Page 120 - Journal of Special Operations Medicine - Fall 2015

An Ongoing Series

Extreme Conditioning Programs:
Potential Benefits and Potential Risks

Joseph J. Knapik, ScD

ABSTRACT
CrossFit, Insanity, Gym Jones, and P90X are examples Keywords: exercise; physical conditioning; extreme cond-
of extreme conditioning programs (ECPs). ECPs typi- itioning program; CrossFit
cally involve high-volume and high-intensity physical
activities with short rest periods between movements
and use of multiple joint exercises. Data on changes in Introduction
fitness with ECPs are limited to CrossFit investigations
that demonstrated improvements in muscle strength, Many Special Operations Soldiers are familiar with
muscular endurance, aerobic fitness, and body composi- extreme conditioning programs (ECPs). These include
tion. However, no study has directly compared Cross- training systems with names like CrossFit (CrossFit Inc.;
Fit or other ECPs to other more traditional forms of www.crossfit.com), Insanity (Beachbody LLC; www.
aerobic and resistance training within the same inves- beachbody.com), Gym Jones (www.gymjones.com),
tigation. These direct comparisons are needed to more P90X (Beachbody LLC; www.beachbody.com), and
adequately evaluate the effectiveness of ECPs. Until others. ECPs typically involve high-volume and high-
these studies emerge, the comparisons with available lit- intensity physical activities with very short rest periods
erature suggest that improvements in CrossFit, in terms between movements, and use of multiple joint exercises.
of muscular endurance (push-ups, sit-ups), strength, and A good example of an ECP is CrossFit, which has been
aerobic capacity, appear to be similar to those seen in described by founder Greg Glassman as a “constantly
more traditional training programs. Investigations of varied, high-intensity functional movement . . . [involv-
injuries in ECPs are limited to two observational stud- ing] universal motor- recruitment patterns.” A typical
1
ies that suggest that the overall injury rate is similar to CrossFit workout involves a warm-up, a strength or
that seen in other exercise programs. Several cases of skill development exercise, and then a “Workout of the
rhabdomyolysis and cervical carotid artery dissections Day” (WOD). The WOD varies with each training ses-
have been reported during CrossFit training. The symp- sion but typically involves a 5- to 20-minute high-in-
toms, diagnosis, and treatment of these are reviewed tensity activity containing exercises that might include
here. Until more data on ECPs emerge, physical train- weight lifting (including barbells, kettle bells, and
ing should be aligned with US Army doctrine. If ECPs other devices), gymnastics, running, rowing, and/or
are included in exercise programs, trainers should (1) plyometrics. Workouts are often conducted in groups,
have appropriate training certifications, (2) inspect ex- injecting a competitive element. The WOD is available
ercise equipment regularly to assure safety, (3) introduce online for those who desire to train on their own, but
ECPs to new participants, (4) ensure medical clearance CrossFit-affiliated gyms are also available across the
of Soldiers with special health problems before partici- country.
pation in ECPs, (4) tailor ECPs to the individual Soldier,
(5) adjust rest periods to optimize recovery and reduce This report will review the available research on the ef-
fatigue, (6) monitor Soldiers for signs of overtraining, fectiveness of ECPs for improving physical fitness and
rhabdomyolysis, and other problems, and (7) coordi- will examine injuries associated with ECPs. Most of the
nate exercise programs with other unit training activi- available investigations on ECPs have focused on Cross-
ties to eliminate redundant activities and minimize the Fit and, thus, this review will necessarily be largely lim-
risk of overuse injuries. ited to this training system.

108