Hour Work Week, also published a book called The Four-Hour Bodyvii, which includes the concept of activating your brown fat to boost fat burning by exposing yourself to frigid temperatures. He claims you can increase your fat burning potential by as much as 300 percent simply by adding ice therapy to your dieting strategy. A LiveStrong article backs up Ferriss' claim statingviii:
"A NASA scientist told ABC News that's no hyperbole. In studying the effects of temperature on astronauts, he saw people's metabolism boost by 20 percent in environments as mild as 60 degrees. A Joslin researcher told National Public Radio that 3 oz. of brown fat could burn 400 to 500 calories daily."
Ferriss' Ice Therapy is based on the premise that by cooling your body, you're essentially forcing it to burn much more calories by activating your brown fat. His suggestions, from easy to 'hard core,' include the following. If you want to give his technique a try, make sure you advance slowly. It may be inadvisable to go straight to the ice bath if you're not used to frigid temperatures:
- Place an ice pack on your upper back and upper chest for 30 minutes per day (you can do this while relaxing in front of the TV for example)
- Drinking about 500 ml of ice water each morning
- Cold showers
- Immersing yourself in ice water up to your waist for 10 minutes, three times per week. (Simply fill your tub with cold water and ice cubes)
Fasting—Another Metabolic Booster Technique
Besides ice therapy or gadgets keeping your palms cooled, there are other techniques that can help give your metabolism a boost to increase fat loss. One often ignored strategy is periodic fasting, which may offer multiple health benefits, as long as it's done properly. Periodic fasting, such as eating very lightly for two days a week, has been found to trigger a variety of beneficial hormonal and metabolic changes that may help prevent age-related brain shrinkage, heart disease, diabetes, and possibly even cancer.
Recent research also suggests fasting before exercise may help you to achieve your fitness results faster. For example, in one such studyix, 19 men were divided into two groups—one practiced aerobic training after fasting for Ramadan (which requires fasting from dawn to sunset for one month), and the other trained after eating. During each session, subjects underwent anthropometric measurement, completed a dietary questionnaire, and provided fasting blood and urine samples. The fasting group experienced reductions in both body weight and body fat, the latter of which remained unchanged in the fed group. The researchers concluded:
" … [A]erobic training in a fasted state lowers body weight and body fat percentage. In contrast, fed aerobic training decreases only body weight. In addition, Ramadan fasting induced change in some metabolic parameters in FAST, but these changes were absent in FED."
Exercising while fasting effectively forces your body to shed fat, as your body's fat burning processes are controlled by your sympathetic nervous system (SNS), and your SNS is activated by both exercise and lack of food. The combination of fasting and exercising maximizes the impact of cellular factors and catalysts (cyclic AMP and AMP Kinases), which force the breakdown of fat and glycogen for energy.
Can Fasting Take Your Fitness Program to the Next Level?
According to some fitness experts, such as Ori Hofmekler, fasting may indeed push your exercise program to the next level. The reason for this is because exercise and fasting yield acute oxidative stress, which actually benefits your muscle. According to Hofmekler, acute oxidative stress is essential for maintaining optimal muscle:
"Technically, acute oxidative stress makes your muscle increasingly resilient to oxidative stress; it stimulates glutathione and SOD [superoxide dismutase, the first antioxidant mobilized by your cells for defense] production in your mitochondria along with increased muscular capacity to utilize energy, generate force and resist fatigue. Hence, exercise and fasting help counteract all the main determinants of muscle aging."
But that's not all!
The combination of fasting and short intense exercise also triggers a mechanism that recycles and rejuvenates your brain and muscle tissues. The mechanism in question activates genes and growth factors, including brain-derived neurotropic factor (BDNF) and muscle regulatory factors (MRFs), which in turn signal brain stem cells and muscle satellite cells to convert into new neurons and new muscle cells, respectively. This means that exercise on an empty stomach may actually help to keep your brain, neuro-motors and muscle fibers biologically young.
