Do you have to be in good shape to tolerate high-intensity short interval training?
High/intensity short/interval training is a type of exercise that stresses the body hard for a very short period of time. In other words, it is hard exercise, but you don’t have to spend much time doing it.
That you don’t have to spend much time exercising appeals to most people, but you may wonder if you can tolerate it. Is it safe to exercise this way if you are not in great shape?
The reviewed research should answer that question, but make up your own mind after reading this.
It may surprise you that anybody would even try this with people in the shape that they were. The researchers took patients with signs of chronic heart failure and had one group do high/intensity short/interval training, and had another group do the regular continuous aerobic exercise training(Koufaki P et al. 2014).
The program lasted for 6 months and the participants were tested for cardiorespiratory fitness at the start and at the end.
Peak oxygen uptake, sit to stand and gait speed improved equality in both groups, no difference in results.
The researchers concluded that the training adaptations were achieved in the high intensity short interval training group despite a significant reduced time commitment and reduced work volume when compared to continuous aerobic exercise training.
There is really no reason to waist time exercising for a long period of time unless you enjoy the exercise itself. The high intensity training was also tolerated well.
Maybe it should not be a surprise that people with heart failure can exercise like this.
Years ago people were advised not to do any exercise after they had a heart attack, believing exercise would increase their risk for another heart attack. That has been changed because we know better now, that exercise is one of the things that will help prevent heart problems.
Physical ability test rates the likelihood of dying.
Who knew that even at the age of 53 you can get an idea about your risk of dying without doing extensive laboratory testing. Put another way, it can give you an indication of how likely you are to achieve a long and healthy life.
The reviewed research tested 1355 men and 1411 women at age 53 and followed them for 13 years(Cooper R, et al. 2014). The three tests consisted of grip strength, chair rise speed and standing balance time. The chair rise speed was done by timing how long it took to rise from a sitting position to standing with straight back and legs, and then sit down again 10 complete times as fast as possible.
The results suggested that the participants that were in the lowest one-fifth when it came to performance were almost four times as likely to die during the follow up compared to the ones in the highest one-fifth. The participants that were not able to do any of the tests were more than eight times more likely to die than the best performers.
This shows how important it is to stay in good shape even at middle age. Keep in mind that these tests, even if they were testing physical ability, also reflected on the biochemistry of the body, since balance is affected by receptors and the health of the nervous system. The nervous system is again affected by free radicals related to the food we eat and our lifestyle.
Can exercise be dangerous?
We have all heard that exercise is healthy and it is, but is it healthy for everybody and are all types of exercises healthy?
This is what you need to know.
When lifelong competitive endurance veteran athletes were compared with younger endurance athletes and control age-matched participants, they were found to have myocardial fibrosis which is abnormal changes to the heart muscle(Wilson M,et al. 2011).
This finding was significantly associated with the years spent training, the number of competitive marathons and ultra endurance marathons completed.
Keep in mind that this was hard endurance training and extreme endurance competition over a lifetime, it does not mean that exercise is not good, it just means that this type of activity does not seem to be the best.
Another study compared participants with coronary heart disease with different levels of physical activity(Mons U,et al. 2014). They found that participating in strenuous endurance exercises more than 5 hours per week increased cardiovascular mortality. Exercising less than twice per week also increased the risk.
What does this all mean? It means that it is important to be sure you get enough recovery time, and long hours of endurance training is not the best way of spending your time. You are more likely going to reap more benefits if you do high intensity, short interval training and include some resistance training the other days.
One of the important things to keep in mind is that recovery from the exercise is as important as the exercise itself. Without proper recovery it just adds stress.
Is reducing your salt intake really that healthy?
We don’t need the same amount of salt all the time. Why is that?
When it is hot and we perspire more, or when we exercise and perspire more, we lose more salt which needs to be replaced. On days like that, we need to eat more salt. One of the reasons why runners sometimes get cramps is because of a high salt loss and not enough salt intake to compensate.
The reviewed research is interesting because it looked at salt intake and mortality related to all cause mortality and cardiovascular disease events(Graudal N,et al. 2014). Looking at data from 25 studies it was found that both low salt intake and high salt intake are associated with increased mortality.
This makes sense. Before you cut out all salt, make an assessment of how much you perspire and take into consideration what your blood pressure is.
If your blood pressure is high and your ankles are swollen, obviously you may need to reduce your salt intake. On the other hand if you perspire a lot because you exercise and your blood pressure is normal, you probably don’t need to reduce your salt intake.
High intensity exercise is best, but what kind?
I have written about high-intensity short-interval training several times, because more and more research is teaching us how to maximize our exercise benefits. Research has proven that it’s a very effective way of exercising. So how can you use this principle when exercising to get the best results?
The secret is revealed in the reviewed research.(Cochran AJ,et al. 2014). These researchers compared:
- High-intensity short interval training performed on a stationary bike, done either for 30 seconds with 4 minutes of rest in between intervals repeated 4 times.
- One set of continuous exercises that were matched for total energy output and required 4 minutes to complete as fast as possible.
Strangely enough, even though energy output was the same, the results were not!
After the first exercise session both protocols produced similar increases in markers of AMPK, p38 MAPK and PGC-1alpha mRNA expression. These are proteins related to mitochondrial energy production in muscles. These proteins were also measured after six weeks of exercising three times per week. Here are the surprising results:
The continuous exercise protocol did not produce the same increase in these markers after six weeks as the short interval protocol with rest in between sets did. It turns out that intermittent stimulus is important for maximizing muscle adaptation.
If you want maximum results from exercise it needs to be short, very intensive intervals. You need rest in between the intervals to recover.
When you exercise this way your actual exercise time will be very short, only two minutes per session.
Walk fast to get help with with weight loss.
Walking has been promoted as an easy way to lose weight and stay in shape, but is it really effective? That is exactly what the reviewed researched investigated.
The participants a total of 4511 adults aged 18-64 years were included in the study(Fan JX, et al. 2013). The body mass index (BMI) were measured and accelerometers were used to evaluate minutes per day of high intensity bouts of walking of either 10 minutes or more, or less than 10 minutes. This was compared with lower intensity walking of 10 minutes or more per day and lower intensity walking of less than 10 minutes per day.
It was found that both higher intensity short-duration or walking long-duration were related to reduced BMI or risk of overweight/obesity. Neither the short walks or the long walks of lower intensity were found to have a positive effect on BMI or risk of overweight/obesity.
The message is that even less than 10 minutes of walking per day can help you prevent weight gain if it is high intensity walking. This is another example showing that it is the intensity of the exercise you do that is important, not the time you spend doing it. The more intense you exercise, the less time you need to spend doing it.