CYCLING PERFORMANCE TIPS
Last updated: 5/2/2016
BASICS OF A
(Proven Strategies to Decrease Cardiac & Diabetic Risk Factors)
I recently attended an interesting conference on the effects of diet on cardiovascular risk
facotrs. I was impressed with both the benefits of diet on vascular disease risk factors
as well as the data that demonstrated diet to be even more effective than many "high
powered" prescription medications in reversing the metabolic changes of abnormal glucose
and lipid metabolism. I thought it would be fun to summarize a few of the ideas and then to
speculate on what lifestyle changes one might easily make to keep themselves healthy.
But before we go further, I want to stress again that this is about a baseline healthy
lifestyle - and all evidence continues to point towards carbohydrates alone as the
underpinning for the energy needs of the cyclist while on their bike.
Abnormal lipids, probably as a result of abnormal glucose metabolism (insulin resistance
or pre diabetes) are a significant factor in the development of cardiovascular disease.
There are proven dietary and life style strategies that are proven to help pts with
severe vascular disease (prior MI, stroke, etc.), so it would seem safe to speculate
that the same strategies would be beneficial for everyone (but especially if they had
undiagnosed insulin resistance). The current presumption is that this "prediabetic"
condition can be present for years before full fledged diabetes with an elevated blood
sugar is diagnosed - and the entire time blood vessel damage is ongoing.
Here is another way to look at this. There are multiple risk factors:
which are factors in aggravating insulin resistance. And the more severe the insulin
resistance the greater the odds of
- Sedentary lifestyle
Improve any of the multiple risk factors and the odds of developing blood vessel
- Dyslipidemia (decreased HDL, increased LDL and triglycerides)
In reviewing the literature, it is extremely common to note that certain dietary changes
improve both the risk of DM and risk of heart disease in the same direction and by the
same relative amount. Again, strong suggestive evidence that it is insulin resistance
that is the common factor for both development of overt diabetes mellitus and
cardiovascular disease. In fact, I heard one lecturere say that if one followed
all the dietary and life style recommendations that follow, the chances of developing
diabetes type 2 were almost nil.
The dyslipidemia CV risk factors include
Focusing on changing the balance of these three is the goal. Statin drugs will lower
the LDL, but have no effect on the other two. Dietary changes will affect the balance
in a way that is actually more effective than statins alone, and will allow one to
decrease their statin dosages if adopted. An increase in the HDL/LDL ratio is a well
know predictor of a decrease in cardiac risk factors while the LDL alone seems to be a
weak one. And the triglyceride/HDL (TC/HDL) ratio is a superior predictor for (IHD) ischemic
heart disease compared to LDL alone (Am J Cardiol 1997:79:756).
- an increase in the LDL (or bad cholesterol) levels
- a decrease in HDL - HDL functions to clear cholesterol from the periphery and transport it back to the liver. (a 1 mg/100ml increase in HDL = 2-4% lower risk of a cardiac event)
- and an increase in triglycerides.
Many of these dietary recommendations are elements of the Mediterranean diet (actually
Cretan diet as that island is the locale where it is eaten most consistently). The
Med Diet stresses increasing the intake of fruits, vegetables, whole grains, olive oil,
omega 3 fatty acids, nuts, beans/legumes, and minimizing saturated and trans fats.
Does the Mediterranean Diet work? The EPIC study (NEJM 2003:348:2599-608) followed
22, 0423 people over 44 months. Adherence to a Med Diet was rated on a scale of 0 to 9.
For each 2 point improvement in adherence, there were 33% fewer deaths from heart disease
and 24% less from cancer.
Why do we think a Mediterranean diet is so effective in decreasing cardiovascular and cancer risk factors?
Here are several resources available to those interested in learning more about the Mediterranean Diet:
Here are the keys to improving your risk factor profile
- The increase in omega 3 fatty acids Circulation 2002:105:1874-5
- Its anti-inflammatory effect (lower CRP) JAMA 2004:292:1440-1446
- By improving endothelial function JAMA 2004:292:1440-46
- By minimizing insulin resistance and lowering the serum insulin levels, it reverses
early metabolic syndrome JAMA 2004:292:1440-46
- Avoid rapidly absorbed carbohydrates
- These are foods with a high glycemic index and include sweets, potatoes, white flour, white rice, and potatoes
- Will lower LDL levels
- Eggplant 200 gm every other day or okra 100gm every other day (viscous fiber)
- Psyllium fiber 10gm day = 7% lower LDL (Am Jr Clin Nut 2000:71:472-9
- Oat Bran 4 - 8 Tablespoons/day 10-26% decrease in LDL (JACN 1998:17:601-608)
- Whole grain diet
- The coarser the better. Pumpernickel rye is good!
