The Secret of Exercise

Praise Hashem with All Your Soul (and Every Breath)

בראשית רבה יד, ט. על כל נשימה ונשימה שאדם נושם

צריך לקלס לבורא. מה טעם, כל הנשמה תהלל יה, כל נשימה ...

Maimonides writes that every morning one should rise early and exercise. How much exercise? Until the body begins to heat up.

Why early in the day? Probably because that's when it's best to do so; Perhaps because the muscles, which were totally relaxed all night, will thereby achieve proper tone for the rest of the day. Also, much of the blood can now stream to the musculature, because little remains in the now-empty, upper alimentary tract that would compete for the supply. (Which is why before the morning's food intake one should wait after the exercise until a state of rest is achieved, when blood can again be allocated to the alimentary tract, to take care of digestion).

Why until the body heats up, and not any more? Because, I believe, a heated state is harmful; Whereas an aerobic state - that maintains itself until that heated state is reached, is best, and here's why:

I think the key to exercise's efficiency is the deep breath! The deep breath serves to propel the lymphatic streams. Increased flow of lymph promotes:

1) Recirculation of protein that escaped from vascular capillaries;

2) Washing microbes away from tissue and into the lymph nodes where they can be neutralized;

3) A good "dry-state", where excess lymph within tissues is removed.

4) It also provides a generous dose of oxygen.

Exercise, by virtue of muscle contractions and stretches, press on the lymphatics and thus advance the stream along its one-way direction. While this is an important result, a much more significant propeller is the act of deep breathing. Under sedentary conditions, the shallow breath uses but a minor portion of the lung's capacity. The deep breath, on the other hand, mobilizes a larger than average capacity and this, in turn, draws a larger than average volume of blood into the lung parenchyma, which induces a larger than average lymphatic exudate.

This is the key point - the secret! For deep breathing does something that even general muscle movements cannot do, and that is, to rapidly advance the flow. At the peak of exhalation you create the greatest rush of lymph, and the deeper the breath at the peak of inhalation, the greater the rush will be.

"Deep diaphragmatic breathing stimulates the cleansing of the lymph system. Exhaling is more important than inhaling because when you exhale the vacuum produced in the lungs will exert a drawing force that pulls poisons from the blood into the lungs for elimination. This increases the rate of toxic elimination by as much as 15 times the normal rate" - Dr. J.W. Shields, MD, LYMPH, "Lymph Glands, and Homeostasis." Lymphology, v25, n4 Dec. 1992, p 147.

Mind you, I don't think Maimonides said, "Don't sweat". He said, "... until the body heats up." By this I think he means anaerobic exercise, which can induce pain, if not tissue damage.

It goes without saying deep breathing even without exercise also provides benefit.