Women Only Articles
Exercising For Two
I often see women who are pregnant who want to know what they can or can not do while they are pregnant. The most important thing to realize is that in most circumstances pregnancy is a healthy state and not a disease state. Nonetheless pregnancy is a stress to the body and the health of the mother and baby must be taken into consideration. In essence, pregnancy in itself puts the mother into a training state. Cardiac or heart output is raised 30-50%.
The two main concerns in exercise in a pregnant female is reduced blood flow to the fetus and increased heat during exercise which may cause harm to the developing fetus. Initially it was thought that the exercising mother would rob the fetus of blood flow. This has now been shown to be not true. The other main concern is how regular exercise will effect labor and delivery Exercise has not been shown to either effect time of labor or birth weight size. In fact some studies have shown that women who exercise have shorter labors and slightly larger babies than those that did not exercise.
Obviously if there are medical problems with the mother or past or present obstetrical problems exercise will have to be limited or curtailed. Check with your physician before you continue or start a exercise program. There are other mild precautions. Exercising while lying on your back after the fourth month may alter the blood flow to the fetus and should be avoided. Your center of gravity is lower and will effect your balance. It also places more strain on the lower back. Due to the release of hormones a women's joints and ligaments will become looser and more prone to injury. It is therefore advisable to avoid jerky and ballistic movements.
The pelvic floor is especially vulnerable when you are pregnant. It is important as it supports the uterus. To strengthen these muscles ""Kegel"" exercises are performed. A women learns this exercise by contracting the muscles which will stop her urine flow. Once the exercise is learned it is performed on a regular basis where the women will hold the muscles tight for 10 -15 seconds and then relax. There are some sports which should not be done while you are pregnant. The most common are scuba diving, water skiing, and horse back riding. Hot tubs and saunas should be avoided. Certain activities are easier to do while pregnant.
The best is swimming or aquabics where the water provides floatation. Cycling is good but stationary cycling at home or at a club is the safest. Walking as opposed to jogging will be easier, especially in the third trimester. In summary for the average healthy pregnant female exercise can be maintained or even initiated.
The following are some final tips.
1/ Be consistent and allow your body to adapt to the exercise while pregnant
2/ Do not exercise if ill or in very hot humid environment. Be extra careful at high altitude (>11'000 feet) where the oxygen is less.
3/Use proper equipment including supportive shoes and sports bra.
4/ Do a good 10 minute warm up and cool down.
5/ Heart rate should not exceed 140 beats per minute( This is the current recommendation but it is not a strict rule for the female who is a regular exerciser who may feel comfortable at higher rates)
6/ Limit strenuous activity to 15 minutes
7/ Exercise that involve breath holding while exerting ( heavy weight lifting) should be avoided.
8/ Maintain proper hydration and nutrition to support the pregnancy and exercise
9/ Women who were previously sedentary should start off especially slow and increase very gradually.
10/ Get up very slowly from the floor after floor exercises.
11/ Stop exercise immediately and see your doctor if any unusual symptoms occur.
Exercise In Pregnancy
This weekend we had our annual staff picnic. From our small clinic at The Sport Medicine Specialists there were 26 children under the age of seven. Needless to say we have seen a lot of pregnant woman over the last few years. These are an active group and woman who were used to a regular dose of exercise. All of them wanted to continue their exercise regime while pregnant. They wanted to know what would happen to their bodies and what was safe for them and more importantly their baby. Pregnancy is a healthy state, but there are definite changes to the body and there are definite needs for the growing fetus. While mothers want to stay fit the most important thing is to not affect the growth and development of the baby. The actual energy cost of being pregnant is about 300 calories a day, Therefore the pregnant woman must eat more and if they are going to exercise and they should, they must increase their calorie intake to meet the increased needs.
Their weight must be monitored to ensure they are gaining the appropriate weight. Pregnant woman do not do as well in heat. They have less capacity to dissipate heat and must be more careful in the hot humid environment. If a woman does get overheated there is potential risk to the fetus.The advice is to make sure you are drinking adequate fluids and to avoid exercising in high heat and humidity. The actual weight of the growing baby and the changes in the female body make a woman more prone to falls. High risk sports such as horseback riding, surfing, water skiing, should be avoided. Even cycling later in pregnancy may be putting an inexperienced rider at risk. The previous skill level of the female is important. While it may be safe for a good snow skier to ski during the first and second trimester, it would be inadvisable for a beginner.
During pregnancy, the hormonal changes make the joints and ligaments loser. While this obviously aids in delivery, it may make a woman more prone to injury. Back pain is more common in pregnancy. Woman also become more uncoordinated. This will affect both their performance and risk of injury. My wife who is an excellent golfer, looked like a mere mortal on the course when she was pregnant. Circulation is critical to the development of the fetus. The baby gets its nutrition from the blood of the mother. The heart output increases by 30-50%. Studies of fetal growth show that the transient diversion of blood from the fetus to the mother during exercise is transient and has no effect on the fetus. What can be a concern is the position of the mother, especially in the later months. When laying on their back the uterus may rest on the aorta and inferior vena cava which are the important artery and vein to the lower limbs.
