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Comparing Different Ground Contact Times Between The Highest Jumpers In The World
Mar 27, 2025
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My name is Isaiah Rivera and I have the highest officially tested vertical on the planet at 50.5 inches and am the co-founder of THPstrength, a company that focuses on vertical jump training for athletes.
What makes me a little different from most athletes that jump high is that I started with a pretty low vertical and documented my entire journey on this channel. Here is my journey in a nutshell:
14: Started working out to jump higher for basketball
16: Hit my first dunk and shortly after found out about the world of pro dunking
17: Trained like a madman and hit my first between the legs dunk
18: Entered my first professional dunk contest
19: Knee pain almost made me quit dunking
20: Met my coach John Evans, who helped me get rid of knee pain
21: Won my first international dunk contest
22: Tested a 48 inch vertical and started coaching full time
24: Tested a world record 50.5 inch vertical
The reason I make so much free content about jumping higher now is because it’s a resource I wish I would’ve had when I was in high school that would’ve prevented a lot of unnecessary mistakes and injuries.
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0:00
Buckle up, folks. We have an absolute burner. You're going to need to put your thinking cap on
0:06
use your big brain, because we are going to dive into ground contact times as it applies
0:11
to the most elite jumpers in the entire world. That is what we're talking about. Isaiah and I
0:16
did a lot of prep for this specific podcast. So what we're going to do is we're going to pull up
0:21
jumps, we're going to look at ground contact times, and then we're going to look at the flight times. Why is this relevant, you may ask? Well, the shorter the ground contact time on a given collision
0:29
the more elastic that collision so if you're a human versus a deer for example and you're really
0:35
squishy on the ground for a long time that means your tendons are losing a lot of energy
0:39
in the form of heat and they're not efficient as a spring versus if you're going to eat you
0:44
yeah and the deer will eat you if you're not elastic enough the deer is going to catch you
0:50
yeah and the deer is very springy on and off the ground very short ground contact times
0:56
very long tendons and the tendons are able to deform and store a lot of energy very quickly
1:00
and then dissipate that same thing's true in i think elite athletes and we can get into the
1:05
titan conversation but i have many thoughts about this so let's uh let's get into it isaiah go ahead
1:11
let's share some jumps and let's look at some play a little a little guessing game i guess i'm gonna
1:16
i'm gonna show you some jumps and you gotta guess the flight time and the ground contact time okay
1:23
I think I can do this. All right. First up. See where we're at
1:29
We got Cole Satnam. You want to hike him? Sautnam. Sautnam. All right
1:37
So that's, he's five. That's probably eight. He's getting his head close to the room
1:43
He's five. What is he, five, nine? Yes. Five, 10 in shoes, I believe
1:47
44-inch jump. He's probably looking at eight, nine, eight, nine, eight, eight, eight
1:53
8.85. Ground contact time for Cole. He's probably like 2.95, 3.10. He is .907 seconds
2:09
Okay, I guess 8.88, 8.90. And .288 on the ground contact. I was a little long with my guess on the ground contact time
2:18
and I was a little low on the height. Oh, CJ? Yeah, this man
2:23
this is like 265 ground contact time grabs the rim i don't know how he lands it's kind of hard to
2:29
tell i'd say he's like nine three around there nine two nine three light time point nine two
2:35
three ground contact time point bro i i i almost got that perfectly all right now
2:44
let's look at i actually want to compare we have two okay so this so let this be known cj
2:50
jumped higher and he had shorter ground contact time relatively cool. Now this is Isaiah
2:55
I know all your flight time. I know what this is. But the viewers might not
3:01
0.963 and your ground contact time was 267. The flight time was actually 0.98
3:10
0.98 on that? Yup. Damn, I didn't realize that was such a massive jump. Okay
3:17
So 0.98. and ground contact times 267 then we have dax oh wait so so ground contact time was the same as cj's
3:27
almost yeah like marginally faster or the same it was the same uh it was a little faster
3:37
a marginally faster and a way bigger jump all right so then we got dak
3:41
uh in the threes 320 310 was and then flight time nine uh nine five seven
3:55
nine five seven was flight time ground contact time was i lost your deck oh 0.326 so i was
4:05
really close on that one i'm getting better as i see more of these so for perspective he had
4:11
