Written by Dan Gwartney, M.D.
15 September 2014

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The Phil Heath Advantage: Training At A Mile High

 

 

Numerous factors contribute to fat loss. Achieving the level of definition acquired by professional bodybuilders requires more than consulting a calorie chart. Reaching the pinnacle demands that every accountable factor be taken into consideration, as the entire field has dedicated equal effort, and has comparable genetic advantages by the time they reach the Mr. Olympia stage.

             There is one factor that may have gone unrealized until recently, given the emergence of Phil Heath, a resident of the Mile High city— Denver, Colorado. As realtors (annoyingly) repeat, “location, location, location.” It has been proposed that Heath may enjoy certain physiologic advantages by living and training at high altitude; Denver is situated at an altitude of 5,280 feet, one mile above sea level. The atmospheric consequence of sitting amongst the clouds is reduced air pressure, and reduced partial pressure of oxygen. The common way of saying this is that the “air gets thin.” An interesting choice of words, as people tend to get thin as well.

             One can track across various nations and see a trend toward greater body mass index (a general measure of obesity) among low-altitude populations, as compared to those who live at higher altitudes (e.g., mountain-dwelling tribes). It is possible that there may be cultural bias toward size, or issues relating to food availability. However, even in the United States, a similar observation relating to altitude and obesity can be noted by comparing state obesity rates with altitude.1 There is a cluster of higher prevalence obesity risk along the Gulf Coast (essentially sea level); the lowest ranked obesity risk is in the mountain states, including Colorado. While there is disparity in poverty and education, food availability should be uniform. The communities in Colorado are very active; hiking, skiing and other recreation participation rates are impressive. It is interesting that the rates of total inactivity (absolutely no exercise or recreational activity) are highest in the same areas with the highest obesity rates, despite having all that oxygen to breathe. Colorado, Utah, and Idaho rank at the top for active participation in sports or recreational activity.2

 

Fat-loss Benefits of Living as a Highlander

             mile1There are pathways affected by altitude that directly support reducing fat mass, or accelerating breakdown and oxidation of fatty acids (fat burning). If evidence proves correct, it seems that high-altitude living may decrease appetite, and promote the use of fatty acids for calories. Additionally, ambient temperature patterns may play a role; thermal neutrality (living in the same, comfortable temperature range all day, every day) is associated with weight (fat) gain.3 Denver has seasonal variations that range from tolerably cold but freezing lows for five months of the year, to pleasantly warm highs in the mid-60s to upper 80s the remainder of the year. Temperatures that do not impede outdoor activities, but rouse the body to react to thermal change. The thermoneutral temperature for humans is about 82°F, so Denver residents are forced to maintain body temperature through activity, brown fat activation (which burns fat for heat instead of energy), or wearing more insulated clothing.4 Coastal zones have stable temperatures most of the year, dependent more upon latitude than season. Thus, it is not uncommon to see obesity rates rivaling the United States in prosperous coastal areas, particularly those that have embraced the Western diet.

             There are some barometric pressure-related effects of altitude training accounting for fat-loss benefits of living as a highlander. Initially, there is a loss of appetite, but it is not due to changes in the hormones that regulate energy expenditure or appetite.5 Altitude sickness tends to reduce the appetite, but this quickly resolves as the person acclimates to the vascular effects of low pressure. People who live at higher elevation experience hormonal changes that decrease appetite and increase energy expenditure. In the absence of anabolic training and drug support, this can cause a loss of muscle as well as fat— just like any hypocaloric setting. One study demonstrated a 3:2 ratio of fat to fat-free mass loss in young, healthy, adult women after 21 days.6 Non-hematologic effects (other than increasing red blood cells) are fairly rapid, occurring within 18 days according to one review; the optimal altitude exists between 2,500- 3,100 meters (8,000-10,000 feet).7 More extreme elevations begin to catabolize lean mass (muscle), particularly in the limbs.8 Many professional bodybuilders actually have difficulty consuming enough calories, even at sea level, to gain additional muscle mass. Thus, attention needs to be paid to consuming sufficient calories to offset the loss of appetite for this group. For the recreational bodybuilder, who often has difficulty with appetite control, this may be a boon to fat-loss efforts. It is much easier to resist “cheat meals” when one is not ravenously hungry.

