Body Bootcamp: Former intelligence officer keeps his finger on the IDF’s pulse

Yuval Heled has been tasked with keeping Israel’s soldiers fit and healthy.

Female soldiers from the Caracal Battalion practice evacuating an injured soldier (photo credit: NOA CITY-ELIYAHU / BAMAHANE / ISRAEL DEFENSE FORCES)
Female soldiers from the Caracal Battalion practice evacuating an injured soldier
WHEN IT comes to military technology, Israel has long been acknowledged as among the best in the world, producing systems and weapons designed to give maximum protection to its soldiers and civilians, as well as maintaining an offensive edge over regional enemies.
For a nation whose army is primarily made up of conscripts joining soon after high school, there is a huge weight of responsibility on the Israel Defense Forces to not only train new recruits to the highest possible standards, but also to do everything in its power to reduce potential injuries or loss of soldiers and return them safely to their families after the obligatory two years (for women) or 32 months (for men) of military service.
Lt.-Col. (res.) Dr. Yuval Heled, director of the Institute for Military Physiology, based at the Sheba Medical Center in central Israel, has made it his mission to establish optimal guidelines for soldiers to help save lives and minimize the physical risk factors a soldier might encounter on a daily basis – in training and in combat.
The 48-year-old former intelligence officer, an acknowledged international expert on the study of human physiology in extreme conditions, recently ended his time in uniform but will continue in his key role. He has been a pivotal figure in the development of health policies for the military since 1997 when his work as a scientist and researcher began to be widely acclaimed.
During last year’s war in Gaza, Heled tells The Jerusalem Report, he was in direct contact with commanders, answering queries about soldiers’ physical readiness to continue or carry out missions after having already been in the field for extended periods.
In the United States, where he did his post doctorate at USUHS (the Uniformed Services University of Health Sciences in Bethesda, Maryland), he was recently made an associate professor and received a medal in recognition of his scientific achievements.
He has also had a special research facility dedicated in his name – the Dr. Heled Environmental Chamber – an unprecedented acknowledgement by the US medical fraternity of his innovations, which have benefited not only soldiers from his own country but also those of Israel’s closest ally, as well as impacting the world of sports science.
It was on his first day at his desk as a civilian scientist that I arrived at Sheba where, discreetly tucked away from public view, the laboratories and offices of Heled’s unique research project can be found. The walls of his new office were still bare, and the recently awarded US medal had yet to be given pride of place. It was propped up on the floor awaiting the arrival of a picture hook.
Heled cuts an impressive figure. He looks physically fit, and is a good advertisement for his advice on training regime, diet and lifestyle. He received me in a mercifully well air-conditioned environment. It seemed wholly appropriate that my interview with one of the world’s leading experts on extreme heat tolerance was taking place on a scorching morning where outside temperatures were already pushing up toward 40 degrees Celcius (104 degrees Fahrenheit).
I started by wondering what are the guidelines for soldiers on such a baking-hot day? “On a 40-degree day like today, our policy is that you are forbidden to perform extreme exercise; they can only do light work. We need, though, to divide this into training and into wartime. In wartime, you only need to be aware of the risks. You cannot tell a soldier not to attack or defend because of the extreme heat.
“For moderate heat load and exercise, we recommend about a liter of water per hour.
We also have regulations on how much to eat, how much salt to add after a few hours on a long march, etc. So there are very specific policies,” he explains.
The main focus of his work is how best to prepare soldiers to successfully deal with extreme conditions. Dehydration in a hot environment can be fatal.
“We found out that if you don’t actually tell a person how much to drink during extended exercise, he would not drink as much as is required. If you are doing a routine, short exercise, you cannot become too dehydrated, but most military missions and marches are for hours. This is why you need these policies, otherwise they won’t drink and they’ll dehydrate and increase their susceptibility to heat-related injuries.
“Heat is one of the main issues we deal with,” he says. “We actually have a heat chamber, which we established here a few decades ago, for a heat tolerance test. So, if a soldier has suffered from, or is suspected of having suffered a heat-related injury or illness, according to IDF policies they have to go through a heat tolerance test before being returned to duty. We set this protocol.
