The American Heart Association recommends that all adults get 150 minutes of moderate activity each week, or 75 minutes of more-vigorous activity. This exercise can include sports, swimming, biking, jogging, walking or any other activity that gets your heart rate up and your body moving. The AHA suggests incorporating strength and stretching exercises into your routine. However, if you exercise too intensely and experience shakiness and weakness, learn to avoid those feelings by being aware of certain contributing factors.
Lack of Sleep
When you don't get the sleep your muscles need to repair themselves, you can end up feeling fatigued and shaky after a strenuous workout. During a study undertaken by researchers at Stanford University in 2007 and presented at the 21st Annual Meeting of the Associated Professional Sleep Societies, athletes who got adequate amounts of sleep experienced less fatigue, better mood, and increased performance. Get between seven and eight hours of sleep each night for optimal health and performance levels.
Proper hydration is key to good health. Many of your body's functions need water to work properly. Dehydration can cause symptoms of fatigue, shakiness and weakness during and after a workout, as well as muscle cramps and nausea. The American College of Sports Medicine recommends people drink 2 to 3 cups of liquid -- water is best -- at least two hours before exercise, at least 1/2 cup of water every 15 minutes during a workout, and 2 to 3 cups of water post-workout for every pound lost during that workout. In addition, if the workout duration is 60 minutes or more, you should drink a sports drink rather than plain water in order to replace carbohydrates and electrolytes lost during the workout.
Also called low blood glucose, hypoglycemia happens when blood sugar levels drop below normal levels. Glucose provides energy to the muscles and, during a workout, levels can drop even further. Hypoglycemia can cause symptoms of shakiness, dizziness or light-headedness, weakness, hunger, confusion and sleepiness. Eating a proper diet with adequate nutrition for your activity level is essential for people who work out. Eat a balanced diet, and if you feel any of these symptoms during a workout, eat a small snack to bring your blood sugar up to an acceptable level.
If you are new to exercise, doing too much too soon can cause dizziness, nausea, shakiness and weakness. Speak to your health care provider and a personal trainer if you need help designing an appropriate workout for your current fitness level. If you feel shaky or weak during exercise, stop immediately and rest. Leave 48 hours between weight training sessions on the same body part to allow time to heal, and always give yourself a minimum of one to two rest days a week when it comes to cardio workouts.