Asset 19 angle-down-bold angle-left-bold angle-right-bold angle-up-bold Asset 10 certifications Asset 14 close-bold close Asset 8 Asset 12 menu Asset 18 Asset 17 Asset 6 Asset 16 Asset 9 Asset 15 Asset 11 Asset 13

Get answers to all your questions!

Things like:

How long is the program?
Is the program and exam online?
What makes ACE's program different?

Call (888) 825-3636 or Chat chat icon now!

June 2011

P90X, Insanity and Rushfit: A Side-by-Side Comparison of TV’s Most Popular—and Extreme—Workouts

3 programs


P90X™, Insanity™ and Rushfit™—turn on your TV or computer, and you’ll be hard pressed to miss an infomercial from one of these products claiming that it will transform your body into the “best shape of your life.” Given their extreme popularity (and subsequent profitability), it’s no surprise that these programs have spawned sequels and imitators. Interestingly, each product includes some slick marketing educational piece demonstrating the program’s revolutionary training method for shaping your physique, whether it be through “Muscle Confusion,” “Max Interval Training” or “High Intensity Interval Training.”  Hardly revolutionary, these are training modalities that are generally categorized under Metabolic Conditioning (MC). After all, years before these programs existed, renowned researcher Dr. William Kraemer, a professor of kinesiology at the University of Connecticut, Storrs, demonstrated the merits of muscle confusion (non-linear or undulating periodization), including the ability to induce greater levels of metabolic stress and adaptation upon the body. And Tabata, LaForgia and colleagues demonstrated the benefits of high-intensity interval training (H.I.I.T.) approximately 15 years ago. BeachbodyTM (which produces both Insanity and P90X) and others have successfully turned these concepts into revenue-generating goldmines. Of course, popularity is no guarantee of effectiveness, so ACE decided to put P90X, Insanity and Rushfit to the test in a head-to-head match-up to evaluate each on the basis on efficacy, science and safety.

A Brief Review of Metabolic Conditioning

Before we get started, let’s briefly review the overall concept of metabolic conditioning (MC), which is defined as training that incorporates more integrated (whole-body), high work rate–type exercise sessions of moderate loads (resistance), coupled with shorter active recovery periods (activity during recovery) or even no-recovery periods. One key goal is to boost caloric expenditure during and after workouts (i.e., excess post-exercise oxygen consumption, or EPOC). This form of training is generally achieved through a combination of one or more of the following:

  • Manipulating load (force generated) or the amount of resistance

  • Manipulating the volume of work performed (usually quantified by the amount of sets times the number of repetitions performed in a session)

  • Manipulating power or the rate at which work is performed

The initial strength improvements often witnessed early in a program are attributed more to neurological changes within the body as opposed to increases in muscle mass or size.

Metabolic conditioning represents many different things to different individuals. To the athlete, it is specific training that mimics the demands of their sport—more specifically, the movement patterns and energy pathways needed for performance. To occupational professionals (e.g., firefighters, military servicemen or -women), tactical metabolic conditioning is task-specific, preparing them to perform their jobs successfully, efficiently and free from harm. For most people, however, MC is really just about health and fitness, with workouts designed to focus primarily upon helping individuals lose weight by increasing the number of expended calories during exercise and recovery. To a lesser extent, they also emphasize building muscle mass, which in turn increases the body’s metabolic flame (the increase in resting metabolism associated with having more muscle tissue). Contrary to many of the testimonials offered within infomercials, the reality is that while muscle conditioning (endurance, toning, etc.) is a likely outcome, most adults are lucky if they achieve significant muscle gains during these relatively short, defined program timeframes (e.g., 60, 90 days or eight weeks). While muscle typically takes four to six weeks after beginning a workout to start showing any increase in mass and size, a majority of research only shows adults gaining 2 to 4.5 pounds during studies lasting eight to 52 weeks.

Initial Product Impressions

Through both infomercials and the Web, all three products utilize an effective marketing strategy to capture interest, especially through vicarious experience (seeing others successfully performing the workouts). Thus, after ordering each product, task number one was to review the introductory segments of each program, then take more time to review all the DVDs. Table 1 compares the costs, requirements, and overall appeal of the host and presentation of the workouts, while Table 2 details the goals, objectives and format of each program.


