Does Active Flexibility Reduce Speed and Quickness?

Question

I am training for basketball/football to get Faster with Speed.

Currently exercising in "Dynamic Flexibility" and believe this can help extend leg range, and obtain faster strides to a certain extent (see track and field picture below). Question is, will "Active Flexibility" reduce speed quickness? Here is my theory :

In Dynamic Flexibility, a person tries swing kick the leg out high as possible. This gives you the higher stride range. WITH NO Active Flexibility, the leg will automatically spring recoil back to original position, since the lack of flexibility will pull it back. This allows body to work like a elastic spring coil.

When training for Active Flexibility, like cheerleader picture below, The leg will not retract back fast enough since the flexibility exists. Let me know what the studies show, or what the correct answer is.

Definitions:

In Dynamic Flexibility, person tries to swing kick their leg up as possible with momentum.

In Active Flexibility, person tries to extend their leg high as possible without any support or momentum.

Answer 1

If I am interpreting your question correctly, it boils down to something like

"If someone has a muscle that can be stretched further, would it have less explosive potential?"

TLDR: Probably not. Even if it does, the effect is likely minimal, and the injury protection benefits you get from staying flexible are worth the slight performance decrease. Dynamic stretching has been shown to have the greatest increases on explosive performance out of the different types of stretching.

the leg will automatically spring recoil back to original position, since the lack of flexibility will pull it back. This allows body to work like a elastic spring coil.

This is a response called the myotatic/stretch reflex. It is a protection against tearing muscles and is involuntary. It is commonly used in powerlifting during the squat to help them change direction at the bottom of the lift. This is why it is so much easier to "bounce" at the bottom of a squat even though there isn't anything it is physically bouncing off of. I haven't ever heard of it being used in sprinting, but I suppose it is the same concept, confirmed by this 2001 study, showing enhanced stretch reflex contribution to force production in sprint trained athletes.

When training for Active Flexibility, like cheerleader picture below, The leg will not retract back fast enough since the flexibility exists.

If the cheerleader would quickly extend the leg to that position without warming up first, she would experience the myotatic stretch reflex similar to anyone else. The main difference is simply that it would happen at a different location, but it would still happen. I can't find any evidence that it would be a stronger or weaker contraction just because she is more flexible.

There is a 2019 meta-analysis attempting to clear up some previous research on different types of stretching before muscle strength and power performances. In this article, it talks about how static stretching has been shown to decrease performances slightly (1-2%), but that it can still be useful to prevent musculotendinous injuries, so they recommend that static stretching should cautiously be applied. Dynamic stretching on the other hand, has been shown to improve explosive performance by up to 10% and decrease injury rates.

The idea behind dynamic stretching is to warm up your muscles, and increase flexibility so you can perform the exercise with full range of motion easily. In this 2014 study they explored what the optimal protocol for dynamic stretching is. These stretches should simulate the exercise you are looking to do. Ideally you should be doing 10-15 reps or 10 yards 1-2 times to get blood pumping and the muscles ready.

Answer 2

No having active flexibility will not slow you down. It strengthens relevant muscles in the lower body (all of them).

Active flexibility is like weight lifting. Your dynamic stretch is plyometrics. They're complimentary and you will get more results together than individually.

https://www.frontiersin.org/articles/10.3389/fphys.2019.01026/full

Here is a study showing that 5 meter times and torque improved significantly in the combined weight lifting-plyometric group versus the plyometric group which did not improve significantly there.

To be clear, active stretching requires strength to resist the stretch. Hence the strength loss that follows long intense stretching. This is also strength building. Passive stretching does not create the same training effect.

Look into Kneesovertoesguy if you want to be athletic. You need strength in as large a range of motion as possible. If anything you want both active and dynamic stretches since one is strength and the other is athleticism, to put it simply.

Here is the beginner routine in short:

Walk backwards
Shin lift
Split squat (lunge)

and

Deep push ups
Dumbbell rows with hold at top

In-depth: Knees Over Toes Guy's Beginner Workout

How to Restore Athletic & Resilient Shoulders

Programming involves 12 weeks of slowly developing strength and flexibility generally, so go ahead and spend 12 weeks on these three. You can do them daily and go by feel. No pain. 3 sets with 5 - 15 reps is good. Focus on the muscles and getting a stretch, improve your form. Take a video or get a mirror.

After reaching the standards in that video go ahead and add these to your routine:

Calf raises w/ flexion of tibialis anterior
Incline hamstring stretch/Jefferson curl
Bodyweight leg extensions (knee against wall stretch)
Piriformus good mornings (Pigeon stretch)
Loaded butterflies (Lying leg extended wall stretch)
Wide leg loaded groin stretch (standing wide groin stretch)
ATG Split Squat with weight
Incline hip/oblique weighted raises

This is the video describing the exercises and strength standards to reach:

Knees Over Toes Guy's Mobility Checklist

After reaching 25% BW on the relevant exercises and mobility and repetition goals with no pain besides whatever soreness from other workouts, go ahead and add the next exercises to your routine.

Add Nordic Curls and Foot Lifts.

10 Reasons to Lift Weights With Your Feet

Nordic Hamstring Curl Tutorial From The Standards Program

Make sure to watch all the videos. After reaching the standards described in the videos, increase repetitions and slow down the movement to as slow as possible -- go for 1 minute ultra slow reps each exercise before doing your sport. Don't worry about progressing with these though, just stay consistent and make slight progress simple and easy.