My Top 3 Internet Fat Loss and Fitness Gurus
By Paul RogersI get to read a lot of articles from many different internet trainers, nutritionists and health and fitness experts. Sometimes it’s just curiosity and sometimes I really learn from what they have to say.
Although I mostly rely on my own research of the scientific literature for assessing the worth and veracity of any particular aspect of the preventive health sciences, expert writers and commentators can help by providing analysis, exploration and summary of what’s reasonably known about any particular subject; from fat loss to muscle building and the prevention of the big three preventable diseases — cancer, heart disease and diabetes.
As far as fitness, fat loss and nutrition are concerned, but not necessarily preventive health in its wider aspects, here are three guys I enjoy reading. That’s not to say there are not others of similar worth, especially academic and institutional professionals that specialise, but these guys have a good grasp of nutrition and fitness training combined with practical experience – and they also know how to convey a message with lucid communication. They all have their strengths and I might even disagree with a minor point here or there, but read up on their blogs and free articles and you will learn a lot about weight loss, fitness training and general nutrition for the masses — pretty much without any loony stuff or weird approaches — which is more than can be said for some other sites.
Each of them has something to sell but none are too pushy. And by the way, I don’t do commissions or affiliate stuff with these people at all. By all means buy their products, but they all have plenty of free content to keep you going for some time.
The 7 Mega Principles of Diet and Exercise for Fat Loss
By Paul RogersYes, I am somewhat proud of the fact that if you do a Google search (at the main google.com site), an article of mine still comes up number 1 for the term fat burning. It’s an article I wrote for About.com Weight Training over 12 months ago. I am surprised at this because Google records about 3.1 million records for the search term ’fat burning’. And when you see all the goony, loony web sites and weight loss schemes and supplements and silly diets and downright ripoffs that plague the internet, it does seem unlikely that a truthful and accurate article still has a chance of getting to the top. Three cheers for Google.
In any case, for Christmas I’ll do the KISS thing and “keep it simple, stupid” by summarising the no-fail approach to weight loss that emphasizes fat loss and muscle maintenance. If it fails for you, then you are either eating too much, moving too little or have a genuine pathology or genetic disorder — and mostly this is rare as a cause of obesity.
7 Rules to Rule Them All
- Don’t sweat the small stuff. The number 1 rule is not to get hung up on the trivia. This is the 90/10 rule or whatever you want to call it. The idea is that you must concentrate on putting most effort into doing the things that bring you most return and success. It’s okay to follow up on the small stuff after you get the big picture correct. Don’t get distracted by “insider secrets” or any of that web marketing hype. There are no insider secrets to achieving and maintaining normal weight. But that doesn’t mean there are not serious challenges.
- It’s the calories stupid! Even though I saw Tom Venuto use this phrase recently, I first used it in 2001 in a book I wrote called The Organic Factor. Even so, I’m sure quite a few people have come up with this independently, it’s so very obvious. This is one of the pieces of “big stuff” that I refer to in the rule above. You need to get into negative energy balance territory (but not too negative) to lose weight and that means eating less and exercising more. And the best way to cut calories? Limit animal fats, added fats, added sugars, alcohol, and reduce excessive portion sizes.
- Adopt a lifestyle. Most diets will work for a short while – low-carb, low-fat, meal replacement shakes, you name it. If you take in less than you expend in energy, you will lose weight. However, you need to find an eating and exercise pattern that suits you, that works, and that you can adopt more or less every day of your life.
- Do Regular Aerobic Exercise. Aerobic exercise is walking, running, treadmill, cycling, swimming, class aerobics and rowing. You need to put some effort in so that you puff and sweat to some extent. Do this at least 5 times a week, for at least 30-40 minutes, even if it’s walking fast around the block.
- Do Regular Weight Training. Get to a gym or buy some dumbbells and a bench for home and do at least 2 sessions of weight training each week. It helps maintain muscle and bone while you lose fat and builds strength, flexibility and mobility for the future.
