14? Weight train 5 days a week ad 15 minutes of boxing a day. Hm. What kind of weight training are you doing? A split routine - meaning say arms, chest, neck back and abs Monday, Wednesday, Friday and legs Tuesday and Thursday or are you training the whole body each and every day? If you are training the whole body (hitting each muscle every day) Stop it. Weight Training is not the actual muscle building period, it is the period which strips and tears and ripps the muscle, the 24 to 48 hours after the training is were the real muscle building takes place and should be a period of NO extra stress on the muscle to get the maximum results. Ideally a split routine goes with low weight high reps - it is linked with definition and endurance training. There is some muscle bulking, however the main goal is to increase the body's ability to move weight over a greater period of time. This is a form of Cardio exercise, you are increasing the heart rate and keeping it up over a longer period of time. Bulking or "mass" building is high weight, low reps and is essentially targeting the major muscle groups one right after the other causing the body to be able to move higher weight over a short period of time. It also leads to the greater growth of muscle since thicker muscle fibers can lift more weight (heavier loads). This is not very cardio-like and should be supplemented with a cardio exercise. Ideally Mass building should be done one day, then a cardio should be done the next. Both are burning energy, if you expend all of your energy in the weight training, then you do not have the energy to get an effective cardio for that day. Different people respond to different periods of "rest" between workouts. The Average is 48 hours - two days, however some get impressive results with a three day rest period between workouts especially with mass building. Lets assume you are doing a mass training program and are incorporating boxing and running into your work-out. Monday, Wednesday and Friday - Full body workout with weights. Tuesday OR Thursday boxing 20 to 30 minutes - building up more time. The alternerate day should be running. Thus if you pick Tuesday for boxing, then Thursday should be running. Saturday either running or boxing. In fact each week you could switch between the two, providing variation in your routine to a point. Carbohydrates are important too your routine. Basically you need to eat higher carbohydrate load 20 to 300 minutes before any exercising. Carbohydrates are foods that convert into sugars, sugar is the body's source of energy - basically gasoline for the body. Carbs convert slowly to sugars, releasing them slowly and steadily into the blood stream giving you an added energy boost over a longer period of time. This means you will have the energy to perform your exercises longer and even better. you need to think in the terms of a diabetic, http://www.mendosa.com/gi.htm Provides useful information on the glycemic index. The type of foods are explained, you want to steer away from things like corn syrup, sugar based sodas, instead you want to eat things like rice or potatoes 20 minutes prior to your work out - by that time the food is being converted into sugars and you will hae abundant energy to perform. Rest is essential. There is such a thing as too much exercise which can have the opposite effect, meaning lose of muscle mass, loss of strength. Rest between workouts and kinds of workouts even passing on amy work out for a day can be more beneficial than pressing yourself to do more exercise. The Idea behind weight training is to exhaust the muscles. You do x number of reps to where the last rep your muscle fails - or is unable to complete the rep. since you are doing that with each muscle group you are training you are exhausting the body and should not have the energy (and some times not even the will) to follow up with ahead cardio like running or boxing. For boxing and running to be effective they should be on their own day you should start off small, just a few minutes and gradually over the weeks build up your time and in the case of running/jogging distance. The idea is not so much as to totally exhaust yourself, but to get the heart rate up and keep it up over a period of time. You should not be drop down on the floor tired after such exercises, a little tired, but with enough energy too walk around, to move to cool over by stretching and walking gradually. As time progresses you will be able to go further and longer.