- Sterols and stanols - present in whole foods
- 2 gm/day will lower LDL by 10%
- essentially absent in most breads, bagels, pastries, pasta. If it doesn't say 100% whole grain, it probably isn't.
- 1 serving of whole grains per day decrease cardiac death rate by 30% AJCN 1998:68:218-19, 248-57
- demonstrated decrease in the risk of DM on a whole grain diet Diabetes Care 1997:545-550
- Smoking - not good for anything
- From 3 alcoholic drinks per week up to 2 drinks per day provide a 20-50% cardiac risk reduction. JAMA 2001:285:2004-2005
- 5 - 10 drinks per week have lowest risk of developing DM Diabetes Care 2000:26:18-22 (type of alcohol didn't matter in this study)
- Resveratrol which is in red wine has a CV protective effect.
- More in Cabernet Savignon than in Pinot Noir
- Also present in cranberry juice - a glass a day will increase your HDL levels
- Fuits and vegetables
- increase fruits and vegetables - 5 to 9 servings a day
- fruit juices generally bad because of free sugar.
- Fats - the focus should be on replacing satuated fats and trans fats with unsaturated fats
(read more about fats).
- Mono unsaturated (olive oil and nuts) are the best. Will improve the lipid profile with lower LDL and lower TG. JAMA 1994:271:1421-8, Am J Clin Nut 1998:67:577S, Diabetes Care 1999:22:889
- extra virgin olive oil or canola oil are good fats
- 40 gm of olive oil per day led to a 48% decrease in daily antihypertensive med dose Ann Int Med 2000:160:837-42
- oil from nuts 5 oz/wk 35% decrease in IHD risk BMJ 1998:317:1341-345
- Trans fats - partially hydrogenated vegetable oils used in many baked foods and margarines. 2-10 x worse than
saturated fats for IHD risk. Increases risk of DM by 40%
- more fish (omega 3 fats) light tuna in water, wild salmon, herring, sardines, mackerel and less preserved meats
- 30 grams of fish per day = 50% reduction in cardiac mortality NEJM 1985:312:1205-9
- 5 times per week = 31% less heart disease in diabetic pts Circulation 2003:107:1852-57
- Volunteers fed a 60% CHO, 25% fat diet versus 40% CHO, 45% fat with Calories equal had lower HDLs without a
change in LDL questioning the idea of substituting CHO for fat to lower risk. Am J Cardiol 2000:85:45-48
- When used in a diet, a 33% fat diet was more effective in achieving weight loss
than a 20% diet. Int J Obesity 2001:25:1503-1511
- Nuts - preferred are raw almonds, pecans, hazelnuts, Brazil nuts.
- Less DM, even peanut butter 5z/week JAMA 2002:288:2554-60
- Almonds improve metabolic syndrome versus pasta 84g/day Int J Obesity 2003:27:1365-72
- Raw almonds 2 handfuls (73 gm) LDL down 9% (Circulation 2002:106:1327-32)
- Cheese - aged cheeses are better than processed cheese.
