The Science of Strength Training - Part 3
Good nutrition is a crucial part of a strength training program. Training with weights creates the stimulus; your diet provides the raw materials for building muscle. Eating the right foods will increase your energy levels, maximize your gains in the gym and improve your health. It will also provide the fuel and fluids needed for intense training, speed up your recovery after training, reduce fatigue and help achieve a healthy body composition.
Nutrition for Strength Training
Proteins
Protein is important for muscle growth. Heavy strength training stimulates an increased uptake of amino acids from the bloodstream. These amino acids are then built up into new contractile muscle proteins, actin and myosin.
To build muscle you need to take in more protein than you excrete – i.e. be in a positive nitrogen balance. A deficiency will result in slower gains in strength, size and muscle mass, or even muscle loss – despite hard training. However, there is not a linear relationship between protein intake and muscle growth. Muscle growth depends not only on your protein intake but also on the intensity of your training (i.e. the training stimulus) and your genetic potential for muscle growth.
In practice the body can adapt to variations in protein intake. Over time the body becomes more efficient in conserving it so you break down fewer muscle proteins during intense training. This is often sufficient to maintain an anabolic environment and induce muscle growth. One study found that the protein requirement/kg body weight of advanced strength trainers was 40% less than that of novice strength trainers.
How much?
It is generally recommended that athletes need 1.5 – 2.0 grams/kg body weight/day of protein compared with the recommended daily allowance (RDA) of 0.75 grams/kg body weight/day for the general population. Divide your protein intake into five or six meals spaced out every 3 hours. Aim to include 20 – 25 grams protein in each of your meals. Eating this way maximizes protein absorption and minimizes fat storage. Individual protein requirements may vary; depending on the athletes sporting activities and body make up etc.
Too much protein
Consuming more than 1.8 grams protein/kg body weight/day will not make you stronger or more muscular. In a study of strength athletes carried out at McMaster University, Ontario, athletes consuming either 1.4g/kg body weight/day or 2.3g/kg body weight/day experienced similar increases in muscle mass. Those with the higher protein intake gained no further benefits. Once your optimal intake has been reached, additional protein is not converted into muscle.
Which foods?
You should get the majority of your protein from food sources rather than supplements. Animal sources (poultry, fish, meat, dairy products and eggs) generally have a higher biological value (BV) than plant sources (tofu, beans, lentils, nuts and cereals). However, if you eat a mixture of animal and plant sources, you will get more amino acids as well as a better range of other nutrients (fiber, vitamins, minerals and carbohydrate). If you’re trying to gain muscle mass but want to keep body fat under control, choose lower-fat protein sources like skinless poultry, low-fat dairy products and protein powders.