“We have physiological criteria. I have been here for 18 years ‒ five years as a commander ‒ during which time I created a finely tuned algorithm. This test is a physiological test working in the heat chamber. Based on all the data we have gained from many tests on the treadmill, we decide according to the criteria if this guy is good to go, or that this guy is out.
“Some guys you can tell just by looking at them; some are overweight, low fitness, big body mass, high fat percentage, but those guys don’t normally go to combat units.
Those that are in the combat units have already been through a natural selection.”
It’s not the less capable, less driven soldiers who may lack motivation who are among those most at risk in extreme heat conditions.
It’s the super-fit, over-motivated soldiers who, according to research at the Institute, can be a high risk to themselves.
“In physiology, we speak about the central governor, which is our brain. When your temperature is high and you are exhausted, what tells you to stop is the central governor.
Those soldiers who are over-motivated, who can be the best athletes or even in special forces, sometimes ignore what their brain is telling them. Sometimes, it can endanger them. This is why we have policies based on the heat tolerance test.”
It transpires that there is still no definitive scientific explanation as to why some people are more heat tolerant than others, even those in peak physical fitness. It’s an area into which Heled is keen to delve further.
“One of my missions is to try and find molecular and biochemical markers and, in the future, genetic markers that will allow us to understand why this happens. This will be a future aid in selecting athletes, and maybe even soldiers. That doesn’t necessarily mean there is going to be genetic selection, but in understanding that there is a genetic difference and understanding what those differences are, we will better be able to select, and most importantly, better able to intervene.
“As a military scientist, I have to give the military answers today. Most of my studies are very practical, very applicative. I need to tell the soldier how to work with NBC (nuclear, biological, and chemical) clothing in the heat, how much exertion they can do, how much rest to take. I need to give answers on how to survive on the battlefield today.”
One area in which Heled believes his research has made a big contribution in saving soldiers’ lives is in his directive for stabilizing soldiers in the field and delaying the standard “Scoop and Run” action of evacuating injured or sick soldiers from the field into a helicopter or ambulance as fast as possible and taking them directly to hospital. Heled has determined that, in the case of heatstroke, this is more likely to endanger the life of the patient than help them and has issued guidelines.
“What happens is that it is important to achieve a target temperature of below 40 degrees. If someone has heatstroke and a 42 degrees temperature and is still breathing, heart beating and so on, the traditional advice was to put him on IV and get him to hospital. This actually causes damage to his brain, his liver, everything. I would say that one of my best achievements has been to delay ‘Scoop and Run.’ We have saved lives.”
Heled’s research showed that by aggressively pouring water – ice is rarely available in the field – onto the patient, the body temperature can be reduced by 0.2 percent per minute. Within a 10-15 minute time frame, body temperature can be sufficiently reduced to enable a far safer evacuation of the patient for medical treatment. The advice, where conditions allow, is not to put the soldier into an ambulance until the temperature is around 38.5 degrees.
“You can have 100 percent success at saving heatstroke cases if you treat them aggressively in the field ‒ assuming that field conditions allow you to do so,” Heled relates.
“When a soldier collapses in the field, he can collapse for many reasons. In our guidelines, we allow the physician to make the decision.
His default is to cool them down, then go to the hospital, but if he has any suspicions that other factors are involved, then the immediate evacuation option is at his discretion. As far as I know, the US military now tends to do the same.”
The question of whether or not female soldiers should be allowed to serve in combat in elite units has been a hot topic in the US for some time and has also been taxing the IDF. There are a number of battalions where women serve alongside male soldiers, such as the Caracal battalion, which patrols Israel’s border with Egyptian Sinai.
I asked Heled how he related to the issue of equal rights for men and women regarding combat roles. He took a few moments to think before answering.
“There are political issues around this. My view, though, is that females can serve in combat units, but up to a certain point where a line should be drawn. Women, in general, are more fragile than men, although some do not like to hear this. But these are physiological facts. Studies have shown that only one percent of women can match the physical achievements of 10-15 percent of men.”
I point out that in the war against ISIS in Iraq and Syria, reports suggest that Kurdish women have proven themselves highly capable of taking on and beating a force that has carried all before it against male armies and militias in the same region.
