Editor's note: article pictures feature NutriForce sponsored athletes Alessandra Pichelli (4th in the 2013 CrossFit Games) and Scott Panchik (4th in the 2013 CrossFit Games).
High intensity exercise has quickly become a growing trend within the fitness community because it allows for more work to be performed in a shorter period of time and it helps the athlete achieve higher levels of anaerobic fitness. As our lives become busier, extended workouts or high volume training methods with multiple sets and extended rest periods are not practical for the average person due to lack of motivation, attention span or their busy lifestyle (work, school, children etc.)
High Intensity strength training promotes shorter rest periods and work performed for multiple muscle groups simultaneously so that when one muscle group is resting, the other is under tension. This gets users in an out of the gym substantially faster and increases the overall intensity and perceived exertion of the workout. While research has shown that longer rest periods equate to greater gains in maximal strength, experiencing results and adaptations to exercise are not as dependent on rest periods. 
The more important aspect of high intensity exercise that has made it popular is the results. Research has shown that high intensity interval training (running, rowing or high repetition resistance training) improves anaerobic as well as aerobic endurance while moderate intensity endurance training can only improve aerobic endurance.  This is one of the basic principles of high intensity for many CrossFit workouts.
Mike Mentzer (bodybuilder who was at the forefront of high intensity strength training for muscle growth) was once quoted as saying “High Intensity Strength Training is more aerobic than aerobics”. The concept of high intensity training boosting aerobic endurance and maximal oxygen uptake more efficiently than aerobic exercise is true, however this isn’t entirely correct for high intensity strength training at lower repetitions with less explosive movements. 
However, both forms of training have been shown to stimulate growth hormone and testosterone (promoting the release of fats for energy) as well as post exercise oxygen consumption (an increase in oxygen intake following exercise to overcome the oxygen deficit created by high intensity exercise, this leads to continued caloric expenditure after the workout.) The rule of thumb here is that the best way to maximize fitness is to include high intensity interval training with your resistance training program for efficient body composition and endurance improving workouts. Research has already shown this method of training being beneficial for improving the cardiovascular system and body composition in the long term. 
This style of training presents athletes with greater physiological demands that must be overcome to sustain exercise. You need: oxygen delivery to working muscle which is required for their continued function, ATP formation which is the form of energy the body utilizes and muscle PH control as an increase in muscle acidity (H+, hydrogen ions) is reported to interfere with muscle contractions.
Improving performance alone is not enough unless you can recover adequately from one workout to the next. Muscle tissue damage from training must be repaired for proper function during the next workout and delayed onset muscle soreness from inflammation must be kept under control to ensure adequate recovery.
Key sports nutrition ingredients
The sports nutrition ingredients to look for that will support your efforts to increase exercise intensity will directly attempt to counter some of the difficulties your body will face as previously mentioned.
Agmatine sulfate to promote nitric oxide
To improve oxygen delivery, we must look to ingredients that promote nitric oxide, something typically associated with bodybuilders ‘pumping up’. The truth is that nitric oxide is a gas that is naturally released by our bodies to dilate blood vessels and improve blood flow. The ‘pump’ that bodybuilders experience is a result of blood not flowing back out of the muscle, causing muscle volume to temporarily increase. High intensity athletes will greatly benefit from nitric oxide delivering oxygenated blood to their working muscles.
One of the best ingredients for promoting nitric oxide in the industry today thanks to L-arginine’s effectiveness being debunked (for the use of sports performance) in research [5,6,7], would be Agmatine Sulfate. Agmatine is derived from L-Arginine and has brain protective properties. It inhibits NOS (nitric oxide synthase) which are enzymes that catabolize nitric oxide production form l-arginine. 
So instead of consuming l-arginine (an amino acid your body already produces) Agmatine Sulfate improves the effectiveness of your body’s own nitric oxide production by reducing the enzymes that limit its effects. NutriForce Sport’s Pre-WOD (Workout of the Day) features AgmaPure™ Agmatine Sulfate from a natural starting material that is arcaine free unlike the other Agmatine Sulfate products currently on the market.
Beta-alanine to amplify creatine's benefits
NF Sports Pre-WOD also features Creatine Monohydrate, one of the most common and researched supported ingredients for supporting ATP formation to promote increases in strength. Carnosyn® Beta-Alanine is included to reduce muscle acidosis and is research supported to improve endurance capacity when combined with creatine.
 Beta-Alanine is also supported by research to improve sprint performance and muscular endurance in college football players , improve high intensity interval training performance  and sprint performance during endurance cycling. 
Beet root for improved endurance
Additionally Pre-WOD includes ingredients like Beet Root which is growing increasingly popular in research for its endurance boosting benefits. It is available in its original version which includes a high dose of caffeine as well as a caffeine free version that includes a high dose of central nervous system supporting vitamin B12. Both versions however include Taurine to help promote the regulation of adrenal side effects from caffeine and Tyrosine to promote focus.
BCAAs to promote recovery
To promote proper recovery from exercise, the most fundamental thing you can do along with your healthy diet is ensure adequate protein intake. Athletes looking for a boost in recovery through supplementation due to the stress of high intensity exercise will turn to BCAAs (Branched Chain Amino Acids) for help.
These are essential amino acids: Leucine, Isoluecine and Valine that are considered to be the most vital for anabolic signaling and they are one of the reasons whey protein is considered to be a superior source of protein in conjunction with exercise (whey protein has a higher concentration of BCAAs than other leading forms of protein as well as a faster digestion time). Supplementation of these amino acids independent of protein has been supported by research to: improve the anabolic activity of protein sources other than whey , reduce muscle loss when you’re unable to train  and aid in the promotion of recovery and muscle growth even if you’re already supplementing with protein. 
There are many BCAA products on the market, but only Natural Amino from NF Sports includes Cherry Pure™, a tart cherry extract supported by research to reduce muscle pain caused by inflammation and recovery. [16-18]
In today’s world the general public is receiving more and more information in regards to their health without the time or motivation to follow through with improving their current state. High intensity exercise programs not only shorten the duration of activity to accommodate for time (when performed independently), but they also incorporate group training and instructors who aid in motivation (ex: CrossFit).
Proper nutrition as always is necessary to support energy levels and results from exercise. However proper supplementation will ensure you can perform optimally and recover from every workout, furthering your progress towards better results. Pre-WOD is to be taken 20-30 minutes before exercise and Natural Amino can be taken before or after exercise.
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