"My Burden Is Light!"

The following article appeared in Discover magazine August 1995:

One of the most startling sights on a first trip to Africa is a common one: women carrying things on their heads. Try to carry a suitcase on your head, and you’ll probably bite your tongue in concentration and wave your arms madly for balance. But African women walk for miles with heavy jugs of water or pots of food as if they weren’t carrying anything. Energetically speaking, they aren’t! Researchers have found that the women can carry enormous loads without using any extra energy. They aren’t defying any laws of physics, though; they’re being good
PENDULUMS.

In 1977 a team of Harvard physiologists, in Kenya to study the locomotion of wild animals, found themselves distracted by the load-carrying women. “When we tried to pick up the loads, we were just amazed,” says Norman Heglund. “We wondered how the devil they did it.” As a first experiment, Heglund’s team convinced some Kenyan women to wear breathing masks as they carried their loads; the idea was to measure the women’s oxygen consumption, calculate how many calories they were burning, and then compare their performance with that of non-Africans. There the experiment ran into a snag: the non-African researchers couldn’t match the carrying capacity of the Kenyan women, at least not with their heads. Heglund and his colleagues had to resort to backpacks and to using old measurements from American Army recruits.

Still, the results were extraordinary. The African women could carry a fifth of their weight without burning a single extra calorie. And although larger loads did require more energy, the increase was only half of that needed by the American soldiers. Some women could carry 70 percent of their weight.

Funding agencies haven’t exactly been desperate for the answer to this riddle, so it’s only recently that Heglund has managed to get a step closer to one. While spending a year teaching at the University of Nairobi in 1989, he had some Kenyan women walk across force plates; last year in Belgium he repeated the experiment with European students. Force plates are devices that register the vertical and horizontal forces exerted by a walking animal.

A walking human is like a pendulum swinging. When the pendulum is at its lowest point, it is moving fastest, and its energy is almost all kinetic energy of motion. As the pendulum climbs up one side of its arc and is slowed and finally stopped by gravity, that energy isn’t all lost. Most of it is stored as potential energy and is converted back into kinetic energy when the pendulum starts to fall again. But some of the energy is lost to friction, both in the bearing and between the pendulum and the air.

Similarly, when you walk, the kinetic energy of your forward movement turns into potential energy as you rise on one foot and is converted back into kinetic energy as you fall onto the other foot. But with each footfall, only 65 percent of that kinetic energy is carried over into the next step; 35 percent is lost, mostly to internal friction in your leg. That 35 percent has to be made up by your leg muscles, which convert food energy into kinetic energy.

The 35 percent rule applies to Kenyan women too - until they start carrying things on their heads. Heglund’s force plate readings allowed him to calculate how much energy his subjects were transferring from one step to the next. Without a load, Kenyan women and Europeans both transferred 65 percent. When the Europeans carried loads on their backs, they still lost 35 percent - but now, since they were bearing more weight at the same speed, that 35 percent represented more energy in absolute terms, which they made up by burning more calories.

In contrast, the Africans simply became better pendulums. When they carried a fifth of their body weight on their heads, they somehow managed to transfer 75 percent of their energy from one step to the next, losing only 25 percent to friction. With a greater load, one woman even reduced her loss to 15 percent!

Heglund doesn’t know what biomechanical trick the Kenyan women are using - THEY COULDN’T TELL HIM! But it must have something to do with carrying things on your head. People who carry things for a living, he notes, from Kenyans to Sherpa mountain guides, tend to use their heads. “It’s just amateurs like us that use suitcases and backpacks,” Heglund says. [End of article]

As I finished reading the above article, the words of Christ in the Gospel came to mind: “Come unto Me, all you that labor and are heavy laden, and I will give you REST. Take My yoke upon you, and learn of Me; for I am meek and lowly in heart, and you shall find REST for your souls. For My yoke is easy, and MY BURDEN IS LIGHT.”
(Matthew 11:28-30)

Much the same type of “burden carrying” is available to the Christian as is used by the Kenyan women. Christ did not say that He would remove our burdens. He said that when we learned to TRUST in Him, our burdens would SEEM lighter.

By years of physical training, the women have found that carrying the load on their heads was as easy as not even having the load there at all. No extra energy was expended. But this ability required diligent practice and probably many loads dropped to the ground.

The Christian who comes to know his living union with Jesus Christ can have the same burden release as the Kenyan women have learned. Christ promises to provide the power energy to handle any burden of a Christian IF THE CHRISTIAN WILL TRUST IN CHRIST TO DO IT.

But the development of this trust is not instantaneous. Just as the women required physical training, we, as Christians, require spiritual training. AND THAT IS WHAT OUR HUMAN LIFE IS ALL ABOUT! As we feel the load of our burden start to shift and fall at times, we tend to want to grab it in our own strength. We tend to want to expend our own potential energy instead of allowing Christ to use His spiritual kinetic energy. There is much the same spiritual “pendulum rule” as the physical. And Christ is operating the pendulum.

There is a story in the Old Testament about a man named Uzzah that always seemed strange to me. David was moving the Ark of the Covenant from one place to another on a team of oxen. The Ark started to slip and fall as the oxen stumbled, and Uzzah leaped forward to grab the Ark to prevent damage. God immediately killed Uzzah on the spot for his rashness and disobedience in touching the Ark. (II Samuel 6:6-8) Wow! What a penalty! No second chance there! God’s using of the Law’s severe penalty here I see as a lesson for Christians today. It is a serious matter to try to take up our own burdens. God has promised to carry our burdens with His OWN ENERGY. If we rashly try to do the job in our own strength, we, in effect, turn our back on God’s promises. Christ WILL do the job for us.

And when it comes down to the bottom line, CHRIST’S PENDULUM RULE IS EVEN MORE EFFICIENT! Not 65-35, not 75-25, but the efficiency can approach 100-0 even with the heaviest load.

What do I mean? The more we develop the daily spiritual habit of placing our trust totally in the hands of Christ, the more He says that we can REST. And what is rest? Not only do we not USE energy at rest, but we actually recharge and strengthen our potential energy by rest.
You mean having a burden carried by Christ can give us MORE energy than we had before? Yes. How it works, I have no idea. Just as it is a mystery to me how Christ can live within me in a living union of Spirit to spirit — just as it is a mystery to the scientists how the African women can expend no extra energy from their burdens - it is a mystery how TRUST in Christ can create a recharging PEACE in the midst of apparent trouble. BUT IT DOES! THE BIBLE PROMISES IT. I BELIEVE THE BIBLE. MY BELIEF BRINGS THE PEACE!

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