I heard you say on a forum that speed is an example of power expression and the speed the limbs move is not such a determining factor when it comes to running speed compared to the force each footstrike delivers. Can you go into more detail on this?
Sure. When I work with athletes who want to run faster often their initial thought is that the speed at which they cycle their legs is the determining outcome for sprinting speed. Here's the example I use with them to explain the process.
Sprinting speed could be thought of as a display of power.
Power = force x speed
Sprinting speed is a combination of stride length and stride frequency.
Stride length- is a product of ground reaction forces, or how much force you naturally put put against the ground with each stride to propel you down the track
Stride frequency- is how fast your legs move or how fast you cycle your legs as you run. This is often measured in strides per second.
Sprinting speed = stride length(ground reaction force) x stride frequency (speed the legs move)
If you elevate your body off the ground in a harness to remove your bodyweight from your feet and cycle your legs as if you're sprinting, or simply lie on your back and cycle your legs as fast as possible as if you're sprinting - you might find that with either variation you can get around 5 strides per second, with good full extension. World class sprinters will cycle their legs at around this rate when they run so it's obvious that if you could cycle your legs with good full extension when you run as fast as you do when your feet are off the ground than you are already capable of cycling fast enough to run extremely fast.
However, why can't everybody run as fast as an olympic sprinter or cycle there legs with good full extension at 5 strides per second when they sprint? It's because when you add your bodyweight into the equation you add force and now not only have to cycle your legs quickly but also do so while moving your bodyweight down the track. Moving your bodyweight adds a lot of additional force to overcome.
Now you might take a beginner who fits the description above and get him out on the track and find they can only get in 3 full stride cycles per second and quickly improve this to 4 stride cycles per second. But that still doesn't compare to the 5 stride cycles per second they can get when you remove your bodyweight. So the limiting factor isn't how fast the legs move (speed) but how much force is behind each stride. As force increases from improvements in speed-strength the gap between the speed which your limbs move in an unloaded movement and the speed which your limbs move when dealing with your own bodyweight decreases.
The same type thing can be said of the vertical jump. Assuredly most here are probably capable of straightening there legs fast enough to jump 40 inches but the force they put behind that is a limiting factor.
So, when you add your own bodyweight into the equation this increases force as you now have to overcome your bodyweight with each stride. If you increase absolute or limit strength you will be able to move your bodyweight with a lower percentage of maximum effort. If you increase reactive strength, starting strength, and rate of force development you increase the speed that you can develop force but not necessarily the absolute speed that your limbs move. So, basically you can probably get as fast as you ever want, even to a highly competitive level, without really boosting the speed side of the power equation at all.
You can most assuredly dramatically increase your sprinting speed without increasing your stride frequency just by increasing your stride length naturally and this comes from improving ground reaction forces (not intentionally trying to cover more ground with each footstrike). In fact, technically I have seen people get faster and slower at the same time! They're sprint times improved, their stride length dramatically improved, and their stride frequency decreased. You can also find plenty of people who can move their limbs extremely fast without loading, but add loading or bodyweight into the equation and watch them run or move and you get a different story.
Now all this is not to say that an elite sprinter can't cycle their legs 8 or 10 times per second without any load or that you can't increase the speed at which you can move your limbs. However, the gains there are generally more limited and most of your gains will be determined by what you can do on the force side of things once you add loading in the form of your bodyweight. I hope that makes sense.
Q:I have a question concerning how you have your athletes perform drop jumps. I saw a video that said an athlete should stick the landing and then their momentum should carry them backwards. I always thought that you should land more on the balls of your feet and this you usually causes the momentum to shift more towards the toes than the heels. It would seem that learning to absorb force and then falling backward would leave the athlete in a comprimising position both on the field and as they progress to depth jumps.
It really depends but a lot of people are going to have an imbalance between the posterior chain and the quadriceps. What you're trying to do with this version of depth drops is to use the hamstring and hips as much as possible to absorb the force. To do that you need to shift the center of gravity back as far as possible so that you land with the knees behind the toes.
When you perform a depth jump you really can't engage the posterior chain to a good extent unless it's already programmed in. The natural progression is depth drops as you describe first, followed by depth drops on the toes, again with the hips back, followed by regular depth jumps. Proper form should be mastered with each version before advancing on to the others. You can watch someone depth jump and see which muscles are active or inhibited. If they land with the knees well over the toes they're using a lot of quadricep. If you're doing them yourself you should feel your butt and hamstrings engaging and not your knees/quads. Try pushing your center of gravity and hips back and you should be able to feel what I'm talking about.
If a guy has quads that are firing out of proportion to the hips/hamstrings (as many people do) then they will jump, depth jump etc. with overactive quads and develop knee problems. That version of drop jump is good to begin to reprogram the body and build proper movement mechanics.
Q: I have 2 questions:
1) Is the time of the day when I workout important ? I mean can I workout early in the morning,late at night,noon, after noon or evening and get the same results? and is it important to keep it constant?
2) is it possible to have 2-3 boxing practices plus 2-3 basketball practices in a week and not only to not overtrain but even improve in vertical and speed(since it requires a lot of gym and plyo work) at the same time? (basketball is more important to me then boxing)
A: 1. Yes, you can work out at anytime and get results but you will have a hard time doing max anything first thing in the morning so keep that in mind. For maximum power, speed and strength work it helps to be up at least 4-6 hours. It is important to keep your training time relatively constant because your body gets used to perking itself up for your workouts. If you compete then try to get in at least a couple of weeks of training at the same time as your competition. For example, if you were going to a powerlifting meet and knew you'd be lifting in the morning it would help if you can get in a couple of weeks of training in the morning so your body will be used to it.
You can also often provide a substantial kick by changing your training time. That is, if you're not seeing the results you'd like or are feeling stale then go ahead and change the time of day you train.
2. Yes, it is possible to have boxing and basketball practice concurrently during the week and improve at both but the extent you can improve both will be limited by your individual makeup. One things for sure, you won't need to do any specialized speed or plyo training!
Boxing is speed dominant and basketball is speed dominant. So, if for boxing you need a more powerful punch the boxing practice will take care of your speed but to increase strength you'll need to add weight training. Same with basketball. It will give you all the plyo and speed work you need but do nothing for your strength. But if you start adding additional sessions (weight training) to both your practices you have to make sure you pay special attention to recovery.