That may be true from my experiences on the Ninja Warrior course at the new adventure park in the West Midlands, considering the number of attempts it took me to complete one of the sections.
The new park is the latest to be opened across the country for the popular ITV show and aims to give people of all ages and sizes the chance to mirror what the athletes are doing on a Saturday evening on your TV screens.
As part of the opening day, I was among a select few invited to take on the challenges of each course, with three courses of varying difficulty on offer, as well as a challenging wall climb at the end.
While not as fit as I used to be and working with a sore shoulder, I decide to get going and try out the courses to see what it's all about.
I don't get off to a particularly sparkling start when I find I lack the necessary spring to do the opening step pads, which are a standard on the show, although one of the pro-ninjas helping people shows me how to do it through just a quick motion bounce.
I keep trying it a few times, but decide to move on to the first obstacle, a set of swings for a section which requires co-ordination and balance and, if goes wrong and you fall off, a quick trip to the crash mat below (No water for people to fall into here).
Although a bit wobbly, I do complete the obstacle, but find the next one, two tilting beams, a little bit more challenging when I suddenly find that they move the further up them that you go, precipitating my first of several trips to the mat.
My bad shoulder stops me doing any of the swinging obstacles, although you can see the challenges as one means climbing up, then climbing down again, while another involves swinging until you can grab the next hold.
However, I then complete a second swinging section, this time with smaller swings to step on, and a balance beam, before taking on the first of the three final walls, a slanted section which leaves me driving my legs to get up enough to pull myself up.
I'm already breathing heavily and sweating and that's just the first course. I try bits of the other courses and realise I'm not a young person any more, but still have a go, with members of the Ninja Warrior team cheering me on.
As I get to the end of my time on the course, I decide to try the other two walls, which are curved and go up a lot higher each time.
I conquer the first one at the first attempt, to my own surprise and spirited applause, and have a bash at the final wall, getting my hands up top, but lacking the strength at that time to pull up, leaving me sliding down to the ground.
With words of encouragement from the pro-ninjas and advice on how to approach it, I thunder up the final wall again and, this time, get enough up to be able to pull myself up.
It's a suitable climax to an experience which was hard work, but good fun and worth trying – and that's before you even get to the inflatable park at the side.
The ninja Warrior Uk Adventure is based at Crown Wharf Retail Park in Walsall, close to junction 10 of the M6. General admission starts from £12 per person and £3.50 for mini ninjas aged six and under.