You should train 2-3 days per week for strength using multi-joint, compound movements. Do 4-6 reps per set and aim for 3-4 sets for each exercise. Train movements that cover the entire body-squats, deadlifts, presses, rows, pulldowns, or pullups- and split them up across the 2-3 days. Add a little weight to the bar each time you train. If you’re experiencing pain, reduce the weight on the bar, change the range of motion, or switch to an exercise that closely resembles the one that hurts. Don’t go to failure. Add in cardio 1-2 days per week to round out your physical development using low impact options like biking, rowing, sled pushing, an elliptical, or a versaclimber.
Now add the word “usually” to each sentence. Yes, most of the time that’s a great way to train- until it isn’t. There are times you should go to failure. There are times when you should perform different exercises. There are times when an injury may not be solved by exercise alone. There are times when you can’t add weight to the bar and need to do more reps or sets or something else. Individuals have different responses to training. Adjust accordingly.