Occasionally everyone feels a random bout of weakness during a diet and exercise regime, because it's the body's way of rebooting or adjusting to the workload. But according to the National Federation of Professional Trainers, feeling chronically weak or fatigued during dieting and exercise for a sustained time may signal an infection, illness or other serious health-related condition. If you feel weaker than usual during a diet or exercise program or notice any changes in your energy level lasting more than a few days, contact your physician.
过度训练
One common cause of feeling weak during an exercise program is overtraining. When you start a new fitness program, you may not know how many times a week you should train or how long your sessions should be. According to the American Council on Exercise, overtraining can lead to dehydration -- which can cause you to feel dizzy, fatigued and nauseated. Overtraining can also cause chronic muscle fatigue, which makes it impossible for your muscles to keep up with the amount of tears you cause through exercise. Try taking a week off from training to see if you begin to feel better. If this weakness persists, contact your physician.
Not Enough Carbs
不吃足够的食物 - 主要是碳水化合物 - 通常是一个饮食或运动计划期间身体虚弱的原因。低碳水化合物饮食已经诱使许多人节食不健康的方式进行实验，常常导致各种健康相关的条件。碳水化合物是身体能量的主要来源。它们含有大量维持生命的维生素和矿物质。限制碳水化合物危险的低水平可导致低血糖，营养不良，肌肉萎缩和疲劳。
迪sease
如果你开始的饮食和运动疗法，并通知你开始感到较弱或疲劳，也可能是由于疾病得不到及时治疗。据运动医学的美国大学，已知可引起虚弱和疲劳一些医疗问题是贫血，纤维肌痛和肥胖。这可能是从运动的压力会导致病情通过较弱的肌肉显现出来。这是纤维肌痛和肥胖尤其如此。如果你怀疑你的弱点可能是由于疾病得不到及时治疗，就医。
Infection
Changes in diet and physical activity can cause a drop in your immune system, leaving you susceptible to bacterial, fungal or viral infection. Typically in an exercise environment, a large amount of germs take advantage of your low immune system and use the opportunity to invade your system. If you exercise in an environment that is unclean or used by others, you may have caught a bug that caused you to become weaker due to infection. Improper dieting can also cause your immune system to weaken if you don't get enough essential vitamins and minerals. It's best to see your doctor if you feel you may have recently been exposed to any pathogens.
Considerations
Do not equate "diet" with starvation. A well-balanced diet that includes complex carbohydrates and protein is essential. Not eating enough or not eating the right kinds of food will leave you feeling weak and dizzy during or after a workout. Approach "dieting" as a lifestyle change and develop a healthy eating plan. The Centers for Disease Control and Prevention has guidelines for developing an eating plan that will help you manage your weight.
- Sports Nutrition Manual: National Federation of Professional Trainers, Mark P. Kelly et al.
- ACSM’s Resources for the Personal Trainer: American College of Sports Medicine
- American Council on Exercise Personal Trainers Manual; Cedric X. Bryant
- Centers for Disease Control and Prevention: Healthy Eating for a Healthy Weight