The Black Diamond Forearm Trainer is a cheap and cheerful hand and forearm strengthening device that can help you become a better climber or lifter.
I came across it while looking at the various grip training tools available. The theme was clear. Either cough up a load of cash for expensive grip and climbing tools or train like a bodybuilder doing endless sets of forearm work (no thanks).
However, the Black Diamond Forearm Trainer is different. And I’m going to explain each benefit one by one so that you can decide if it’s right for you and your forearm anatomy.
It’s lightweight and portable
I actually like hand grippers for building strength. But like any physiological adaptation, gaining hand strength for climbing or any other activity requires sufficient rest. So it’s not like you can use those grippers every day, and they certainly won’t fit in your pocket.
The Black Diamond Forearm Trainer, however, will fit in your pocket. And at just 112g/4oz, it won't weigh you down, either.
I actually think that keeping it in your pocket is a smart idea because it encourages you to use it while at work. Which brings me nicely to the next point.
It’s not noisy
Many grip strengtheners give out awful noises that attract unwanted attention from onlookers (you know, like your darling work colleagues). But being a rubber ring, the Black Diamond Forearm Trainer is much quieter—virtually silent—because it doesn’t have unlubricated metal parts like traditional grip trainers.
As such, it’s a great little tool to use while on conference calls and the like. And if you think about it like that, you’re basically getting paid to strengthen your hands on the job (but don't tell your boss that).
And who knows, it might even counteract the potential side effects of chronic typing on ridiculously small screens (aka on the smartphone).
It loosens up your hands
If you’re a bodybuilder, then you might not really care about this benefit. But, for the rest of us, any device that can improve our grip by loosening up our hand muscles (which can get very tight while working) can only ever be a plus.
I’ve learned in recent years that grip strength is very specific. For example, you can have impressive forearm muscles but still struggle to have the hand strength necessary for regular climbing.
That’s why I love the Black Diamond Forearm Trainer. It’s a highly specific training tool that strengthens the small muscles that gym-loving meatheads would overlook (and probably don’t realize even exist!).
It’s a wonderful warm-up device
Not sure what to do before your next climb?
Give the Black Diamond Forearm Trainer a try. After all, it works all the major muscles of the hand and forearm without you needing to bring any fancy equipment with you. 
Just be prepared for the “what’s that ring thing?” questions from your climbing buddies. I find that people are always intrigued when you’re getting results from such a simple tool.
It’s a proven product
In today’s crowded marketplace, only top-tier products stand the test of time (with a few hyped-up exceptions). The Black Diamond Forearm Trainer has been on the market for 6+ years and has garnered countless 5-star reviews singing its praises.
That means that the other people have done the hard work for us. They’ve tried the Black Diamond Forearm Trainer and have verified its authenticity, so we don’t have to. But even if it was a poor product…
It’s cheap as chips
For about the price of a designer coffee, you can own the Black Diamond Forearm Trainer. But unlike holding your cute little coffee cup, the Black Diamond Forearm Trainer will actually strengthen your hands and make you a better climber or athlete (I don’t know what activity you do). 
Related training tools
The verdict on the Black Diamond Forearm Trainer
So yeah, this product is pretty cool, and I’m glad that I came across it. It definitely seems like it's worth a shot if you want to work on your grip and hands without buying expensive equipment or living in the weight room.
- Jones, O. (2020, September 6). The Muscles of the Hand - Thenar - Hypothenar. TeachMeAnatomy. https://teachmeanatomy.info/upper-limb/muscles/hand/
- Macias, K., Brown, L., Coburn, J., & Chen, D. (2015). A Comparison of Upper Body Strength between Rock Climbing and Resistance Trained Men. Sports, 3(3), 178–187. https://doi.org/10.3390/sports3030178