There are psychological and physiological strategies
Lifeguards should utilize to decrease boredom and increase vigilance. Many athletes, pilots, and long haul drivers already use these techniques effectively. More specifically, lifeguards should try to change positions or assignments at least every 30 minutes. In addition, moving frequently, mild exercise, working with a partner, cold water, and lowering ambient temperatures have proven to increase attention and concentration. Moderate increases in physical movement, respiration, and heart rate stimulate neurological pathways, which in turn improves attention, concentration, and vigilance. In short, research supports the view that an active and interactive lifeguard is more alert than a passive one. Lifeguards who continually sit rather than stand, walk, and otherwise move cannot maintain the same level of vigilance as those who are always in motion. The lifeguard who gets lifeguard training will sits stands and strolls while on duty, as required by the five minute scanning strategy ,and should be more alert physiologically and psychologically, provided she is well rested and not overly stimulated by other environmental factors.
Perceptual Body Blindness
For more than a quarter of a century, cognitive psychologists have been studying the phenomenon of perceptual blindness. Perceptual blindness can be simply explained as failing to detect the obvious in critical situations. Human beings are bad observers and poor monitors. We fail to see the most obvious things because although our eyes take in a tremendous amount of visual stimuli, very little of the data received by the eyes is actually encoded or recorded by our brains. Therefore we may see a lot but perceive very little, one reason humans are not infallible when it comes to drowning prevention and another reason why lifejackets are so important for non-swimmers. In essence, we as human beings see what we expect to see and what we want to see. That is why lifeguards and parents miss drowning victims: They don’t want or expect people to actually drown and die on their watch. This happens on the subconscious level and may be described as perceptual body blindness. Although there are many forms and causes of perceptual blindness, the results are the same—drowning due to a lack of perception. Being aware of this concept and expecting the unexpected may help lifeguards and parents alike who are providing surveillance around the water.

Circadian Rhythms Human beings
Just like animals and plants, have biological clocks that predict levels of alertness and fatigue, with both levels fluctuating and alternating throughout each day. Unfortunately, peak times for alertness do not often coincide with the busiest times of the day at the pool. In general, people are most alert in the early to midmorning hours and again in the later afternoon. Between noon and the early afternoon, most people experience increased fatigue and reduced alertness. This is not comforting for those who supervise and manage beach lifeguards because these times of fatigue most often occur when the beaches are the most crowded.