The Under Armour Project Rock 4 is the perfect fusion between highly cushioned running shoes and responsive and adaptive cross-training shoes.
It’s as if the Hoka Clifton and Nike Metcon got together and formed a high-performing cross-training shoe that is also cushioned just enough for cardio days.
At first glance, the Under Armor Project Rock 4 looks like your standard cross-training shoe, but it’s built to tackle so much more than zippy agility work.
The UA Charged cushioned provides athletes with plush step-in feel that works to protect their knees and joints as you train. This high level of cushioning is unique when comparing this shoe to standard cross-training shoes, which is why it’s also ideal for cardio work as well.
The Rock has had 4 knee surgeries over the years, so crafting a training shoe with high-end shock-absorbing cushioning comes as no big surprise.
The addition of the UA HOVR technology in the midsole also provides what Under Armor calls a zero-gravity feel. As you move through your gait cycle, this proprietary foam cushioning absorbs the impact when training on hard surfaces.
Whether you are running on a treadmill or dabbling in CrossFit, the dual foam cushioning in this trainer is designed to keep your stride light and bright while protecting your joints.
This midsole makes this shoe just a tad heavy, but the extra protection is well worth it for athletes that need a little extra protection.
The outsole of this training shoe seems a bit schizophrenic but in a good way! It blends the features found in your standard daily trainer with the features found in a good cross-training shoe that work quite well together.
For cross-training, the UA TriBase helps to really ground your feet down to the floor for added power when weight training. The added triangular shape to the outsole rubber really grips the ground under your feet for a strong and stable base that is perfect for squats, burpees, or any style of dumbbell lift encountered in CrossFit. While the TriBase is meant to maximize ground contact, it is still quite flexible to boost agility.
For runners, the toe box and the heel counter are uniquely designed to provide a solid landing in your heel, and zippy toe-offs in the toe box.
What I love most about the forefoot design of the outsole is that it is composed of a super-grippy rubber with a ribbed design that sticks to the ground for quick and zippy movements.
The full-length rubber outsole is insanely durable and built to last no matter what you throw at it. With no exposed EVA foam underfoot, this outsole provides a bright and responsive ride that feels nice and supportive.
It’s important to note that while full-length rubber outsoles are more durable and responsive, they are also fairly heavy. The complex nature of the outsole boosts durability but can weigh you down a bit on those long workout days.
The upper of the Project Rock 4 is built to contour to the shape of your foot, boosts breathability, and has a few unique features to keep your feet locked in place.
The upper is composed of a UA’s proprietary Compression mesh Energy Web that provides just as much cushioning to the top of your foot as it does to the bottom. This unique upper is blended with the same HOVR materials that are found in the midsole to wrap your feet in 360 degrees of plush cushioning.
While it may not fit your foot like a glove at first, this is a type of shoe that only gets better with time as it contours to the shape of your foot.
What I also love about this upper is that it boasts a TPU midfoot strap that is often only found in cross-training and powerlifting shoes. For weight lifters, this strap helps to lock your foot in place so you can really dig into the lift.
For runners, it works to enhance lockdown so that your feet don’t shift around inside of the shoe as you push yourself to higher speeds.
I’ve reviewed a lot of shoes, and I have to admit that the Project Rock 4 doesn't exactly fit into one specific box. It’s not a dedicated running shoe and it’s not a dedicated cross-training shoe.
While it boasts similar features to high-end cross-training shoes such as the Nike Metcon, the high level of plush cushioning makes it stand out from the pack.
Cross-training shoes typically don’t include a lot of midsole cushioning, and daily training shoes typically don’t come equipped with TPU midfoot straps and outsole features that ground you down to the floor. So, who exactly is Project Rock 4 built for?
Overall, I would recommend this shoe for anyone that likes to float from machine to machine at the gym. The build of the outsole isn’t exactly made for running on the trails or any type of outdoor workout. It’s a gym shoe through and through.
The high level of cushioning in the midsole and heel counter really shine on cardio machines such as a treadmill, elliptical, rowing machine, or bike.
Plus, the build of the outsole and TPU straps along the top side of your foot provide excellent stability and control when engaging in weight training or CrossFit. It does a little bit of everything.
I combed through quite a few user reviews and found that this shoe runs true to size. If you are a size 10 in other Under Armor shoes, the 10 in the Project Rock 4 will fit just fine.
For newbies to UA, I suggest taking good measurements of your feet and comparing those numbers to UA’s sizing chart. When in doubt, you can always head down to your local shoe store to give them a test spin before you slap down your credit card.
Many previous users bought them right off of the website, however, and ran into few issues in terms of sizing. The super stretchy upper really contours to the unique shape of your foot, and the TPU clips allow for a lot of play to help you achieve that perfect locked-down fit.
I found that the price tag of the Project Rock 4 was just a little bit higher than I expected. While it comes in at a pretty steep price point, you are getting a whole lot of shoe in one compact package!
This design is packed with advanced features to help ground you down to the floor when engaging in weight training, and the highly cushioned outsole is great for cardio days.
Essentially, you are buying a cardio shoe and a cross-training shoe all in one, making it an overall excellent value.
Under Armor stuck with a very similar dual-density midsole and highly cushioned heel collar, but made small improvements to the style of the upper and performance of the outsole.
The most notable change between these two shoes is the addition of the TPU midfoot clip. This clip helps to boost stability when weight training, but also enhances lockdown when engaging in cardio work. This additional feature makes the shoe just a bit heavier, but it is well worth it for those that need a little extra support in the midfoot.
The outsole of this shoe is still made from a full-length rubber outsole with the TriBase grip in the midfoot but made some small improvements to the treads.
What I love most about this improved outsole is that it boasts a grippy ribbed design that helps runners achieve a strong and snappy toe-off that feels a lot more agile than the previous design.
Overall, the changes are small but make a big difference!
Due to the dual nature of this shoe, it leans more into the category of ‘jack of all trades, master of none.’ For runners that shy away from the weight machines or CrossFit, you may benefit more from a dedicated running shoe, and vice versa.
However, if your daily workout fluctuates with your mood, Project Rock 4 is one of your best options!