Hydration and Hyponatremia from Hopkinton to The Hub

Marathon Monday may have passed, but another will be here in no time.

The third Monday in April, both Patriots Day and Marathon Monday, marks a day off for grammar schoolers. For college students, Marathon Monday is a day of liberal libation use, and for the runners, it is the culmination of months of training.

It is widely known in Massachusetts that Boston’s world-renowned footrace runs annually on Patriots Day, but only an exclusive group of people actually understand the months of training and dietary dedication required to be in shape for the grueling run.

Training for a marathon takes months or longer, depending on how fit a marathon runner-to-be is at the beginning of his race preparation.

‘Give yourself a year to train if possible,’ Sean Brewer, a marathon runner, said. ‘Slowly build’ by doing progressively longer runs’hellip;it is a long, slow process.’

Brewer, 42, a lawyer from Brooklyn, N.Y., who has run in four New York Marathons since 1999, said he was a casual runner before he began his training. He said it took him about six months to train for his first marathon, and he ran at least four days per week in the months leading up to it.

‘Make sure to do’ at least two training’ runs of around 20 miles in preparation, but’ far enough in advance so that you are fully recovered,’ he said.

A marathoner’s diet is just a variation of a well-balanced diet, including fruits, lean proteins and oils, starchy and non-starchy vegetables and whole grains, Laura Thompson, a registered dietitian at Boston University’s nutrition and fitness center, said.

‘The secret to keeping up energy levels and preventing muscle fatigue throughout training is putting back into your body what you take out,’ Thompson said.

Because of the increased amount of exercise and calorie burning during marathon training, Brewer said he has to eat more food to stay fit.

‘It’s really important to replenish your energy stores when training for a marathon,’ Aaron Blum, a marathon runner and an athletic trainer at Boston University, said. ‘A marathoner might eat a few more snacks a day to keep up with the extra calories they burn from longer distance running.’

Human bodies store carbohydrate energy, known as glycogen, in the liver and muscles. Our bodies rely on glycogen when performing higher intensity exercises, like running a marathon, Thompson said. A marathon runner needs glycogen levels to be as high as possible and the best way to achieve that is to refuel with carbohydrates almost immediately after training runs, she said.

Runners use the term ‘hitting the wall’ to refer to the point in a marathon when glycogen stores are depleted.

The infamous Heartbreak Hill, a half-mile uphill section of the course near Boston College, would be challenging in any case, but lives up to its menacing name because it occurs 20 miles into the race after most runners have hit the wall.

‘The morning of the marathon, runners should consume a breakfast consisting of mostly carbohydrates in an effort to top off their glycogen stores for the long race ahead,’ Thompson said. ‘Kind of like how you would top off your gas tank before a road trip.’

The Boston Marathon presents some pre-race challenges because runners are bused out to the starting line in Hopkinton and often have to wait some time before the race actually starts, Thompson said.

Having a few snacks on hand, such as small granola bars, Gatorade, or any other high carbohydrate snack that will not bother your stomach, may be good idea just in case you get hungry, she said.

A common practice in the days leading up to a marathon is ‘carbo-loading,’ where runners eat fewer carbohydrates three or four days before the marathon, and then eat a very high carbohydrate meal two days before the race, Blum said.

Hydration is an important component of training and running a marathon, though it is not as simple as drinking lots of water. Besides the depletion of carbohydrate energy stores, dehydration and excessive hydration are two of the other most common physical ailments runners face during a marathon.

Dehydration is the major cause of muscle fatigue and muscle related injuries and occurs when an athlete does not replace the water he loses through sweating, Thompson said. In most marathons, water stations are available at almost every mile to prevent dehydration.

‘Drink at least a few sips of water and/or Gatorade at every water station even if you don’t feel thirsty to avoid dehydration,’ Brewer, the Brooklyn lawyer, said.

Too much water can be a problem for marathon runners also. Excessive hydration causes hyponatremia, or low blood sodium levels, Thompson said. People lose sodium when they sweat, so physical activity dilutes the body’s sodium concentration and drinking water further dilutes the concentration.

‘This is why it is so important to mix hydrating with water and Gatorade to help keep sodium levels from falling too low,’ she said.

But proper training and a sound diet might not be enough to conquer the punishing demands of running a marathon.

‘Some people just don’t have the alignment in their bodies to withstand the repetition for 26 miles,’ Gary Skrinar, a retired Boston University health sciences professor, said.

A runner could collapse during a marathon if he has not properly trained, does not replenish with water and electrolytes or runs in conditions that are much colder or warmer than what he is used to, Skrinar said.

Even after a marathon is over, the body may pay a physical toll for weeks after.

‘My legs usually ache for several days and I don’t feel fully recovered for about 2 weeks,’ Brewer said.

After his first marathon, Blum said he had difficulty walking on stairs for about a week, but he learned from his mistakes and felt ‘pretty good’ two days after his second marathon.

There is an infinite number of websites with bigger and better fitness guidelines for a marathon runner-to-be, but experts agree that most important component of training lies outside the realm of enumerated lists.

‘You have to put in the time and the energy to run a marathon or you are likely to have a fairly miserable experience during the marathon itself,’ Blum said.

With thousands of people running marathons each year, very few do it for prizes or competition. But considering the time, energy and physical demands involved with completing a marathon, its place in the hallowed halls of athletic achievement seems secure.

Brewer said even after months of tough training and a couple weeks recovery after a race, it is all worth it because he feels in much better shape in the end.

‘Although training for a marathon may seem daunting at times, if you put in the hours and run the miles, the moment you cross the finish line is one of the most gratifying experiences you can have,’ Blum said.