This may decrease blood flow to the fetus and must be avoided after the first trimester. Most evidence suggests that moderate exercise during a normal pregnancy has no adverse or beneficial effects on maternal weight gain, length of gestation or labor, infant birth weight or health of the baby. There are some studies that suggest that regular exercise has a positive effect on labor and delivery. There are certain situations in pregnancy that a woman should either not exercise or limit their exercise. The doctor should be consulted if their any signs of pain, dizziness, shortness of breath, faintness, bleeding, rapid heart rate at rest, difficulty walking, contractions of the uterus, or loss of fetal movement. ALL woman should consult their doctor before they start exercising to make sure it is okay. Certain medical conditions may change the advice they are given. Exercise during pregnancy maintains muscle tone, strength and endurance. It improves mood, energy and self image. It is recommended that pregnant woman exercise at a moderate level within the above guidelines.
Women In Sport
I was interviewed this year by a television reporter at the Toronto Marathon at which I am the Medical Director. One of the main questions that I was asked was what the difference was between the genders. She wanted to know if women could ever run at the same speed or even faster than their male counterparts. The other question was if they had a different injury profile. There is no doubt that females have exponentially improved in their times but what was the reason for this. The first thing you have to look at is what is the basic difference in body type between the sexes. Women are obviously smaller than males. There is a 7-10% difference in height and a 15-20% difference in weight. When comparing body parts there is no difference between males and females at the comparable weight. Women's centre of gravity is only 1% lower than a males. Perhaps the biggest significant difference is the alignment of the lower extremities. Women generally have wider hips.
Therefore there legs start out wider and come in towards the knee making them knock kneed. The lower legs than flare out to compensate and finally the feet tend to fall in or pronate to balance the body. With all these angles in the lower extremity there are uneven forces especially in the knee which may in fact lead to injury. This malalignment is also more inefficient in forward propulsion. No one would argue that women are not as strong as males. Research has shown that females have 33% less strength than males. This will vary between muscle groups and populations. Women are weaker in the upper extremity relative to the lower extremity when compared to males. They have also compared strength relative to body weight. Overall females are still weaker but leg strength relative to the lean body weight is almost the same as males.
The efficiency of exercise is very important when comparing potential. The easiest sport to compare efficiency is pure running. There are two ways to run faster. You can either increase your stride length or you can increase your stride frequency. At slower speeds it is the stride length which is increased to increase your speed but as you reach your optimal stride length it is the increase in stride frequency which will ultimately make you a faster runner. Male runners have a greater stride length and females have a greater stride frequency for the same speed. Female runners when tested at various running speeds were found to spend more time in the air than males. Combining this information with the fact that females have a shorter stride length means that the females have a stronger push off. If this is the case then you would think that females would fatigue more than males. Fatigue would affect the velocity of the push off and the amount of time spent in the air.
This is in fact true in that females have a longer flight time early in a long distance race and this gradually decreases where in a marathon the males would have a longer flight time in each individual stride than the females. The reporter was very interested in if females would ever approach males in times in the marathon. There is no doubt that the times in female runners have decreased at a large rate in the last few decades. Female times in the marathon have improved an average of 80 seconds per year in the last 90 years. Male times have only improved at a rate of about 40 seconds per year . Some people would then say that it is only a matter of time before the women are running faster than the males. The other important factor you have to look at is the nature of the sport. It is only since 1984 that marathoning has been an Olympic sport. It was thought previously that women could not withstand the rigors of the training required to complete the marathon.
Therefore it has only been recently that women have adopted proper training techniques to maximize their performance. This is the reason for the vast improvement in times in the last few decades. Now never is a strong word, but the growth in improvement in times has plateaued to a similar level as males, so I do not think they will ever run as fast as males(without drug manipulation). The other aspect to look at is the injury rate in females as compared to males. There are some injuries that are unique to women. They include breast problems and injuries to the female genitalia. They sustain the same bone and tendon injuries as males but the incidence may vary. Women have a higher rate of knee and lower extremity injuries than males. This may be due to the difference in biomechanics as mentioned above.
With more angles in the lower extremities than males there are more stress on the joints especially the knee where the patella may track more to the outside. This puts more stress on the under surface of the patella causing pain. Women are more prone to stress fractures in sport. This is thought to be due to the female athlete triad. This consists of disordered eating, irregular or loss of menstruation, and osteoporosis. The bones become weaker and more likely to fracture and heal at a slower rate when fractured. Participation in sports by women has increased significantly since the 2nd century where women were threatened with death for not only participating in sport but by even watching male athletics. Today women participate in every sport and the funding and support is increasing along with it.