Short, intense weight training:
Record every workout in detail, including date, time of day, order of exercises, reps, and weight. This is your experiment, so you need to control the variables to accurately assess progress and make adjustments.
Eat more frequently; when you’re underweight you may feel full a lot faster. Eat five to six smaller meals during the day rather than two or three large meals.
Choose nutrient-rich foods. As part of an overall healthy diet, choose whole-grain breads, pastas and cereals; fruits and vegetables; dairy products; lean protein sources; nuts and seeds.
Try Smoothies and Shakes. Don’t fill up on diet coke, coffee and other drinks with few calories and little nutritional value. Instead, drink smoothies or healthy shakes made with milk and fresh or frozen juice, and sprinkle in some ground flaxseed. In some cases, a liquid meal replacement may be recommended.
Watch when you drink.Some people find that drinking fluids before meals blunts their appetite. In that case, it may be better to sip higher calorie beverages along with a meal or snack. For others, drinking 30 minutes after a meal, not with it, it may work.
Make Every Bite Count. Snack on nuts, peanut butter, cheese, dried fruits and avocados. Have a bedtime snack, such as a peanut butter sandwich, or a wrap sandwich with avocado, sliced vegetables, and lean meat or cheese.
If you haven’t done weight training in the past, have a coach show you the correct form to avoid injury. Using heavy free weights at a high intensity can lead to injury if you don’t use the correct form.
Carbohydrates (Very Important)