higher not as high as isaiah's 50 wait pause this not as high as isaiah's 50 inch jump in flight time
4:18
mind you how you land plays a big part of this but you can kind of just generally if you're in the
4:23
nine fives you're probably close to 50 if you're nine fives to nine sixes you're close to 50
4:28
if you're anything over nine sixes like nine seven and up you're probably well over 50 and then at
4:35
Your ground contact times are going to be really accurate here, but Dax was way longer on the ground, way longer on the ground
4:43
but his flight time was, like, longer than anyone ground contact time
4:48
So he's spending a lot more time on the ground, but his flight time is relatively similar to Isaiah's on some of his jumps
4:54
50-inch jumps. Yeah. Now we have, I forgot his name, but Chinese Dunker
5:00
who's insane at 360 scoops. it's huge massive times nine that flight times nine five change nine six nine six one to nine
5:11
five five in that range i'd say it's like nine six two i think is this flight time there was a
5:16
huge jump you can just tell and then the ground contact time oh wait play it again
5:23
he's probably 278 280 280 282 that's my guess 282 so he was 0.955 flight time
5:39
0.955 what did i say 0.961 that was a good guess yeah so definitely you know 48 to 50 in there
5:47
somewhere he's holding the rim so that's going to elevate the flight time for sure but yeah he's
5:51
my height by the way like we're like the exact same okay and then ground contact time um what
5:55
did i say two to seven three two seven five is is actually pretty slow oh really yeah his is 317
6:04
go back that the guys that have longer flight times they don't get knee to knee
6:11
so see how he's hitting the ground and then that puts yeah that makes sense that makes sense
6:16
And the same with Dak versus someone like me and CJ are actually
6:22
that's not CJ. Let me, Oh, CJ's jump is over here. Oh
6:29
my thing's glitching. It's all right. It's all right. Just let it
6:34
I see what you're saying. There we go. All right. There we go. So now for CJ's
6:40
look at how close together, mind you, the Chinese dunker, he hit like right here like that foot that left leg was already on the ground versus cj cj also
6:52
hinges a lot yeah and then if you look at my where's my 50.5 inch jump i'm very similar to cj
7:02
it like cj but with not as much hinge like i more upright but look at like we planting those two legs way closer together in terms of the timing Yeah And then if you look at Dak Dak was a longer flight or longer ground contact time
7:21
Oh, actually look at that. It's crazy. Yeah. Keep going. He just amortizes a long time
7:31
man. That is weird. So Dak is jumping like me and CJ
7:36
but amortizing way longer. I think it has to do with the run and velocity more than anything else
7:42
He's pretty slow. Yep. He like walks in. So would you say the ground contact time
7:50
Actually, let's look at the longer. I think it's both of what you said. So like Ryan's is really long
7:55
I just looked at this one. So I know it. His flight times, it was 0.91, 0.908 or 0.92 or something
8:04
It was a 48 inch jump. and then his ground contact time is like 320 or something
8:09
330? No, 362. Oh, God. So he's basically walking in. No, I think it might
8:19
I'm not sure here, actually. Oh, yeah, they're all slow-mo. Yeah, so he runs really slow, though
8:23
He basically walks in and just does a penultimate step. Yeah. And then I don't know how he does
8:31
Does he need a knee? Yeah, he didn't need a knee. but he just he's close though yeah and he just he just lowers a lot like look how low he is
8:40
watch how much his knees bend yeah he's just really low and he rolls his knees forward like
8:46
he just amortizes over a long time so running velocity seems to be the the biggest thing and
8:52
then how low you are and how low you are which is in line with high jump um and so this is goes
8:58
into a really long and just out of i feel like people will be curious kill gannon the highest
9:04
high check we found of his 961 flight time 0.284 ground contact time so he's in that
9:11
probably 49 to 50 range and he advertises similarly to cj and i and then i know that
9:19
daniel guido's was like 220 or something like that his was crazy fast and he had like a 47 48
9:24
inch vertical so this is something i've looked at for years because i've always looked at isa i used
9:30
to think ground contact time was like one of the biggest indicators of success in jumping and then
9:34
i looked at my own and it just kind of convoluted things when i was like what this isn't like adding
9:38
up so one of the things that i've long said is ground contact time is very
9:44
the intra-rater reliability is good to to look at meaning like from person to person over time
9:51
longitudinally, you can maybe make some inferences, but when you're just looking at person to person
9:56
it doesn't necessarily work for two foot jumping because you see those examples where you'll have
