. Physical Development - Manitoba Parent Zone | Healthy Child Manitoba

Physical Development


Remember the days when you'd wish your child would sleep in – even just until 7:30 a.m.? Fast forward to a sleepy, grumbling teen and you might wish you still had a perky wide-awake toddler! First, you are not alone and second, this is completely normal. Some of the changes in your teen's brain and social life directly affect your teen's sleeping patterns.

After-school activities, sports, clubs, movies, television and texting may keep teens very busy in the evenings. Teens often stay up later than they did just a few years ago but they still need about nine hours of sleep every night. If your teen is spending time instant messaging, texting or playing video games instead of sleeping, one remedy is to set limits on technology use and agree on a set time when phone and game use will end. It's a good idea to speak to your teen about the importance of sleep and, if necessary, one solution might be to remove from his bedroom any technology that keeps him awake.


Teens physically need lots of sleep because their bodies are growing and changing so quickly. These changes mean puberty. Your teen's body will become adult-like in size, shape and sound. While girls physically mature at younger ages than boys – at around age 15 for girls and 16 for boys – it's important to keep in mind that all children develop at different rates depending on heredity and other factors.

Puberty usually begins at around age 10 for girls when breasts begin to form. Following the development of breasts, you can expect your daughter to go through a growth spurt, pubic hair growth and underarm hair growth.

Menarche is the first period or menstruation a girl will have. For Canadians, this usually occurs between ages 12 and 13. Many girls are aware of menstruation before they have a first period and they usually have mixed feelings about this event. Talking to your child before her first menstruation is important. She may have some sexual health education in school, but having parents talk about menstruation lets her know she can ask questions and discuss her changing body with you if she needs to. If you talk about menstruation as a normal life event it may also reduce any shame or embarrassment your teen may feel.

Boys usually begin puberty around age 11 when testes begin to enlarge and the skin covering the testicles (the scrotum) changes in colour and texture. Shortly afterwards, pubic hair will begin to grow and the penis will enlarge. Around age 13, your teen will begin his growth spurt and his voice will deepen. Around age 14, his penis and testes will have finished growing and about a year later his pubic hair growth will also be completed.

At around age 13 your son will have his first ejaculation. Boys are less likely to speak to friends or family about ejaculation so it is a good idea to speak to him before it happens. It's also a good idea to talk to your son about nocturnal emissions, or wet dreams. Wet dreams are when a boy ejaculates in his sleep. Many boys know about ejaculation and erections, but they don't often talk about it in a way that gives them positive or accurate information.

When you talk to your child about puberty and sex, you can let your child know that sexuality is a normal and private part of life and that he or she can always talk to you about any questions and concerns. To ensure your teen understands how to care for all parts of the body without being embarrassed or ashamed, it's best to provide positive and accurate information.

It's important that parents talk to their teens in a non-judgmental way. Many families find it easier for one parent to discuss puberty and sex, but it is often better for teens if all parents are able to talk about it. It is also best to talk to teens about sexuality and sexual health in multiple, shorter conversations throughout their childhood and teen years as this will let them know that you are always around to listen, talk and provide answers.

For many teens, puberty and the next few years can be very difficult because their bodies are adult-like but their minds are still developing. Often the quick physical changes do not give teens much time to adjust to their bodies and hormones. Many teens are also confused about the different messages they receive from family, friends and media about sexuality, independence and the teen years.

Here are some resources for talking with your teens about sexuality: