Adidas Solar Glide 4 and Solar Glide 4 ST Review
By Senior Contributor Nathan Brown and Founder/Chief Editor Matthew Klein
Adidas has been re-imagining much of their lines throughout 2020/2021, including the all new Adizero Line including the Boston 10, Adios 6, and Adios Pro 2. However, some of the other lines have retained some classic Adidas elements for those afraid to make the jump, incluidng the Solar Glide and Solar Glide ST. The Solar Glide 4 maintains a Boost midsole with a rim of firmer EVA, a Torsion system, and an overall traditional trainer construction. The Solar Glide 4 ST is similar with a stable frame in the midsole that provides full length stability.
Specifications for Adidas Solar Glide 4 (per Adidas)
Weight: 11.5oz / 326g (men's size 9)
Stack Height: 32mm (heel), 22mm (forefoot)
Drop: 10mm
Classification: Daily Trainer
Weight: 11.0oz / 312g (men's size 9)
Stack Height: 32mm (heel), 22mm (forefoot)
Drop: 10mm
Classification: Daily Stability Trainer
RUNNING SHOE SUMMARY
Solar Glide 4 (Nathan): In a culture of running shoe construction with lots of innovation, the Solar Glide 4 may be a refreshing taste of traditional trainers with an emphasis on durability while others may find it lacking that new-age lightweight and propulsive feel that is more commonly found in modern trainers. Wherever you land on that spectrum, the Solar Glide 4 delivers a firmer-riding, consistent, durable, and heavier shoe.
Solar Glide 4 ST (Matt): A traditional ride with new age stability, the Solar Glide 4 ST is a heavy duty stability shoe for long and easy mileage. A slightly wider fit and comfortable heel provide plenty of room, while a stable frame in the midsole provides forward guidance throughout the length of the shoe. Almost full length Boost provides some cushioning, but the ride is stiff overall and takes some time to break in. A stable, stiff and protective ride with a little more apparent stability than previous models, the Solar Glide 4 ST continues as one of the only current Adidas stability shoes for those who want a high mileage trainer.
FIT
Solar Glide 4 (Nathan): The upper of the Solar Glide 4 is a layered mesh that, consistent with many other Adidas models, is lower volume. The shoe fits true to size, with possibly just a little extra length. However, given the lower volume, I would not recommend sizing down for length as it is only a touch long. The layered mesh is on the thicker side and the tongue is gusseted, which adds another layer of material through the midfoot. This made for a very warm running shoe, and I found my foot sweat even when it was 45 degrees outside. Outside of the warmth, the padded and stretchy tongue contributes to an overall comfortable upper. Given the lower volume, it is also very secure and I did not have any problematic heel slippage. The thicker overlays, which includes the 3 stripes logo, also contribute to midfoot security from the upper. Finally, the heel has a split rigid heel, where the posterior aspect is open, allowing space for those with sensitive achilles or calcanei.
Solar Glide 4 ST (Matt): The Adidas Solar Glide 4 ST fits me true to size in my normal US men's size 10. The overall fit is slightly wider, with mesh material that stretches well particularly in the forefoot. The heel fits more normal, with Adidas's split heel counter providing plenty of security on the medial and lateral sides of the foot while leaving the posterior section open. This and the thick heel counter locks the rearfoot in well while keeping pressure off the calcanei. So for those with sensitive heel bones this is an excellent shoe. The midfoot has thick overlays and the Adidas logos integrate with the laces well to provide custom security. The laces stay locked in and I did not have to lace lock the shoe. The forefoot fits wider, with stretchy mesh that allows the toes to spread. The mesh at the forefoot does sit low, providing lower volume and security while still giving the toes enough room. The tongue is perfect in thickness, is gusseted and stays in place. The upper is very comfortable, but is best to use with socks. The rearfoot and midfoot have very comfortable against skin feel, but the toe guard can be a little irritating on the toes. The upper overall is fits slightly wider but has plenty of adjustable security in the midfoot with a great lock down in the heel and plenty of room for the toes.
PERFORMANCE
Solar Glide 4 (Nathan): The midsole of this shoe consists mainly of Boost, an EVA rim that spans both sides of the shoe from the rearfoot up through the toes, and a, extended plastic torsion system with a unique construction. The torsion system starts in the medial rearfoot (reaching into the midsole on the medial side), extends most of the width of the midfoot, and then extends to the forefoot in a forked pattern. This overall increases rigidity, but the forefoot is still overall flexible at slower paces. The Boost midsole with EVA rim runs rather firm, and the heavier weight combined with flat geometry makes this shoe a bit laborious at higher speeds. Additionally there is only a very mild heel bevel in the presence of a posterior heel flare, which makes heel striking more abrupt. I would notice soreness in the muscles on the front of my shin (tibialis anterior and peroneus tertius) after longer runs in this shoe. The firmer ride and level construction lead to an overall flatter ride, but one that doesn't change over many miles. This shoe will do best for those without an excessive heel strike who prefer a firmer and more traditional ride underfoot.
