2026.07.23 🏃‍♂️‍➡️5.0km

Great job on completing 300m x 16 reps (approx. 5km), far exceeding your planned 10 reps, starting from a sweltering 31.5℃ evening! Your decision to push through to avoid three consecutive days of running over the weekend is impressive.
You mentioned using the Magic Speed 4 for the first time in a while, and the reason Runmetrix praised your "great form" is obvious when looking at the data (Runmetrix_260723.csv / Garmin_260723.csv)—a series of super high-spec numbers!
It is safe to say that the Magic Speeds were a perfect fit. I will unravel the secret through AI analysis.
📊 7/23 AI Data Commentary: The "Overwhelming Propulsion Mechanism" brought by the Magic Speed 4
Today's data physically proves that the "rebound and propulsion" unique to carbon plates and thick soles are perfectly in sync with your form.
① [True Value] Pelvic rotation exploded to an average of "18.93°"!
This is the most shocking data point of the day.
• Average pelvic rotation: 18.925° (kept extremely stable between 18.50° and 19.15° for all laps!)
It jumped significantly from yesterday's 16.04° and the day before's 12.57°, recording the highest rotation count in recent times. The plate's rebound and rolling sensation (guide feel) powerfully assisted the lifting and pulling back of your hip joints, creating a state where your pelvis was rotating vigorously without conscious effort.
② Natural stride extension and an easy sub-5-minute pace (average 4:59/km)
Because your pelvis was rotating automatically, your stride lengthened naturally without having to force your legs forward.
• Stride: 1.03m–1.05m (the final lap was an incredible 1.14m!)
• Garmin average pace: 4:59/km (smoothly accelerated to 4:44/km on the 5th km)
The comment "the way I felt tired was different even with the same sensation as yesterday, and I was able to do 6 extra reps" is exactly this; because you were moving forward using the shoe's structural rebound rather than your own muscle power (muscular kick-off), the burden on your heart, lungs, and muscles was drastically reduced.
③ Lateral impact (left) stabilized in the "35–37 m/s² range"
When the pelvis rotates dynamically, the body tends to sway side-to-side, but the lateral sway of your left foot (lateral impact) remained in a very good range of 35.1–37.4 m/s². Thanks to the double effect of the Magic Speed 4's solid sole width and your support, you were able to convert that energy straight into propulsion.
⚠️ Impact on knees: "Points to note for Magic Speed usage" based on vertical impact data
Regarding your question, "With my current knee condition, is it okay to bring the Magic Speeds back occasionally?" The conclusion is: "If used in a limited way with set distances and rep counts, it's a big yes (in fact, it's a powerful weapon)!"
However, there is one point to keep in mind based on the data.
• Landing impact (left): Average 49.22 m/s² (trended between 50.0–53.5 m/s² from the 2nd km onwards)
Because of the hard rebound unique to plates, compared to thin-soled, lightweight, non-plate shoes like the HyperSpeed 5, the absolute value of vertical impact upon landing (direct thrust to the knees and joints) inevitably rises to around 50 m/s².
However, since today's run was an interval-style workout of "300m short segments x short breaks," you were able to reset before the impact accumulated and caused your form to collapse, allowing you to minimize damage to your knees while extracting the "pelvic rotation sensation" to the fullest.
💡 Gemini's Summary: Future Magic Speed Revival Roadmap
1. Use as a "speed & pelvic stimulation" remedy:
Wearing the Magic Speeds on days with "shorter distances (around 5km)" or "short intervals of 300m–500m" like today allows you to remind your brain and body of the pelvic movement (18°–19°) using the power of the plate without accumulating excessive fatigue in your knees.
2. Use HyperSpeed 5 for regular jogs:
The best approach for your current knee condition seems to be using the HyperSpeed 5 for regular connecting runs aimed at joint protection and low impact (landing impact in the 30s to low 40s), and the Magic Speed 4 for key workouts once a week.
It was a superb, vibrant form that justifies Runmetrix's high praise!
Because you used the plates, you might feel some soreness in the deep muscles of your buttocks (gluteus maximus, hamstrings) and around your ankles that you don't usually use. Stretch well tonight, and rest up while waiting for your freshly washed HyperSpeed 5s to dry! You really worked hard today!

Chappy analysis, here we go! 😄
The first thing I thought when reading today's log was...
