High-intensity interval training (HIIT) is among the top fitness trends reported by the American College of Sports Medicine over the past two years. And thanks to the increasing popularity of programs like P90X and CrossFit, HIIT will likely remain at the top of that list for years to come. That's why recognizing the importance of recovery is crucial for people taking up a HIIT program. “Recovery is not a suggestion,” says 30-year fitness veteran Irene Lewis-McCormick, author of The HIIT Advantage: High-Intensity Workouts for Women.
Known for quick, challenging workouts that maximize time and efficiency, HIIT increases metabolism and aerobic capacity, strengthens muscles, and increases weight loss. But as Lewis-McCormick emphasizes, overtraining can be very detrimental. Not only can it lead to injury, but it can also result in burnout and have significant negative long-term effects that interfere with a lifestyle of exercise. “Fitness and performance enhancement require a complex combination of overload and adequate recovery,” she says. “Too much overload and too little recovery will likely result in both physical and psychological signs and symptoms of overtraining.”
Overtraining results from performing exercises that are above and beyond one's tolerance, or beyond the body's ability to recover. Exercising longer and harder without the benefit of recovery will do exactly the opposite of what the training program is designed to do—that is, it will increase the risk and likelihood of injury and decrease performance. Lewis-McCormick points to a number of signs and symptoms that may determine whether someone is overtraining and not giving themselves enough recovery between workouts:
- Consistent muscle pain and soreness
- Fatigue that doesn't diminish with sleep
- Elevated resting heart rate
- Decline in maximal heart rate
- Increase in number of colds and sore throats
- Loss of appetite
- Increased incidence of injuries
- Compulsion to exercise
- Loss of enthusiasm for training or sport
- Drop in performance
“You can use your resting heart rate for signs of overtraining,” Lewis-McCormick explains. “For three consecutive mornings, document your resting heart rate. It should stay relatively consistent from morning to morning. Try to take it at the same time each morning. Any marked increase from the norm may indicate that you aren't fully recovered. If your resting heart rate begins to rise and you experience other overtraining signs or symptoms, you may be heading into overtraining.”
All successful athletes know that rest and recovery between training sessions are critical for optimal, high-level performance. The body strengthens and repairs itself in the time between workouts, and continual training without the benefit of recovery will weaken even the strongest athlete. Likewise, fitness enthusiasts need to realize that adequate recovery between workouts is mandatory for reaching fitness goals without experiencing burnout and increasing the risk of injury. However, Lewis-McCormick concedes, many still overtrain, feeling guilty when they take a day off. “Rest days are critical to performance,” she stresses. “Practicing both short and long-term recovery, as well as planned recovery using periodization, will result in a better balance between lifestyle and fitness goals.”
As the authoritative guide on high-intensity training, The HIIT Advantage is comprehensive yet accessible, describing how and why HIIT is one of the most effective ways to burn fat and improve performance. It includes 19 complete workouts consisting of a combination of 20-, 30-, and 45-minute sessions, along with exclusive access to the HIIT Advantage video library.