10:00
a DAC that's, you know, on the ground for 320 milliseconds and jumping 50.5 and you'll have
10:06
Isaiah on the ground for 260. And that's a long time. That's a huge, huge discrepancy between
10:12
time intervals for a jump. Like in one foot jumping and unilateral, you would never see
10:17
a discrepancy like that i mean maybe we also have a jumper versus like a speed jumper but like
10:24
it two foot jump strategies are relatively similar so what were you gonna say we also have this this
10:29
is from our our thp community and i asked everybody what their ground contact times and their verticals
10:36
um and you get some interesting thing they said if they were one footer or two footer so
10:41
here we have a 32 inch vert 0.39 ground contact time and this is more average verticals right we
10:46
just looked at purely elite guys 3 7 ground contact time 30 inch vertical uh 30 inches 0.333
10:54
uh 42 inch vertical 0.283 33.3 45 josh wabell 305 so like um oh it's crazy so this one was
11:08
interesting gene perez his approach by like he's has one of the fastest run-ups i've ever seen i
11:16
might be able to find his jump uh we'll find it later but uh but yeah this is the lowest ground
11:21
contact time where i've seen from a guy that's lower than a 40 inch vert so this and this is
11:27
kind of what i was saying i think the run in blossom how much you lower is the biggest determinant of that so if you're really low you're gonna have a really long ground contact time and if you're
11:36
running relatively slower you're gonna have a really long ground contact time that pretty much coincides with what you see in high jump power jumpers have really long ground contact times
11:44
compared to speed jumpers. That's not, not always, but generally. And the reason why is because they don't have
11:49
as high of a run of velocity. Generally speaking, there are exceptions to the role. Don't get me wrong
11:54
But like Fabian, for example, his ground contact time is 220. And his, he's a massive, massive power jumper
12:02
with probably a 45 inch vertical. The same jumper or the same high jumper height
12:07
you could say like another 233 jumper, you know, they're, they could run in around
12:11
close to eight meters per second. And they might be on the ground for 180 milliseconds
12:17
That's 40. What is that? 10, 20% difference. That's huge. 20% difference is massive
12:25
You're not talking small margins. Like, you know, like 20% for perspective in terms of jump height
12:31
You're looking at, what is that? Like 10%. That's like an eight inch difference in jump height
12:36
You know what I mean? And if you're an elite guy, that's just massively different. So, you know, in my lens of things, it, I've never really looked at it as like a determinant of your success. I think that generally, your tendon properties, your jump technique, etc, you're probably going to fall in a given category, assuming your max effort. And then what you want to do is generally see how that changes over time
13:00
And what I do think happens is that as guys learn to control that speed and they learn to take that momentum upwards, generally you'll see ground contact times go down
13:11
That's not always the case, but generally I think you see a trend downwards for a given jumper longitudinally over years, their ground contact time will go down
13:20
It's not something you want to force though, I don't think. It's just adding the momentum to the approach
13:24
what i'm gathering from that is ground contact time isn't something you should seek to minimize
13:30
like i shouldn't go out and be like if i get this lower i'm gonna jump higher it's more a result of
13:36
it's a sign of other things improving so contact time is a product it is not a
13:43
cause it is it is a what is it was that cause and effect or whatever yeah it is enough it's not an
13:52
It's an effect, not a cause. It's an effect, not a cause. The cause of ground contact times being shorter
13:57
are that you're running faster. You have very good tendons or better tendons
14:04
Your rate of force development is better. Maybe you are coordinated and you're contracting muscles earlier
14:10
which is you can't control that necessarily. That's subconscious. And it's happening at a level that is not
14:18
what would you call that volitional It non And it yeah it an effect of all of the other things that go correctly or are correct right You running very fast You very low
14:34
You're very powerful. Those are the things that determine your ground contact time
14:38
You can look at ground contact time to tell you maybe about yourself. It's going to tell you
14:43
things about yourself. Maybe you can make inferences about it in terms of, okay, my ground
14:49
contact time on this jump was really, really slow versus really, really fast. What does that mean
14:53
