Though this was a programme for my wife, the same thing applies to most people new to training and at 15 you need time to build tendon and ligament strength too, a programm similar to this will certainly help you start packing on the muscle and will hopefully help you get there injury free, you see so many relative novices start to lift too heavy too soon and that results in injury then you have to take 2 steps back whilst you recover
"As a personal trainer (insert your comments here

), i see a lot of beginners to the gym being shown small isolation exercises and 10 to 15 rep sets, when what they really need is a balanced routine thats designed to start building strength not only in the big muscles, but in the proprioceptive muscles (the muscles used to balance) , tendons and ligaments. It also needs to be progressive, with a learning curve on intensity.
My wife started lifting weights about 6 months ago, when she started in the gym we stuck to one exercise per bodypart.
Chest - Barbell bench Press
Back - Lat Pulldowns (would change this to bent barbell rows now)
Shoulders - Dumbell shoulder Press
Legs - Squats (deep at least to parallell)
Arms - Dumbell extensions and dumbell Curls
These exercises were chosen so that there was a certain amount of proprioception needed.
We trained the same workout 2 times per week doing 2 sets of eight to 12 reps. When 12 reps was reached we increased weight until only 8 reps was manageable and worked up.
Approximately 4 weeks in to this we increased to 3 times per week and 3 sets, still continuing with the 8 -12 rep sysytem
Then after about 4 weeks again we changed the system slightly, by this time my wife was beginning to understand about intensity in her training, so we went to a split routine
We now train tuesday, thursday, saturday, tuesday, with an upper body, lower body workout, meaning that every 3rd workout has a longer rest period.
We have also included a second, isolation, exercise for the larger muscle groups.
The Important thing is the constant increase in intensity, either by increasing weight or reps
So since her training has started the weights have increased to the point that she is lifting, not only more than most of the women in the gym but more than what half of guys lift.
This In my mind is the ideal way to begin the training of a total beginner
Once training has continued for atleast 6 months the newbie would have built a muscle base, strengthened tendons and ligaments and have a working knowledge of lifting weights correctly.
Then the fun can begin, here we can go towards HIT, high volume, 5x5, 10 x 10 etc etc. Depending on which area you want to progress into (powerlifting, bodybuildine, strongman, strenght sports, general health etc)
So Start slowly, build strength in the muscles tendons and ligaments, learn proper exercise technique, learn how to continually progress and raise the intensity level and from purely a training perspective you will see muscles and strength grow.
Of course to continue there are other things like Diet, proper nutrition and supplementation, rest etc, but thats another post

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