Solar Glide 4 ST (Matt): The midsole of the Adidas Solar Glide 4 ST is made up of a bottom layer of Boost, an EVA Stable Frame on both sides of the shoe from the heel to the forefoot and an extended plastic torsion system that also goes the full length of the shoe. The ride overall is stable and rigid, thanks to the torsion system and stiffening from the Stable Frame. The heel bevel and toe spring are fairly small, so some of the stiffness maintains even as the shoe breaks in. Like the Solar Glide 4, there is some posterior heel flare in the rear. With the small heel bevel, this makes heel landings a little clunky. Despite taking some time to break in, the Solar Glide 4 ST is extremely durable. I have 50 miles on my pair and there is no wear on the outsole. The nubs on the bottom provide decent traction and do well on both road and mild trails. The tough outsole does add some firmness to the ride, but the Boost midsole still provides protection. The softness from the Boost is concentrated in the heel and the ride firms up as you transition to the forefoot. This makes for an especially stable forefoot. The stable frame sitting right under the foot makes the ride slightly more firm overall, with the more softness in the heel the harder you land. Overall the ride of the Solar Glide 4 ST is more rigid and stable, in line with many older traditional stability training shoes.
STABILITY
Solar Glide 4 (Nathan): The Solar Glide 4 is a neutral trainer. There is some sole flaring in the heel which gives some stability, but it narrows through the midfoot and therefore runs quite neutral. Additionally, the torsion system adds some rigidity to the midfoot transition with the extensions to the forefoot providing some smoothness for that transition off of the more narrow midfoot. Given the overall firmer feel, it was hard to differentiate between the EVA rim and the Boost, so it is hard to tell how much that rim contributed to the overall stability. In the end, you get a truly neutral trainer that verges on the more stable end of the spectrum, as long as you aren't sensitive to heel flares.
Solar Glide 4 ST (Matt): The Solar Glide 4 ST is a moderate to high stability training shoe. The full length Stable Frame provides stability throughout the length of the shoe. The heel counter sits farther forward given that it does not connect at the heel. This provides medial and lateral stability at the heel. The full length torsion system comes up into the heel, adding additional stability at the medial rearfoot. It continues into the midfoot and splits in the forefoot, adding further rigidity and guidance at the front. The sole is on the wider side, providing a broad stable platform. Additionally, the Stable Frame sitting under the foot provides a slightly firmer ride. The Solar Glide 4 ST is a stable shoe overall, providing full length stability. However it may be so stable that it becomes too rigid for some people.
THOUGHTS AS A DPT / FOOTWEAR SCIENCE
Nathan: With companies, including Adidas, starting to do a really good job incorporating bevels into their heel construction, we haven't had to talk about the effects of posterior heel flare much recently. However, this shoe begs me to bring it up again for another discussion. A posterior heel flare is an extension of the midsole beyond the base of the heel. A longer flare, particularly with a firmer foam like you have in the Solar Glide, is going to increase the torque/moment around the ankle joint when the heel hits the ground. This places increased demand on the muscles in the front of the foot to control the movement of the mid/forefoot to the ground. This increased demand may be fine for some, but it also can predispose you irritation of the muscles/tendons on the front of the shin (tibialis anterior and peroneus tertius). The Tibialis Anterior is one possible muscle that contributes to "shin splints". There really is no funcitonal benefit of a posterior heel flare, so I'm glad the overall trend has moved away from them. The people who will be least affected by them will be mid to forefoot strikers as they won't get the ground reaction force of hitting the extended heel first.
Matt: The numerous methods of stability in the Solar Glide 4 ST are fantastic, but like everything in life there is a balance. Frequently, adding stability to a shoe means increasing the rigidity of a shoe. There is a point of adding rigidity that the shoe becomes too stiff and it becomes difficult to transition through. This occurs in the Solar Glide 4 ST. The Stable Frame and extended torsion system both add a high level of rigidity to the sole that causes the ride to become too rigid. This occurs in the heel from the posterior heel flare and small heel bevel and at the forefoot with the stiffness and the small toe spring. This normally should be compensated for by a more significant rocker, both a larger heel bevel and toe spring. It could also be compensated for by deep flex grooves in the forefoot (at least at toe off). The Solar Glide 4 ST, however, does not utilize these methods, making the ride extremely stiff and a bit clunky. Those who land farther forward are less likely to notice this as the forefoot does break in with time and increase in flexibility. The heel however remains rigid. This will work very well for someone who wants a stiff and stable shoe for easy miles and recovery runs. However when it comes to any sort of pace change, the rigid ride will inhibit faster transitions.
RECOMMENDATIONS
Solar Glide 4 (Nathan): I have two main recommendations. This upper is mighty warm. It would be great to be thinned out a bit with also a little more volume in the toe box, which likely would be accomplished with thinning out the upper a bit. The other recommendation would be to shave off the posterior heel flare or create a bevel like Adidas has in the Adizero line.