Okay. Well, that means you probably were running faster on the day. And that means that you're
14:57
you know, you're relatively stiffer in terms of your stiffness. If it's the same jump height
15:03
uh, okay. Well, what does that even mean? Could be readiness just on the day. So that's why it's
15:09
like within a couple of months, I don't really think it means much, but when you're looking at
15:12
like a 43 inch jump in 2017 versus a 50 inch jump in 2024 you know six years later like in Isaiah's
15:22
case or seven years later or 2025 um I think it's really informative in that sense so like
15:30
I have a couple jumps where I think I sent I sent I might have sent them to you or I sent them in
15:38
chat somewhere but the first time I ever like hung on the rim or one of the first times I ever hung
15:42
on the rim, which is probably like a 32 inch jump or something like that. I was at 0.333
15:48
Then around the time where I had a 40 inch jump where I could like East Bay and that type of
15:53
thing, those were my best dunks. That was a 300 millisecond jump. And then my 50, my first 50.5
16:00
jump was like 0.28 something ground contact time. And then two years later, when I jumped
16:08
arguably a little bit higher, probably an inch, it was probably a 51 inch jump, 51.5
16:12
that was 0.267 on flight on ground contact time so you got shorter ground contact times maybe the
16:19
same jump heights in some cases yeah what was your height check uh the height check was 0.971
16:28
or are you which one are you talking about on that day your highest high check ever um
16:34
i actually don't know i can i can run it it was 0.983
16:39
it was something like oh yeah that flight time i thought you meant the ground contact oh i don't
16:44
know what the ground contact time is but i would be curious to see it yeah so the i'll do it right
16:49
now we'll pause for a brief intermission and we're back isaiah we time skipped what was it
16:58
uh 0.982 on the flight time so my highest jump ever ever or at least flight time
17:07
could have landed lower but go ahead uh and then ground contact time was 272 and this is what the
17:15
jump 272 okay so 272 is faster than your 50.5 inch jump slower than your slower than your
17:27
50.5 it's a little faster than my first 50.5 jump and a tiny bit slower than my 50.5 inch jump last
17:40
year which was probably more like 51 or 51.5 so we're looking at this kind of in between and
17:47
this is kind of marginal like these are marginal changes but it seems like your sweet spot is
17:51
between like 265 and 275 that's where you kind of fall you know for this case and the run-up speed
17:56
was pretty fast those are high adrenaline i'm full sending it yeah exactly but uh i wouldn't say it's
18:04
like you're sprinting into it you know i mean you're just paced it's very rhythmic it's very rhythmic approach so yeah i mean in in conclusion i would say you can look at these changes over
18:13
time i would encourage you to do that and see if you notice anything generally you're going to see
18:17
that you probably have an ideal ground contact time that again is in effect as a result of a lot
18:24
of other variables and i think over time it probably goes down for better jumps because
18:29
you're running faster is there any training application in your opinion i don't think in
18:36
the i i think it's no not really because it doesn't determine the training laws the training
18:42
laws stay the same. The training consequences of that are such that you're going to go general
18:49
specific. You're going to finish the year of the most specific stuff towards the end, and then
18:54
you're going to back off. Maybe potentially it determines which plyos or how you do plyos
19:00
It might change that. It might change if you want to go and lean into what Randy and Rolf have been
19:06
doing, it may change your lens on, on which exercises are specific or non-specific because
19:12
at that point you have a lot more options. If you're going to say, look, ground contact times
19:16
for guys that are jumping 50 or between two 60 or two 50 and three 30. I mean, it basically gives
19:24
you a lot more of a window of what would be considered in the specific in the weight room
19:28
Right. I mean, 300 milliseconds is a long time to generate force. So TPVs can be 0.3 to whatever
19:36
and it's relatively specific. So yeah, I think it maybe changes it in that lens
19:41
But here's the other thing is like, that's just concentric TPV. So the thing about concentric TPV is
19:47
that's half of the time that that jump was happening. Like it's possible that you were eccentric
19:54
for a brief period, isometric for a brief period and concentric for a period, right
19:58
But let's say that the period of time you were actually concentric during that jump, if it was 270, let's say that most of the time
20:03
you were concentric because that's what good athletes do, then maybe you're 180 milliseconds, maybe 200. You know, I don't think you're eccentric
