Response to reader

I feel sleepy after exercising

Hi Dr Gardner,

I have a question. I have been on an exercise programme since late May (five days per week-5:30 am-6:30 am); weight 155 lbs, height 5ft. The programme includes aerobics and abdominals. I have noticed that instead of feeling energetic and alive, I'm feeling very drained and sluggish, even to the point of feeling sleepy around 10:30 am-11:30 am. Do you know what may have caused this? My other concern is, I'm not losing pounds just inches around my waist. Thanks in advance for your kind assistance.

- Joan

Check the exercise prescription

Dear Joan,

Exercise is medicine and, like any other, if the prescription is not correct you will have an adverse experience. Your prescription appears to be too potent or intense. Based on your fitness profile you probably should have started by exercising alternate days for half an hour each day and then increase both the number of days and the time gradually. It is clear that you have started the programme with too much work.

The prudent way to start an exercise programme is to start with what you can manage comfortably to prevent the side effects that you have been experiencing. As the workload becomes more manageable you could either increase the number of days or increase the length of time you exercise. The volume and frequency of your exercise is too much. When you exercise too hard, for too long, and too often you will feel drained of energy and naturally feel sleepy and sluggish.

Nervous system activity

Exercise is psychoactive, it can change the way you feel, think and act because of the functional or pathological changes it brings about in your nervous system. Exercise can depress or slow down nervous system activity and induce sleep as you have been experiencing depending on your exercise prescription.

On the other hand, exercise can also increase your nervous system activity and induce a sense of well-being, self-confidence and alertness. The correct assessment of your fitness profile and your exercise prescription will point us in the direction of the changes that should be made to reverse your unfortunate experience.

A reduction in your waistline is a good observation even though you are not losing pounds. This kind of change in your body composition is indicative of replacing fat tissue with muscle. It will take a larger volume of fat tissue to weigh the same as a smaller volume of muscle tissue because the muscle tissue is more dense or compact than the fat tissue.

Thus, in order to see a weight change you will need to reduce your calorie intake or maintain your regular intake and exercise more. However, based on the problems you have been experiencing you should try to resolve your sleep and energy issues then approach your body composition concerns with the addition of exercising with weights to increase your muscle mass.

Dr Kenneth Gardner is an exercise physiologist at Holiday Hills Research Center; email: yourhealth@gleanerjm.com.