Exercise during your twin pregnancy is not only safe, it has many benefits to both you and your babies.  Benefits include the following (to name a few):

• less weight gain
• less likely to development gestational diabetes
• less likely to end up with stretch marks and 'twin skin'
• less back pain
• less pain in joints
• relieves constipation
• sleep better
• more energy
• have easier labor and deliveries
• return to pre-pregnancy weight faster

Both walking and swimming are safe and have many health benefits for you and your twins

Be aware that it is possible, even likely, that before the end of your twin pregnancy you will be put on modified exercise.   If this happens, it is important to speak with your doctor or midwife about what exactly is off limits.   While it may not be okay to run or lift weights, your doctor or midwife may fully support you swimming or going for walks.  Regardless of whether or not you have been put on any type of restrictions by your doctor, there are some exercises that are best to avoid during your pregnancy.   These include: contact sports; scuba diving; horseback riding; and skiing.

Despite the activities you choose during your twin pregnancy, always use common sense.   If the activity requires jarring activity, leaping, heavy bouncing, or anything that could cause abdominal injury, you are better off avoiding it.   Many doctors also recommend you avoid doing anything that requires lying flat on your back, such as bench press, after the first trimester.

Exercise in any form should be discontinued if it is causing you to feel any pain, light headed, nausea, dizziness, or contractions.