How To Get Fit With 3 Minutes Of Exercise A Week: BBC Doc Tries "HIT"

New research revealed on a BBC TV Horizon programme broadcast in February 2012, suggests it is possible to improve some measures of fitness with just 3 minutes of exercise a week. Medical journalist Dr Michael Mosley, like many people, is not a great fan of exercise for its own sake, and set out to find how little he would need to do to get fit. And he discovered some surprising facts about health benefits of HIT, or High Intensity Training.

Challenging Current Thinking

"It goes against everything I was taught in medical school, and everything I have ever read since", gasps Mosley to camera, as he completes a vigorous bout of pedalling on a stationary exercise bike while scientists look on.

Mosley, who trained as a medical doctor before moving into journalism and broadcasting, introduces the one-hour programme, "The Truth About Exercise", by saying that what he discovered about exercise, thanks to the latest research, has challenged his view, and altered the way he lives his life.

High Intensity Training

A main theme of the TV programme is High Intensity Training (HIT), where you do a number of shorts bursts of intense and effortful exercise with short recovery breaks in between. 

HIT is not new, but has come to prominence in recent years as more researchers have looked into and measured its health benefits.

There are various forms of HIT, depending on the intensity and duration of the effortful bursts, and your fitness goals.

(The HIT in this article is not to be confused with another type of workout also called HIT: a strength-training made popular in the 1970s by Arthur Jones, now practised by many bodybuilders, where you work with weights and perform sets of repetitions to the point of momentary muscle failure.)

Recent HIT research shows, for example, that doing ten one-minute sprints on a stationary exercise bike with about one minute of rest in between, three times a week, is as good for improving muscle as many hours of less strenuous conventional long-term biking.

Professor Martin Gibala and his team at McMaster University, Hamilton, Ontario, Canada, carried out a study on college students, and discoverd HIT delivers the same physical benefits as traditional endurance training, even though it takes considerably less time, and surprisingly, involves doing less exercise.

Types of HIT

In Gibala 's student study, the participants had to pedal at their maximum possible effort level on a specially adapted lab bike. The thinking then was that "all out" was an important part of the HIT method.

But then, in 2010, Gibala and colleagues published another study in The Journal of Physiology, where they showed how a less extreme form of HIT worked just as well for people whose doctors might be a bit worried about them adopting the "all out" method, for instance those who might be older, less fit and overweight.

In that form of HIT, the workout was still beyond the comfort zone of most people (about 95% of maximal heart rate), but was only half of what might be regarded as an "all out" sprint.

On the BBC programme, Mosley tries a form of HIT developed by Jamie Timmons, professor of ageing biology at Birmingham University in the UK. In Timmons' form of HIT, the bursts of high intensity are at maximum effort, but of very short duration (20 seconds at a time).

Timmons told Mosley, who was doing no weekly exercise at the time, that he could expect to see improvements in a number of measures of health if he did just three minutes of HIT a week, for four weeks.

Simple Program

The HIT program he asked Mosley to follow was quite simple and can be done on a standard exercise bike:

1. First, you warm up for a couple of minutes with some gentle cycling: then you cycle as fast as you possibly can ("hell for leather", as Mosley describes it) for 20 seconds.

2. Then, you cycle gently again for a couple of minutes while you catch your breath, then do another 20 seconds "flat out".

3. Then, for a final time, two minutes gentle cycling to catch your breath, followed the third period of 20 seconds at "full throttle".

And that's it. Do this HIT program three times a week, and you have a total of 3 minutes a week of intensive pedalling, and about 6 minutes of gentle pedalling.

Mosley said he was somewhat sceptical, but he did as Timmons instructed: he followed this HIT program for four weeks, totalling 12 minutes of pedalling at "full throttle" and 36 minutes at a gentle pace.

Insulin Sensitivity

Timmons had tested Mosley for a number of health indices before he started, and then, after his 4 weeks of HIT, Mosley went back to the lab to be re-tested.

A main test was for insulin sensitivity. Mosley was particularly keen to see this result as his father had been a diabetic and had died from complications linked to the disease.

When they measured Mosley's insulin sensitivity before he started his HIT exercise regime, the result showed he was just inside what would be regarded as healthy tolerance.

