High-Intensity Interval Training Is Time-Efficient and Effective, Study Suggests

ScienceDaily (Mar. 12, 2010) — The usual excuse of "lack of time" for not doing enough exercise is blown away by new research published in The Journal of Physiology.

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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. Astonishingly, it is possible to get more by doing less!

"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."

HIT means doing a number of short bursts of intense exercise with short recovery breaks in between. The authors have already shown with young healthy college students that this produces the same physical benefits as conventional long duration endurance training despite taking much less time (and amazingly, actually doing less exercise!) However, their previous work used a relatively extreme set-up that involved "all out" pedaling on a specialized laboratory bicycle. The new study used a standard stationary bicycle and a workload which was still above most people's comfort zone -about 95% of maximal heart rate -- but 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 among us) 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. Exercise also improves the way muscles use the oxygen to burn the fuel in mitochondria, the microscopic power station of cells.

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. Martin Gibala and his team have shown 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?"

Martin Gibala says "no time to exercise" is not an excuse now that HIT can be tailored for the average adult. "While still a demanding form of training," Gibala adds, "the exercise protocol we used should be possible to do by the general public and you don't need more than an average exercise bike."

The McMaster team's future research will examine whether HIT can bring health benefits to people who are overweight or who have metabolic diseases like diabetes.

As the evidence for HIT continues to grow, a new frontier in the fitness field emerges.

Latest Research

Extreme obesity affecting more children at younger ages

(Electronic health records used to study 711,000 children)

March 18, 2010 (Pasadena, Calif.) – Extreme obesity is affecting more children at younger ages, with 12 percent of black teenage girls, 11.2 percent of Hispanic teenage boys, 7.3 percent of boys and 5.5 percent of girls now classified as extremely obese, according to a Kaiser Permanente study of 710,949 children and teens that appears online in the Journal of Pediatrics.

This is the first study to provide a snapshot of the prevalence of extreme obesity in a contemporary cohort of children ages 2 – 19 years from a large racially and ethnically diverse population using the recent 2009 U.S. Centers for Disease Control and Prevention extreme obesity definition. Previous research was based on recent National Health and Nutrition Examination Survey (NHANES) data and included information on obesity but not extreme obesity.

"Children who are extremely obese may continue to be extremely obese as adults, and all the health problems associated with obesity are in these children's futures. Without major lifestyle changes, these kids face a 10 to 20 years shorter life span and will develop health problems in their twenties that we typically see in 40 - 60 year olds," said study lead author Corinna Koebnick, PhD, a research scientist at the Kaiser Permanente Southern California's Department of Research and Evaluation in Pasadena, Calif. "For example, children who are extremely obese are at higher risk for heart disease, type 2 diabetes, fatty liver disease and joint problems, just to name a few."

Researchers used measured height and weight in electronic health records to conduct a cross-sectional study of 710,949 children ages 2 – 19 years in the Kaiser Permanente Southern California integrated health plan in 2007 and 2008. Children in the study had an average of 2.6 medical visits per year where height and weight were measured.
The study found that 7.3 percent of boys and 5.5 percent of girls were extremely obese, translating into more than 45,000 extremely obese children in this cohort. The percentage of extreme obesity peaked at 10 years in boys and at 12 years in girls. The heaviest children were black teenage girls and Hispanic boys. The percentage of extreme obesity was lowest in Asian-Pacific Islanders and non-Hispanic white children.

According to the recent CDC recommendations, extreme obesity is defined as more than 1.2 times the 95th percentile, or a body mass index (BMI) of more than 35 kilograms/meter squared. Obesity is defined as more than the 95th percentile or a BMI of more than 30 kg/m2. Overweight is defined as more than the 85th percentile or a BMI of more than 25 kg/m2. The BMI is a reliable indicator of body fatness and calculated based on height and weight. For children, BMI percentiles are the most commonly used indicator to assess the size and growth patterns of individual children. The percentile indicates the relative position of the child's BMI number among children of the same sex and age.
"Our focus and concern is all about health and not about appearance. Children who are morbidly obese can do anything they want -- they can be judges, lawyers, doctors -- but the one thing they cannot be is healthy," said study co-author Amy Porter, MD, a Kaiser Permanente Baldwin Park pediatrician who leads the Pediatric Weight Management Initiative for Kaiser Permanente's Southern California Region.
"The most important advice to parents of extremely obese children is that this has to be addressed as a family issue. There is rarely one extremely obese kid in a house where everyone else is extremely healthy. It's important that everyone in the family is invested in achieving a healthier lifestyle," Porter said.

