Because all these biorhythms begin on the day of our birth, we can know our ups and downs ahead of time, as in the graph above. As each line of biorhythmic energy rises, we have more energy. As it drops towards the bottom of the graph, our energy decreases. Because our biorhythms are flowing at different speeds, they will not all meet at that same birth point again, until we are 58 years and 66 days old.

In terms of the , it's as if we had three(four if you count the intuitional cycle) rechargeable batteries in us. For half the time, the batteries are charging up and we are building our energy, and for the other half of our time, the batteries are depleting, and we are regenerating our energy levels.

There is no good or bad associated with the cycle highs and lows. It is more like the vision of Yin and Yang, the Chinese symbols of the harmony of opposites: receptive and expressive, summer and winter. There is no way to avoid these swings, and we can use them to our advantage, like the surfer who sees the wave coming and catches it at just the right moment.

Because our biorhythms flow as a wave, there is one day of change from high to low and back again, between the high and the low, which is referred to as a "Critical" day. There are two types of Critical Days. The day when your curve goes from the high (positive) phase to the low (negative) phase. And when the curve goes from low (negative) to high (positive) phase. The critical line or cross-over point divides the top half of the graph from the lower half, and is the point at which we switch over from recharging to expending energy or from expending energy to recharging.

This is the major volatile point of change in our continuing wave of change. The "critical line or cross-over point" is the day when we are most vulnerable - physically, emotionally or intellectually - depending on which biorhythm line is crossing the critical line. It's the time when we are changing direction, from outward-looking to inward-looking, or vice-versa, and is likely to be a period of confusion, illness, or crisis.

When you pass through this central point - on that day and even on the day before (a preview of things to come), everything may go haywire in our life. A number of statistics show that accidents tend to happen on one's Critical Days. One study shows that almost 80% of all traffic accidents happen on the drivers' Critical Days. In other accidents involving bodily harm, 70% of those affected by the accidents were experiencing their Critical Days. In Japan, where statistical evidences are plenty, the correlation between Critical Days and accidents are take quite seriously. In Japan, many companies track the Biorythyms of taxi drivers and truckers are routinely checked to minimize the number of accidents from happening.

A double transition day is when 2 of your cycles change polarity on the same day. This day may be difficult, especially if both cycles are changing polarity in tandem. A triple transition day is when 3 of your cycles change polarity on the same day. Triple transition days are rare, occurring once every 7-8 years.

The toughest days are multiple transition days immediately following one another. JFK Jr. left on his last flight during one of these phases. All three of his cycles had transitioned within a 48 hour period. Each one of us may have this combination once or twice a year. It's nice to know about this combination in advance so that accidents, and hurt feelings may be avoided.