FYI...

FYI – In the West Indies the daily diet's “food” starches also include coco, dasheen, eddoe.

The differences (or not) between them have always been a point of contention.  From my research, here is what I have found >>

Coco (cocoyam) is the root of the Callalloo bush. (*yes! BOTH the plant used Trinidadian dish AND the Jamaican plant – give me a minute, nuh!)

The tuberous vegetable are the root found underneath the leafy Callalloo plant.

What is called Eddoe cocoyam in Trinidad and Coco in Jamaica, are the younger and less “wild” version. They are picked earlier & therefore have a smaller corm (*tuber/root structure).
The leaves at this stage are what are known in Jamaica as callalloo.

The Dasheen cocoyam has a larger corm, because they are typically cultivated longer or grown in a “wilder” environment & the leaves are allowed to bloom to a more dense structure.
(*you know those “dinosaur leaves” you see on the road side to country…) THAT is also CALLALLOO BUSH! What is known in Trinidad as Dasheen leaf. The Tuberous root structure below, if left unpicked can grow upwards of 9-feet long!
 
Fun Fact :: ALL PARTS of the raw cocoyam plant contain a toxic compound, calcium oxalate, which must be destroyed by thorough cooking before consumption (*which is why raw callalloo, if used as "spinach" tastes funny & goopy..)

In Asian regions & other part of the Caribbean & Latin America you'll also find Taro (Malanga) & Boniato as part of the daily diet's starches.

Paleo & the Sweet Potato

I was asked by @funningdotorg about Sweet Potatoes, and the Paleo diet
This one was a little hard for me to tackle as my Caribbean followers vs. North American followers know “sweet potato” as two different things.
I’ll explain…
Sweet Potatoes - Popular in the American South, and derived primarily from South America (*irony!) these yellow or orange tubers are elongated with ends that taper to a point and are of two dominant types.The paler-skinned sweet potato has a thin, light yellow skin with pale yellow flesh which is not sweet and has a dry, crumbly texture similar to a white baking potato. (*one of the versions, my West Indians know as sweet potato). The darker-skinned variety, which is most often called a "yam" in error, (*more common in North American use as pie-filling, fries, and thanksgiving dinners) has a thicker, dark orange to reddish skin with a vivid orange, sweet flesh and a moist texture.

Yams - The true yam is the tuber of a tropical vine (Dioscorea batatas) and is not even distantly related to the sweet potato. the yam is a popular vegetable in Latin American, Caribbean &  African markets, with over 150 varieties available worldwide. Generally sweeter than the sweet potato this tuber can grow over seven feet in length.
(*fun fact: The word yam comes from African words njam, nyam, nyami, or djambi, meaning "to eat”; which could also be where the patois expression “food” came from for ALL tuber starches…hmmm)

That put aside… In Regard to Paleo
In The Paleo Diet Dr. Cordain recommends avoiding high starch foods because they are usually high-glycemic load foods, which cause hyperinsulinemia (*high levels of insulin in the blood, leading to pre-diabetes). However, sweet potatoes ARE allowed, especially in the post-workout period. Sweet potatoes are different from potatoes in that they do not contain several harmful substances such as saponins and lectins/leptins (*according to research, these increase your intestinal permeability if consumed regularly and may over-work your immune system). On the other hand, sweet potatoes should be restricted if you are struggling with being overweight, at least until your body weight normalizes to within a safe weight range.

According to How to Eat Like a Caveman - early hominids probably ate large amounts of sweet potatoes as some hunter-gatherers did in Kitava, Papua New Guinea. Logically, it is hard to speculate on a “universal diet” because availability would have depended on climate, season, latitude, culture, etc. Meaning, the carbohydrates they ate varied substantially. However, there is a BIG difference between potatoes and sweet potatoes. Potatoes are members of the nightshade family (*so are eggplants) and contain the toxin alkaloid solanine. Due to the higher in concentration of toxins found when the potato is in its raw state, and due to the unlikelihood of having been eaten raw, potatoes are usually out of the question (*for Paleo eaters) as they would have to have been a more “recent” dietary addition.

As to whether Sweet Potatoes are tolerated or actually encouraged in the Paleo Diet…
Again, according to research, one current stream of thought is that all humans evolve out of Africa and therefore did not evolve eating sweet potatoes (*since “actual” sweet potatoes are from South America). While humans evolved eating tubers for perhaps 500.000 years, the actual tubers consumed should have been African varieties (*i.e.Yam, Cassava or Dasheen). On the other hand, this vegetable is the main staple in the traditional diet of Okinawa, one of the most successful diets in terms of longevity.

So, long story made only a wee bit longer by summarizing... from what I have read, depending on your level of “commitment” to Paleo >> it's about metabolic advantage & cellular reaction, not “recreating” an historically accurate palate, per se.

