No Time To Exercise? Do Interval Training Then!

“I would like to exercise more but I just don’t have enough time!”, I’ve heard this excuse so many times in my life that it is has become one of the few things that really gets to my nerves. Fortunately (for me) the "lack of time" excuse has been blown away by a research published in The Journal of Physiology.
The study, from scientists at Canada's McMaster University, adds to the growing evidence for the benefits of short term high-intensity interval training (HIT) as a time-efficient but safe alternative to traditional types of moderate long term exercise. Surprisingly, it is possible to get more by doing less!

Evidence

HIT means doing a number of short bursts of intense exercise with short recovery breaks in between and according to the published study HIT produced the same physiological adaptations in the body and improvements in performance as continuous cardio at a moderate pace. "We have shown that interval training does not have to be 'all out' in order to be effective," says Professor Martin Gibala. "Doing 10 one-minute sprints on a standard stationary bike with about one minute of rest in between, three times a week, works as well in improving muscle as many hours of conventional long-term biking less strenuously.”
Another study published in the American Journal of Clinical Nutrition found that those who practiced high-intensity interval training for 15 weeks had a reduction in subcutaneaous fat that was nine times greater than those who performed steady-state cardio workouts for 20 weeks.
And the list goes on and on.

HIT are for everybody

The researches at McMaster University have already shown in a previous study that HIT produces the same physical benefits as conventional long duration endurance training despite taking much less time.
However, their previous work used a relatively extreme set-up that involved "all out" pedaling on a specialized laboratory bicycle.
The new study, instead, used a standard stationary bicycle and a workload which was still above most people's comfort zone, about 95% of maximal heart rate, but still only about half of what can be achieved when people sprint at an all-out pace.
This less extreme HIT method may work well for people (the older, less fit, and slightly overweight) whose doctors might have worries about them exercising "all-out."
We have known for years that repeated moderate long-term exercise tunes up fuel and oxygen delivery to muscles and aids the removal of waste products.
Running or cycling for hours a week widens the network of vessels supplying muscle cells and also boosts the numbers of mitochondria in them so that a person can carry out activities of daily living more effectively and without strain, and crucially with less risk of a heart attack, stroke or diabetes.
But the traditional approach to exercise is time consuming.
This study shows that the same results can be obtained in far less time with brief spurts of higher-intensity exercise.
To achieve the study's equivalent results by endurance training you'd need to complete over 10 hours of continuous moderate bicycling exercise over a two-week period.
The "secret" to why HIT is so effective is unclear. However, the study by Gibala and co-workers also provides insight into the molecular signals that regulate muscle adaptation to interval training. It appears that HIT stimulates many of the same cellular pathways that are responsible for the beneficial effects we associate with endurance training.
The upside of doing more exercise is well-known, but a big question for most people thinking of getting fit is: "How much time out of my busy life do I need to spend to get the perks?"

Be sure to hit the right heart rate intensity

What you want to be sure of is hitting the right heart rate intensity. The most common mistake with HIT is not going hard enough on the effort and not going easy enough during recovery.
You need the juxtaposition of near maximum and minimal effort because this produces the desired physiological response.
After a perfectly executed interval routine, your body experiences the so-called excess post-exercise oxygen consumption. During this stage your body tries to catch up with the oxygen demand put on it during the session.
The body tries to return to homeostasis and the harder it has to work to return, the more calories your body burns to get you there.
As a general rule, you should aim to work between 85 and 90 percent of your maximum heart rate on intense bursts and you’ll need a heart rate monitor to eliminate the guesswork.
To calculate your max heart rate use 220 minus your age if you’re a man and 206 minus 88 percent of your age if you’re a woman.
Then recover for as long as it takes you to get back down to 60-70 percent of your max.
It’s crucial to have a solid aerobic foundation so you know your joints can tolerate the intensity of interval training and your body can call on the appropriate fuel to burn during exercise like fatty acids.
Also, having a solid base will ultimately help you go at higher intensities for longer while buffering more lactic acid, which means you’ll get much more from your interval training.

Considerations

“I have no time to exercise” is no longer an excuse, everybody can find 30 to 45 minutes everyday to train and do some HIT.
I personally do it at least twice a week: I run 30 seconds at maximum speed and recover for three minutes; ten times for a total of 35 minutes training, which is really nothing compared to the results I get!

The Iron You