Table 1: Initial Product Impressions

Category Rushfit™  Insanity™ P90X™
Cost $89.99 (+S/H) $119.85 (+S/H) $119.85 (+S/H)
Website URL

Initial Impressions from Web site and Introduction DVD

Overall Appeal Engaging, although the scale of the production is much smaller than the other products
• Appears niche-specific with celebrity MMA fighter Georges St-Pierre, which could be interpreted as either positive or negative, depending on one’s interest level in MMA
• St-Pierre introduces his trainer, Erik Owings, who is the program creator and exercise leader
Very engaging and inspirational, which is   Beachbody’s signature style.
• Utilizes a strategy of targeting one’s competitive fervor and baiting consumers to step up to the challenge
Very engaging and inspirational, which is  Beachbody’s signature style.
Delivery DVD product attractively bundled and presented; includes Web site support and extras DVD product attractively bundled and presented; includes Web site support and extras DVD product attractively bundled and presented; includes Web site support and extras
Host Delivery and Style Owings adopts a straight-forward, directional style of coaching (instruction).
• Clear and concise, but may be perceived as a little dry at times
• Scientific explanations are offered at an appropriate level for consumers.
St-Pierre takes on a supportive role in coaching—English may not to be his primary language and his comments and content are sometimes difficult to understand.
Shaun T (creator) adopts a directional style of coaching (instruction), blending it with street vernacular.
• Scientific explanations are offered at an appropriate level for consumers.
• His lack of scientific knowledge is clearly evident in his instructional inconsistencies and coaching miscues.
Tony Horton (creator) adopts various coaching (instruction) styles, from counseling to directional.
• Very engaging speaker and quite comical
• Easy to comprehend with a comforting delivery (reassuring for novice exercisers)
• Scientific explanations offered at an appropriate level for consumers
Additional Requirements No investment into additional products or equipment needed outside of the recommended 2–25 pound dumbbells, a stopwatch and an exercise mat
• A simple nutrition plan is included (no supplements needed). 
• Barefoot training (while appealing to me, perhaps not for everyone)
No investment into additional products or equipment needed except for perhaps a stopwatch
• Beachbody is a master of the upsell (tying additional revenue streams to its products). 
* Beachbody’s programs are directly linked with sales of their supplements and shakes.
Requires significant investment into purchasing fitness equipment to perform workouts (e.g., dumbbells, pull-up bars, yoga blocks, all sold by Beachbody)
• Likewise, Beachbody ties additional revenue streams to their products—in this case, an extensive supplement line.




Table 2: Program Objectives, Format and Details

Category Rushfit™  Insanity™ P90X™
Overall Physiological Goal(s) Consistent with the primary goals of MC—lose weight and improve conditioning and definition
• Greater emphasis on muscle endurance than on muscle building or strengthening
• Offers a variety of exercises to develop skill-related parameters
• Attempts to induce metabolic stress by manipulating program variables (load, volume, etc.) and training modes (endurance, power, quickness, etc.) in a non-linear fashion
Consistent with the primary goals of MC—lose weight and improve conditioning and definition
• Emphasizes muscle endurance and cardio training
• Skill-related training emphasizes plyometrics (jumping drills used to develop power) and other skill-related parameters to a lesser degree
• Attempts to induce metabolic stress by manipulating program variables (load, volume, etc.) and training modes (endurance, power, quickness, etc.) in a non-linear fashion
Consistent with the primary goals of MC—lose weight and improve conditioning and definition—but also emphasizes (as an option) muscle building and strengthening
• Offers a variety of exercises to develop skill-related parameters
• Attempts to induce metabolic stress by manipulating program variables (load, volume, etc.) and training modes (endurance, power, quickness, etc.) in a non-linear fashion
Format 6 DVDs (5 + bonus), each with unique training objectives
• 8-week program starts with general conditioning then progresses to a more technical and tactical approach
• Training calendars (plan) are provided for beginner, and advanced conditioning levels, including recovery days
10 DVDs (9 workouts + Fit Test)
• 60-day training calendar is divided into 2 x 4-week training phases, separated by a 1-week recovery period
• While each workout is labeled uniquely, they generally fail to differentiate significantly between workouts

