Nothing quite prepares me for the adrenaline rush as the first pair of cows pound across the sodden padi field, their jockeys yelling as they become immersed in giant mud plumes that rise 7m into the air.

I am in West Sumatra to watch pacu jawi, a spectacle of macho sporting prowess. Here, a padi field in Padang becomes a gladiatorial arena, where riders do battle with the mud and their bovines in front of an excited crowd.

The waft of smoke from satay stalls and the smell of fried bananas, combined with crouching women selling groundnuts and toys, give the event an instant festival atmosphere in the village of Parambahan.

The tradition of pacu jawi has been alive for hundreds of years. Pacumeans "race" and jawi means "cow", although this is slightly misleading as the cows can be bulls.

Ostensibly, it is a celebration-cum-entertainment for the rice farmers after harvest season. However, there is also a commercial significance as cow owners vie to show off the strength and stamina of their animals. Their value increases if they perform well.

In the surrounding fields, the farmers prepare and groom the cows, while the jockeys bolster the wooden harnesses for 30 seconds of spine-tingling and punishing action. Each jockey rides a pair of cows, balancing on wooden yokes, holding only the cows' tails to steer. Apart from the obvious difficulty of hanging on, the cows can also turn abruptly at any time and career off the field, sometimes into the screaming crowd.

As if the thundering of hooves and mountains of flying mud are not enough, there is also great delight when the cows split in opposite directions, leaving the rider splayed and ultimately face down in the mud.

This rare sporting event goes on for 11 months around Tanah Datar's 15 districts, with 11 districts being chosen to host the races, each for four weeks. So it is almost a year-round family day out, attracting crowds that sometimes exceed 500 at the opening and closing events of each village.

Due to the conditions of the padi fields, the village venues are sometimes not chosen until a few weeks before the event, but tour companies will advise travellers when they book their trip.

To reach the villages, it is normally a winding two-hour trip into the hills above Padang by car. Racing usually begins around midday, leaving time for refreshments on the way. Races finish between 3 and 4pm.

Foreigners are still a novelty at most of the events - I spend 20 minutes having selfies taken with insistent locals, all of whom are extremely friendly, hospitable and happy to have us witness their extreme sporting spectacular.

It is an afternoon full of heart-pumping excitement, watched by old and young alike. While it is a very muddy affair, it is a great way to encounter the Sumatran people authentically on their home turf.

• John Foreman is a freelance photographer from Britain.