Try to do strength exercises for all of your major muscle groups on 2 or more days per week for 30-minute sessions each, but don’t exercise the same muscle group on any 2 days in a row.
Don’t hold your breath during strength exercises. Holding your breath while straining can cause changes in blood pressure. Breathe in slowly through your nose and breathe out slowly through your mouth.
Gradually increase the amount of weight you use to build strength. Start out with a weight you can lift only 8 times. Use that weight until you can lift it easily 10 to 15 times. When you can do 2 sets of 10 to 15 repetitions easily, add more weight so that, again, you can lift it only 8 times. Repeat until you reach your goal.