13 DVDs (12 workouts + extra DVD)
• 90-day program divided into 3 training blocks, each with 2 phases (3- to 4-week adaptive or mastery phase and 1-week recovery phase)

3 training programs:
• Classic: regular program
• Doubles: includes additional cardio exercise
• Lean: more toning and less strength training

DVD Workouts • Strength and Endurance
• Explosive Power Training
• The Fight Conditioning Workout
• Abdominal Strength and Core Conditioning
• Full-body Strength and Conditioning
• Bonus DVD: Balance, Agility and Stretch
• Fit Test
• Plyometric Cardio Circuit
• Cardio Power and Resistance
• Cardio Recovery
• Pure Cardio and Cardio Abs
• Core Cardio and Balance
• Max Interval Circuit and Fit Test
• Max Interval Plyo
• Max Cardio Conditioning and Cardio Abs
• Max Recovery
• Chest and Back
• Plyometrics
• Shoulders and Arms
• Legs and Back
• Chest, Shoulders and Triceps
• Back and Biceps
• Ab Ripper X
• Cardio X
• Yoga X (recovery program)
• Kenpo X (recovery program)
• X Stretch (recovery program)
• Core Synergistics (recovery program)

Program Specifics

Training Sessions 5–6 days/week
Beginner Program:
• Add cardio 2–3/week for 30 min, progressing to at least 40 min at 70–80% of maximum heart rate (MHR) 
Intermediate Program:
• Add cardio 1–2/week for 30 min, progressing to at least 40 min at 70–80% MHR
Advanced Program:
• Add cardio 1–2/week for 30 min, progressing to at least 40 min at 70–80% MHR
6 days/week
Follow DVD programs
6–7 days/week
Follow DVD programs
Session Duration • Uses a consistent warm-up/cool-down plus stretching program (approx. 16–20 min)
Workouts: 5 circuits (some repeated) x 5 min each, with approx. 60-sec recovery between circuits
• Uses consistent warm-up circuits/cool-down plus stretching program (approx. 12–25 min)
Workouts: 20–50   min, using repeated circuits of varying durations
• Uses varying warm-up/cool-down plus stretching program (approx. 12–15 min)
Workouts: 20–50 min, using repeated circuits of varying durations
Program Layout Three Program Levels:
• Beginner levels follows lower volume (frequency) and intensity (DVD program) to develop base conditioning
• Intermediate and advanced levels increase training volume (frequency) and intensity
• Program layout is generally consistent (i.e., specific programs on set days, and programs repeat on consistent basis).
Month 1: 5 DVD programs (all without word “Max” in the title)
• 6 days training, plus Sunday recovery
• No apparent rhyme or reason to program selection or sequence (i.e., some programs offered more frequently, and intervals between same workouts varies from 4 to 7 days) 
Recovery Week: 1 DVD program 6 days in a row
Month 2: Remaining 4 DVDs coupled with previous ones
• 6 days training, plus Sunday recovery
• Again, no apparent rhyme or reason to program selection or sequence (i.e., some programs offered more frequently, and intervals between same workouts varies from 4 to 10 days) 
Three Phases:
Training Block 1:
• Weeks 1–3 (Adaptive and Mastery Phase) feature split routines focusing on specific body parts
• Week 4 (Recovery Phase) features lower-intensity, active-recovery workouts
Training Block 2:
• Weeks 5–7 (Adaptive and Mastery Phase) features split routines focusing on specific body parts, workouts change slightly from Block 1.
• Week 8 (Recovery Phase) features lower-intensity, active-recovery workouts (same as Block 1)
Training Block 3:
• Weeks 9 & 11 repeat Block 1 (week 1–3 workouts)
• Weeks 10 & 12 repeat Block 2 (week 1–3 workouts)
• Week 13 (Recovery Phase) features lower-intensity active recovery workouts (same as Block 1)
• Features 3–4 weeks of higher-intensity training, plus 1 week of lower-intensity recovery workouts
• Follows more traditional resistance-training format with split routines, which allows adequate muscle-group recovery


How Do the Three Programs Measure Up?

The three programs are compared side-by-side for overall content, quality, training purpose(s) and strengths. A 1 to 10 scoring system (Tables 3, 4 and 5) is used for qualitative and quantitative purposes to evaluate each parameter measured, with a “1” indicating “poor” and a score of “10” indicating “excellent.”