- Move more at home and work. Under-rated and misunderstood, this is the science of NEAT or “non-exercise activity thermogenesis.” Moving more at home or work builds a feedback system that upregulates your metabolism. Get a pedometer and try to rack up 5,000 steps each day. It can be gardening, housework, playing with kids, lunchtime walks at work, stair walking, anything in addition to programmed exercise. Upper-body movement counts as well.
- Get a brain plan. Tackle weight loss as a personal project. Keep a diary, set goals, review your progress each week, do lots of internal head talk, adjust your approach when necessary, be patient, stick to a lifestyle you can tolerate, and get encouragement from friends or a group.
That’s the nub of it. No secrets, no surprises. Good luck.
What You Don’t Know About Saturated Fat That Could Harm You
By Paul RogersWhat you probably do know is that most dietary recommendations say that you should keep your consumption of saturated fat and cholesterol in food low in order to lower your blood cholesterol and consequently your risk of heart disease.
The usual recommendations are that saturated fat should be no more than 10% of total calories and cholesterol less than 300 milligrams each day – and for people with existing signs of heart disease, less than 7% saturated fat and under 200 milligrams of cholesterol each day.
If you read widely of internet health and nutrition sites, you may also be aware that fringe movements exist that say this is not true; that it’s a government conspiracy and so on, and that saturated fat and cholesterol are as harmless as soft fruit. You can read one of my responses to that. It’s surprising how many otherwise knowledgeable pundits get taken in by this stuff.
What you may not know is that too much saturated fat in the diet has other adverse effects beyond how it raises blood cholesterol. Here is a short summary.
Saturated Fats Cause Dementia
Here is what one research team has to say about saturated (and trans) fat and cognitive function.
“Diets high in fat, especially trans and saturated fats, adversely affect cognition, while those high in fruits, vegetables, cereals, and fish are associated with better cognitive function and lower risk of dementia. While the precise physiologic mechanisms underlying these dietary influences are not completely understood, modulation of brain insulin activity and neuroinflammation likely contribute.” (Ann N Y Acad Sci. 2007 Oct;1114:389-97.)
And another:
“Moderate intake of unsaturated fats at midlife is protective, whereas a moderate intake of saturated fats may increase the risk of dementia and AD, especially among ApoE epsilon4 carriers. “ (Dement Geriatr Cogn Disord. 2006;22(1):99-107. )
Saturated Fats Cause Insulin Resistance
This conclusion provides a pointer to findings from several similar studies:
“A change of the proportions of dietary fatty acids, decreasing saturated fatty acid and increasing monounsaturated fatty acid, improves insulin sensitivity . . . ” (Diabetologia. 2001 Mar;44(3):312-9.)
And:
“Therefore, prevention of the metabolic syndrome has to be targeted . . . and . . . to improve insulin sensitivity and associated metabolic abnormalities through a reduction of dietary saturated fat, partially replaced, when appropriate, by monounsaturated and polyunsaturated fats.” (Clin Nutr. 2004 Aug;23(4):447-56.)
Saturated Fat Slows Blood Flow in the Arteries
Here is what recent studies found about how saturated fat essentially clogs the arteries. (The endothelium is the layer of cells lining the inside of blood vessels and arteries. It is important in regulating blood flow.)
“High SFA (saturated fat) caused deterioration in FMD (flow-mediated dilation) compared with high PUFA, MUFA, or CARB diets. Inflammatory responses may also be increased on this diet.” (Arterioscler Thromb Vasc Biol. 2005 Jun;25(6):1274-9.)
And:
”Consumption of saturated fat reduces the anti-inflammatory potential of HDL and impairs arterial endothelial function. In contrast, the anti-inflammatory activity of HDL improves after consumption of polyunsaturated fat.” (J Am Coll Cardiol. 2006 Aug 15;48(4):715-20.)
And:
“Consumption of an SAFA-rich meal is harmful for the endothelium, while a MUFA-rich meal does not impair endothelial function in subjects with type 2 diabetes.” (Diabetes Care. 2008 Dec;31(12):2276-8.)
