After an intense workout, you probably feel tired -- your muscles ache, you're hungry and you're ready to relax. But imagine that fatigue going deeper into your tissues and organs, changing the way you think, move and feel. Physical exhaustion has a number of potential causes, both physical and emotional.
Physical exhaustion signifies extreme fatigue to the point at which the body can't continue functioning. Causes range from heat exhaustion and athletic over-training to an underlying disease or intense emotional stress. Although physical exhaustion can usually be cured with rest and proper nutrition, fatigue that doesn't go away may be a sign of chronic fatigue syndrome. According to the Mayo Clinic, this disease often results in ancillary problems such as headaches, muscle pain and loss of concentration.
Common signs of physical exhaustion include dizziness and overall weakness. Simple physical overexertion is often the culprit, but there's a more dangerous possibility. Heat exhaustion also causes you to feel dizzy, weak and unsteady on your feet. According to the Merck Manual, it doesn't matter whether you've been physically active or not, the heat causes your body to lose water and electrolytes through your sweat. If you don't replenish them, you will feel exhausted, weak and dizzy.
The US National Institutes of Health (NIH) describes confusion as an inability to think with speed or clarity, affecting your ability to remember things and make decisions. Causes include a fluid or electrolyte imbalance, a lack of sleep, low blood sugar and low oxygen level. All of these connect with different forms of exhaustion. Heat exhaustion causes electrolyte imbalance, while extreme exercise or athletic training can cause a drop in blood sugar or oxygen level. A lack of sleep is in itself a potential cause of exhaustion. The good news is that exhaustion-based confusion is temporary, clearing when the body replenishes itself.
When you overwork your muscles, they begin to leak calcium, resulting in fatigue, strain and weakness. According to a 2008 study by the Columbia University Medical Center, researchers found this leak in mice who swam daily for three weeks and in humans who biked for three days in a row. Dr Andrew Marks warns that calcium leaks can occur in people who exercise three hours a day at high intensity for several days or weeks in a row. A few days of rest will fix the problem, he reports.
Muscle cramps happen to 67 per cent of triathletes and 18 to 70 per cent of endurance runners and cyclists, often at the end of a race. In 2005, researchers from the University of North Carolina and two Alabama universities tried to pinpoint the cause of these cramps: Is it exhaustion, dehydration or an electrolyte imbalance? Increased hydration and a proper electrolyte balance didn't affect the rate at which their subjects cramped during exercise. Researchers noted a difference between fatigue-based cramps and heat-based cramps; most of the study's observed cramps were fatigue-based. If you experience localized, muscle-specific cramps like those of the study's participants, there's a good chance physical exhaustion is the cause.