- Beans - 4x/wk = 19% lower Ischemic Heart Disease (IHD) risk
- Coffee >6 cups per day had 30-50% decrease in risk of DM
- Catechins 50 mg/day = 25% decrease in CHD mortality
- Black tea also contains catechins
- 5 cups of coffee per day lowered LDL 7.5 - 11.5% (Davies Jr Nut 2003:133:3298S-3302S)
- 1 -2 cups of coffee per day loweed relative risk of heart disease and stroke J. Epid 1999:149:162-7)
- Chocolate (also high in catechins)
- Aim for >70% dark chocolate when you buy it
- 20 gram per day
- Magnesium increases insulin sensitivity JAMA 2004:291:1056-57
- In green vegetables, nuts, cereals, beans, chocolate
- Higher Vit D = less insulin resistance 800 units per day JACN 2004:79:820-5
- Niacin - a 5 to 25% reduction in LDL as well as increasing the HDL (one of the few things that will do so)
- Garlic 1.8 gm/day lowered total cholesterol 9% (Ann Int Med 1993:119:599-605)
- Cinnamon 1g/day with decrease in FBS of 18-29%, triglycerides 23-30%, LDL 7-27% Diabetes Care 2003:26:3215-18
How to eat
There is evidence that carbohydrates eaten at night will form fat more easily than those
eaten at noon (when you are still more active). It is reasonable to speculate that as you
are using CHO for energy, they are selectively metabolized (over glycogen stores) in
the afternoon, while at night instead of replacing glycogen stores, absorbed carbohydrates
are converted into fat. Emphasize lean meat and vegetables at night - carbs in the
morning or midday.
Life style Issues
- Regularly eating breakfast decreased risk of DM 37-55%
- walk 30 min daily - LDL particles changed in size and become less atherogenic
- exercise 1 hr 4x a week increases HDL 10%
- Being fit is better than being thin JAMA 2004:292:1179-87
- Less than 6 hrs sleep per night = 1.6 to 2.5 risk ratio to get DM
Bottom Line - how could these facts work for you in your daily nutrition program?
- Eat breakfast
- Eat the bulk of your carbohydrates at breakfast and lunch
- Take those vitamins with a glass of cranberry juice
- Take a multivitamin daily - and be sure it has have 800 units of vitamin D; add in 1
gram of fish oil as a capsule and also magnesium supplements
- Eliminate as much as reasonable all white flour, white rice, and potatoes - use brown rice and whole grain breads.
- Eat a cooked whole grain cereal or steel rolled oats when possible for
breakfast (cold cereals are not comparable, even granolas).
- Use only low fat milk
- Peanut butter on a piece of 100% whole grain toast is a quick breakfast
- A couple of cups of coffee a day can be a good thing - even three or four
- A snack during the day might be a handful of almonds (raw or at least not roasted in transfats)
- 1 alcoholic drink a day - make it red wine if possible
- Use olive oil whenever feasible (canola is second)
- The more vegetables the better.
- Sweets only for special occasions - grab the dark chocolate if you have it handy
- Have fish as often as possible (see below)
- Blue cheese and other aged cheeses are better than processed cheeses
- Fat Calories are not necessarily bad - even if you want to loose weight - and may be
better than an equivalent number of CHO calories
The Mukilteo Diet
Over the years, my thoughts as how this all might come together have evolved. The result is
what I will call "The Mukilteo Diet" which I first put to paper (computer screen actually) in
May of 2016. The final piece was an article that stressed a point not often mentioned in other diets,
that when you eat is as important as total caloric balance.
I was a gastroenterologist, seeing patients with liver and other digestive tract complaints
for 35 years. (And for those of you wondering about the name of the diet, I live in Mukilteo.)
Over the years, I noticed a dramatic increase in the number of patients referred with the diagnosis
of "fatty liver". A fatty liver refers to the increase of fat in the liver cells which in turn can
produce inflammation and ultimately scarring (cirrhosis) in a small percentage. Fatty liver is
seen in metabolic syndrome and pre-diabetes/diabetes, both more common in overweight individuals.
By some estimates fatty liver now affects upwards of 25% of the population. Fatty liver, diabetes, and
obesity overlap in their underlying physiology and are all impacted (both positively and negatively) by
diet. When I explained this to patients, that a change in diet was a simple start to impact the liver
fat accumulation, the next question was predictably "what can I do ?" The following summary of
my answer to them is not only a reasonable first step in treating these 3 conditions, but also a set
of guidelines for healthy eating.
Although the traditional dietary approach to "too much fat" has been an emphasis on losing weight,
it is not quite that simple. Carbohydrates, and the insulin release they stimulate, are a more
important factor than previously suspected. Thus the source of one's daily calories (carbohydrate
versus fat) and when they are eaten during the day are equally as significant as the total
daily calorie balance.
These five factors all play a role in any healthy diet but need special attention in any
comprehensive dietary approach to the weight loss as well as the treatment of glucose intolerance
and fatty liver (steato-hepatitis).