Overall, you should be able to see that the case against too much saturated fat in the diet is convincing – one way or another — and it’s not just about cholesterol. Bear in mind that vegetable sources of saturated fat are not inconsequential. Olive and soy oil are about 15%, corn and sunflower about 12% and peanut oil around 20%. However, consuming saturated fat and cholesterol together in animal foods may present the greatest combined risk, and whole nuts or seeds, even with some saturated fat, the least risk.
- Parrott MD, Greenwood CE. Dietary influences on cognitive function with aging: from high-fat diets to
healthful eating. Ann N Y Acad Sci. 2007 Oct;1114:389-97. Review.
- Laitinen MH, Ngandu T, Rovio S, et al. Fat intake at midlife and risk of dementia and Alzheimer’s disease: a
population-based study. Dement Geriatr Cogn Disord. 2006;22(1):99-107.
- Morris MC, Evans DA, Bienias JL, et al. Dietary fats and the risk of incident Alzheimer disease. Arch Neurol. 2003 Feb;60(2):194-200. Erratum in: Arch Neurol. 2003
- Vessby B, Unsitupa M, Hermansen K, et al. Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study. Diabetologia. 2001 Mar;44(3):312-9.
- Riccardi G, Giacco R, Rivellese AA. Dietary fat, insulin sensitivity and the metabolic syndrome. Clin Nutr. 2004 Aug;23(4):447-56. Review.
- Keogh JB, Grieger JA, Noakes M, Clifton PM. Flow-mediated dilatation is impaired by a high-saturated fat diet but not by a high-carbohydrate diet. Arterioscler Thromb Vasc Biol. 2005 Jun;25(6):1274-9.
- Tentolouris N, Arapostathi C, Perrea D, et al. Differential effects of two isoenergetic meals rich in saturated or monounsaturated fat on endothelial function in subjects with type 2 diabetes. Diabetes Care. 2008 Dec;31(12):2276-8.
- Nicholls SJ, Lundman P, Harmer JA, et al. Consumption of saturated fat impairs the anti-inflammatory properties of high-density lipoproteins and endothelial function.J Am Coll Cardiol. 2006 Aug 15;48(4):715-20.
The Fitness Wars Are Futile
By Paul RogersI’ve put up a permanent page called Fitness Wars because I thought it should be a little “sticky.” It discusses the very strange culture of strength trainers who seem to react to cardio and aerobics with a crucifix held at arms length.
It’s a very odd response to a very important component of health and fitness conditioning and wellbeing programming.
Anyway, I’ve explored some of the origins of this antagonism and I take a look at aerobic conditioning in this context.
Dioxins in Food and Water Could Cause Diabetes
By Paul Rogers
Agent Orange - from imjoshdotcom
I’ve been aware of an increasing number of recent studies that seem to show that the chemical pollutants called POPs – dioxins and similar compounds – could be at least partly responsible for the current epidemic of type 2 diabetes. Now it’s not conclusive, but some aspects of these investigations are certainly interesting. Like the fact that when controlled for dioxin content of tissue, even obese people were at no higher risk of type 2 diabetes if their dioxin levels were low. This could be a chance occurrence, or other factors could cause this to occur, but overall there are some compelling aspects to this research.
Here is what one author had to say:
“The strong associations seen in quite different studies suggest the possibility that exposure to POPs could cause diabetes. One striking observation is that obese persons that do not have elevated POPs are not at elevated risk of diabetes, suggesting that the POPs rather than the obesity per se is responsible for the association. ” [Rev Environ Health. 2008 Jan-Mar;23(1):59-74. Review.]
POPs are “persistent organic pollutants.” This class of pollutants includes dioxins, PCBs, DDT, DDE and many chlorinated organic pesticides. They accumulate in your body and in the fat of the animals we eat.
History of Dioxins and Diabetes
Some years ago I worked in occupational and environmental health and safety, advising on toxic chemicals and health. As well as working to establish the first chemical list for Australia’s National Pollutant Inventory, I also helped out the local Vietnam vets with their Agent Orange herbicide case. Much of the finer detail of the toxic risk assessments involved dioxins — exotic chemical contaminants that result from chemical manufacture and combustion. Levels of dioxin were very high in Agent Orange. There are over 200 varieties of dioxins, furans and polychlorinated biphenyls (PCBs) – chemicals with somewhat similar structure and varying toxicities to humans. Sometimes the toxicity of these dioxin-like chemicals are referred to collectively with ‘toxic equivalents’ or TEQ.