“Women can be great soldiers,” Heled agrees, “but it’s a cost-benefit question, as well. Do you want to involve the whole selection process to find just one woman capable of joining an elite brigade? Women can serve in the naval commandos, but in order to find this woman – it could be one out of thousands – you might have to injure quite a number along the way as women are up to five times more susceptible to over-use injuries.
Even after doing intensive training they are still more susceptible.
“The bottom line is that you need to take the strongest and fastest people to the battlefield, sometimes involving hand-to-hand combat, who may be required to carry an injured soldier, weighing 100 kilograms, and run with him. This is the bottom line. The military can be a brutal area, and in these areas you should place the people who are best able to survive. We are talking about extreme situations. Some women are definitely capable of doing this and certainly not every man is capable of making it to the commandos.
“Women in Israel and the US do very good field operations, but I would say that on the front line, with the potential of engaging in close combat, I would still recommend leaving things as they are.”
Heled noted that at the time of our discussion no women had completed the elite training course for the US marines or similar units. However, a few days later, two women did become the first to ever make the grade in the US Army Ranger course, joining the 94 men who also reached the required standard on a course that had an overall 75 percent dropout rate. Although the two women are now Ranger-qualified, no woman is eligible to serve in the elite regiment.
The question of just how relevant some of the IDF’s military training is to actual dayto- day soldiering and missions has prompted Heled and his colleagues to reconsider and revise many schedules.
“A few years ago, at the end of training, the parachute and special forces troops were required to do a 120-kilometer march. But then we asked, “When is an Israeli soldier actually required to march 120 kilometers?” The answer: never. So what we have done in the last few years – and this is true also for the Australian and US military – is evaluate to see what the combat mission actually needs you to do, and the training is changing.
“When we allowed females to become pilots, we actually changed the whole basic training of all pilots. Does a pilot really need very extreme physical training? No. So it’s not like women should only do 50 percent.
You need to train all soldiers according to the mission.
“It’s good also for infantry. They might be required to walk for 20 kilometers in the heat and carry a backpack weighing up to 60 percent of their body weight, so take that and match the training accordingly. Studies are now showing that when you reduce the intensity of training, you increase performance and reduce injuries. It’s true you need to have sleep deprivation and other factors, but you don’t need to break them.
So it’s all scientific.”
What changes, then, does Heled foresee in the next 10 years? Will the IDF change noticeably from the army we know today? “We need to delve deeper into the human body and see if we can try and find markers that will help us prevent injuries, to induce performance and have better intervention.
Epigenetics (an area of particular interest to Heled) cannot change the genes you are born with, but if you change your way of life you can turn these genes on and off. Nutrition, education, exercise psychology, and many other things can also help make changes.
Maybe we can change training and nutrition and match it to personal factors and criteria, and change the susceptibility to diseases? “Most of the conferences I’m invited to are sports medicine because everything I do can be applied to athletes. It’s the same physiology, but in the military it is more complicated.
I always say that maximal performance is required of athletes who live in optimal conditions, but we also require soldiers to have maximal performance without living in optimal conditions; getting up in the night for guard duty, living in a tent. It’s easier with athletes. You tell them to sleep eight hours a night, eat this at a certain time, and drink that amount. It’s a lot easier than with soldiers.
“Then there’s the technology. When you think about just six years ago, everything that we have in our smartphone right now an intelligence unit didn’t have then. So where might we go in the next 20 years? We are getting to the stage where, from a physiological point of view, we have achieved almost 100 percent of what a human being can do, so what we are trying to do now is create technology that will assist a soldier.
“You probably know of the exoskeleton that DARPA [the Defense Advanced Research Projects Agency of the US Department of Defense] was trying to develop to make a soldier see faster, move faster and react faster.
Now, we have all kinds of medical devices that help us monitor a soldier remotely, telling us if he is alive, if he is tired, to increase his performance in external situations. From my point of view, this is the future.” ■
Paul Alster is an Israel-based journalist. His website is, and he can be followed on Twitter @paul_alster
This article originally appeared in The Jerusalem Report.