20:11
the whole time or sorry, a concert the whole time and definitely not all the muscle fascicles
20:16
So even if that's the case, you're still like way shorter, you know, and then in sprinting
20:23
it's like you could be isometric or concentric almost the entire time. So it's like a little
20:28
bit different because as you get those longer intervals, it's almost impossible for you to have
20:32
a solely concentric action that's not going to happen unless you're like under 160 milliseconds
20:39
probably or 180 160 probably in that case maybe it's all isometric or all concentric because it's
20:46
almost impossible to have a full active stretch warning cycle in those cases in my opinion
20:51
for elite athletes so you know it's like you could probably build in some some specificity
20:59
and tpv exercises in that 200 millisecond range or you know i wouldn't go much shorter than that
21:05
um maybe like yeah 200 180 but the thing is in the weight room that's so fast
21:10
like you're and then the knee joint angles are knee and hip joint angles are non-specific at
21:16
that point you'd have to have you're basically doing a plyo at that point yeah like to have the
21:23
specific joint angle and tpvs is jumping it's two foot jumping like you could do like you could do
21:31
a squat jump like i don even know you need a collision and at that point yeah it just like a plyo like you doing barbell squat jumps really light and you just jumping or like you know step ups you could probably get 200 to i mean it depends on how you going to view it like let say
21:47
you're using 200 300 milliseconds for tpv you could definitely get that with probably like an
21:52
8 to 12 inch step up or something which is relatively high and in that case you'd really
21:57
have to hit the box hard the loads would have to be optimized to hit those tpv times you'd have to
22:01
play around with some stuff um another big one that they do is like a step down where they'll
22:06
use a side box similar things you're probably going to be in that 12 inch to probably like
22:11
eight inch range maybe six and then if you're looking at like squat jumps and things like that
22:16
like barbell squat jumps yeah i mean you're just going to do standard squat jumps you're just doing
22:20
plyos cleans it's variable because it it tpvs are off the floor don't really apply off a box
22:29
you might be able to get relatively high, but then you're probably pulling from like
22:33
like above the knee, pretty high above the knee. And in that case, you're
22:38
you're getting a double knee bend, which kind of changes things as well. So maybe you could bump the TPV times up quite a bit
22:43
I think that for cleans, our TPV times are what, like 0.4 generally or something like that
22:49
Off the floor or on the floor, off the floor, off the floor
22:54
I've been getting, I think in the 0.5. Okay. My TPVs. I think off the box, I'm around three, four off the box
23:02
I'm around three, four. Yeah. I don't know. You're probably similar to me. We generally fall in the same kind of range
23:08
Sometimes it's higher, but TBB is weird because that first pull, you're setting up the second pull
23:13
So it's like, if you really just want to do it, what's that
23:17
It's like, it almost doesn't count. Exactly. Yeah. Like borderline doesn't count. So yeah, it's, it's just kind of convolutes things
23:24
Um, and it makes things really complex and you have to kind of really think about it a lot
23:29
Right now I'm testing a 21 week micro cycle, 21 week, 21 micro cycles consecutively, subsequently
23:36
following this progression with one of my high jumpers and then a different high jumper
23:41
Who's also, they're both well-trained. One's elite, one's not elite, but they're both towards their genetic ceiling
23:46
So that's kind of what I'm saying is like, okay, you're both near genetic ceiling. You've both done very different things
23:51
Let's see who gets the better result. And I'm going to run them side by side using two different approaches
23:57
one is very tpv dominant and determined the other one is not more traditional long conjugate sequence
24:02
systems so we're going to see for two for one foot jumping um for sprinting i think it works
24:07
incredibly well but for for vertical jumps off one foot i'm not fully convinced yet i'm trying
24:13
to determine what uh what what the results are going to kind of indicate um i know long sequence
24:18
systems don't generally work for sprint times for elite guys in my opinion it just doesn't work
24:24
super well um from what i've seen if you run under like 10 8 you kind of got to start shifting your
24:29
training style and uh for guys slower than that long conjugate sequence systems old school stuff
24:35
multis it worked really really well but then as you shift down in the ground contact times
24:40