Studies of manufacturing workers exposed to dioxins and similar compounds had already revealed a higher incidence of diabetes, and animal tests had confirmed this possibility to some degree.
The early emphasis of dioxin toxicity research was on birth defects and cancer. However, it took some time for the US Veterans Affairs Department to acknowledge limited evidence in support of a connection of Agent Orange exposure with type 2 diabetes, to the extent that disability pensions are now paid on this basis.
Other pieces of research seem to fit the puzzle. It seems that endocrine disrupting chemicals in general, especially ones that persist in the environment, are associated with diabetes. And a most recent research study suggests that the much-publicized plastics residue bisphenol-A is also possibly involved.
POPs and Diabetes: What You Can Do
While these contaminants are everywhere – from the Antarctic to the purest looking lake water – they also contaminate food by accumulating in animal fats – and which we consume in meat, chicken, dairy and fish products and fats.
If you want to reduce your intake, you really need to either find wild or organic and lean products from pristine places, or reduce your intake of animal foods, especially fat, or perhaps do a combination of both. This issue is also another reason why high-meat and fat diets like Atkins low-carb can be a recipe for disaster. And as for those so-called diet gurus who say we should eat more saturated fat . . . here’s a very good reason not to.
- Rignell-Hydbom A, Rylander L, Hagmar L. Exposure to persistent organochlorine pollutants and type 2 diabetes mellitus. Hum Exp Toxicol. 2007 May;26(5):447-52.
- Rylander L, Rignell-Hydbom A, Hagmar L. A cross-sectional study of the association between persistent organochlorine pollutants and diabetes. Environ Health. 2005 Nov 29;4:28.
- Ropero AB, Alonso-Magdalena P, García-García E, Ripoll C, Fuentes E, Nadal A. Bisphenol-A disruption of the endocrine pancreas and blood glucose homeostasis. Int J Androl. 2008 Apr;31(2):194-200. Epub 2007 Oct 31. Review.
- Wang SL, Tsai PC, Yang CY, Leon Guo Y. Increased risk of diabetes and polychlorinated biphenyls and dioxins: a 24-year follow-up study of the Yucheng cohort. Diabetes Care. 2008 Aug;31(8):1574-9. 2008 May 16.
- Michalek JE, Pavuk M. Diabetes and cancer in veterans of Operation Ranch Hand after adjustment for calendar period, days of spraying, and time spent in Southeast Asia. J Occup Environ Med. 2008 Mar;50(3):330-40.
Recommended Dietary Intakes - Do You Need Supplements?
By Paul Rogers
Photo by Untitled Blue
Here’s a quick definition of RDIs — or RDAs as they are called in some countries.
Optimising Diets for Chronic Disease Risk
Other Standards in Nutrient Reference Values
- EAR (Estimated Average Requirement). A daily nutrient level estimated to meet the requirements of half the healthy individuals in a particular life stage and gender group.
- RDI (Recommended Dietary Intake). The average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97–98 per cent) healthy individuals in a particular life stage and gender group.
- AI (Adequate Intake - used when a recommended dietary intake cannot be determined). The average daily nutrient intake level based on observed or experimentally-determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate.
- EER (Estimated Energy Requirement). The average dietary energy intake that is predicted to maintain energy balance in a healthy adult of defined age, gender, weight, height and level of physical activity, consistent with good health. In children and pregnant and lactating women, the EER is taken to include the needs associated with the deposition of tissues or the secretion of milk at rates consistent with good health.
- UL (Upper Level of Intake). The highest average daily nutrient intake level likely to pose no adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects increases.
- AMDR (Acceptable Macronutrient Distribution Range). An estimate of the range of intake for each macronutrient for individuals (expressed as per cent contribution to energy), which would allow for an adequate intake of all the other nutrients whilst maximising general health outcomes.