Timmons told Mosley that research from a number of centres shows that doing 3 minutes HIT a week can improve insulin sensitivity by 24%. And this is exactly the amount by which Mosley's own index improved.

But bigger improvements than this have also been recorded, albeit with a slightly different HIT regime.

A 2011 study by Gibala's group at McMaster published in Medicine & Science in Sports & Exercise found a 35% improvement in insulin sensitivity after only two weeks. 

Their sedentary volunteers (average age 45) had done no exercise for over a year, and only had to work at 60% peak power (80- 95% of heart rate reserve). Their biking regime was 10 times 60-second bursts of intense pedalling with 60 seconds of recovery time in between each, performed three times a week (the whole workout, including 3 minutes of warm-up and 5 minutes of cool -down, lasting less than half an hour).

Insulin sensitivity is important for keeping blood sugar or glucose stable. When you eat, your digestion starts putting glucose into your bloodstream. This causes the pancreas to release insulin, a hormone that triggers body tissue to absorb circulating glucose. 

If your insulin sensitivity reduces, the pancreas has to release more and more insulin to keep blood glucose levels stable. 

Abnormally low insulin sensitivity is known as insulin resistance, a condition that results in high levels of insulin, glucose and fats circulating in the bloodstream. It is a main risk factor for metabolic syndrome, which increases the risk for coronary artery disease, stroke, and type 2diabetes.

It is not clear how HIT affects insulin sensitivity, but Timmons, and some other scientists that Mosley spoke to, suggest it could be because HIT uses many more muscles than conventional aerobic training.

HIT engages 80% of the muscles of the body, compared to up to 40% during moderate jogging or cycling. HIT engages not only leg muscles, but also the muscles in the upper body, such as the arms and shoulders. 

One of the effects of exercise is to break down glycogen in muscles. Glycogen is a stored form of glucose. The theory is that removing stores of glycogen makes way for fresh glucose to be deposited from the bloodstream. So the more muscle tissue that come under this influence, the more space that is available for new glucose deposits.

Aerobic Fitness

There are some things that HIT will not necessarily do for you. For example, in Mosley's case, it didn't improve his aerobic fitness, the other main health index that Timmons and colleagues tested. 

The scientists said the reason Mosley's aerobic fitness did not improve after HIT was because of his genes. A genetic test, taken before he did the HIT, predicted that no matter how much exercise he did, his aerobic fitness was unlikely to improve to the same extent as someone whose genes resemble those of Olympic gold medallists.

The evidence that ties aerobic fitness to health shows that one of the best predictors of a healthy long life is the body's ability to take in and use oxygen while we are exercising maximally. The more blood the heart pumps around the body, the more oxygen our muscles use and the lower our risk of disease and early death.

And that is why aerobic exercise is promoted as important to health. The UK government's guidelines for instance, say people should do 150 minutes of moderate, or 75 minutes of vigorous, exercise every week. (While this is what the guidelines state, it appears that more than three quarters of Brits don't attain this level).

Thus biking, brisk walking, swimming, running, endurance training, are all promoted as moderate to vigorous aerobic workouts that increase the body's ability to take in and use oxygen, something the scientists measure as VO2 max: the maximum volume of oxygen used during exercise. The higher a person's VO2 max, the more resilient they are to illness.

But new research is begining to show that perhaps this does not work for everyone.

In 2010 the Journal of Applied Physiology published a large study, led by Timmons, that showed although aerobic exercise can and does increase VO2 max, it varies, according to genetic make-up.

In a large sample of hudreds of people, all following the same supervised aerobic exercise regime several hours a week for months, there was a spectrum of results, ranging from some who experienced little or no increase in VO2 (the non-responders) to those who showed a huge benefit (the high-responders).

Timmons and the very large international group of researchers, concluded that in the case of the non-responders, it is unlikely that aerobic training results in lowering their risk of heart disease and other chronic illnesses.

They discovered they could predict, by looking at just 11 genes in a person's genome, where they will fit on the spectrum of non- to high-responders. Apparently, around 15% of the population are non-responders, and around 20% are high-responders.

The Link Between Exercise and Health Is an Individual Thing

A group of experts is currently reviewing the UK government guidelines for exercise. On the BBC Horizon programme, Timmons, a member of the expert group, told Mosley the problem with the current guidelines is they don't take into account the variation in individual response to exercise, so there is no guarantee that following such a regime will actually give you the right results.