"This publication is only the beginning. Now we are trying to quantify the health risks and long-term effects associated with extreme obesity, determine which groups are affected most, and develop strategies for population care management to reduce these health risks. Children's health is important and we have a long way to go," Koebnick said.

More fruits & veggies!

This past weekend, I conducted a family workshop.  It was my first one and I wanted to make it positive about good things to eat instead of limiting the bad stuff.  So one of the goals was to bring about an awareness of fruits and vegetables - and how to get kids (and their parents) to eat more.  Did you know that only 2% of our kids in U.S. consume the recommended daily allowance on a regular basis?!  As a parent, I struggle with how to do this without resorting to tricks (i.e., hiding vegetable and fruit puree in other foods or covering it in Ranch or cheese sauce).  I want our daughter to LIKE fruits and veggies.  And the only time tested way to do this, is continual exposure.  One of the handouts I used comes from the "Healthy Kids Challenge" http://www.cigna.com/pdf/parents/5aday.pdf.  The handout includes a weekly chart for checking off the number of different colors of fruits and veggies that you eat.  We're on day 4 of using the chart and our daughter, who likes accomplishing challenges, has eaten at least 5 servings of fruits and vegetables (one day it was 9).  We only count fresh produce - no juices.  Let me know what works for you - or if you use the chart, how's that working?  I'm going to go eat my grapefruit now...

Join the movement to stop childhood obesity

As you probably know, the number of obese and overweight children and teens have doubled and tripled, respectively, in the past 30 years.  For the first time ever, the lifespan of our children is expected to be shorter than ours.  Here's a website with lots of information and links to other sites for helpful ideas, stats, etc.  http://www.letsmove.org/   What do you think?  How can we help locally?

Spring Break Schedule

Monday - regular schedule except 10 a.m. Barre None is cancelled
Tuesday - regular schedule
Wednesday - closed except for the 10 a.m. Barre None class
Thursday - closed
Friday - closed

Asian Chicken Salad

Here's another easy recipe....

3 chicken breasts
1 small head of bok choy (or 1/2 of a large), thinly sliced
1/4 cup finely chopped cilantro
3-4 scallions, sliced on the diagonal
3 carrots, grated
4 TBL low sodium soy sauce
4 TBL seasoned rice vinegar
2 TBL sesame seed oil
4 TBL slivered almonds

Poach the chicken breasts in enough water to cover. Poach at least 10 minutes until cooked through. Cool and shred. Toss bok choy, cilantro, carrots, and scallions. Add chicken. Make dressing using a 2:1 ratio of the soy sauce/rice vinegar to the sesame seed oil. Lightly dress the portion of salad you will eat. Top with some almonds that have been lightly toasted in a dry frying pan.

According to nutritiondata.com the recipe analysis is as follows for 4 servings: 275 Calories/serving, 22% carbohydrates, 33% fat, 45% protein

Food Synergy

We all know which foods are good for us but some foods are even better when eaten in combination. For example, more of the iron in spinach is absorbed when ingested with a vitamin C-rich food such as citrus. Here are some combos that work synergistically:

Spinach + citrus fruit (increases iron absorption)
Tomatoes + broccoli (greater cancer-fighting qualities when eaten together)
Vinegar + sushi rice (decreases glycemic index by as much as 35%)
Tomatoes + healthy fat (the body absorbs more of the carotenoids in the tomatoes)
Vegetables + any healthy fat (increases absorption of the phytochemicals)
Herbs and spices + meat (reduces the levels of harmful cancer-causing compounds produced by grilling by 88% - so include herbs and spices in the marinade!)


Here's an easy spinach salad that we could call the "Synergy Spinach Salad"

Spinach leaves
Red onion, thinly sliced
Grapefruit or Strawberries or Mandarin Oranges
Feta Cheese, lightly sprinkled
Dress with orange juice (yes, just orange juice from the juice pitcher or freshly squeezed)
a few grindings of black pepper

Even my daughter eats this salad though she leaves the onion behind.