HIIT vs HVIT – A Hungry Tiger or Killer Bees?
Intensity takes practice. It takes practice in thought and in body.
For our Primal program, we recommend lots of low-intensity cardio (walking, not running) with brief, high-intensity training (HIT). HIT can focus on strength, cardio, endurance, performance, or power.
One kind of HIT uses intervals of varying intensity and length; you’ve probably heard of high intensity interval training (HIIT). You may even think you’ve done it. You’re probably wrong.
What many of us do is considered chronic exercise — hours of running, cycling, swimming, or gym classes without anything truly intense. If you can do an exercise for an hour with little rest, it is not high-intensity. These steady-state aerobic activities result in a demand for high carbohydrate intake, since liver and muscle glycogen stores are frequently depleted by long duration exercise and insufficient rest periods. This kind of exercise can:
- atrophy muscle
- add fat, despite the sweat (because this exercise pattern promotes carbohydrate intake which diminishes the ability to use fat for fuel)
- cause chronic inflammation (from excess insulin due to carbohydrate intake and from leaving muscle in a catabolic state too long)
But there are many people who avoid high-intensity exercise because they see themselves as unfit and think HIT of any kind is for athletes, marathon runners, or body builders. HIT is for EVERYONE. Everyone healthy, that is. As long as you don’t have a condition in which a high heart rate will cause medical concerns, you can do HIT. In fact, you should be doing HIT. But what kind?
Likely you’ve heard HIIT is a fountain-of-youth because it requires shorter work out times and improves:
- aerobic and anaerobic fitness
- blood pressure
- cardiovascular health
- insulin sensitivity
- cholesterol profiles
- abdominal fat and body weight
But to get these benefits, as well the added post-exercise fat burning (from excess post-exercise oxygen consumption, EPOC), you’ll need to really push yourself for consistent intensity with each interval. High intensities are what provide a post-exercise metabolic response. Despite how HIIT is shared in fitness magazines, HIIT is hard to achieve for average adults for two reasons: most of us do the interval timing wrong and most of us can’t push ourselves hard enough during the work interval.
- Recovery Mistake: HIIT requires longer recovery periods during and after the work out than other forms of training. That is, if you do a high-intensity interval (say push up burpees) for 30 seconds, you should spend about 2 minutes in active recovery (such as walking or surrenders) before the next high-intensity interval. Also, you should limit HIIT to 1-2 times per week and avoid other exercise that taps your fast-twitch muscle, since it can take days or even weeks to recover. This means avoiding power and plyometric moves the rest of the week.
- Consistency Mistake: HIIT requires maximal effort throughout the entire work interval. How many of us can truly exert all-out effort? Those who do likely become amateur or professional athletes. Most of us can push ourselves into discomfort occasionally but rarely into extreme discomfort consistently.
So if we do HIIT, we find ourselves with an unchallenging work out because we don’t go hard enough and have too much time to recover between intervals, or we alter the work out to give us less recovery over longer work intervals, in which case our volume of exercise increases and intensity decreases.
Training at high intensities is about training muscle that uses principally the glycolytic energy pathway (and phospagen). This path provides ATP to the muscles for about 2-3 minutes before it must regenerate sufficiently to tolerate another high-intensity work interval. If sufficient recovery isn’t provided, we can’t maintain intensity of performance (that doesn’t mean we aren’t maintaining high effort).
What constitutes enough time is the real question. Generally, experienced trainers aim for active recovery intervals of two to three times the work interval. The work intervals are usually around 20-45 seconds.
High volume intensity training (HVIT) is what most of us are really doing. It’s moderate intensity, where we reach heart rates around 70-80%.
The disadvantage is that when we adjust the work-recovery period to 1:1 or less, our volume of exercise goes up and our glycolytic process doesn’t recover, leading our intensity to suffer on succeeding intervals. We also run the risk of dropping down and exercising at that steady-state level, where we aren’t challenging our fast-twitch muscle as much as our slow-twitch and staying comfortably in the aerobic zone.
There are advantages to HVIT. Because we can maintain the work out longer than HIIT, we have a greater capacity for fat-burning and muscle-building, as well as improving hormone sensitivity, than we would doing steady-state exercise. And progressing HVIT to HIIT is possible with practice.
Forget heart rate formulas. You can use a heart rate monitor, but that’s a lot of money for an unnecessary gadget ($100 buys a a good set of dumbbells). A simple way to gauge your intensity of performance is to take the Talking Test: if, during the exercise, you can speak only in short words, like “yes” or “no”, and cannot speak whole sentences because you’re breathless and cannot sustain the work for long, you’re doing high intensity. Maintaining exercise during that period is one important step toward better fitness. Start by trying to be at 90% for 5-10 minutes or so. Trained athletes can maintain this state for an hour. (If you feel pain, can’t catch your breath, feel dizzy or nauseated, take a break!)
The difference between HIIT and HVIT is a range, not a number. If you get into a work out where you are not progressively losing your breath, you’re stuck in the aerobic zone. Get out! Go for intensity. It takes practice.
HIIT is like running from a tiger for 4 minutes.
HVIT is like running from a swarm of killer bees for 20 minutes.
Either way, you better live to the last minute, or you haven’t failed in the right way. Because failure is your success!