- Caloric Balance - if weight loss is a goal, then you will need to eat fewer calories a day
than you will use. It is the mantra that is the basis os all weight loss plans. It is simple to
understand and each diet then goes on to explain how you can easily eat less with their program.
A negative caloric balance will ultimately translate into fat loss. As there is individual as
well as day to day variability in water retention, it may not show an immediate effect on the
scale. And when you go into negative caloric balance, the body will slow its metabolism a bit
to compensate, so the loss may not be as dramatic as hoped. But in the end if you eat fewer
calories than you expend, you will lose weight. If you have achieved your goal weight, then
stepping on the scale every morning before breakfast will reinforce that you are remaining on track.
- If you want to lose weight, eat fewer calories than you expend.
- When you eat - When you eat your calories is just as important as the caloric balance. You
should eat the bulk of your calories early in the day (before 2 PM). Aim for a 25-50-25 split for
breakfast Ð lunch- dinner. Any calories, especially carbohydrates, eaten early in the day are
preferentially used by your active muscles during the subsequent 3 or 4 hours rather than being
stored as fat (in the liver as well as fat cells) for later use when the muscles are
not active (evening, sleeping).
If you do cut back on your evening calories Ð and for double bonus points focus on a plant
based, low carbohydrate meal Ð you are moving towards an intermittent fast as described by
Dr. Mirkin. A fast does not need to be a total elimination of calories.
His post has
references as well as a list of identified benefits.
To quote directly from Dr. Mirkin: "Intermittent fasting" does not mean complete avoidance
of foods and drinks. Instead, you markedly reduce your intake of food during certain periods.
The benefits of intermittent fasting can
be seen as long as you significantly reduce your total caloric intake during those periods.
Intermittent fasting appears to work by
A decrease in your evening carbohydrates will directly increase the use of body fat metabolism
and use. My blog post Optimizing The Use of Body Fat As An Exercise Energy Source - train high, sleep low reviews the physiology and logic.
It is even more effective if you exercise just prior to deplete muscle glycogen stores
and "force" or stimulate fat metabolizing pathways. The results are clear. The subjects
on a post exercise carbohydrate restriction burned 8.7% of their total body fat while the
control group lost just 2.6%. Both were on equi-caloric daily diets so this was not
just fat loss from calorie restriction.
- increasing the body's sensitivity to insulin and reducing
an overactive immunity, called inflammation (Cell Metabolism, Feb, 2014;19(1932-7420):181Ð92).
- lower blood pressure (British Journal of Diabetes and Vascular Disease, April 2013)
- lower cholesterol and triglycerides (Am J Clin Nutr, Nov 2009;90(5):1138-43)
- reduce body fat (Int J Obes (Lond), May 2015;39(5):727-33)
- lower insulin (Am J Clin Nutr, Jan 2005;81(1):69-73)
- lower blood markers of inflammation (Free Radic Biol Med, March 2007;42(5):665-74)
- increase speed and endurance in athletes (Med Sci Sports Exerc, April 2016;48(4):663-72)
- Move to a daily 25-50-25 distribution of calories (breakfast-lunch-dinner).
- Minimal carbohydrates for the evening meal Ð bonus points for a plant based meal.
- Maximize the effect with an afternoon exercise session.
- What you eat (cabs versus fats/protein) and glycemic load - there is a growing
body of evidence that a healthy diet (especially if you are trying to lose weight or
treat fatty liver or a pre-diabetic tendency) means a decrease in the percentage
of total daily calories provided by carbohydrates.
When carbohydrates are absorbed from the intestinal tract, they elevate the
blood sugar level which in turn stimulates insulin release from the pancreas.
Insulin is required to move glucose (the absorbed form of the carbohydrates) into
the muscle cells where it is used for energy or stored (in the form the carbohydrate
glycogen or fat). A carbohydrate with a high glycemic INDEX is more rapidly
absorbed and the blood glucose rise higher which provides an extra stimulus
to insulin secretion. Some foods contain only a small amount of carbohydrate
per serving (a carrot is an example) which is rapidly absorbed, so the idea of
glycemic LOAD as a measure of the glucose surge makes more physiologic sense
as a measure of pancreatic stimulation. Here is a
nice summary of glycemic index versus glycemic load and
a quick link to a list which
compares glycemic index and glycemic load of common foods.
