A farm consultant is urging farmers to spend less time on quad bikes and more on mountain bikes - and says that farmers are doing less physical exercise than ever before.
Ian Handcock studied the effects of increased automation in technology on dairy farms, and found many middle-aged farmers were at risk of heart disease from not getting enough exercise.
He said the use of automated shed systems, and of quad bikes and tractors, was leaving farmers unfit.
"Well over half a day is dealt with sitting on a quad bike. Maybe taking the cows to the shed, milking and putting the cows away - and the other time can be spent on tractors or quad bikes," he said.
"There's very little physical activity so they're not burning calories and they stop losing weight."
Mr Handcock said farmers who were fit and healthy were more decisive and generally happier.
He said everything on a farm was done at cow pace so there was no reason for farmers not to hop off the motorbike and stretch their legs.