It's safe to say that most people reading this article are aware of the necessity of maximum strength to most athletic endeavors.  After all, most facets of strength are based on maximum strength.  Think about this...you want to become a faster runner.  Now most coaches theorize that running speed is highly correlated to two major factors: stride length and stride frequency.  There is much debate about whether or not stride length can be appreciatively increased once an athlete reaches a certain level.  This intuitively makes sense, because we never see Olympic sprinters covering the track in 8 or 10 steps!

So that leaves most of our focus on stride frequency.  Most coaches develop many methods to try and get their athletes to increase their leg turnover during their runs.  Maximal treadmill runs, high-speed leg kicking, light weight drills, etc. are all used.  While there might be some limited results gained from these methods (and I'll let you and your results be the judge in that), the development of maximal strength is perhaps one of the dominant qualities that a sprinter could develop.

Strength is defined as the ability to produce force, and it has a vector component (both a direction and a magnitude).  German researcher Schmidtbleicher theorized that maximum strength is the primary quality linked to power performance (1).  This again makes sense because you can lift, say, 50% of your maximum weight on any lift fairly quickly (at least I hope you can, otherwise there are other issues that need to be addressed!). 

Now lets imagine that you increase you maximum weight used on our target lift (for example, squats) from 400 to 450 pounds.  And lets take your initial weight used for speed reps (for this example, 50% of 400 for 200 pounds).  The 200 pounds now represents about 45% of our new maximum.  You would now be able to impart more force to the bar throughout every rep for every set.  You, in essence, have more "horsepower" to back up your lifting 

This same idea would be related to the sprinter in that their "implement" or weight used in sport is his bodyweight.  If our hypothetical sprinter increases his maximum lift in the squat or deadlift, yet remains at the same bodyweight, he is now able to display more power with every step throughout the race.  The more power he can display, the quicker his leg turnover will become, since with each step he is blasting the ground with maximum force (well beyond his maximum squat, for sure).

Michael Stone and colleagues (2) recently performed a research study on track throwers and the relationship to maximum strength.  They studied 11 throwers of high caliber over a period of 8 weeks.  Their conclusion was that, "maximum strength markedly contributes to power and explosiveness at light and heavy loads" (2).  This again would provide great insight to the notion that maximum strength improvements are necessary for power increases and performance increases in sports that rely on power output.  

Power can be trained with several methods, but for straight weight sets, loads between 45% and 65% of the athlete's maximum appear to offer the most benefit.  These numbers would change if the athlete has access to chain and band methods of altering the force/tension relationship of the exercise.  As well, shock methods or depth jumps may be utilized, which will be covered in an upcoming article. 

You should also remember that you need to factor in your bodyweight when performing exercises like squats.  To fail to do so will result in using too great a weight on certain power exercises.  The best method to do this is by using "appropriated weight", a method devised by Dietrich Buchenholz. 

To appropriate your weight in the squat, you take your 1RM and add your body weight percent factor.  This is the percent of bodyweight you are lifting in this exercise, which research has shown to be about 85% of your total weight.  This gives you your "actual weight".  You then take this number and multiply it by your desired training percent to give you a "cured percent".  Finally, take this result and subtract out your Bodyweight percent facor from above.  Your result is the "appropriated weight" that you should use.

Let's complete an example to help with understanding.  Say you have a squat 1RM of 300 pounds.  Add the bodyweight percent factor (BPF) to this.  We'll suppose our athlete weighs 200 pounds.  This gives a BPF of 170 (the weight you are squatting out of your total body weight).  So our actual 1RM is really 470 pounds. 

Now, you want to use 65% on your work sets, so multiply the actual weight by your desired percent (in this case 65%) to give you your cured percent (CP).  In our example we have 305.5 pounds as our CP.  We finally subtract out our BPF to give us our appropriated weight, which in this case is 135.5 pounds.  This should be the weight you use on your squats. 

That most people usually do is just take a straight percentage of their 1RM, which would give you 195 pounds.  This is too heavy!  You need to appropriate your weights or risk using too much weight to properly train power development.  I will touch on weight appropriation more in another article.

References:

1.  Schmidtbleicher, D. Training for power events. In: Strength and Power in Sports. P.V. Komi, ed. London: Blackwell Scientific Publications, 1992.

2   Stone, M.H., K. Sanborn, H.S. O'Bryant, M. Hartman, M.E. Stone, C.Proulx, B. Ward, and J. Hruby. Maximum strength-power-performance relationships in collegiate throwers. J. Strength Cond. Res. 17(4): 739-745. 2003.