So…. Enjoy your tubers!!!
If you don’t like “sweet” sweet potatoes, try to find the Caribbean version (dryer, yellow & crumbly) or try instead Taro, Cassava or Cocoyam

-----------

Health BenefitsSweet Potato Nutrition Facts (for one medium size sweet potato)
Calories 128
Fat 0.39 g
Protein 2.15 g
Net Carbs 31.56 g
Dietary Fiber 3.9 g
Calcium 28.6 mg
Sodium 16.9 mg
Potassium 265.2 mg
Folate 18.2 mcg
Vitamin C 29.51 mg
Vitamin A 26081.9 IU

Source: US Department of Agriculture

The U.S. Center for Science in the Public Interest ranked the sweet potato “number one in nutrition of all vegetables.” (*The higher the score, the more nutritious the food)

– This was the Top 5 >
Sweet potato, baked 184
Potato, baked 83
Spinach 76
Kale 55
Broccoli 52
Source: The CSPI, Washington D.C. copyright 1992

**Points were given for content of dietary fiber, naturally occurring sugars and complex carbohydrates, protein, vitamins A and C, iron and calcium. Points were deducted for fat content (especially saturated fat), sodium, cholesterol, added refined sugars and caffeine.
High Vitamin Content - more than 300% of your daily value of vitamin A, a high quantity of vitamins C, B5 and B6. All of which contribute to general health and fat loss. You also get plenty of potassium, copper and manganese. These nutrients help to protect against heart attack and stroke and the potassium helps maintain fluid and electrolyte balance in the body cells, as well as normal heart function and blood pressure.
High in Fiber - Fiber is slow digesting. This means that it takes a long time for high fiber foods to leave your stomach and enter your digestive tract. This prevents overeating, thereby reducing the chances of high calorie intake and potential weight gain. Over 16% of suggested Daily Intake of fiber and fiber takes more energy to burn, making the sweet potato a major fat burning food.
Low Calorie - Sweet potatoes typically contain around 100-130calories per serving, whereas white potatoes, may contain as many as 400-500 calories per serving. (*avg 230cal); Also, among root vegetables, sweet potatoes offer the lowest glycemic-index rating, because the sweet potato digests slowly, causing only a gradual rise in blood sugar so you feel satisfied longer.
High in Water Content - With the exception of bone and fat your body is composed almost primarily from water, and therefore it is of no surprise that it responds favorably when you eat foods that contain high amounts of water. Like fiber, water takes up a lot of room in your stomach.
*I will post my next blog with some delish, and Paleo-friendly Sweet Potato recipes!

The benefits of being NEGATIVE!

In response to @forresterOD

Q: Are negative reps really superior when it comes to building mass?

Negative training, or Eccentric-focused lifting, is a relatively easy concept. Basically, instead of dropping a weight like a stone after the positive force (*the concentric action, the contractile force), you purposefully control the return portion of the action, focusing on the resistance against gravity.

NB: You don't need to incorporate emphasis on the negative into every set, but the eccentric (negative) and concentric (positive) portion of the rep should ALWAYS be performed in a controlled fashion.

The “uncontraction” as it were, is this “negative movement”. While a positive movement is actually working the muscle, a negative movement also puts the tendons and supportive structures to work. Tendon strength needs to increase exponentially with muscle strength. (*side-note, YES the opposing muscle group will be in the contractile/control phase and as such you will also be working said other group. BUT bear with me for the cause…)

You have to keep in mind that the amount of weight you can lift is going to be determined by your current strength. Your body, however, is capable of MORE strength when putting something down than it is when picking something up.

One thing to remember is that most of the microtrauma (muscle tearing that causes DOMS) and later hypertrophy – muscle building after the repair of these traumas – occurs during the eccentric phase of the movement. Concentrating on doing this on every set would almost certainly lead to over training-due to lack of proper recovery.  So compounding this over and over throughout your workout would most likely cause so much microtrauma that you'd never fully recover.

FYI ::

This technique was based on research showing that most of the strength and size gains accrued from weight training occur during the negative portion of a rep. So does most of the delayed muscular soreness you feel after an intense training session (or after you try an exercise to which you're not accustomed).

The explanation given was that when you lower a weight, you use fewer muscle fibers, but those fibers work harder to control the weight.  As a result, more damage occurs. The body then repairs those fibers, making them thicker as an accommodation to the higher load imposed by negatives, and result in an increased muscular strength and size.

The extreme damage to fibers during negative training came with a cost, however: the need for increased recuperation. When many bodybuilders became aware of this extra fiber damage and consequent needed rest time, they reduced the number of times they trained a muscle group each week.

There is scientific evidence that we are stronger in the negative (or lowering) portion of a weight exercise than in the positive (or lifting) half. Reverse-gravity, or negative, reps are performed by lowering the weight approximately four times slower than usual, utilizing eight to 12 seconds for the descent.

Let’s use the bicep curl as an example – You can start with an actual curl, or you can start at the end-position (*hands up by shoulders).  Lower the weight through the entire downward portion of the rep, taking  5-15sec to do so. Once you’ve reached the bottom of the eccentric phase (*the natural concentric start position) explode right into the concentric phase, 1-3sec to raise the weight back up. Speed is of the utmost importance here, as you “rest” back at the end position prior to the next eccentric lowering.


#tip – for beginners, I recommend using a 1-2sec count to raise & a 5-8sec count in lowering.

What this does is cause your brain to signal ALL of the muscle fibers to fire simultaneously, in order to control the lowering & then POWER the weight back up. You're essentially training fibers that you may not have recruited before.  (*When you do this with heavy weights you also activate motor unit recruitment.)

That said, do your heaviest negative training in the earliest part of your workout. The motor units will remain active for a while and you'll essentially be stronger throughout your training session. You can use negative bodyweight training (*pull ups, push-ups) at the end of workouts as “burners”.  Failure reps are GREAT here.  Nothing works lats & biceps like 30sec chin-up iso-hold (*holding thru the peak position, midway down, until you CAN’T) negative-lowering reps!

Hope that answers your question / Helps!