             The composition of food needs to account for changes in the metabolism that occur at altitude, increasing carbohydrates and protein content to counter the loss of lean tissue.9,10 During exercise, there is an increased dependence on glycolysis (sugar as a source of ATP energy), increase in lactic acid, and loss of body water. Over time, the mitochondria become more efficient, allowing the body to burn fat for calories at a greater rate despite a relative lack of oxygen.11 The relative loss of body water is about 3 percent of bodyweight in active people.12 This could lead to a drier, leaner appearance in bodybuilders.

 

Gaining the Mile High Advantage

             mile2Now, many people cannot travel to the Himalayas, or even to Denver. Is there any means to gain some of these Mile High advantages in New Orleans, Tampa or other low-lying cities? Quite possibly. An excellent review on obesity and hypoxia was published in the journal Obesity Reviews.13 The authors follow the emerging science on the interrelated hormones and neurotransmitters that regulate energy balance, describing the effect of hypoxia (reduced oxygen) on energy signaling, as well as the balance between anabolic and catabolic processes in tissue. Consider for a moment, this is seen with hypoxia, not altitude. This provides a sound basis for investigating the effects of following a “live high, train low” or “live low, train high” protocol. The example of endurance athletes who initially lived and trained in high-altitude locations for months prior to competing in the Olympics; later, cyclists who would sleep in hypobaric chambers (high) but train in low conditions; and now, living in “low” conditions but training in hypoxic chambers all offer insight to the body’s response to different environments.

             There are several kits for homemade hypobaric chambers, which may be optimal for endurance athletes. However, for the bodybuilder who is seeking to build mass as well, the opposite approach holds merit as well— training or napping in a hypoxic chamber for 30-90 minutes a day. A simple method might be to use air tanks, such as used in scuba diving, filled with a nitrogen-rich mixture reducing oxygen content to 12-15 percent. Several studies have investigated the use of intermittent normobaric hypoxia (reduced oxygen at a normal air pressure, not at altitude). There are reports of improvements in measures of cardiorespiratory fitness, fatty acid oxidation and metabolic risk factors.14-16 As hypoxic training is associated with a reduction in antioxidant status, it is vital that the diet be supplemented with potent antioxidants (e.g., vitamin E, vitamin C, NAC, etc.).17

             Intermittent hypoxic training results in some interesting hormonal and functional changes.18 Hypoxia-inducible factor (HIF) is a hormone that is produced in response to low oxygen levels, including the “live-low, train high” scenario. Among its effects is the activation of the POMC pathways in the brain, resulting in an increase in the metabolic rate, and suppression of appetite.19 Interestingly, the 5-alpha reductase drugs impede HIF production. A counterregulatory enzyme that degrades HIF, called FIH, may also increase. FIH appears to be the oxygen-sensing molecule, as its activity is reduced in hypoxic environments. Mice bred to be deficient in FIH are hypermetabolic (burn calories faster), have reduced bodyweight and greater insulin sensitivity.20 Thus, a low-oxygen environment reducing FIH activity may provide many of the same benefits.

 

What’s Next, Atmospheric Gyms?

             Hypoxia stimulates the release of leptin from fat cells, as do inflammatory cytokines (e.g., IL-6, TNF-alpha); the cytokines are elevated in hypoxic environments in animal studies, but human studies have not replicated those results.21 Leptin decreases the appetite, and increases the metabolism by reacting with the very same POMC pathways in the brain that are activated by HIF. Leptin also stimulates a pathway called AMPK which increases glucose uptake and fatty acid oxidation (fat burning) in skeletal muscle.22,23 If IL-6 is elevated, which happens during exercise, the lipolytic effect in muscle would be augmented even further.24 It would be an interesting experiment to see if obese people who are typically leptin resistant might respond to intermittent hypoxic therapy.

             Despite the observations having been recorded for many years, the field of intermittent hypoxic therapy is in its infancy. While there are certain effects related to altitude that would not be mimicked, it is possible that we might see the advent of atmospheric gyms— creating a hypoxic, even hypobaric training environment. At this time, the best one can do is continue to observe. If Phil Heath continues to excel in competition, we may begin to see a migration of bodybuilders to Denver and other high-altitude locales.

 

 

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