Solar Glide 4 ST (Matt): My major recommendations are on the sole. Given the rigidity, I would encourage Adidas to reduce the posterior flare, increase the bevel (similar to the Adizero line) and increase the toe spring. Another option at the front is to add some deeper flex grooves. Regardless of which method used, this will improve the forward transition and actually add guidance to this shoe. The other suggestion I have is to reduce the thickness of the upper. This adds a significant amount of weight that could be reduced. I would love to see this shoe in the mid to low 10 ounce range as this will help to make it smoother
WHO THIS SHOE IS FOR
Solar Glide 4 (Nathan): The Solar Glide 4 is for people who loved the trainers of 5-10 years ago and are looking for that traditional construction in a new shoe. The Solar Glide 4 is a firmer, heavier, and flatter ride that can also eat away high milage easily. It also is still full of Boost, so it's a solid option for Boost lovers. It runs in the $140 realm, so at that price point you can get a myriad of other trainers. You really want to have this style of trainer to go this route.
Solar Glide 4 ST (Matt): The Adidas Solar Glide 4 ST is a more traditional training shoe with several newer methods of stability. The stable frame feels like it provides both medial and lateral stability, while a more forward medial and lateral heel counter stabilizes the heel while reducing pressure on the calcanei. The fit is on the wider side, yet remains secure due to the adjustability. The ride is on the stiffer side thanks to the posterior heel flare, the numerous methods of full length stability and the lack of a significant rocker. While the ride is a bit clunky, those who want stability shoe with full length guidance, an upper perfect for those with wider feet and sensitive heel bones and do not want a rockered sole, the Adidas Solar Glide 4 ST will be perfect for you.
GRADING
Nathan
Fit: B- (too warm, low volume, a little long, but does lock down well and is comfortable)
Performance: B- (Very consistent, but too heavy and flat to pick up the pace)
Stability: B+ (Narrow midfoot and posterior heel flare keep this a truly neutral shoe)
DPT/Footwear Science: C- (There are a lot of components, but everything is firm/rigid and they don't interact in any special way, posterior heel flare unnecessary)
Personal: C (Posterior heel flare aggravates my shin)
Overall: C+
Matt
Fit: B (Wide fit that can be secured easily. Heavy upper, lower volume but still comfortable. Thicker than necessary however)
Performance: C (Clunky, firmer ride. Stiff and heavy with posterior heel flare. Best for those who land farther forward)
Stability: A- (Great stability. Stable Frame, split heel counters, torsion system and wider last all provide full length guidance)
DPT/Footwear Science: B-/C+ (Great stability, but poor execution of ride. Stiff. with poor transition. Posterior heel flare unnecessary. Stability too rigid that impact transition)
Personal: C (I want to like this shoe more, but works far better as a walking than running shoe. Too rigid and heavy)
Overall: C+ (Good stability, but rigid ride. Great fit, but upper heavier than necessary. Okay for those who land farther forward for easy runs. This line needs an upgrade, hopefully from the influence from the recently well designed Adizero line).
VIDEO REVIEW
Matt and Nathan dig further into the Solar Glide series for a video review.
CHECK OUT GEAR WE LOVE
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Asics Metaspeed Sky: Chief Editor Matt Klein can't stop racing in it, even on trails (not advised)
Hoka Arahi 5: One of the best stability shoes of the year, and the best walking shoe as well. Versatile.
Feetures Socks: Massively grippy socks that will make you feel more one with the shoe
Huma Chia Gel: Natural and goes down easy. Powered Contributor Nathan Brown to his marathon
Trigger Point Foam Roller: Help get those knots out post-run and feel better for tomorrow
Theragun Massager: This small version is great on the go for working tired legs
Ciele Hat: Our team's favorite running hat of choice!
FURTHER READING
Check out Adidas in 2021
SL20.2 - Daily Trainer
Supernova+ - Old school trainer
Adizero Adios 6 - Workout trainer
Adizero Boston 10 - Training companion to the Adios Pro
Adizero Adios Pro 2 - Super shoe
Ultraboost 21 - Max cushioned trainer/A vibe
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Thanks for reading!
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TESTER PROFILES:
Doctor of Physical Therapy
Movement Performance Institute Certified in Advanced Functional Biomechanics
Dr. Brown is a 155 lb male with notable PRs of 18:18 5K, 39:25 10K, 1:29:01 half marathon, and 3:54 marathon. He typically runs between 20-50 miles per week at a variety of paces from 8:00-9:00 min/mile for recovery runs to 6:45-7:15 min/mile for tempo runs. He typically prefers shoes that provide some cushioning underfoot but still maintain a more firm and responsive feel.
Editor's Note: As always, the views presented on this website belong to myself or the selected few who contribute to these posts. This website should not and does not serve as a replacement for seeking medical care. If you are currently injured or concerned about an injury, please see your local running physical therapist. If you are in the Los Angeles area, I am currently taking clients for running evaluations.
Contact us at doctorsofrunning@gmail.com
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