In-Season Strength & Conditioning: Building Speed and Power

Posted by Megan Fischer-Colbrie on Feb 27, 2017 7:00:00 AM

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In-Season Strength & Power

What happens in an elite training program as athletes move into the thick of their competition season? How do athletes take advantage of the strength and endurance they have built up so far? The short answer is it depends on the sport. The long answer I will address here because the truth is that many sports commonly value speed and power in competition. From the golf swing to the first 15 yards of a sprint, explosiveness and acceleration are traits that can be perfected with proper training.

Where Speed Comes From

Speed requires a level of strength. It makes sense that without sufficient strength to propel one’s body on land or through water there will not be significant speed available. Our preseason blog post focused on strength training as the foundation for in-season sport-specific work because of this idea. In order to discuss strength and speed, we must cover a bit of muscle physiology. There are different muscle fiber types within any muscle. We will consider two primary types—slow twitch fibers (known as MyHC I) and fast twitch fibers (known as MyHC II…these are further divided into IIA and IIX if you are interested in researching this). These variations are characterized by their function within the muscle, namely the velocity of contraction they produce. Each athlete carries different ratios of MyHC I and II in their muscles, and this, in part, is why some people are described as more sprint-oriented while others appear to have slower acceleration. Turns out that there is a relationship between maximal concentric strength and percentage of MyHC II fibers, meaning a person with a larger proportion of fast twitch fibers will be able to obtain higher muscle force and power output during fast movements than someone with a smaller proportion of fast twitch fibers.


Speed Work


How to Increase Your Speed

Okay so this seems intuitive: if you’re born with fast twitch muscles, you should play a sport because you are innately athletic. But for coaches and athletes, how can we increase speed and power beyond what we start out with? The key is to somehow increase the proportion of MyHC II fibers, but is this possible? Researchers are in consensus that heavy resistance exercise training will increase MyHC IIA and decrease MyHC IIX, while MyHC I is essentially unaffected. Translation: Your really fast fibers are traded for still fast, but not quite as fast fibers, and slow fibers are unaffected by resistance training. It may seem unfavorable to trade in your fastest fibers whose contractile velocity is the greatest, but that is only the case when looking at each individual fiber. When looking at the whole muscle, this decrease is more than outweighed by gain in contractile strength and power. The enhancement in muscle force and power following 3-4 months of heavy resistance strength training mainly occurs because fast fibers exhibit a two fold greater hypertrophy overall than slow fibers (remember how slow fibers are relatively unaltered). Voilà! You will end up with not only a bigger muscle but also one that is composed with a higher proportion of fast fibers.


Improving Your Power

Improving your power comes from how well you execute tasks in training. To develop your power, you have to emphasize the initiation of whatever propulsive movement you are about to perform. Focus on being explosive in the thrust of a squat, off the wall of a flip turn, or in the toss of a medicine ball. In the weight room and in your sport-specific training, choose to execute your drills with strength and speed, instead of going through the motions steadily. Changing how you perform a power movement will change your body’s natural inclination for that motion as the neuromuscular system adapts to the training stimulus. Repeated power exercises such as squat jumps and weighted ball tosses help the engaged muscles learn to transition from extension to contraction as quickly as possible. A recent study concluded that 4 weeks of drop jump training improved jumping performance in well-trained athletes without a concomitant change in strength. The improved performance is thought to be due to neural factors that control the jump movement. By practicing a movement with power, you can train your brain to execute the movement better without any increase in strength.



Greater speed and power are achieved through training one’s mind and body. Both require a foundation of strength training. For more information regarding preseason strength training, please check out this blog post! While everyone may start with different muscular composition and propensity for speed, each athlete can work hard to increase the proportion of fast fibers present in muscle and teach the body to be explosive. Set your mind on improving your speed and power, and get ready to see the results in this exciting phase of your season!


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Topics: S+C