Kenyan and Ethiopian runners have dominated middle and long-distance races since they began participating in the 1968 Mexico Olympics and they are not about to stop.
Both nations have produced winners in many global events as they continue to cement their dominance both on the road and on the track.
In Kenya, many athletes have dominated the Olympics and various marathons conducted globally.
In more recent times, Kenya has seen world marathon record holder and two-time Olympic champion Eliud Kipchoge's dominance on the roads.
He has not only won Olympic gold in two consecutive Olympics, but he is also the first man to run a marathon under two hours and he has already been dubbed as the Greatest Of All Time.
His dedication, ambition and hard work have inspired many since his debut in the early 2000s.
As a result of his success and many other top athletes, there has been a remarkable uptake of running and many full and half marathons for non-professional athletes have been held in Kenya.
The question however has been how tough or easy is it to run a marathon?
"Running a marathon is no easy feat and this is perhaps why many of these athletes get so much appreciation for their accomplishments," says coach Bernard Ouma, founder of Rongai Athletics Club and a Sports Science graduate.
Psychological, physiological toll on the body
Rongai Athletics Club is the home for middle distance runners like Timothy Cheruiyot, the reigning world 1500m champion, former champion Elijah Manangoi, Timothy Sein, Winny Chebet, George Manangoi and Vincent Keter, the world Under-20 champion.
Ouma, who did his Sports Science studies in Budapest, Romania said: "Anyone who has attempted running at least 10 kilometres understands that it takes a serious psychological and physiological toll on the human body."
"After a marathon, the most evident effect is that of muscle fatigue that arises from high lactic acid build-up and markedly lower glucose levels," he said.
Ouma continues: "More specifically, there are micro-tears that occur when the muscles recruited are strained beyond their capacity and this leads to soreness after the event.
"Furthermore, certain biomarkers are affected from their baseline levels due to the high demand placed on the body.
"After races, for example, inflammation occurs leading to chemotaxis which is the migration of white blood cells from capillary vessels to larger vessels as an immune response. This makes the body susceptible to cold infection due to the lowered immune response as the body recovers.
"Another key biomarker affected is the stress neurotransmitter, cortisol. This is released by the brain as a response to the stress that is placed on the body during the marathon and remains elevated from baseline levels," Ouma said.
A study conducted in Japan on ultra-marathoners showed that high levels of cortisol also lead to high glucose levels due to high levels of adrenaline, the fight or flight neurotransmitter.
While this is all good for purposes of the event as it ensures the body is responsive, it lowers testosterone which slows down muscle protein synthesis and general recovery.
The most critical change is the loss of water of up to two litres and other electrolytes through sweating.
After a race, it is therefore imperative that one immediately takes water at the very least for rehydration.
Thereafter it is ideal to consume glucose and the electrolytes such as sodium in liquid form as it is most easily absorbed in this state.
United States-based marathoner Betsy Saina says recovery after running a marathon is key and will determine if one will run again.
"Running a marathon is never a consistent affair, there is so much sacrifice involved and its recovery requires a lot of attention, one needs lots of carbohydrates which are energy giving foods to restore the glycogen and glucose lost during the event, and lots of rest," says Saina, who is currently on maternity leave.
For the recovery of the muscles, the importance of proteins cannot be overemphasised.
This will aid the body in the recovery of the muscles through protein synthesis and restoring the musculoskeletal structure for training and future events. Intake of fruits and vegetables will also aid in recovery.
After a taxing event such as a marathon that usually takes months to prepare for, it is highly likely that one might be in a celebratory mood and take some beers due to a feeling of sheer accomplishment.
Studies conducted show this is not a good idea.
"Alcohol by its nature is a diuretic, which means that it makes the body lose water and crucial electrolytes such as sodium. After a race, the body is already dehydrated and taking alcohol only exacerbates this. Furthermore, consuming alcohol right after a race interferes with muscle protein synthesis which slows down muscle protein synthesis and consequent recovery," Ouma said.
Elite marathoners therefore cannot afford to lose time as recovery is paramount.
The study done in Japan also noted that elite marathoners take time between races for periods of at least four to six months for full marathons, meaning an athlete can comfortably do two full marathons a year.
"This ensures longevity in the sport. At the elite level, it is important to undergo a blood test to show the levels of the biomarkers and record the data to improve and maintain high levels of performance. In present times, it is easier to conduct such tests and even easier to make sense of the information with the advent of technology to ensure desired results," Ouma noted.