- SDT (Suggested Dietary Target). A daily average intake from food and beverages for certain nutrients that that may help to prevent chronic disease.
Dietary Supplements
Supplementation has a role to play, but it needs to be done with caution, restraint and knowledge. The bottom line is that there will be individuals and population groups that do not meet the RDIs for individual nutrients.
- This can result from poor nutrition practices or even special diets poorly implemented. Low-carbers could be short on fibre and vitamin E; vegans on zinc, iron and B12; and very low-fat dieters on long chain omega-3.
- Populations in nutrient poor regions might lack iodine and selenium; and certain cultural habits like full body clothing can result in inadequate vitamin D intake in the absence of food or supplement sources.
- Athletes and heavy exercisers may need a modest increase in some nutrients, but this is usually accounted for by increased calorie intake — as long as the extra food is nutrient dense for the most part.
- Older people absorb vitamin B12 less well and this may require supplementation. The ill or infirm who do not get adequate sun exposure may require vitamin D supplements.
- Pre- and during pregnancy, folate supplementation is a useful reassurance against neural tube abnormalities.
However, not only is it likely wasteful to take mega-doses of supplements, it may even be unsafe. The recent scientific examination of vitamin E and beta carotene in high supplement doses has not yielded promise and has suggested adverse effects. If you feel you need to take an individual supplement or a multi, first check out the excellent information at the Office of Dietary Supplements at the NIH. then try not to exceed the RDI by more than a few times for any individual nutrient, unless there are indications that it’s safe and effective to do so.
Burn That Belly Fat With High-Intensity Training?
By Paul Rogers
Photo: Soldiersmediacenter. Jarad Bargas
A recent study by researchers at the University of Virginia found that high-intensity exercise training disposed of more belly fat in obese middle-aged women than lower-intensity training of the same energy expenditure.
The idea that doing high-intensity interval training burns off stubborn fat and visceral belly fat has been around for quite a few years. The premise has always lacked strong evidence in my opinion — or at least reasonable qualification. Any number of internet training and fat-loss gurus are promoting this idea.
What is High-Intensity Training?
First up, we need to get the concept straight. What exactly is the ’interval training’ or ‘high-intensity training’ or ’high-intensity interval training (HIIT)’ that we hear so much about?
Interval training is intermittent training, often near your maximum, in which you do a lap of an oval, or a spin on a bike, or 60 seconds on a treadmill very fast, then you recover, and do it again several times. That’s simple enough.
For example, I’m a masters sprinter and in training I might do 10 x 100 metres at 95% capacity, or 10 x 40 metres at 100% capacity. This is high-intensity interval training in real life. But I’ve been a marathoner and triathlete as well (don’t ask), and high-intensity training for those disciplines is mostly entirely different; say, 2km fast, 2km slow, 2km fast; or 6 x 400 metres at 90% capacity, or even, I might add, 5km at race pace, which is still high-intensity training, even if not interval training. And further, I know that if you run 40 to 60 miles a week in marathon or triathlon training you’ll burn fat . . . lots of it. So what’s this HIT stuff all about?
Early Investigations Were Not Adequate
One problem with some of the earlier studies was that they did not set a rule for what constitutes ‘high intensity’. The study I quoted above used lactate threshold to determine this, an excellent idea. And few earlier studies actually compared the different intensities for the same energy expenditure, which is what needs to be done to get a reasonable comparison.
You can’t just do 6 spins on a stationary bike for 30 seconds flat out and expect to burn the same amount of calories and fat as someone who does 30 minutes on the treadmill at 85% capacity, or even a 90-minute run at slow pace for that matter. Energy expenditure, which just about always includes some fat and glucose burning, is going to be a product of intensity X time for any physical activity.
In that event, the best approach for fat loss and fitness goals is likely to be a combination of interval training, weight training and cardio at different intensities. Big surprise eh? No, that’s right, it’s not. It almost reflects the recent exercise guidelines issued by the US government for general health and fitness.