As mentioned, insulin facilitates movement of carbohydrate into muscle
and fat cells. And if it is not immediately use by a working muscle, after
an evening meal or a bedtime snack, it is converted into fat. To decrease
carbohydrate fueled fat production you could a) decrease the total percentage
of carbohydrates in your diet, b) eat foods that contain low glycemic load
carbohydrates which will decrease the production of insulin to facilitate
the movement into fat cells, or c) eat more of your carbohydrates early in
the day or just before/while exercising. With vigorous exercise, glucose
will move into the muscle cell without insulin (it is insulin INDEPENDENT)
and any blood sugar spike is blunted. Thus the idea of glycemic load is
less important if carbohydrates are eaten just before or during exercise.
- Carbohydrate calories should be a smaller part of your total daily calories.
- Low glycemic load carbohydrate containing foods are preferred.
- The bulk of your daily carbohydrates should be eaten in morning or before 2 PM.
- Exercise - adding exercise to your diet program provides 3 benefits.
- First, it increases the total calories you will be using during the
day both for the exercise itself as well as from a persistent elevation
in total calories metabolized per hour in the few hours post exercise.
- Second, while exercising, blood glucose will move into the muscles
cells without the need for insulin which blunts the blood sugar spike seen
after eating a high glycemic index food.
- Third, when exercising, you decrease your muscle glycogen stores.
Then, if you limit your post exercise carbohydrates, you stimulate fat
metabolizing pathways to refill the glycogen storage deficit in the muscle.
This magnifies or leverages the benefits of a low carbohydrate diet.
The exercise can be as simple as an afternoon walk - which only has to be
20 minutes to be of benefit - or as complex as a
rigorous training program. There are a number of programs out there -
here is a short video. And a recent study shows that even a few minutes of intense exercise
in a 10 minute exercise program will provide these benefits. So lack of time is
not an excuse.
- 20 minutes of exercise a day will magnify the benefits of a lower carbohydrate diet.
- Microbiome (colon bacteria) - The bacteria in our colon were traditionally
considered as "outside our body" and irrelevant to health. But we now understand that
products of bacterial metabolism of the food we eat are actually absorbed and
impact metabolism. Here is an intriguing article that illustrates the point.
And the colon's bacterial balance will change in a matter of days
based on our diet.
I feel certain that we will find that colon bacteria play a significant role in
the development of fatty liver and glucose intolerance or pre-diabetes - most
likely via the production of intermediate chemical products from the metabolism
of the foods we eat. And that it is the microbiome that is involved in the weight
loss benefits we see with a shift to a plant based diet.
To summarize, these are the components of my Mukilteo diet. And if you want a go
slow approach, I put them in what I think is their relative order of importance.
- No sugar supplements.
- Decrease the amount of meat in your diet relative to plant based protein sources.
- Move towards a daily 25%-50%-25% distribution of calories (breakfast-lunch-dinner).
- Decrease the percentage of daily calories from carbohydrates - low glycemic load foods preferred.
- The bulk of daily carbohydrates to be eaten by 2 PM. Minimize carbohydrates in the evening meal - bonus points for a plant based dinner.
- As protein is increased, increase the amount that is from plant based protein sources.
- 20 minutes of exercise a day will magnify the benefits of a low carbohydrate diet.
- If you want to lose weight, eat fewer calories than you expend.
Q.You suggest eating fish as much as possible. I ate tuna 4 times a day until I heard
about murcury. You should mention eating lower mercury fish more often (eg: sardines),
and higher mercury fish less often (eg: tuna). - CR
A.You make a good point. This is particularly an issue for women who are prgnant
or are considering becoming pregnant as mercury is a toxin on the developing fetal nervous
system. The same may be true in young children. Less is known about the potentially
harmful effects of mercury on men (or women who are not interested in having children) as
an adult's nervous systems is felt to be much less sensitive to the effects of mercury.
There is a significant variation in the mercury content of fish,
and even in tuna there are some forms which are safer than others from the
perspective of mercury levels (light tuna is better
than white tuna, for example). And perhaps the safest approach of all is to
use fish oil capsules daily.
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