Exercise Biology

Nutritional Tips for Vegetarian Lifters

2009-11-06T03:50:18+00:00

Here are some nutritonal tips fore vegetarain lifters:

Low Total Calories in Vegetarian Diets

It has been shown that energy intake is usually lower for vegetarians than non –vegetarians.

Vegetarian lifters should try keeping a count of their total calories and get more energy dense, low fiber foods.

High Carbohydrates in Vegetarian Diets

Almost 50-65% of the total calories came from carbs for vegans and 50-55% for a lacto-ovo vegetarian.

The high carbs are good for endurance athlete but it is not so great if you into lifting. As you will see, the high carbs minimizes the availability of protein in the vegetarian diets.

Low Protein in Vegetarian Diets

Vegetarian diets generally contain less protein than meat diets. Among lacto-ovo and vegan diets, vegans tend to have the lowest protein intake (around 10-12%).

Meal Combing for Proteins

Since plant proteins are incomplete proteins(lacking or insufficient amount of a few amino acids), food combining is recommended to make it a compete protein.

For example, by combing grains & legumes (rice and beans) in the same meal, you get the missing amino acids and make it a complete protein .

Now it is known that you don’t have to have it in the same meal as long as you have a variety of foods throughout the course of the day.

Low Creatine levels in vegetarians

It has been shown that creatine levels are pretty low in vegetarians.

Supplementing creatine to vegetarian diets has shown increase in muscle and strength significantly. So it won’t be a bad idea to use creatine.

Low Iron Absorption in Vegetarian Diets

Studies have shown vegetarians get ample iron, but iron absorption is impaired.

Consumption of fresh fruits, vegetables and juices rich in vitamin C can enhance Iron absorption in vegetarians.

Low Zinc levels in Vegetarian Diets

Total zinc intake is lower in vegetarians compared to non-vegetarians. Also strenuous exercises increases zinc loss from the body.

Like iron, zinc absorption also seems to be a problem in vegetarians. Soaking beans, grains & seeds increases zinc absorption or bio-availibilty.

Vitamin B12, Riboflavin, D, & Calcium

Vegetarians, especially vegans, are at risk of low intake of these nutrients because the main sources of these are animal products.

Fortified foods like breakfast cereals and soy products are the only source of B12 for vegans.

Can Workouts Designed To Increase Testosterone Increase Muscle Mass?

2009-10-24T03:32:15+00:00

It has been shown that moderate to high volume workouts, using large muscle group exercises & short rest intervals cause an acute spike in testosterone levels.

Theoretically, these acute spikes in testosterone are claimed to increase muscle growth and strength.Let’s see what the evidence says:

Study 1

Injection of testosterone has shown to increase muscle mass & strength.

The increase in muscle & strength was also seen without any weight training exercise whatsoever.These studies clearly show the benefit of testosterone on muscle growth & strength.
Limitations: The studies we are talking about use supraphysiological doses of testosterone which are far greater & incomparable to the exercised-induced tiny spikes in testosterone.

Also exercised-induced testosterone spikes do not change the resting values of testosterone;it only lasts for 45-60 min.

Study 2

Suppression of testosterone has shown to decrease muscle mass & strength in weight training folks

Limitations: The suppressed levels of testosterone in the study reached the levels of hypogonadal individuals.

So the only sensible conclusion we can make from this study is that we need minimum levels of testosterone to maintain/or increase muscle mass & strength.

Study 3

Resistance training increases testosterone receptors

Limitations: That’s well and good, but it is yet to be shown that a workout program designed to increase testosterone is more effective in increasing these steroid receptors compared to a generic weight training workout.

We are also unsure if this increase in receptors contribute to a greater increase in strength and muscle mass.

Study 4

Combined leg & biceps training shows greater isometric strength in biceps compared to just biceps training.

Limitations: This study is some scientific proof to the anecdote of how squats can add inches to your arms. The study showed significant increases in testosterone and isometric strength when leg training was added to the arm training.

However, the study did not measure muscle size, the increase in isometric strength could have been due to neural adaptations, and the mean initial strength was higher in the arm group which skewed the results a bit.

Study 5

Increase in muscle & strength without any exercise- induced increase in testosterone.

Limitations: This study concluded that you only need basal levels of testosterone to promote muscle growth and strength increase.

