To get into top physical shape, fuelling your body is as important as training it.
Eating the right foods at the right times can optimize your physical performance and give you a competitive edge.
Though dietary needs vary from sport to sport, one formula holds true: A fitness-friendly diet must contain carbohydrate for fuel, protein to build and repair muscles and fluids to cool the body.
A fit body also relies on meeting daily requirements for vitamins and minerals, some of which change once you hit 50.
Use this nutrition guide to help you stay fit at 50 and beyond.
Fuel with carbohydrate Carbohydrate-rich foods deliver glucose into your bloodstream for immediate energy; the rest is stored in muscles as glycogen - the primary fuel for all types of exercise. The more glycogen your muscles store, the longer you'll be able to continue training before feeling tired.
Include carbohydrate-rich foods such as whole grain bread, pasta, cereal, rice, fruit, legumes and dairy products at all meals and snacks.
During exercise, consume 30 to 60 grams of carbohydrate per hour to help spare muscle glycogen. Sports drinks, energy bars, energy gels, bananas and fig bars work well.
Increase protein Protein needs increase with exercise, but not dramatically. Protein is used to repair muscle tissues and support a healthy immune system.
Endurance athletes require roughly 1.2 grams of protein per kilogram of body weight each day, while strength athletes need 1.3 grams per kilogram.
Good sources include lean meat, poultry, fish, egg whites, legumes, tofu, milk and whey protein. But don't overdo it. There's a limit to the rate at which protein can be synthesized into muscle.
Excess protein will either be burned for energy or tucked away as fat.
Fuel and recover A pre-workout snack, eaten one to two hours before exercise, can help reduce muscle-tissue damage from weight training.
After any workout, eat a combination of protein and carbohydrate within 30 minutes, and again two hours later, to help your muscles recover, grow and re-energize.
Smart choices for pre- and post-workout snacks include yogurt and fruit, an energy bar or a small sandwich with lean protein. If you opt for a protein shake, mix it with a source of carbohydrate such as milk, soy beverage or unsweetened fruit juice.
Drink up Drinking adequate fluids is essential for top athletic performance. Even slight dehydration can cause early fatigue during exercise. Every day, women should consume nine cups (2.2 litres) and men 13 cups (3 litres) of fluid.
While exercising, drink 125 to 175 millilitres of water every 10 to 15 minutes. Sports drinks are recommended during exercise that lasts longer than one hour to help replace lost fluid and electrolytes. They also deliver glucose to working muscles for energy. After exercise, replenish lost fluids by drinking 500 millilitres of liquid for every pound of body weight lost.
Boost calcium At 50, daily calcium requirements increase from 1,000 milligrams to 1,500 milligrams. Getting enough calcium - along with a daily 1,000-IU supplement of vitamin D - will help maintain strong bones and prevent stress fractures.
Unless you're drinking five cups of milk a day (1,500 milligrams of calcium), you'll need to rely on supplements to ensure an adequate intake.
Get vitamin B12 Turning 50 also affects your vitamin B12 status. B12 is a nutrient that helps convert protein and carbohydrates into energy that muscles can use. Even a small deficiency can result in reduced performance and recovery.
Studies suggest that up to 30 per cent of people over 50 may not produce enough stomach acid to properly absorb B12 from foods. The daily recommended intake is 2.4 micrograms.
Include iron Men and women require eight milligrams of iron each day to help maintain high energy and concentration. Good sources of iron include red meat, enriched breakfast cereals, whole grain breads, dried fruit, legumes, tofu and nuts. A daily multivitamin and mineral supplement will also help you meet daily iron needs.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. www.lesliebeck.com.