Chapter 5: Sports & Nutrition

Nutrition is the science of food and its relationship to health and sports performance. A well-balanced diet is the cornerstone of any athlete’s training regimen.

1. Balanced Diet & Nutrition: Macro & Micro Nutrients

A balanced diet contains adequate amounts of all necessary nutrients required for proper growth, maintenance, and repair of the body.

Macronutrients

Nutrients required by the body in large amounts. They provide energy and structural building blocks:

• Carbohydrates: The primary and most efficient source of energy (4 kcal/gram). Crucial for endurance athletes.
• Proteins: Essential for building, maintaining, and repairing muscle tissues (4 kcal/gram).
• Fats (Lipids): Concentrated energy reserves (9 kcal/gram). Vital for hormone production and absorbing fat-soluble vitamins (A, D, E, K).
• Water: Makes up about 60% of body weight; essential for temperature regulation and metabolic processes.

Micronutrients

Nutrients required in trace amounts. They do not provide energy directly but regulate bodily functions:

• Vitamins: Organic compounds regulating metabolism. Divided into fat-soluble (A,D,E,K) and water-soluble (B-complex, C).
• Minerals: Inorganic elements like Calcium (for bones), Iron (for hemoglobin to transport oxygen), Sodium, and Potassium (for nerve impulse transmission).

2. Nutritive & Non-Nutritive Components of Diet

Nutritive Components: Provide energy and calories (Carbohydrates, Fats, Proteins). Non-Nutritive Components: Do not provide energy/calories but are essential for health:

• Water: As mentioned, maintains fluid balance.
• Roughage (Fiber): Indigestible part of food. Soluble fiber manages blood sugar; insoluble fiber prevents constipation.
• Color compounds & Flavor compounds: Makes food aesthetically appealing and appetizing, stimulating digestive enzymes.

3. Eating for Weight Control

Achieving and maintaining a healthy weight requires balancing caloric intake with expenditure.

• Healthy Weight: A weight corresponding to an optimum BMI (18.5 to 24.9), minimizing the risk of lifestyle diseases.
• Pitfalls of Dieting:
  • Skipping meals slows down metabolism.
  • Extreme caloric restriction leads to muscle loss instead of fat loss.
  • Dehydration (“water weight” loss) is falsely perceived as fat loss.
• Food Intolerance: The digestive system’s inability to properly break down certain foods (e.g., lactose intolerance). It is localized to the digestive tract, unlike food allergies which involve the immune system.
• Food Myths: Common misconceptions like “Eating late at night causes weight gain” or “Drinking water during meals is bad for digestion.” Factually, total caloric intake over the day matters for weight, not just the timing.

Competency-Based Questions

Q1. A weightlifter wants to build muscle mass during off-season training. However, his coach notices a drop in his energy levels during workouts.

a) Which macronutrient should be the primary component of his diet for building muscle tissue?
b) If the weightlifter consumes 150 grams of protein, how many total kilocalories (kcal) of energy is he deriving strictly from protein? Support your answer mathematically.

Answer: a) Proteins are the primary macronutrient required for building, maintaining, and repairing muscle tissues.

b) 1 gram of protein yields exactly 4 kilocalories of energy. \[ E = \text{mass in grams} \times \text{caloric content per gram} \] \[ E = 150 \times 4 \] \[ E = 600 \text{ kcal} \] The weightlifter derives 600 kcal from protein alone.

Q2. During a long-distance marathon, an athlete collapses due to extreme muscle cramps and an inability to sweat properly.

a) Identify the specific non-nutritive component and the specific micronutrient (mineral) the athlete is most likely deficient in during the race.
b) A typical resting metabolic rate implies a baseline energy requirement. If a person consumes solely water and fiber for two days, explaining using metabolic principles what pitfall of dieting this implies.

Answer: a) The non-nutritive component missing is Water (leading to dehydration and lack of sweating). The specific micronutrients (minerals) missing are Sodium and Potassium (electrolytes whose depletion causes severe muscle cramps).

b) Consuming solely water and roughage provides zero caloric energy. This extreme caloric restriction is a major Pitfall of Dieting. To meet the baseline Resting Metabolic Rate, the body is forced into a starvation mode where it begins breaking down lean muscle mass (catabolism) to extract glucose and energy, fundamentally lowering the overall metabolic rate and weakening the individual physically.