Mosley said his experience of HIT, and what he learned about the research Timmons and colleagues were doing linking genes to exercise response, made him rethink a number of things about exercise: such as, the more you do, does not necessarily mean the more you benefit. 

In the same way that technological advances in genome research are moving us into an era of personalized medicine, perhaps we are also moving toward an era of personalized exercise, says Mosley.

What we are learning is that the link between exercise and health is an individual thing. Methods like HIT are useful, because very quickly, without spending a lot of time and effort, you can find out what works for you, and what doesn't, and fine-tune a program that you can fit more easily into your lifestyle.

Warning

A word of caution: as always, before you take up a new form exercise, if you have any medical conditions, please talk to your doctor about it first. 

For instance, in the case of HIT, if your doctor thinks it is OK for you to try it, be sure to discuss whether the very high or moderate intensity form is more appropriate, and be clear about the benefits you may reasonably expect.

Young Athletes: Injuries And Prevention

High profile events like the Olympics bring the hope that witnessing and celebrating dedicated athletes at the top of their game, will inspire young people to take up sport and physical activities that help them develop confidence, lead more satisfying lives, and not least, secure long-term health by reducing their risk for developing chronic illness like diabetes, obesity, cancer and cardiovascular diseases.

But unfortunately, if they don't take appropriate measures, young athletes can instead, end up in pain, on a different path to poor health, due to avoidable sport injury. 

James R. Andrews, a former president of the American Society for Sports Medicine (AOSSM), said in May this year, the US has experienced a tremendous rise in the number of young people taking up sport. Estimates show 3.5 million children aged 14 and under receive medical treatment for sport-related injuries, while high-school athletes account for another 2 million a year.

"This makes sports the leading cause of adolescent injury. Along with time away from school and work, these injuries can have far-reaching effects," said Andrews.

This article looks at some of the common and less common injuries in young athletes. It then reviews a new project that is tracking injuries in Olympic athletes, introduces some ideas about avoiding and minimizing injury, and finishes with a list of tips for preventing sport injury in children.

Common Sport Injuries

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, which is part of the National Institutes of Health in the US, the most common sport injuries are due to accidents, poor training practices or using the wrong gear or equipment. People can also hurt themselves because they are not in shape, or because they don't warm up or stretch enough.

Some injury experts in the US have said they are also seeing more and more young athletes injured because of overuse and doing too much, and this may partially explain the growing numbers that drop out of sport by the eighth grade. The most common sports injuries are:

• Knee injuries,

• Sprains and strains,

• Swollen muscles,

• Achilles tendon injuries,

• Pain along the shin bone, and

• Fractures and dislocations.

While injuries in young athletes are similar to the ones that affect adults, they can't always be treated in the same way because their bodies are not fully developed. 

Take for example knee injury.

One type of knee injury is damage to the anterior cruciate ligament (ACL). This is a severe injury that occurs most often in athletes who play football and other contact sports. 

Twenty years ago, doctors were seeing few children or adolescents with ACL injuries. Today, these injuries are more common because youngsters are taking up sports earlier, and pushing themselves more competitively.

Another reason for the rise in young people with ACL injury, say researchers from the Hospital for Special Surgery (HSS) in New York City, is that more and more young athletes are specializing in one sport, putting them at risk of injuries normally only seen in professional athletes.

But this type of knee injury in young people is a particular concern because it is not easy to repair in growing bodies, for instance ACL reconstructive surgery that works well in adults can potentially cause uneven limb length or other deformities in growing bodies. That is why often the best course has been "benign neglect". However, clinicians are beginning to realize that not operating can also lead to problems, such as early arthritis.

There are alternatives to conventional ACL reconstructive surgery, that have lower risk of damage in growing bodies, such as the All-Inside, All-Epiphyseal ACL Reconstruction (AE), but this is not commonly available.

Clinicians are calling for more research to be done into sports injuries in younger people.

Back and Neck Injuries

Back and neck injuries are much less common in young athletes, but when they occur, they can cause enormous frustration. The athlete must complete a comprehensive and demanding rehabilitation program before returning to competitive sport: in some cases, they may never return to their given sport.

