Howcast - Call it the time-strapped person's guide to fitness: All these activities provide a big calorie-burn payoff in record time.

Howcast -If you don't pack on those extra pounds in winter, you won't have to struggle to lose them again in the spring. Save yourself the hassle and stay trim year-round with these proven methods.

Howcast -If you have scrap gold -- gold with no artistic or antique value -- you can calculate its market value before taking it to a dealer.

Howcast -Learn about diamond carat size from private jeweler Kate Hemphill in this Howcast video.

Not all exercise is created equal: the best activities for calorie-burning are aerobic and sustained.

When running for more than 30 minutes, you'd better hydrate along the way. For every 1% dehydrated you get, your performance can suffer up to 5%.

Monitoring your weight is difficult when it can fluctuate three to five pounds in a single day. This system will help.

Boredom, negative feelings, weekends, and holidays can trigger you to overeat. Reach your goal by staying motivated and sticking to your diet.

Sometimes the koala joeys play switcheroo on their moms.

How zookeepers target train animals and what it's used for.

Hint: it's a species that hails from Africa, where its name derives from.

Zookeepers work to keep a routine weigh-in as quick as possible so they're not separated from mom for too long.

Zookeepers at the San Diego Zoo weigh and measure new giraffe calf Obi.

This newborn rhino doesn't know it yet, but its existence is very important. Yair Ben-Dor has more.

Meet Tony and his mom Funani at the San Diego Zoo's river hippopotamus exhibit and learn all about this young calf's development.

Having a new giraffe calf at the San Diego Zoo is always an exciting event.

Weighing 2,000 pounds and with characteristic mustache-shaped horns forming what's known as a "boss," this is one tough animal you wouldn't want to mess with.

From birth to now, he's gained about 800 pounds.

Males can weigh more than 2,000 pounds!

How zookeepers target train animals and what it's used for.

Target training is used to get the meerkats to stand on a scale so they can be weighed.

Some days, it's more like "paddles" than "steps."

Get a behind-the-scenes look at how African penguins are cared for at Little Rock Zoo.

Sometimes the koala joeys play switcheroo on their moms.