Table 3. Program Specifics

Category Rushfit™  Insanity™ P90X™
Program Specifics
Health-related Parameters (1-10 scale) (8)
Emphasized endurance over strength
Cardio component is weak
Sound flexibility programming
Emphasizes cardio and endurance over strength
Flexibility programming is questionable (static after warm-ups, wrong cueing of muscle groups)
Emphasizes almost all parameters of fitness
Sound flexibility   programming
Skill-related Parameters (1–10 scale) (9)
Good variety of exercises and integrated movements to train these skill variables, good emphasis on quickness
Primarily power (low-to-moderate plyometric based), with some attention to other skill variables
Good variety of exercises and integrated movements to train these skill variables
Program Design and Progression (1–10 scale) (8)
Science-based design and progression
3 programs for different conditioning levels
Good variety of exercises (not too many), but arranged conveniently in 5-minute circuits
Cardio programming guidelines are weak
Little clarity or evidence of science in exercise selection or program design
Utilizes numerous exercises, but many exercises are indistinguishable from each other
Science-based design and progression, follows traditional split routines, becomes repetitive in Block 3
Utilizes numerous exercises, which is good in terms of variety, but is sometimes confusing

Recovery Periods between Bouts and Sessions (1–10 scale)

Good use of active recoveries; decent muscle-group recoveries between sessions; excellent plyometric design and use of work-to-recovery ratios
Good use of active recoveries; poor muscle-group recoveries between sessions; alarming plyometric design and use of work-to-recovery ratios
Good use of active recoveries and muscle-group recoveries between sessions;
solid plyometic design and work-to-recovery ratios
Safety Disclosures
Prior to Exercise (1–10 scale)
(10) (10) (10)
Overall Program
Safety—Reducing Potential for Injury (1–10 scale)
(9) (4)
High plyometric volume, lack of biomechanical coaching and knowledge, lack of understanding of energy pathways (i.e., appropriate work-to-recovery ratios) mean this program increases the risk of excessive fatigue, compromised technique, muscle soreness and possible injury
OVERALL: 53/60
36/60 53/60




Table 4. Coaching and Delivery

Category Rushfit™  Insanity™ P90X™
Coaching and Delivery
Delivery and Motivation (1–10 scale) Erik Owings (7)
Offers clear instruction on exercises and modifications
An effective coach, but may not be charismatic enough for the consumer
Georges St-Pierre (5)
Messages lack clarity and he is sometimes difficult to understand
Shawn T (8)
Inspiring and engaging speaker
Tony Horton (10)
Inspiring, engaging speaker and establishes rapport effectively with participants; injects humor effectively
General Subject Matter Knowledge (1–10 scale) Erik Owings (9)
Georges St-Pierre (5)
Shaun T (6) Tony Horton (9)
Coaching Cues and Correctness (1–10 scale) Erik Owings (9)
Thorough review and instruction on the foundational movements, although he does miss key technique cues
Cognizant of movement quality; coaches form using feedback throughout workouts
Shawn T (4)
Lack of foundational science knowledge (physiology and kinesiology) evident in coaching cues; regularly overlooks biomechanical mistakes
Incorrect identification of muscle function (e.g, role of core, stretching hip flexors)
Tony Horton (8)
Thorough review and instruction on the foundational movements, although he does miss key technique cues
Cognizant of movement quality; coaches form using feedback throughout workouts
During stretching, confuses dynamic with ballistic stretching
OVERALL: Erik Owings 25/30
18/30 27/30



Table 5. Specific Program Components (Assessments, Warm-up and Cool-down)

Category Rushfit™  Insanity™ P90X™
Initial Assessments (1–10 scale) (8)

Total number of repetitions performed in 60 sec with 20-sec recoveries

Test Battery:
Air squat

Number of tests is appropriate

Strategy of maximal repetitions in 60 sec promotes poor technique and perception of failure

Tests primarily assess muscle endurance, which is relevant as they reflect key body movements

Sequence alternates nicely between body segments to allow for appropriate recovery and avoid compromise in technique

More complex/power-type exercises should be assessed first before progressing to simpler, smaller muscle groups; sequence to allow muscle group recovery

