Firefly: The Sports Recovery Device


Exercise can leave you feeling amazing – crossing the finish line, beating a personal best or even just making it all the way around. But the side effects of exerting yourself more than your body is used to can be a surprising kick in the teeth. Delayed Onset Muscle Soreness in particular is my least favourite thing about working out – a taster session in Chinese Pole (which I highly recommend) left me unable to raise my hands above my head for a solid week.

Firefly – a high-tech sports recovery tool for athletes – is here to to help. Firefly can reduced DOMS within 24 hours as it increases lower limb blood circulation, accelerating the removal of metabolic waste immediately after strenuous exercise.

Firefly is an alternative to “active recovery” techniques such as going for a light jog the day after or casual swimming. My boxing neighbour will go for a casual 10k run the day after a bout. I’m nothing if not impressed. In addition to DOMS, firefly claim to prevent venous thrombosis and oedema.

Out of the packet firefly looks like a pair of giant plasters. You simply strap the lightweight (16g) devices them behind each knee and they take over – mimicking the blood flow rate of walking while you flow over by the drinks tent. The last thing you want moments after a race/workout is to fiddle and firefly is fiddle free – there are no wires to set up, no smartphones to pair or even any settings to tweak. You simply rip them out of the packet, affix them to your legs (or the common peroneal nerve at the top of the fibula bone if you were curious) and feel the neuromusclar electro-stimulation.

Fitting instructions for the Firefly
Fitting instructions for the Firefly

Firefly is powered by a single wristwatch size battery, with one button control of the on-board software. The straps are unobtrusive and mould to the knee, although they do look a little weird. The adhesive water-based conductive hydrogel is quite secure – I tried a few kicks and cartwheels after application and everything stayed in place. After running 10k for an LGBT Pride event, I felt perfectly fine to teach a 2 hours capoeira class and cycle 10 miles across London. That may not be the most scientific test available but I certainly felt lighter. 

Firefly aren’t messing around – they have been actively targeting elite athletes for and had a number of Team GB, premiership footballers and rugby players as happy users. Mike Alsop – runner of 7 marathons in 7 days across 7 continents (and quite possibly world’s fittest man) is a big fan.

Each application lasts 24 hours, after which you simply throw the device away. This felt more than a little wasteful – especially when one pair will set you back £20-30. Then again if you are a serious amateur or pro level runner, these costs are minimal.