As Ori explains:
"Fasting promotes muscle breakdown along with the removal of broken proteins and damaged cells towards recycling. Nonetheless, to fully rejuvenate your muscle, you need to grant regeneration of new muscle cells. And that's where the short intense exercise comes into play. It turns on the mechanism that converts muscle satellite cells into new muscle fibers. And it targets your fast neuro-motors and helps keep your fast muscle fibers intact."
Guidelines for Exercising on an Empty Stomach
While exercise and fasting may help counteract all the main determinants of muscle aging and boost fat-burning, compared to working out after eating, fasting incorrectly can be more harmful than helpful.
For starters, you need to make sure that you're not fasting to an unhealthy extreme. In other words, fasting does not mean that you starve yourself for days on end. Instead, intermittent fasting involves either fasting completely or simply minimizing your food intake during the day to small servings of light, low-glycemic, mostly raw foods such as fruits, vegetables, whey protein or lightly poached eggs. Eat your main meal of the day at night, so your "fasting" time consists only of the daytime hours, either fasting completely or eating light, mostly raw foods every 4-6 hours.
Hofmekler recommends working out 30 minutes after your latest snack, followed by a recovery meal, within 30 minutes after your workout. This recovery meal is crucial, and must include fast-assimilating protein, as this will help prevent brain and muscle damage from occurring. Whey protein is an ideal option here. Ori explains:
"When you implement intermittent fasting you put your body into a strong catabolic state. Your body is literally eating up and destroying damaged and injured brain and muscle cells. You rapidly accelerate this process when you exercise in this state. It's this very powerful synergy that will allow you to effectively rejuvenate your muscle and brain. This is the radical new approach that very few know about and even fewer have implemented.
The MAJOR danger though is that you will need to rescue your muscle tissue out of this catabolic state and supply it with the proper nutrients to stimulate repair and rejuvenation. If you fail to supply these nutrients at the proper time you can hurt yourself.
Your post exercise recovery meal is critically important. It's needed to stop the catabolic process in your muscle and shift the recycling process towards repair and growth. If you fail to feed your muscle at the right time after exercise, you won't just miss this window of opportunity to restore and build your muscle, you'll actually let the catabolic process go too far and potentially waste and damage your muscle."
A Less Extreme Option: Exercising Before Breakfast
If the idea of fasting—even intermittently—does not suit your fancy, keep in mind that you can get many of the same benefits of fasting and exercise by exercising first thing in the morning, before eating breakfast. As mentioned earlier, training on an empty stomach will effectively force your body to burn fat, while also offering additional benefits. For instance, in one study those who fasted before exercise had increased levels of a certain muscle protein that plays a pivotal role in insulin sensitivity.
My typical exercise program involves exercising in the early AM. On a regular basis, I will try and implement some intermittent fasting by continuing my overnight fast and exercise before breakfast to achieve some of the benefits mentioned above. However, if I notice that I don't have enough energy to complete my workout, I will start eating meals or at least some raw almonds prior to my workout.
As I've explained in numerous articles, insulin resistance is the root cause of most chronic disease, making maintaining proper insulin regulation a primary factor of good health. Just remember that while exercising on an empty stomach can certainly help, it will not make up for a high-fructose diet, so always be sure to cut down on fructose. This includes sports drinks, so trading those energy and sports drinks for pure water is another important factor to keep in mind.
- i MSN Health March 13, 2012
- ii Journal of Clinical Investigation 2012 Feb 1;122(2):486-9
- iii New England Journal of Medicine 2009 Apr 9;360(15):1518-25
- iv https://articles.mercola.com/sites/articles/archive/2012/02/13/scientists-find-brown-fat-to-help-lose-weight.aspx
- v www.webmd.com/diet/news/20080820/brown-fat-new-key-to-weight-loss
- vi Time Magazine January 26, 2012
- vii The Four Hour Body
- viii LiveStrong June 6, 2011
- ix International Journal of Sport Nutrition and Exercise Metabolism February 2012; 22(1): 11-18