Is it permissible for women to go to swimming pools?
Question

I am a Muslim woman aged twenty-eight years, and I want to go swimming so that I can lose some weight. Can I go swimming in a swimming pool wearing clothes that cover me from the top of my head to the bottom of my feet? There are special clothes for Muslim women who want to swim and they cover the entire body, but they cling to the body when wet. What does Islam have to say about this? What if I wear a towel over these clothes and cover myself beforehand and straight after coming out of the pool? Is it permissible for me to swim in this case? Is it permissible for me to swim if there are some men present?.
Praise be to Allah.Islam takes complete care of the Muslim woman and preserves her modesty, conceals her and keeps her away from places of fitnah (temptation). 
Islam enjoins women to stay at home and not go out unnecessarily, so as to preserve their chastity, maintain their dignity and protect them from all evil. 
Muslim women going out to public centres and swimming pools is something that is emphatically forbidden, because it involves a number of evils and negative consequences. 
If these swimming pools are in public centres that are frequented by men and women, this is a great evil. Abu Dawood (4010) and at-Tirmidhi (2803), who classed the report as hasan, narrated from Abu Maleeh al-Hudhali that some women from Syria entered upon ‘Aa’ishah and she said: Perhaps you are the people whose women enter bathhouses? They said: Yes. She said: I heard the Messenger of Allah (blessings and peace of Allah be upon him) say: “There is no woman who removes her clothes anywhere other than her house, but she has torn (the screen) that is between her and Allah.” 
Classed as saheeh by al-Albani in Saheeh at-Tirmidhi. 
At-Tirmidhi (2801) also narrated from Jaabir (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) said: “Whoever believes in Allah and the Last Day should not let his wife enter bathhouses.” Classed as hasan by al-Albani in Saheeh at-Tirmidhi. 
What is meant by bathhouses here is the kind of bathhouses that existed in the past (hamaam or “Turkish bath”), because houses did not have bathrooms at that time. 
The reason why women were forbidden to enter them is because of what happens in them of uncovering the ‘awrah, looking at that which is haram and exposure to fitnah (temptation), although bathhouses at that time were not mixed. 
So what about bathhouses that are mixed and public swimming pools in which ‘awrahs are uncovered and exposed? The scholars of the Standing Committee for Issuing Fatwas said: 
For men and women to swim together and then shake hands with one another after swimming is a great evil and it is not permissible to do it. The one who does that should be denounced and the ruler should prevent them from doing it.
End quote from Fatawa al-Lajnah ad-Daa’imah, 17/49 
If these swimming pools are only for women it is not permissible to go to them either, even if that is less serious than public baths. That is because women uncover their ‘awrahs, and even if the Muslim woman covers her body she will see those naked women and she will not be able to tell them not to do this evil action. 
The scholars of the Standing Committee for Issuing Fatwas were asked: 
I am an engineer working in the holy city; my job is in the building permits department. A citizen has submitted to us a plan for a health centre offering natural remedies, with two sections, one for men and one for women. After studying the drawings and plans it was noted that there is a large swimming pool in the women’s section. The project manager was informed that this swimming pool is not permissible, because swimming requires women to take off their clothes and then put on tight clothes that, even if they do not show her ‘awrah, will show the shape of her body, and as is well known it is not permissible for women to uncover the ‘awrah among other women. So we explained to the project manager that, by way of blocking the means to evil and warding off evil consequences, he should not build this swimming pool because it was highly possible – especially nowadays – that among the workers would be someone who did not fear Allah, even among the women, and might take pictures of the women in secret, whether with a regular camera or a video camera such as is available nowadays. This would cause a great of trouble and would turn this centre from being a centre for healing to a centre of corruption and fitnah. And it is well known that everything that leads to haram is also haram. 
We hope that you can clarify the Islamic ruling on such cases. 
They replied: 
It is not permissible to build a swimming pool for women in the centre mentioned, because warding off evil takes precedence over bringing benefits. 
End quote from Fatawa al-Lajnah ad-Daa’imah, 26/342-343 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) was asked: 
We live in a residential neighbourhood where there is a women’s centre; at this centre there is a swimming pool for women and a sauna. What is the ruling on women going to this centre? 
He replied: 
My advice to my brothers is not to let their women go to swimming pools and sports clubs because the Prophet (blessings and peace of Allah be upon him) encouraged women to stay at home. Moreover, if a woman becomes accustomed to that she will become very attached to it because she is subject to her emotions, and in that case she will become distracted from her religious or worldly duties and she will always be talking about these activities in gatherings. And if the woman does such things that will be a cause of her losing sense of shame and modesty, and if a woman loses her sense of shame and modesty do not ask about the evil consequences except for the one whom Allah blesses by guiding her and enabling her to regain the modesty that was taken away from her. 
I will close my message by repeating my advice to my believing brothers not to let their daughters, sisters, wives or other female relatives under their guardianship go to these centres or clubs. 
End quote from the shaykh’s fatwas for ad-Da‘wah magazine no. 1765/54 
This is not the only means of losing weight; there are many permissible means of doing so and there are other types of exercise that the Muslim woman can do if she adheres to Islamic guidelines. 
For more information please see the answer to question no. 115676 
And Allah knows best.