On Mazingira Day celebrated on October 10, the undeveloped terrain skirting Kasarani Stadium was being interrogated by a master strategist. This windswept, raw acreage is where athletics coach John Mwithiga Thuo, also known as “Warm Up”, was at work.
The air, sharp and unforgiving before 8am, lacerated the lungs and stiffened the joints. Most individuals approaching their late 70s - Mwithiga’s exact age is anything between 75 and 78, a consequence of his father’s exile during the Mau Mau war era and the passing of his mother - would seek refuge indoors.
But he was meticulously defining a 2km circuit for the Kasarani United Cross-Country event, his movement tracked by the rhythmic, metallic click of a surveyor’s wheel. He traversed the unforgiving contours with a honed economy of effort that belied his advanced years, ensuring the shortest, most precise distance was secured with diligence.
Beneath the slightly stooped shoulders and weather-milled complexion lay a core of almost inhuman resilience, forged in the furnaces of military discipline.
Hailing from Ndeiya, 40km west of Nairobi, he is a product of the world’s elite physical training academies: England’s Royal School of Military Physical Training and the Kenya Armed Forces Training School. For 58 years, “Warm Up” has stretched his physical ability, serving demanding tours from the barracks of Lanet and Nanyuki to operational assignments across England, Scotland, and, most recently, the conflict-ridden landscapes of Iran.
Today, his profound expertise is dedicated not to combat, but to charting race paths and cultivating a new cohort of runners in the Ngong Hills. Recently, he stood with his esteemed protégés, Julius Kirwa and David Letting—a renowned triumvirate of Kenya’s most lauded cross-country architects—at Lobo village in Eldoret, validating the National Cross-Country Championships course.
Kirwa, speaking of the man who mentored him at Lanet, described the gravity of his influence: “He is the master. When you contemplate cross-country, you invoke “Warm Up.” Letting invokes reverence. 'There is only one cross-country coach in Kenya, and that is “Warm Up.”
Athletics coach John Mwithiga with runners during training at St Mark's Kigari Teachers Training College in Embu County on March 25, 2019.
Photo credit: File | Nation Media Group
On that morning on October 10, “Warm Up” was clad in retired military khaki trousers, a faded Nike vest, and a matching cap and sneakers. His gaze, sharp as stream-polished stones, absorbed the ground’s every imperfection. As the sun ascended, layers were shed, leaving him in a simple t-shirt. He gathered a small cluster of young athletes—Gen Z runners, many drawn from Kasarani’s demanding streets.
“I am a Gen Z of the 1970s,” he said, acknowledging their raw, possibly rebellious energy. “My validation came from my strength and my willingness to fight. But even “The Cat” realised channelling that rebellious fire requires discipline. You must distil that noise into absolute focus."
Thrusting the measuring wheel into the earth, he paused, flexing his right arm to reveal formidable, age-defying musculature. He then pointed to the darker story etched on his left forearm: two contrasting tattoos. One, amateurish and poorly realised—a crude, green-tinged script—was a youthful, self-inflicted ritual to test his tolerance for pain, a testament to his teenage quest for courage through physical suffering.
Nearby, an intricately etched eagle served as a permanent credo: eagles do not fly with carrion birds. He instructed the boys to inspect the markings. “These,” he emphasised, “are scars of past folly, insignia of a man who confused causing trouble—street brawls, bar fights—with being cool. I, too, was once a Gen Z.”
“I still possess that physical conviction,” Mwithiga said, his gaze sweeping the fields where tomorrow’s champions would run.
“I remain convinced I could walk anywhere and confront any man in hand-to-hand combat. I could still break a man’s neck with my bare hands,” he went on.
His transformation began in earnest in 1971. Transition from East Africa to the punishing regimen of England’s Royal Academy—characterised by icy ablutions and relentless circuit training—was shock therapy. Here, Sergeant Mwithiga mastered the scientific intricacies of the human machine, becoming precision personified. Specialised training extended to the rugged Scottish Sky of Line, blending gymnastics, swimming, and track with intense combat proficiency: Karate, Judo, and Boxing were indispensable proficiencies. By 1976, he returned to Britain for enhanced athletics courses, graduating with a Level II Diploma in coaching, long before celebrated alumni like Robert Ouko and John Velzian.
Upon his return to Kenya, he was a soldier of a different calibre. He embodied the very essence of the “Alpha Male,” a title he wore proudly, fuelled by unparalleled skill and the institutional wisdom gleaned from the world’s most prestigious military training academies.
He rejoined the Kenya Armed Forces as a certified fitness authority, ascending into the ranks of Warrant Officer II. He was among the military elite who had conquered the treacherous peaks of Mt Kenya and endured the rigorous outbound school in Loitokotok—the ultimate synthesis of British discipline and Kenyan tenacity.
Paradoxically, the more ordered and disciplined his professional life became—predominantly stationed at Lanet Barracks—the more untamed and hedonistic his personal time grew.
“I genuinely believed I was Clint Eastwood’s equal,” Mwithiga confessed to the admiring young men. “The quintessential American was a tough guy. I felt compelled to prove it. Every single night.”
His evening ritual was notorious. He would strip down, shirt sleeves rolled up to reveal the magnificent architecture of his biceps and six-pack, often going bare-chest, spoiling for a fight.
“I would move from one bar to the next, one beer at a time, until the late hours,” he recounted. "Searching for any man—any man at all—to challenge me, to test the machine.”
He never encountered his match. People knew him; they were acutely aware of the reputation of the Kenya Army Physical Training Instructor (PTI), whose physical prowess was legendary.
His illustrious career was substantiated by extensive documentation and certifications—from the Kenya Military Academy to the University of Mainz—all affirming his complete mastery over the human engine.
“I was formidable,” he declared. “They understood I could kill with my bare hands. And they were absolutely correct.”
His journey had begun in 1966 when his physical conditioning at the Kenya Military Training School in Lanet caught the eye of Warrant Officer II Allan Vincent of the British Army Training in Kenya (BATKEN), who designated him for elite instruction in Britain, ensuring the foundational fire of this raw, unpolished Kenyan talent was fully ignited alongside seven other promising recruits from across Africa and the Caribbean in 1971.
His subsequent charge was to forge raw, civilian school leavers into unyielding, disciplined fighting units. The physical regimen he imposed was legendary for its severity, its effectiveness, and its profound character-altering impact.
His accolades were not pinned on a uniform but etched onto the souls on the slopes of Mt Kenya. There, under the crushing duress of snow and rarefied air, faltering spirits were fortified, and nascent leaders were truly chiselled.
The individuals he mentored included Major-General Joseph Nkaissery, who would become Minister for Internal Security, Major Munyeki Wachira, Major General Hussein Ali, later Police Commissioner, Army Commander, Lieutenant General Jackson Tuwei, the current AK president and Lieutenant Tom Wanambisi. “They arrived as raw youths,” Warm Up said. “They left as fully-formed men,” he added.
