The history:
In 1902 American physician Theodore Hough discovered DOMS (Delayed Onset Muscle Soreness) after testing "negative repetitions" - lifting weights quickly and lowering them slowly in towards the body - with athletes. Hough believed the resulting aches were due to ruptures within the athletes' muscles. But when he analysed the effects further he discovered the muscles could "quickly adapt and become accustomed to the increase in applied stress". He realised the more negative strength exercises the athletes did, the less their muscles hurt and the less muscular damage they experienced.
The science:
Negative strength training is also known as "eccentric resistance" training. It's been proven to help with muscle growth, strength and conditioning, particularly in older adults. A 2013 study by The University of Notre Dame in Australia found that by training the lower body, in particular the knee extensors, the likelihood of falls was minimised, something that could help elderly maintain their independence for longer. The study focused on negative strength training for 65- to 87-year-olds. After 12 weeks, their knee extensors were 26 per cent stronger.
According to research published in the American Journal of Applied Physiology, negative strength training can help people suffering tendonitis and bone mineral density deficiency. On the weight-loss front, it's been found to enhance fat-cell breakdown and increase metabolism.
The reality:
I arrived in my workout gear, all ready to go, and was paired up with a personal trainer named Josiah. He talked me through how and why we were doing each exercise on the machines, which muscles we were targeting and why counting during your reps helps a lot in an X-Force workout. As I used the machines, Josiah told me to breathe and count faster as I pushed out. Then, as I let the weights come in closer to my body, to slow my counting. I started out racing through counting but by the end of the session I was much steadier and more fluid with my weighted movements. I found it pretty easy but by the end of the 25-minute session I was knackered. Bizarrely, though, I hadn't really broken a sweat.
The verdict:
I enjoyed the training because it was hard. Each set on the machinery was relatively easy to begin with, but as I continued, I definitely fatigued faster and faster. Initially, I didn't really get the endorphin buzz I normally feel after a run or a regular workout. But the next day and even two days after the workout I was very sore. It was a "good" soreness in my muscles however and something I hadn't felt for a long time.
Overall, I thought it was a very interesting form of training. If you do sign up, bear in mind you'll have to do your circuit assisted by a personal trainer at all times. I would definitely try it again, maybe once a week or every two weeks because I was so sore afterwards. I do think if I continued to exercise like this regularly it would sculpt my body into a leaner shape, so maybe I should keep going.