It has been a week since I started swimming in a long course pool. I am not able to swim more than 50m freestyle at a stretch. I am having issues with stamina at the end of 50m. I swim everyday for 1 hour. How much time will it may take for me to do 200m freestyle? I am male, standing 185 cm tall, and 75 kg in weight.
While your question is somewhat confusing, the most common reason for beginners to get out of breath or tired after a very short distance is usually due to poor form and breathing problems.
The most common beginner mistakes:
- Kicking from the knees, not the hips, with toes that are not pointed back, but instead pointing down at the bottom of the pool. This almost completely negates any forward propulsion from the kick and just wastes energy.
- Letting the elbow drop early, and "sliding" your hand back rather than using it to propel you forward.
- Proper breathing. This is very common, and one of the biggest problems that beginners struggle with. A lot of people hold their breath while their face is in the water, and then try to exhale/inhale during the time their face is exposed. This leads to hyperventilation and early fatigue.
Without being able to see a video, those are the most common things I've seen when teaching adults to swim properly. I would highly recommend that you get with someone that knows how to instruct swimming and have them evaluate you.
I have been teaching people of all ages how to swim for 5 years, and everything that JohnP said is correct. However, there is one thing that most people don't realize--it takes a while to build up swim endurance and stamina (several weeks to months depending on the person/workouts/etc.) and the only way to increase swim endurance and stamina is by swimming.
So get evaluated, like JohnP said, so you know what part of technique you need to work on. But, don't be discouraged when you don't see immediate results.
In addition to the two previous answers by Amanda R. and JohnP, here's another very important point: Keep your head down.
Body position is extremely important in swimming, and your saying that you get out of breath already after less that a 50 tells me that you probably have your legs sinking behind you – as a result of your lifting your head out of the water.
At 185 cm and 75 kg you probably do not have much subcutaneous fat to float on, so every bit of your head that comes out of the water diminishes your buoyancy. If you lift your head, your legs sink, and when your legs sink, drag increases a lot.
Try consciously shoving your head under the water and you'll see that you can float horizontally at the surface with almost no effort. Bring that experience into your swimming.