But it does not reject the possibility that increase in exercise –induced testosterone levels could have increased the muscle growth & strength even further.

Conclusion

What it all means is that we are still not sure if workout routines specifically designed to increase testosterone are effective in increasing muscle and strength than the generic workout routines.

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Can Nervous System/ Neural Adaptations Increase Strength?

2009-10-07T18:11:50+00:00

We all know muscle growth will increase strength. But can nervous system adaptations contribute to strength?

Evidence for nervous system adaptations

Beginner’s Strength: It is pretty clear that there is a disproportionate increase in strength during the early phases of training which cannot be explained by just muscle growth. In fact, there is little or no muscle growth during those early stages of a training program (8-10 weeks).

For example, everyone experience pretty big jumps in weight when you started weight training. Or you will see weights going up easily when you try a new exercise. But you will find you are not getting any bigger in that period.

Disuse: As mentioned above, when you stop working out, there is disproportionate decrease in strength which cannot be explained by muscle loss. And this loss of strength is easily recovered with a few days of training.

For example, you will find yourself a lot weaker when you come back to lifting after you take a couple of weeks off . And you might have noticed that you haven’t got any bit smaller or you that haven’t lost any muscle to explain this loss of strength.

Transfer of Strength: It basically means the increases in strength in one task will not necessarily transfer to other tasks which uses the same muscle.

For example, if you use flat bench for your chest and one day if you change it dumbbell chest press, you will find the weights used to be a lot lower than flat bench though they both use similar muscles.

Unilateral Training: When you perform exercises with one leg, strength increases are seen in the opposite leg. The strength in the untrained leg may increase up to 22%. How cool is that? They call it “cross- education”

All the above give enough evidence to suspect the role of nervous system adaptations in increasing strength. The next article will talk a bit about the mechanisms behind these adaptations.

Which is the Most Accurate Body Fat Calculator / Measurement Method?

2009-09-08T00:25:43+00:00

I get often asked about the most accurate body measurement method/calculator. Here we will look at the common body fat percent measurement methods to find the most accurate one

Body Mass Index (BMI)

Body Mass Index (BMI) is just simply weight (kg) divided by height (msquare) and is often used to classify people into categories based on disease risk. Click here to find your BMI

Problem 1. BMI just assumes your body be a tub of fat. So if you are an athlete or someone who lift weights, it just ignores all that hard-earned muscle and might classify as “overweight or obese”. How unfair is that?

Just to be sure, BMI do not estimate bodyfat. Equations are being developed to estimate bodyfat from BMI but the current equations have large errors (>5%) in estimating bodyfat.

Underwater (Hydrostatic) Weighing

Underwater weighing is considered as the Gold Standard among body fat measurement methods/calculators. It is based on the fact that density of muscle is higher than fat and hence muscle sinks and fat floats.

Problem 1. It is based on a two-component model and hence divides your body into two compartments: Fat Free Mass & Fat Mass. Fat free mainly mass includes bone, muscle, water (also glycogen, soft tissues) apart from body fat as shown below.

* Figure shows a two-compartment model and how it divides total body mass.

It assumes fat free mass and fat mass to have a constant density. But it is pretty clear that the density of your muscles and bones do change depending on age, illness, activity, and ethnicity.

If you are 18 and lift weights, your bone and muscle density will be a lot different from a 45 year old sedentary individual.

Problem 2. Fat-free mass is made up of proteins, water, & bone minerals. So if you drink a lot of water before measuring, it can’t help but think it is all muscle (lucky you).

Hydrostatic weighing is used as a standard to even validate other bodyfat measurement techniques. Now tell me how screwed up is that?

Skin Calipers

Skin calipers measures the fat under the skin (subcutaneous) in certain areas to estimate bodyfat. It assumes that subcutaneous fat is proportional the fat inside your body.

Problem 1.Body fat distribution & how well it correlates with the fat inside your body varies based on age, fatness levels , physical activity, and genetics. Some might have more on the thighs whereas others on their abs.

Problem 2. It is based on a two compartment model and hence also has all the problems mentioned above.

Problem 3. There are equations which measures skin thickness from 3, 7, & 9 sites. But, generally, as the measurements increases so does the errors.

