Endurance, in basic terms, is your ability to perform heart-rate raising activity for more than three consecutive minutes. To increase your endurance quickly, you must incorporate healthful behaviors that enhance all of the body systems that play a role in converting the food you eat to energy your cells can use. Furthermore, you must include behaviors that make it easy for your body to regulate the intake of oxygen to your lungs, the exchange of oxygen and carbon dioxide, the transport of oxygen to your working muscles and the removal of cellular waste from your muscles.
Consume a meal with complex carbohydrates, lean protein and healthy fats before your endurance workout, giving your body sufficient time to digest your food; this meal ensures you will have enough energy to exercise for a longer duration, thus providing the stimulation your muscle cells need to increase your endurance.
Wear a beverage belt or keep a beverage bottle nearby to take small sips of a carbohydrate-rich sports beverage; exercise beverages consumed throughout your endurance workout provide your body with an immediate supply of simple sugars, or glucose, so you can exercise longer, increasing your endurance quickly.
Incorporate a 10- to 15-minute light warm-up mimicking your endurance activity prior to beginning your training, thereby increasing the blood flow and tissue temperature of your working muscles; your body becomes more efficient at converting cellular energy into mechanical energy and removing cellular waste so you can perform for a longer duration in a short period of time.
Add five to 10 minutes to each training session, increasing your endurance in a short amount of time; your body adapts by creating more capillaries and producing more enzymes to convert food energy into mechanical energy, enhancing your ability to exercise for a longer duration.
Include one short but intense aerobic workout once a week to enhance your endurance, such as increasing your pace every four minutes for one minute for a total of 30 minutes; this aerobic interval workout forces you to train at a harder pace, enhancing the cardiovascular adaptations so you can increase your overall endurance in a short time.
Refrain from excess resistance training exercises that include heavy or high-volume workouts because such exercises are contradictory to increasing your endurance. Do incorporate one to two weight-training exercises for each major muscle group to strengthen your muscles. Complete three sets of 15 repetitions using moderate weight to help augment your endurance training.
Exercise Physiology, Energy, Nutrition & Human Performance; William McArdle et al.