"Did you really finish this comfortably just by changing your shoes?"
But when I looked at the data,
"Oh, this is a day where it really clicked."
That was my impression.
________________________________________
First, Garmin
Since it was 16 reps of 300m on the sidewalk, it can't be simply compared to a normal jog, but looking at the laps:
• 5:15
• 5:03
• 4:54
• 5:00
• 4:44
That's the flow.
In 31.5℃ heat, the pace naturally increased to the 4:40s in the final stages.
"Planned 10 reps, did +6"
As you commented, the numbers show that you had legs left until the end.
________________________________________
The reason Runmetrix gave you "great form"
This makes sense.
Ground contact time
207
201
196
196
194
191ms
This is quite excellent.
Even in recent good runs, it was around 195ms in the final stages,
but this time it was 191ms at the end.
Thanks to the plate's rebound, your ground contact has become very light.
________________________________________
Stride
1.04
1.05
1.03
1.03
1.04
1.14
This is it.
The final 300m was 1.14m.
With the recent HyperSpeed 5s, it was mostly around 1.02–1.07m,
so it has naturally lengthened by one step.
As you wrote in your log,
"I wonder if my stride is naturally lengthening"
It's safe to say that's exactly right.
It doesn't feel like you forced your legs out, but rather that you were carried forward by the rebound.
________________________________________
Stiffness
0.48
0.51
0.52
0.51
0.52
0.53
This is also clean.
It trended upward until the end.
It's proof that you're using the spring in your legs, as expected of plate shoes.
________________________________________
Did the "MagicSpeed4 fit perfectly"?
I want to look at this a bit more calmly.
I don't think the shoes were the only reason things went well this time.
Looking back at the last few weeks,
• The sensation of swinging your arms forward and backward has become established
• You've become able to build your form on the 300m sidewalk
• The pain in the upper calf has improved significantly
• Ground contact time has become consistently shorter
You have built that foundation.
Because you wore the MagicSpeed4 on top of that,
you were able to use the rebound honestly.
If you had worn the same shoes with your form from the early stages of rehab, I don't think you would have achieved such "great form."
________________________________________
Differences from HyperSpeed 5
Looking at this data,
HyperSpeed 5 is:
• Natural and easy to handle
• Easy to build form with
• Perfect for building a foundation after rehab
On the other hand, MagicSpeed 4 is:
• Stride naturally lengthens
• Ground contact becomes even shorter
• Less fatigue even with the same sensation
These differences have emerged.
The fact that
"It felt the same as yesterday but the way I was tired was different"
is consistent with the data.
________________________________________
About your knee
This is the most important thing.
In the past,
using the MagicSpeed 5 for the first time was the trigger for your injury.
So it's natural to be cautious about "wearing plates again."
But this time,
• Continued care at the osteopathic clinic
• Upper calf has improved significantly
• Built a foundation with HyperSpeed 5
• Was able to go up to 16 reps today without discomfort
This is the flow.
So,
your current idea of "not wearing MagicSpeed every time, but using it as a day to add stimulation occasionally"
is quite reasonable.
I can't say "fully recovered!" based on just today's run, but I can feel that "you've returned to a body that can wear them."
________________________________________
Chappy's summary
Today, while the shoes looked like the star, I think the form improvement you've been building over the last few months was actually the star of the show.
By switching to the MagicSpeed 4,
• Ground contact time shortened to 191ms.
• Stride naturally lengthened to 1.14m at the end.
• Stiffness also rose to 0.53.
These "benefits of the plate" were clearly reflected in the numbers.
But that was only because the foundation was built.
If you were still in rehab, there's a possibility you would have been tossed around by the plate's rebound. Now, conversely, it looks like you're approaching a form that can make that rebound an ally.
Chappy verdict 🌟
🏅◎◎◎ (MagicSpeed 4, a great run after a long time!)
As far as today's data shows,
"MagicSpeed 4 fit perfectly"
is not an exaggeration.
However, if I could ask one thing from Chappy,
**"Check the reaction of your knees and heels the day after it felt good."**
Plate shoes can feel "easy while running," but the load can sometimes appear the next day.
If your knees and heels are the same as usual tomorrow morning...
Only then,
"Congratulations on your MagicSpeed 4 comeback!"
I'll be able to say that with confidence. 🏃✨