Bioelectrical Impedance Analysis (BIA)

BIA is based on the fact that muscle is 72% water and hence is less resistant to the flow of current than fat. Usually BIA is measured by attaching electrode to your wrist and feet and passing a current through.

* Picture shows BIA with electrodes connected and the commonly used hand held & scale BIA.

Problem 1. As you might have guessed everything from drinking a lot of water, emptying your bowels, having more salt in your diet, having a high- carb diet can change the water levels, and along with it your bodyfat.

Problem 2. The commonly seen hand held or scales are called segmental body fat analysers -measures one half of the body -and the equations used in these are yet to be validated.

Problem 3. Since they are based on a two-compartment model they suffer from all the problems associated with a two compartment model.

DEXA

DEXA is slowly replacing to be the gold standard for body composition methods. DEXA is based on a three-compartment model than a 2-compartment model. It can measure the density of fat, bone minerals, and water & protein combined.

Problem 1. This is lot more accurate than the two compartment models but still assumes the density of water & protein. It also has a lot more assumptions which are too technical to make any sense.

Conclusions

As you can see there are lots of errors & assumptions in the body fat methods/calculators we commonly use. So what really matters more than accuracy is reliability. Can the body fat method you use consistently keep track of your body fat changes “accurately”?
Find a method that is cost effective, reliable, and easily accessible.
Skin calipers (measured by the same technician) and BIA (measured under similar conditions) are cost effective, consistent, and easily accessible.

Are Organic Foods More Nutritious Than Conventional Foods?

2009-08-22T14:52:31+00:00

There is a widespread belief that organic automatically means more healthy or nutritious. So what do you really mean by organic food and is it really nutritious than conventional food?

What are organic foods?

Type of Production: Organic refers to the way of production which avoids or largely excludes the use of synthetic fertilizers, pesticides, herbicides, hormones, and antibiotics.It relies mainly on crop rotations, natural fertilizers, biological pest control, and better animal husbandry.

USDA Approval: In order to bear an organic label, the USDA (United States Dept. of Agriculture) has set some strict government guidelines based on how foods are grown, handled and processed.

Process Label: Organic is not a “label” of safety or health or being natural It is just a process label.

Are organic foods more nutritious?

Not More Nutritious:A recent (2009) systematic review – the biggest and most complete review even undertaken in this subject- looked over this issue and found no truth to the claim that organic foods are more nutritious than conventional foods.

And concluded that the differences that were detected in crops (nitrate & phosphorus) were biologically plausible and are unlikely to be of public health relevance.

Are organic foods more safer?

Lack of Evidence: The study above looked at only the nutritional side of the issues. But there is a complete lack of evidence to suggest that organic foods are safer because it contains less pesticides and insecticides.

A review which looked at safety aspect of organic foods conclude,” At our present state of knowledge, other factors rather than safety aspects seem to speak in favor of organic food.”

Conclusions

If you are willing to paying more for organic foods because you think they are more “nutritious” than conventional foods, save the money.
Contrary to the claims, there is no evidence to suggest that organic foods are safer and more healthier than conventional foods.
If you are buying organic foods because you think they are kinder to the environment and taste better, you do have a point.

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Exercise Biology

Nutritional Tips for Vegetarian Lifters

Low Total Calories in Vegetarian Diets

High Carbohydrates in Vegetarian Diets

Low Protein in Vegetarian Diets

Meal Combing for Proteins

Low Creatine levels in vegetarians

Low Iron Absorption in Vegetarian Diets

Low Zinc levels in Vegetarian Diets

Vitamin B12, Riboflavin, D, & Calcium

Can Workouts Designed To Increase Testosterone Increase Muscle Mass?

Study 1

Study 2

Study 3

Study 4

Study 5

Conclusion

Can Nervous System/ Neural Adaptations Increase Strength?

Evidence for nervous system adaptations

Which is the Most Accurate Body Fat Calculator / Measurement Method?

Body Mass Index (BMI)

Underwater (Hydrostatic) Weighing

Skin Calipers

Bioelectrical Impedance Analysis (BIA)

DEXA

Conclusions

Are Organic Foods More Nutritious Than Conventional Foods?

What are organic foods?

Are organic foods more nutritious?

Are organic foods more safer?

Conclusions

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