Most back and neck injuries in athletes are sprains of ligaments or strains of muscles. Aside from trauma, these are usually due to athletic overuse, improper body mechanics and technique, being out of condition, or not stretching enough. The athlete will complain of back pain when active and performing, and will feel relief when resting.

But, occasionally, a more serious condition can have similar symptoms. Because of this, proper treatment of back and neck injuries in young athletes should always include a good evaluation by a doctor, using imaging studies when necessary.

According to the North American Spine Society, the more serious back and neck injuries include:

• Spondylolysis and spondylolisthesis: a particular type of defect in the vertebra of the spine (spondylolysis), and where one vertebra slips relative to another (spondylolisthesis). A common cause of back pain in young athletes, particularly gymnasts because they have to twist and hyperextend their spines.

• Stinger (also called "burner" or "nerve pinch"): where forcing the head back and to the side compresses a nerve of the spinal cord in the neck, or where forcing the head sideways away from the shoulder over-stretches the nerves in the neck and shoulder. Most common in football and wrestling, the injury often goes unreported because symptoms can resolve suddenly and quickly. Can recur and lead to persistent pain or arm weakness if not treated.

• Disc injury: a common cause of back pain in adult athletes, much less so among young athletes, it may or may not be associated with sciatica (shooting pain down the leg). Careful diagnosis, including MRI scans, can help to rule out other possible causes that can mimic disc injury in young bodies that are still growing.

• Scheuermann's Disease or juvenile kyphosis: another common cause of back pain in young athletes during puberty that occurs in the mid- as opposed to the lower-back, and leads to a roundness of the back that worsens to a dome shape on bending forwards. Exercises are often not enough to correct this disease, and if wearing a brace does not relieve the pain, surgery may be required, after which it is unlikely the athlete will be able to resume their given sport.

Research on Olympians: the Injury and Illness Performance Project (IIPP)

Although you can't completely eliminate injury and illness, you can look at ways to reduce the risks. This is the purpose of an ambitious and comprehensive national multisport study called the Injury and Illness Performance Project (IIPP).

Beijing 2008 was the first time the International Olympic Committee gathered data on multisport injury, and the Great Britain (GB) squad showed itself to be the best prepared, recording the lowest average injury rate.

Shortly after Beijing, the UK Sport Research & Innovation Team and the English Institute of Sport (EIS) set up the country's first national multisport injury and illness epidemiological study of its kind.

The project started collecting and examining data in 2009 and is still ongoing. Medical and coaching staff from sports national governing bodies send in detailed information about the occurrence of injury and illness in athletes, and their exposure to risk in training and competition.

Rod Jaques, Director of Medical Services at EIS, says it is important to understand the nature of illness and injury incidence before putting in place new treatments.

14 Olympic sports are involved in the study, each with their own set of data on injury incidence, illness prevalence, and associated risk factors. And each sport has a specific set of recommendations for reducing the risk of injury or illness.

Injury-related results from the project show that since 2009:

• 67% of interruptions to training for British athletes from Olympic sports have been because of injury.

• 43% of athletes will get at least one injury per season, some will have several.

• On average, each injury results in a loss of 17 days of training, and 1 missed competition.

• The rate and severity of injury during training is lower than during competition.

• Overall, injuries to the knee, shoulder, hip and lumbar spine present the greatest risk, and the greatest number of total days lost.

EIS Sports Physician Kate Strachan says that the project is a powerful tool because you can turn to an athlete and say, "you have lost X days due to injury last season". This is just as important to take notice of as making sure you have the best kit and training environment and coach.

Paul Jackson, another EIS Sports Physician, works with pentathletes. He says the information on the link between some lower limb injuries and training load has helped them change injury prevention drills. For some pentathletes, "this means not running and fencing on the same day," he adds.

Debbie Palmer-Green, a Research Scientist at the EIS, says the project signifies a new approach that views injury and illness as "performance threats".

Prehab to Avoid Rehab

Prehab, short for prehabilitation, is a relatively new idea in sports medicine and therapy. It is a personalized exercise program that is individually designed for athletes to help them prevent injury in their given sport.

(There is also another use of the term prehab that refers to improving patients' fitness before undergoing surgery so they make a quicker recovery and can withstand the inactivity that often follows the procedure).

