Your baby is affected when you perform strenuous pregnancy exercises. If you get very hot your baby can also get over-heated and this may be dangerous. As you get breathless, your baby's heart rate also gets faster.

In a healthy pregnancy your baby's heart rate will quickly return to normal when you rest. However, if there are problems with the pregnancy, it may take longer to get back to normal. Your baby's heart may beat slower than it should for a time.

Ask your midwife, family doctor or hospital specialist about safe pregnancy exercise if:

• You have high blood pressure
• You have any medical conditions such as diabetes, thyroid imbalance or heart disease
• You have had any vaginal bleeding during this pregnancy (or have had two or more miscarriages in the past)
• You have a low-lying placenta (seen on an ultrasound scan)
• Your baby is growing slowly (or previous babies have been slow growing during pregnancy)
• You are expecting more than one baby

• Get off the bus one stop earlier than usual and walk home briskly
• Take the long way (or the hilly route!) to the shops or clinic
• Choose a quiet time at your local swimming pool and go for a gentle swim. Some swimming pools offer antenatal swimming sessions (sometimes called ‘aquanatal’ classes) - ask your midwife
• Borrow a yoga book or video from the library and have a go at home. Better still, try a yoga or stretching class for pregnancy
  
  

If you are used to exercising, you have an excellent base to build on during pregnancy. Many forms of exercise can be safely continued during pregnancy - although most women find they have to modify their activity as the months go by. Be flexible - try swimming instead of running, perhaps, or fast walking instead of cycling.

Keep in mind these guidelines:

• Take care with exercise that may put strain on your back or abdominal muscles.
• Don’t push yourself as hard as you normally would. Stop if you get too hot, breathless or tired. Your pulse should not exceed 140 beats per minute.
• It is better to exercise regularly for short periods than to exhaust yourself in one long session. Rest for a few minutes every 15 minutes.
• Most women find three to four exercise sessions a week enough
• Drink plenty of fluids before, during and after exercising to prevent dehydration.
• Eat plenty of starchy carbohydrates to give you energy.
• See your midwife or doctor for regular checks of your blood pressure and your baby’s growth.

Throughout pregnancy, the hormone progesterone causes many of your ligaments and joints to soften and loosen in preparation for labour. Joint injuries and ligament damage may therefore result from exercise that involves jerking actions and sudden movement, for example tennis, squash and jogging. The risk of back injuries associated with weight training or rowing is also increased.

During the later months, your belly gets bigger and your balance may not be so good, so falls become more likely when you do any exercise that requires balance.

Most experts think that the following activities should be avoided during pregnancy because of the high risk of falls or direct damage to you or your baby:

• Mountaineering, rock climbing
• High diving, scuba diving
• Downhill skiing, water skiing, water slides
• Trampolining, gymnastics
• Anaerobic exercise such as sprinting
• Contact sports, competitive team sports