Total number of repetitions performed in 60 sec with approx. 60-sec

Test Battery:
Power jumping jacks
Power knees
Power Jumps
Globe Jumps
Push-up jacks 
Plank obliques 

Too many tests, as they are redundant, thus unnecessary

Tests primarily assess anaerobic endurance, muscle endurance and power, balance and, to a lesser extent, coordination

Strategy of maximal repetitions in 60 sec promotes poor technique and perception of failure

Poor sequencing between body segments with inadequate anaerobic energy pathway recovery within same muscle groups (e.g., introduces push-up jacks and plank obliques at very end rather than interspersed between lower-extremity tests)

Begins with simpler, lower-intensity movements that induce fatigue before testing compound, complex movements later


Total number of repetitions performed to the point of fatigue (POF) with 1- to 4-min recoveries

Offers passing criteria for men and women for each test and allows modifications as needed

Test Battery:
Vertical jump
Toe touch
Wall squat
Biceps curl
In and outs
HR (heart rate) maximizer

While 8 tests is a lot, each assesses different parameters and muscle groups and is, therefore, appropriate

Recovery intervals are more than adequate

Format (reps to POF) is more appropriate than 60-sec reps

Sequence is well designed with power/strength first, progressing to endurance and aerobic capacity

Bases of passing criteria scores is unclear

Warm-ups (1–10 scale) (9)

Good use of warm-up and dynamic movement (approx. 60 sec per movement)

Sequence and planes of movement could be better arranged (i.e., build movement complexity, static-to-dynamic base of support, sagittal to transverse plane)

Misses overall goal of dynamic warm-ups—gradual preparation of various systems; warm-ups increase intensity much too quickly

Inappropriately uses static stretching after warm-ups for plyometric-based workouts

Various stretches are incorrectly performed and miscued

Nice combination of general movements, progressing by building complexity and intensity

Utilizes both dynamic movements and some static stretching (not bad if it complements dynamic movements)

Confuses explanation between ballistic and dynamic movement
Cool-down (1–10 scale) (8)

Not much cool-down offered, but overall solid, post-exercise static stretching

Nice, gradual cool-down with static stretching, but miscues certain muscle groups (e.g., hip flexors)

Too short, especially for deconditioned individuals who will experience soreness with strength training; solid, post-exercise static stretching
OVERALL: 25/30
17/30 26/30


Table 6 provides a cumulative score to reflect the various components of the actual exercise programs, but unlike golf, a low score is not desirable.


Table 6. Overall Scores

Rushfit™  Insanity™ P90X™
Overall Scores 103/120
  71/120 106/120


Scientific Value: Evaluation, Appropriateness and Safety

Rushfit: Overall Exercise Program Impressions

Trainer Erik Owings demonstrates a solid understanding of science, exercise programming and progression. This program offers foundational instruction of key movement patterns that include squats, lunges, push-ups, sit-ups, rotations and dumbbell exercises, but he does miss some important technique cues (e.g., hip-hinging, lumbar stability) and key compensations, such as St-Pierre’s lack of mobility during squats, during which his feet fall into pronation and his heels lift during the lowering phase. This is a bit concerning given the repetitive nature and complexity of some of these exercises and movement patterns.

However, Owings clearly is knowledgeable about training the body and energy systems, as evidenced by his progressions and work-to-recovery ratios (e.g., during his plyometric intervals, he incorporates appropriate work-to-recovery ratios. He also demonstrates easier exercise alternatives and modifications for many of his movements for novice exercisers.

The exercise and movement patterns selected mimic various activities of daily living while also introducing a variety of basic movements and techniques needed by the MMA fighter (especially in The Fight Conditioning Workout). All the participants perform the workouts barefoot, much the way an MMA fighter trains and fights. While I personally believe we all need some form of barefoot training, not everyone should or will want to train barefoot. This does not imply that these workouts cannot be performed with shoes on, but I think some discussion on the matter would have been helpful.

The workouts offer a comprehensive approach to MC training that targets a variety of the health-related parameters of fitness (endurance, strength, flexibility and cardio) and the skill-related parameters of fitness (power, agility, balance, coordination and quickness).

