Written by MuscleTech Research
05 October 2006


MuscleTech Research Report

By MuscleTech Research & Development


Q. My upper calves are good, but my lower calves never seem to grow, no matter what I do. Any idea why this might be and what I can do?

A. This isn't too unusual, as many bodybuilders have a hard time building a nice pair of muscular, diamond-shaped calves. It's generally believed that the calves don't respond as well to weight training when compared to other muscles of the body. This is especially the case with the lower calf, which is more commonly referred to as the soleus muscle.

A recently published study in the journal Acta Physiologica Scandinavica confirms this general belief. The researchers conducting the study sought to investigate the muscle protein synthesis response of the soleus muscle following weight training. In the study, eight subjects completed three unilateral calf exercises: standing calf raise, bent-knee calf raise and seated calf raise. The subjects completed four sets of 15 reps for each exercise. The fractional rate of muscle protein synthesis was then determined in the exercised calf and in the non-exercised calf, both immediately following exercise and three hours following exercise. The results showed that the fractional rate of protein synthesis was elevated in the exercised calf compared to the non-exercised calf. However, this increase was not as great as the increases shown in similar studies on some other muscles of the body. For example, the exercise-induced fractional rate of protein synthesis that has been consistently reported for the thigh muscle (vastus lateralis) is, on average, approximately 200 percent higher than the rate reported in this study for the soleus.1

So to answer your question, one of the main reasons the soleus muscle may be difficult to develop is its poor response to muscle protein synthesis after weight training. Since the growth potential of the soleus muscle appears to be somewhat limited, it's important to train your calves hard and consistently in order to maximize their development. I recommend you train your calves two to three times a week and really hit them hard. Good luck and let us know how you make out!


Q. Is there any nutritional difference between a sweet potato and a regular baked potato? I've heard they're different in terms of glycemic index. Is this true?

A. There are a few key differences between sweet potatoes and regular baked potatoes that are of importance to bodybuilders. And yes, one of the main differences is the glycemic index. However, surprisingly enough, a sweet potato has a much lower glycemic index rating than a regular baked potato. According to the American Journal of Clinical Nutrition, a baked russet potato (150 grams) has a glycemic index rating of 111 (with glucose used as the reference food), whereas a sweet potato has a glycemic index rating of only 48.2 This is a major difference you'll want to take into account when planning your dietary strategies.

Some of the other differences between a baked potato and a sweet potato can be seen in the nutrient comparison chart below.3


Nutrient Comparison Between

 Sweet Potato and Russet Potato



Baked Sweet Potato with Skin (150 g)


Baked Russet Potato

with Skin (150 g)


135 kcal

146 kcal


3.01 g

3.94 g


31.07 g

32.16 g


4.9 g

3.4 g


0.22 g

0.20 g

Other nutrients of difference:

Vitamin C

29.4 mg


19.4 mg

Vitamin A

28,827 IU

15 IU

Vitamin E

1.06 mg

0.06 mg


17,264 mcg

9 mcg


Q. Can your body still break down muscle at night, even if you're getting a good night's sleep?

A. Yes. While sleeping, your body may be forced to sacrifice some of your muscle for the amino acids it needs for its various functions.4 That's why it's a good idea to use a nighttime protein supplement such as Nitro-Tech® Nighttime. This high-quality protein supplement has been designed specifically to help prevent nocturnal muscle catabolism, or in layman's terms, muscle loss during sleep. In fact, if you're already using Nitro-Tech® during the day, adding Nitro-Tech Nighttime to your program will help you build muscle while you sleep!

This research-based protein formula delivers a unique blend of proteins to your muscles while you sleep. The first- a fast-release protein- capitalizes on the growth hormone level spike that occurs about an hour after you've fallen asleep. The second- a sustained-release protein- will help keep your amino acid levels elevated so you can stay in a muscle-building state during the night. Follow this advice, and you'll be sure to help prevent muscle breakdown while optimizing your muscle gains. Sleep tight and don't let the bedbugs bite!


The Nitro-Tech® trademark is owned by its trademark owner and is used with permission.



1. Trappe, T., et al. (2004). Acta Physiol Scand, 182(2):189.

2. Foster-Powell, K., et al. (2002). Am J Clin Nutr, 76(1):5.

3. USDA National Nutrient Database for Standard Reference, Release 17, 2004, www.nal.usda.gov/fnic/foodcomp.

4. Meek, S., et al. (1998). Diabetes, 47(12):1824.