It’s closer than you think: Foreign invaders are gathering, unseen terrorists are silently arming themselves, preparing to strike and take control.

 

Is this a plan for world domination by a foreign country? No. It is a battle fought every day—inside your body, against bacteria, viruses, cancer cells and toxic chemicals. Our defensive fighting force is our immune system, and its warriors are the individual immune cells.

 

If you look at a drop of blood under a microscope, you would see several million small red blood cells. These are the transport systems of the body, the trains and trucks that move energy stores, oxygen and waste products through the body. Scattered among the red blood cells are a few larger cells, the white blood cells of the immune system. These are the foot soldiers of the body’s defenses. Their mission is to cruise the bloodstream, find invading germs, viruses or cancer cells, and attack and destroy them.

 

Just as the military needs to be kept lean and strong to fight off a rapid attack, so must our immune system. The armed forces stay strong and ready by training and exercise. Likewise, your immune system can be trained to respond faster and more powerfully to the enemy’s attack. Let’s look at how you can be healthier by “training” your immune system.

 

First, physical exercise can boost the strength and readiness of your immune system. The number of immune cells actually decreases in sedentary people (couch potatoes), making them more likely to catch colds or the flu. I recommend both strength and aerobic exercise such as running, cycling, in-line skating, rowing or vigorous walking.

 

To strengthen your immune system, you need to exercise enough to raise your heart rate up to 50 t o 75 percent of your maximum heart rate (which can be calculated by subtracting your age from 220) for 20 to 30 minutes, several times a week. You should be able to reach your target heart rate with moderate effort that won’t leave you hurting or gasping for breath. Overtraining, including weight lifting to the point of muscle pain, causes the immune system to weaken dramatically.

 

In general, moderate aerobic exercise will help you fight off colds and flu more easily. There are reports of cancer patients going into remission by exercising rather than using conventional chemotherapy, and of patients with AIDS slowing progression of the disease through exercise. Of course, exercise is not a substitute for conventional medical treatment.

 

The second training exercise for your immune system: Change your eating habits. Have you noticed how trained athletes carefully watch what they eat, downing well-balanced meals and cutting down on high-fat snack foods? They do this so the muscles in their legs and arms respond instantly and powerfully and are not hindered by a sluggish layer of fat. High-fat diets send messages to your brain, telling you to slow down.

 

Thirdly, you can manage your stress. If you are stressed emotional, your brain sends out messages that shut down the immune system. This is why you get sick easier after a period of high stress at work or school. But most of us cannot avoid the stresses of life in today’s fast-paced world. That’s why it’s so important to prepare the body’s immune system for time of heavy stress.

 

The human body’s process of warring against disease reminds me of another war we fight. We are in a spiritual war against Satan and his forces of evil (see Eph. 6:10-18). If we are not disciplined and well-trained spiritually, we cannot fight the battle. But if we take on strength through prayer and the Word of God, we will be able to fight spiritual battles and defeat the enemy.

 

Maybe this is the most important truth of all: We need spiritual challenge and training to be strong—and to fight like a champion. We are in a spiritual war, and the Lord God is our captain. Let’s fight it His way—and keep our spiritual immune systems in top shape.