yeah i think that tpv stuff works really well i've seen it work really well you know but bob
24:45
you can just hit 10 meters per second in a fly that's fast that's like long jumpers hit like
24:50
maybe 10-9 like the guys that really pop up high in the air they might hit 11 meters per second on
24:56
the board fabian's a 6-9 high jumper hitting 10 meters per second at 220 guys that hit 11 meters
25:02
per second way are their sprinters you know they're 10 10-5 you know or sub 10-5 sprinters
25:07
the other thing is jumping as much as dunkers do like you're checking so many of those boxes off
25:14
too like i like i think that's why we can train with high volume and still get better and like
25:21
it's because you're the unchecked off box from jumping a lot is increasing force like how much
25:28
force can you generate uh how how the hypertrophy of the muscle how big that fiber is and i think
25:34
um i've just seen it work too many times like yeah the guy does it's hard to argue with it you
25:41
know what I mean I don't even say it's like high volume to me because like the working sets are
25:45
relatively low I've upped it to four sets of working but that's like in very very rare cases
25:50
where the athletes work capacity is really high um I've also done the opposite so it's just
25:56
yeah it's different strokes for different folks and you really have to just test things and that's
26:01
what we're always doing we're always testing and and trying things and you know really experimenting
26:06
I think Isaiah and I are big on that. We always like to specifically me, but Isaiah is willing to also test things
26:12
If there's good rationale behind it, I don't usually do the things I would do for myself with him
26:16
I'm not going to have him do eight weeks of eccentrics. I will. It's such uncharted territory, like elite two foot jumping training where it's not a team sport or you don't have that variable that I don't think it's correct to make any assumptions on your training
26:35
If you're not playing a sport, you're just trying to jump higher. It's incorrect to make a conclusion based off of a study that's on non elite athletes where they're not jumping once a week
26:45
You know what I mean? Like like they just wait. They just squatted three times a week for four weeks
26:50
And then you make a conclusion based off of your jump training where it's completely different
26:54
You're at a different level. And I think at the point where we're at, it does come down to a lot of testing
26:59
Like we're essentially testing uncharted territory, stuff that hasn't been peer reviewed and stuff like that
27:05
Yeah. And we're, we can't necessarily control for variables quite as well, but we have a lot
27:11
of considerations. It's like when you get to the end of the paper and they're like, Oh, here are some considerations for why we got these results and some con some variables that might've convoluted
27:19
the results. It's like, we kind of do that subconsciously and we account for those like
27:23
Oh, well you did sleep poorly last night. You did, didn't take as much caffeine and we did train like
27:27
this and this and this. And it's like, okay, well that could explain a lot of the discrepancy we're seeing here. So it's also repeatability. Like that's a scientific method is can, is it repeatable
27:36
You know, and there's certain things we've tested and we're like, it's repeatable. I've tested this
27:39
over and over again and guys consistently respond well to this. Um, you know, and then there's
27:44
things where it's like, this is not repeatable and it's really confusing and it's really convoluted
27:48
and it kind of just makes you think twice about things. So, yeah, I mean, that's kind of my lens
27:52
on things. I feel like it's a good place to, to, um, to close it off here. We're closing it on the
27:57
30 minute mark, which I know is fairly long for a podcast, but hopefully this was really
28:01
informative for you guys. If you're interested in getting coaching from us and diving into what is really evidence
28:08
based practice at the highest level, both taking the most current research and applying
28:14
it the best way possible, and then just testing it in real time on other athletes before we
28:18
again, test it over and over again is the results repeatable. And then we give you that product
28:24
You know, it's always improving. the product's always improving. You want that? Definitely go and sign up for coaching
28:29
I'm very confident. I don't want THB Strength to be this kind of watered down brand
28:34
It really is. When people hear THB Strength, I want to think like, oh, that's the most elite
28:38
of elite programming right there. And I stand by that. I really am proud of that accomplishment
28:43
So thanks for watching, guys. And yeah, we'll see you guys tomorrow. Happy Tuesday
28:48
Peace out. Bye
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