Insanity: Overall Exercise Program Impressions

From a scientific standpoint, what is most alarming about the Insanity program is the overall lack of understanding of science, programming and how to effectively train the energy pathways. This is evident from start to finish. For example, DVD #1 features a battery of eight fit tests, each challenging the exerciser to complete as many repetitions of a particular movement in 60 seconds, separated by brief 30- to 60-second recovery intervals. Given the protocols selected, sequence of testing and the work-to-recovery ratios, one must question the validity and purpose of this battery. A good test administrator recognizes the need for purposeful tests that avoid redundancy, utilizes a progressive test sequence (assessing more compound movements first) and also allows for appropriate muscle and energy pathway recovery between assessments. All of these elements are missing, as the tests induce partial fatigue with simpler movements before the more complex and challenging protocols are conducted. Additionally, it strings together a series of almost redundant jumping drills in succession before concluding with two assessments emphasizing the upper extremity. Even the most basic of circuits alternates between the upper and lower extremities to allow for appropriate recovery.

Equally concerning is the intensity of the warm-ups, which last approximately 10 minutes and have the models sidelined in exhaustion. This is followed by approximately five to eight minutes of static stretching, which makes little sense given the mostly plyometric-based training that follows. On a positive note, however, a static stretching component is appropriately included in the post-exercise segment.

The coaching cues and exercise instruction are poor. The introductory DVD begins with some basic instruction and a review of four basic movements that are used frequently throughout the program—jumps, squats, planks and a C-sit. Not only are most of these movements instructed incorrectly, but many of the technique instructions are simply read from a checklist, with almost no explanation or demonstration to the end-user. Additionally, on countless occasions, the trainer emphasizes a specific technique in one area while neglecting other more significant compensations (e.g., missing repeated valgus stress in the knees during jump-landing in many of the female models, while demonstrating a firm core). Most experts agree that it is not advisable to introduce jumping activities until you have successfully instructed individuals how to land correctly, a basic premise omitted with this program.

While each workout features a unique (albeit similar) title, it is almost impossible to make sense of each workout’s objective or differentiators, other than simply inducing fatigue and exhaustion with repetitive exercises and to burn calories. This suggests that the trainer, Shawn T, simply devised a series of exercises (emphasizing low-to-moderate lower-extremity plyometric exercises), then randomly assigned them to different workouts without rhyme or reason.

Dr. Donald Chu, a leader in plyometric training and research, has long suggested that appropriate plyometric volumes for athletes should be based upon training experience and intensity, and determined by the number of foot or upper-extremity contacts. While most of Insanity’s drills qualify as low-to-moderate intensity drills, the number of foot contacts featured in several sessions is almost double the number suggested by Chu, which raises concerns about repetitive micro-trauma or overuse.

No programming philosophy appears to exist for how the workouts are sequenced during the “circuits” (e.g., alternating upper and lower extremities or push-pull movements), and DVDs labeled as “Max” are simply longer workouts. Almost every DVD involves jumping, along with static and dynamic balance drills (to a lesser extent). The “Max Interval Plyo” workout primarily targets muscular endurance and only has four true plyometric exercises. Given their complexity and increased potential for injury, plyometrics are traditionally performed early in a session.

Curiously, Cardio Abs is filled with jumping activities, and the Core Cardio and Balance workout introduces three true balance exercises during the last 14 minutes of the workout. Again, balance training is traditionally positioned toward the earlier phases of a session when concentration levels are higher (e.g., during dynamic warm-ups).

Exercisers are frequently asked to monitor heart rate (HR), but no information or explanation is offered regarding target HR zones or appropriate HR training intensities.

While this program demonstrates popularity among competitive, athletic individuals, perhaps creating a cult-like following, it does present a myriad of concerns for the average deconditioned individual who is simply trying to improve his or her overall health and fitness. Although Insanity’s effective marketing campaign clearly states this “program is not for everyone,” part of its success is attributed to how effectively it baits one’s competitive fervor, whether conditioned or not.

For the average person, Insanity’s exercise intensities, exercise selections, sequences, durations and work-to-recovery ratios are inappropriate and, at a minimum, may breed disappointment. When exercisers are encouraged to use outcome goals (e.g., complete as many reps as possible in 60 seconds) without adequate recovery, it is just a matter of time before individuals begin to perceive failure if they are unable to complete some (or even most) of the assigned drills.