A prehab programme is becoming a regular part of an athlete's training routine

The aim of prehab is to avoid injury by compensating for the repetitive movements and stresses of regular, often daily, training. In some respects, you can view athletic training for peak performance in a sport as a form of repetitive strain, with the potential to result in injury in much the same way as computer operators can get occupational injuries like carpal tunnel syndrome and shoulder problems.

With repetitive use, muscles become tight, the body develops imbalances in strength and muscle coordination. These happen naturally during activity, but because training is repetitive, they become repeatedly reinforced with each workout, unless that workout also incorporates some compensating activity, such as in a prehab routine.

A common problem in athlete training is that many athletes and coaches follow the traditional methods of upper and lower body lifting, or basic sprinting and lifting exercises, as a way to develop strength outside of the specific sport drills. But this can leave the core weak in comparison. A prehab program in this case would start with core stability, perhaps focusing on hips, stomach and back core. 

Once the basic core program is in place and working, the prehab is updated to include more subtle and focused movements that increase dynamic stability and improve skills in the given sport.

To ensure the best chance of success with prehab, the athlete should start practising it before injury occurs. But unfortunately the usual route to prehab is via injury. A typical scenario is the athlete injures him or herself, goes to a sport therapist or specialist trainer for rehabilitation (rehab), and the therapist then persuades them to sign up for prehab to stop it happening again.

Another way to keep prehab useful and working for the athlete, is to ensure it continually evolves with the needs and changing fitness and ability of the individual. The exercises should be progressive and re-evaluated regularly. There is also the important need to challenge and motivate the athlete, and stop them becoming bored, or habituated to the program.

A successful prehab program is one that forms a regular part of an athlete's training routine. The therapist needs to have a detailed knowledge of the athlete's sport, their strengths and weaknesses, and be able to have frank, open conversations with the individual.

Focus on Body's Imbalances

Stew Smith, graduate of the US Naval Academy, former Navy SEAL, and author of several fitness and self defense books, advocates prehab as a way to prevent common injuries of daily life and sport.

He says, to be specific, a prehab program must focus on a person's body imbalances. There are many natural imbalances in the body:

"Basically, for any movement your body makes," says Smith, "there are two or more groups of muscles or joints that are stretching (or flexing) to make (or oppose) that motion." 

Most imbalances, says Smith, occur in the following regions of the body:

• Abdomen/lower back: too many people when working out, focus on stomach muscles and neglect lower back.

• Chest and upper back/rear shoulder: many young athletes try to "bench press a truck" but neglect their upper backs and rear deltoids. This can result in shoulder injury and a sloping upper back.

• Thighs and hamstrings: you need a very delicate combination of exercises so the backs of the legs don't get underworked. Hamstring injuries usually occur when sprinting or jumping, and usually the upper side of the hamstring gets injured. A smart rehab program would include stretching that incorporates the top and bottom of the hamstring connections.

Tips for Injury Prevention in Young Athletes

The American Academy of Pediatrics recommends the following:

• Time off: take at least 1 day off a week to give your body time to recover.

• Take breaks: during practice sessions and games to reduce risk of injury and prevent heat illness.

• Use the correct gear: this should be right for the sport and fit properly, for instance pads for neck, shoulders, elbows, chest, knees, and shins, as well as helmets, mouthpieces, face guards, protective cups, and/or eyewear. And don't assume because you are wearing protective gear you can perform more dangerous and risky things.


Drinking regular fluids should be an important part of your exercise regime.

• Drink plenty of fluids: before, during and after exercise or play to avoid heat illness; wearing light clothing also helps. Coaches and trainers should reduce or stop practices or competitions when heat or humidity is high.

• Build muscle strength: do your conditioning exercises before games and during practice to strengthen the muscles you use during play.

• Increase flexibility: by stretching before and after games and practice.

• Use the proper technique: coaches and trainers should reinforce this during the playing season.

• Play safe: coaches and leaders should enforce strict rules against headfirst sliding (eg in baseball), spearing (football), and body checking (ice hockey), and stop the activity if there is any pain.

They also advise coaches and parents to consider the emotional stress that the pressure to win can cause for a young athlete, and recommend they adopt these principles:

"Young athletes should be judged on effort, sportsmanship and hard work. They should be rewarded for trying hard and for improving their skills rather than punished or criticized for losing a game or competition. The main goal should be to have fun and learn lifelong physical activity skills."