The word is in: interval training works to increase fitness and calorie burn, enhance mood, and provide beneficial change to musculoskeletal and cardio vascular systems. It can also help you break through plateaus! I’ve been using it with several of my clients—and the results don’t lie.
The fitness industry has long battled over high intensity interval training (HIIT) versus continuous aerobic exercise as to which garners greater benefits. To clarify the difference: HIIT, or it’s laid-back cousin MIIT (moderate intensity interval training), involves repeated bouts of high or moderate intensity efforts that range from about 6 seconds to 4 minutes, followed by varying amounts of recovery time. Continuous aerobic exercise is as it sounds: exercise (e.g., running, biking, swimming) that lasts more than 20 minutes and is held steady for the duration. A long-held belief has been that to improve cardiovascular fitness, you had to increase the volume or duration of exercise in this way—longer runs, walks, or bike rides, more time on the treadmill or elliptical machine, etc.
However, the latest research holds that HIIT and MIIT can bring about improved measures of fitness and greater calorie burn in less time, compared with high-volume continuous exercise. Another plus: it helps with fat loss while preserving precious muscle tissue. Other benefits of interval training include:
- Improved VO2 max (i.e., aerobic capacity, or the optimum rate at which the heart, lungs, and muscles can effectively use oxygen during exercise), linked to enhanced protection from heart disease (ref).
- Positive effects on visceral fat and subcutaneous fat loss (ref).
- Improved HDL cholesterol (the good kind) (ref).
|Interval training has been around for a while, as early as 1912. Then, a famous Finish long-distance runner, Hannes Kolehmainen, used interval training in his workouts. A recent research article reports, “As the knowledge of HIIT increased, exercise scientists demonstrated that this type of exercise not only provides performance benefits for athletes and improves the health of recreational exercisers, but it may also be a suitable alternative to endurance training, or continuous aerobic exercise.” (Zuhl and Kravitz. HIIT vs. continuous endurance training: battle of the aerobic titans. IDEA Fitness Journal, Feb. 2012).|
Though continuous aerobic exercise is a good place to start, I will gradually incorporate intervals into clients’ cardio workouts to help them achieve their goals more efficiently. Several of my clients have used interval training in different ways toward different ends. Lil incorporated interval training on the treadmill by cranking it up for 4 minutes, then recovering for 4 minutes, or using incline to increase intensity. She did this using both “built-in” treadmill interval programs and those I designed (she said mine were harder!). Meanwhile, Kate practiced outdoor intervals, gunning for a selected target like a telephone pole or corner, then returning to her base pace—”outbursts” she calls them :). The basic point is to get your heart rate up to between 85% and 90% of maximum for a short duration, followed by recovery or cool-down periods that bring your heart rate back to your regular cardiovascular zone (~50-75% of max heart rate).
Still, continuous aerobic exercise (30-60 min, 3-7 days a week) has a role, since it builds stamina and leads to several other beneficial cardiovascular adaptations, such as:
- Increased cardiac muscle mass
- Greater disposal of metabolic wastes
- More sparing of carbohydrates (thus greater use of fat as fuel).
|A moderate-paced walking program exemplifies a continuous aerobic exercise that lends to long-term weight loss and maintenance. Work up to around 5-7 hours a week for optimal benefit. As always, make sure you have GOOD SHOES. Check out your tread for wear, or better yet, visit your nearest running store where trained employees can help you select the best shoes for your purposes and watch you walk in them. Just do it!|
The bottom line: incorporating a balance of both interval training and continuous aerobic exercise is a “win-win” for optimizing cardiovascular gains and performance goals, such as completing a 5K. That was Lil’s goal, which she’s achieved twice now and is currently gearing up for a third!
Keep moving! — Jen