Whipping Your Pulse Into Shape

A high-intensity workout builds endurance quickly - for ski racer Carlo Janka just as much as for heart patients
Some athletes call it the "puke programme". I can already guess why during the first interval. I'm sitting on the exercise bike, giving it full gas, at 180 watts. My heart-rate monitor shows 167 beats per minute - 6 more, and my heart would be at its limit.
"Come on, come on," Michael Vogt, sports scientist at the Swiss Health and Performance Lab (SHPL) in Bern, cheers me on, "you've done two minutes already." Only two minutes! I still have two more to go, and then four more, and four more, and
four more. 4 x 4 minutes flat out, with only three minutes' rest between each interval - there's no way I can do this, never.
Elite athletes are putting themselves through such high-intensity training (HIT) more and more often. They want to build their endurance - with minimal time investment. Even the first heart patients are pushing themselves to their limits with flat-out intervals. These are meant to get the cardiovascular system going better than long, slow forest runs. And strength athletes, too, have
recently started embracing the HIT principle. The motto for lifting iron: short, sharp, right up to the pain threshold (see box).

Janka, Gini, Viletta suffered for two weeks - with success
Vogt and his colleagues are convinced that HIT pays off quickly. In 2008, they made sure that three of the best Swiss ski racers built a high-intensity HIT block into their summer training for the first time: Carlo Janka, Marc Gini and Sandro Viletta completed eight to ten HIT sessions over two weeks, followed by two weeks of low-intensity endurance training. After the four-week slog, the top athletes could take in eleven per cent more oxygen on average than before. "A crazy effect in such a short time," says Vogt.
How much oxygen is maximally available to the muscles is a measure of endurance capacity - and this, too, needs building in ski racing. Vogt recommended HIT, the turbo-training. Because skiers with their packed training and race calendars have no time for conventional endurance programmes with high volumes.
The idea behind HIT is not entirely new. More than 60 years ago, Olympic champion and long-distance runner Emil Zatopek was already using high-intensity intervals to get into shape. His motto: make training hard, and competition gets easier. His torture programme: 60 x 400 metres. At a conference on HIT recently held at the German Sport University (DSHS) in Cologne, HIT was seen as a rediscovered form of training. "The effects are now being systematically studied for the first time," said Joachim Mester, training scientist and rector of the DSHS. In the last two years alone, there have been more than 100 HIT studies.
The Bern sports scientists presented the first data from their study of 23 Swiss junior skiers in Cologne: 13 had completed 15 HIT sessions in eleven days, 8 trained conventionally. The HIT athletes outperformed the control group subjects on many parameters. Both their oxygen uptake capacity and their performance had improved more. In addition, the HIT athletes' blood volume had increased by ten per cent, compared with "only" three per cent in the control group.
Studies with footballers, gymnasts and swimmers were also presented in Cologne. Cologne sports scientists had young swimmers complete 60-minute HIT sessions each. The comparison group trained for 90 minutes at moderate intensity and swam two kilometres more per session. After five weeks, the HIT athletes improved their 2000-metre time by 21 seconds; the swimmers in the comparison group, by contrast, finished only 14 seconds faster.

Heart patients take in 46 per cent more oxygen
HIT gets you fit, that much is undisputed. Even so, everyone in Cologne agreed that all the old training wisdom shouldn't be thrown out now. "We need to integrate HIT sensibly into existing training," says Vogt. And so people are currently searching
in each discipline for the most effective training protocols.
The 4 x 4 formula is well suited to HIT: four minutes each at 90 to 95 per cent of maximum heart rate, followed by three minutes of rest with light movement each time. Or: 20 x 15 seconds of exertion, each interrupted by 15 seconds of rest. Vogt: "One- to three-minute intervals don't put enough strain on the cardiovascular system. Endurance isn't improved that way." How you push yourself to the max doesn't matter: hill runs or an obstacle course both work.
"Come on, come on, 20 seconds to go," shouts Vogt. My lungs are wheezing. I wrench at the handlebars and grit my teeth through it, somehow. "Great, the first round's done," Vogt praises me. He holds a "how-hard-was-that-for-you scale" under my nose. I point to 19; 20 is the max. Rest. Pedal easy.
By now, the effects of HIT have also been studied on ordinary people like me. In a Canadian study, in which
one group trained their endurance on the long-and-slow principle (10.5 hours over two weeks) and the other with HIT (2.5 hours over two weeks), the gains in performance and the muscular changes were roughly the same in both groups. The cardiovascular system, on the other hand, adapts better the more intense the load, it was said in Cologne. Studies show, in particular, that HIT increases stroke volume and makes the arteries more elastic.
No wonder, then, that the first heart patients in rehab studies are now also whipping their pulse on the exercise bike almost to the max. Norwegian doctors had several patients, who had survived a heart attack and had since suffered from heart failure, complete a twelve-week HIT block. After the training, the HIT-hardened patients could take in 46 per cent more oxygen than before; in the comparison group, who had trained long and slow, it was only 14 per cent. Stroke volume, moreover, only increased in the HIT group. Similar studies have already been carried out with patients who had undergone heart surgery for circulatory disorders.
Among cardiologists, the data have sparked a debate about the intensity of cardio training. Heart patients have long been advised to do endurance training. "Long and slow" has been the motto up to now. This can significantly lower the death rate.

"In the long run, nobody does that voluntarily at home"
"We still favour that approach," says Josef Niebauer, cardiologist and sports physician at Salzburg University Hospital. "We don't do HIT with our patients." For three reasons: the higher the intensity, the greater the likelihood of heart rhythm disorders. In the worst case, that ends fatally. Niebauer also finds interval training not very practical. "It's not much fun. In the long run, nobody does that voluntarily at home." And thirdly, it's not yet clear whether HIT has a lasting effect or whether it improves quality of life.
For fitness enthusiasts and recreational athletes who want to save training time or improve their marathon time, however, Niebauer has nothing against the occasional HIT session. "Provided they're healthy," he says. "A heart check including a stress test at the doctor's is essential beforehand." It's best to train under guidance the first time, recommends sports scientist Vogt. "That way you know what it's supposed to feel like."
For me, it feels like a "19" after every interval. Towards the end of the last interval, I even feel slightly sick. But I make it: 4 x 4 minutes "flat out". My lungs are burning, I'm completely wiped out, but satisfied. And even before I can speak again, Vogt gives me this assignment: "You'll do this three times a week now, for four weeks. After that, we'll test how much more oxygen you can take in." What a resolution for the new year.

Sources: Sabine Olff - Sonntagszeitung, 3.1.2010