Persistent Abdominal Fat and How to Shed It
What the study above suggests is that high-intensity training just might be superior to to lower-intensity training, for equal energy expended, in removing belly fat, especially the visceral fat wrapped around the internal organs that has been shown to increase your risk of heart disease and type 2 diabetes. Naturally, you have to include a nutrition program with some calorie restriction as well.
Even though the study involved a small number of women, 27, it seemed to be well designed. And yet men might respond differently, as might the young or post-menopausal women. It’s an idea that has promise for designing exercise programs for the overweight and people with metabolic syndrome and diabetes and is well worth watching in the future. The main problem is one that is not going to be easily solved: that unfit, obese people are unlikely to take on high-intensity training by themselves and stick to it, despite what you see on The Biggest Loser.
Having said that, there is plenty of evidence that aerobic, cardio type programs help people lose fat in general — even some visceral fat — and aerobic exercise has additional benefits for cardiovascular protection. A combination of weights, cardio and HIT is likely to be the superior program if it can be tolerated.
The Best Type of High-Intensity Training for Obesity?
Heavy people exert quite a shock to the knees when they run long or hard. It’s a real injury concern. Running is often out of the question for obese people, let alone high-intensity running. For this reason, I favour cycle spin classes on a stationary bike. Doing this exercise in a group has advantages. The instructor will encourage hard work, but it’s possible to set your own pace by adjusting resistance and peddle cadence if you get overwhelmed. You’ll get some high-intensity work threaded with lower-intensity cardio — an excellent workout combo. A medical checkup is highly recommended for anyone moving from a sedentary lifestyle to high-intensity training.
The Diet Wars Really Are Over
By Paul RogersJohn Tierney over at TierneyLab recently had a bit to say about the New England Journal of Medicine study that compared an American Heart Association low-fat diet with Atkins and Mediterranean diets.
I’ve discussed the details and the implications in a longer page post called Diet Wars, but the upshot of this and many other bits and pieces of nutrition research from recent times pretty much suggests that we stop wasting time debating low-fat or low-carb or in between and get on with recommending a healthy eating pattern that spans a wider macronutrient range for fat, protein and carbohydrate.
Let’s get the faddists, fanatics and false prophets on the run.
Does Stretching Work for Injury Prevention or Performance?
By Paul RogersIf you’ve been involved in any sort of physical activity for fitness or sports, you probably know that ’stretching’ is highly recommended for the following reasons:
- Increase or maintain flexibility to prevent injury and increase mobility for day-to-day living
- Prevent injury during sports and exercise activity
- Increase performance in sport
- Offset muscle soreness after exercise
It seems to make sense doesn’t it? You feel that muscle let go and you think to yourself: “if only that muscle was a little more flexible, that would not have happened.”
The trouble is, much of the value of stretching got taken for granted over many decades and few scientific studies were undertaken to confirm what everyone assumed was correct: you must stretch.
Now, some of that scientific work on stretching has been done and it’s not quite as simple as logic would have us believe.
Maintain flexibility
To cut to the chase, stretching on a regular basis, perhaps daily, seems to be a good idea for everyone. Regular stretching probably has benefits for increased mobility, balance and injury prevention, especially as we age.
Prevent injury during exercise and sports
While regular stretching of various types may help athletes overall, stretching before or after an event or workout has mixed support for injury prevention, which I’m sure comes as a surprise to many. We all do it in some form because it makes us feel ready to compete. Benefits may be more psychological than physical. However, some recent review studies have been more positive, especially in relation to muscle-tendon injuries. Inadequate study design and confusion of the terms ’stretching’ and ‘warmup’ seems to have confounded much of the early science.
Enhance performance
Static stretching, it seems, may even impair performance in power sports like sprinting and jumping by interfering with optimum stretch-shortening cycle. It’s best not to confuse static stretching with warmups, in which dynamic stretching probably has a place.
On the other hand, some sports like gymnastics and dance require extreme flexibility and the same rules may not apply.
Overall, static, passive of PNF (proprioceptive neuromuscular facilitation ) stretching close to your sport or activity — before or after — seems to have little going for it in relation to performance benefit.
