What animal has the largest heart? It's the world's largest mammal. It weighs more than seven tons. Its heart is so large a child can walk through its four chambers and while bending only to pass through the valves, which are larger than the front door of a house. This mammal's giant cardiac muscle must pump blood to fuel a 100-foot long body. It weighs four tons at birth. As an infant, it drinks 100 gallons of milk a day and gains 200 pounds a day. Approximately 10,000 of these species remain. The mammal's maximum heart rate is 12-20 beats per minute (a hummingbird's is 500 bpm). The mammal travel in pairs, and when the partners communicate, the dialogue can be heard underwater for miles.

What's the answer? It's the blue whale, and it has the biggest heart of any animal.

You can't do your best work or give your best sports performance if you are sleep deprived. Sleep deprivation is particularly popular among college students "pulling" all nighters and "gamers" who swap sleep for hours on the computer. But a recent research study by Chris Mah of Stanford University offered details that there's are optimum amounts of sleep necessary for best athletic and heart performances.

"Athletes who get an extra amount of sleep are more likely to improve their performance in a game," said Mah, who released results from an ongoing study in June. "It's not common knowledge, because if people understood how much of a difference (getting more sleep) could make athletically, they'd incorporate it more into their lives and not focus solely on nutrition and exercise."

The study included 39 adults, ages 22 to 45, whose heart rates were tested twice with portable heart rate monitors - the morning after a 10-hour sleep and then again after five consecutive four-hour sleeps. The report results were published in the journal SLEEP.

The research found that when adults had little sleep at night, they had much faster heartbeats and less heart rate variability the next day. Variability is generally a sign of healthy interaction between heart and brain.

Sleep experts say the amount of sleep each person needs is largely individual. The National Sleep Foundation says adults need seven to nine hours a night, although others do well with five to six hours of sleep per night.

As a racehorse runs around the track, exactly how fast does its heart beat? The answer: Like most questions about exercise performance, it depends. Take Secretariat, the last Triple Crown winner. Secretariat had an enormous heart, weighing 22 pounds and 10 pounds more than others stallions' hearts. (The average weight of a female human heart is 9 ounces and the average weight the human male heart is 10.5 ounces.)

Let's look next at heart rate numbers. A horse's resting heart rate is between 30-40 beats per minute (bpm), much lower than human's average of 72 bpm. The range for maximum heart rate between horses varies greatly - 220 to 260 bpm, while the human range average is 160-210. The range for threshold heart rates for equines is 155-175 bpm. This is a surprisingly low percentage of maximum (it's about the same in humans) and there's no explanation. Training does seem to change threshold heart rates in horses. And the final number, for those of you who have taken a metabolic assessment, a New Leaf mlO2/min/kg test, horses have much larger aerobic capacity - the amount of oxygen that it uses at maximum effort consuming more than 200mlO2/min/kg. Average fit, middle age humans use between 30-40 mlO2/min/kg for women and 35-45 for men.

At the Heart Zones Conference 2007 (November 9-11) you can have resting heart rate, threshold heart rate and aerobic capacity testing. Take a fitness vacation, come to Denver and compare yourself with other humans, not equines. Take a New Leaf Gold Test by signing up now at www.heartzones.com for only $119 (normally $179) and find out your aerobic capacity and maximum and threshold heart rates.

What - The Lab Test

• The test is also known as a VO2 Test (volume of oxygen) or metabolic assessment.
• The test measures gas exchange using a flow meter.

Why

• The Gold Threshold test takes what was previously only available to elite athletes in lab testing and makes it available to everyone.
• This test is the "Gold Standard" of measurement of cardiovascular (CV) fitness with the measurement of the oxygen utilization at different intensities.
• Accurately answers the big question: How fit am I?
• Provides rich physiological data called "The Big 4": heart rate, aerobic capacity, caloric expenditure and setting training zones based on threshold heart rate.

Procedures

• The individual receives exercise and diet instruction in advance.
• A certified Heart Zones Metabolic Specialist administers the test.
• You receive test results and a 15-minute consultation.
• Provides you with lab-accurate data to apply during the conference.

Fees

• Typical VO2 metabolic test range in price from $150-$300.
• Conference special which includes mask, test and results is only $129.

Here's your opportunity to watch the live course - Heart Zones Basic Part 1 led by Sally Edwards - for free. Simply click on http://sallyedwards.podclass.com/tell.php. Just register for the free course and "Tell a Friend" and Heart Zones USA gives you the course and more. You are also entered into a contest to win a six-month free Heart Zones Training program or a free airplane ticket to attend a Heart Zones Seminar and Workshop.