Michael Reid in The Conversation:
First, the physical effort of driving a race car is much greater than that of driving your family car.
Turning and braking require more force due to the high speeds and the unique engineering of race cars. Drivers control the vehicle by constantly engaging the muscles of the arms, upper body and legs.
“There’s tremendous kick-back through the steering wheel,” IndyCar driver Dario Franchitti said in a 2012 interview, “and there’s no power steering, so every movement of the wheel requires a lot of energy.”
After being hooked up to sensors to track the stresses and strains he endured a race, Franchitti learned he needed to generate 35 pounds of force just to steer, and 135 pounds of force to brake.
More here.