Prevent muscle soreness
Soreness after an exercise session is called ‘delayed-onset muscle soreness’ or DOMS. Stretching before or after exercise has long been recommended as a way to reduce or prevent soreness. However, a review of studies in this area did not find any benefit from stretching for the prevention of muscle soreness. Warming up is something different and has more calculable benefits.
Summary of stretching
In summary, the best advice seems to be that we maintain a regular stretching program from day to day, warm up sufficiently before exercise and sport, including some dynamic stretches — leg swings, arm swings are a good example — then warm down with some further stretches, but don’t expect that either performance or muscle soreness will benefit from static stretching at exercise time.
I’m certain this will be debated for many years to come.
- Small K, Mc Naughton L, Matthews M. A systematic review into the efficacy of static stretching as part of a warm-up for the prevention of exercise-related injury. Res Sports Med. 2008 Jul-Sep;16(3):213-31.
- Hart L. Effect of stretching on sport injury risk: a review. Clin J Sport Med. 2005 Mar;15(2):113.
- Herbert RD, de Noronha M. Stretching to prevent or reduce muscle soreness after exercise. Cochrane Database Syst Rev. 2007 Oct 17;(4):CD004577. Review.
How to Boost Immunity With Diet and Exercise
By Paul Rogers
Photo by ktylerconk
How many times have you seen an ad for some wonder ‘erb or other that’s supposed to boost the immune system. It’s echinacea today and some Chinese herb the next, as well as a vast array of products that the supplement industry claim “support the immune system” — whatever that means.
Diet and Immunity
I’m not suggesting that diet and nutrition don’t have an important role to play in maintaining a healthy immune system. Meeting the recommended intake of macronutrients, vitamins and minerals and fats, and consuming copious quantities of antioxidant nutrients as part of healthy eating is bound to promote good immune system function — as far as it goes. However, the evidence for consuming individual dietary components or special foods or supplements beyond the RDI (recommended dietary intake) is mostly speculative or at least inconclusive.
Exercise and Immunity
If you follow a healthy lifestyle approach with healthy eating and a program of physical activity, here are a few things to note about how the immune system responds to exercise:
- A regular, low to moderate intensity exercise habit is associated with a reduced incidence of infection compared with those who do very little exercise or physical activity.
- Heavy, and or prolonged exercise training can impair the immune system, possibly leading to susceptibility to infection, particularly in a period of up to 24 hours after a heavy training session or event.
- Exercising at high intensity for prolonged periods without food — 90 minutes and beyond for example — may make you especially vulnerable to infection as a result of immune system depression.
- Consuming carbohydrate at the rate of 30-60 grams an hour during intense and prolonged exercise can help to maintain immune system function. That’s 1-2 sports drinks and hour or equivalent. (One drink is probably adequate for most situations except for extreme conditions and intensity.)
- Meeting your daily requirements for micronutrients like zinc, iron, and B and C vitamins is essential. Although a multivitamin supplement may help, consuming mega quantities of vitamins and minerals may be counterproductive. See article on Vitamin C and training adaptation.
- A recent review confirmed the value of carbohydrate supplementation and a possible role for vitamin C (note caution above), but no other supplement showed up as useful for heavy exercisers.
It’s worth noting the value of carbohydrate to immunity in a balanced diet and exercise program. Low-carbohydrate intake with low blood glucose, plus the stresses of exercise, increases cortisol production to the point where the immune system is compromised. Low-carb, high-fat diets, especially saturated fat, are not appropriate if you have a robust exercise program. In addition, saturated fat has been shown to impair immune response. Low-carb is not where you want to be if you exercise a lot.
J Sports Sci. 2004 Jan;22(1):115-25. Exercise, nutrition and immune function. Gleeson M, Nieman DC, Pedersen BK.
JEur J Clin Nutr. 2007 Apr;61(4):443-60. Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis. Moreira A, Kekkonen RA, Delgado L, Fonseca J, Korpela R, Haahtela T.
Scand J Immunol. 2008 Jul;68(1):30 42. Differential effects of a saturated and a monounsaturated fatty acid on MHC class I antigen presentation. Shaikh SR, Mitchell D, Carroll E, Li M, Schneck J, Edidin M.
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