P90X: Overall Exercise Program Impressions

One of the first things that is evident from the P90X DVDs is the charisma and humor that characterizes Tony Horton’s teaching style. He possesses a strong ability to engage participants and build rapport effectively, demonstrating skill sets so critical for success when working with people. Additionally, his sense of humor certainly helps alleviate the anxieties many people possess associated with exercise. Undeniably, these traits probably account for much of the success his program has enjoyed.

Metabolic or physiological stress, or “muscle confusion” as he calls it, is nothing new, but he has developed a comprehensive system that puts it into practice. His program design, while not perfect, as no program ever is, is deeply rooted in science. It is evident that he has gone to great lengths to develop his program and consider which of the various parameters of physical fitness should be included. He identifies appropriate exercise modifications for more inexperienced individuals, understands how to train muscle groups (split routines) and how to sequence exercises with appropriate recovery intervals. Although he does miss key biomechanical flaws and cues during his instruction and coaching of various exercises, he is attentive to safety and his instructional cues are generally solid.

Unfortunately, one disappointing aspect of P90X is the need to make a considerable investment into ancillary equipment to complete the workouts. Unlike the other products, the muscle-strengthening focus of P90X requires resistance equipment, which may come as an unexpected surprise to many consumers. While this equipment is readily available within the confines of a commercial gym, most people intend to perform these DVD-based workouts at home. It is no surprise, then, that Beachbody offers all of the necessary equipment for purchase on its Web site. Of course, these items can also be found at most sporting-goods stores, as well.

As with Insanity, exercisers are frequently asked to monitor heart rate (HR), and check target HR zones, but little explanation is offered for why this is necessary. While there is an initial cardio test that measures recovery HR, no information or explanation is offered in the program regarding target HR zones or appropriate HR training intensities.

Dietary Components

For most people, the impact on weight loss of a calorie-restricted diet is greater than the effects of exercise during the initial phases of a weight-loss program. When one considers initial tolerance levels for exercise intensity, duration and frequency for most deconditioned individuals, and the fact that elevated metabolic rates attributed to the addition of a few added pounds of lean mass do not occur for four to six weeks, a successful program to transform the body has to include effective dietary strategies. With that in mind, let’s take a look at how the three programs stack up in terms of nutritional and weight-loss advice.


Rushfit’s nutrition guide is very simple, suggesting healthier sources for the three macronutrients (carbohydrates, protein and fats) and a variety of effective dietary strategies. The program also offers pre- and post-exercise snack or meal guidelines. While the pre-workout macronutrient proportions and hydrationstrategies fall in line with recommendations from current research, the post-exercise guidelines prove somewhat questionable. The general nature of their workouts is anaerobic endurance, which utilizes carbohydrates as a primary fuel, necessitating glycogen replenishment during recovery, especially during the first one to two hours post-exercise when recovery rates are greatest. Reducing carbohydrate intakes to 35 percent of consumed calories during this period only serves to retard glycogen recovery, which normally can take 24 to 36 hours. Consequently, progressively lowering available glycogen stores will compromise energy and performance levels in successive workouts.

The body requires carbohydrates to metabolize fats completely, and if an individual’s carbohydrates stores become progressively depleted, his or her fuel utilization will be compromised. Without adequate carbohydrates provided by the diet, the body turns to a viable alternative to convert specific amino acids to glucose for fuel or to allow it to continue burning fats. Unfortunately, 99 percent of these usable proteins exist in the form of muscle tissue; thus, this practice simply promotes attacks on muscle protein.


While protein is crucial to recovery for muscle synthesis, suggesting 55 percent of the post-exercise calories originate from protein stores is excessive. Various research studies demonstrate a 3:1 or 4:1 ratio of carbohydrates-to-protein as optimal for enhancing recovery rates after exercise.

Estimates of daily caloric expenditure or caloric need are important, yet very difficult to ascertain. Many rely upon standardized formulas (e.g., Harris & Benedict) and standard activity factors to estimate current activity and total daily energy expenditure. While these formulas are commonly used, it is important to understand that they can feature large margins of error of as much as 500 to 750 kcal per day.


Beachbody’s business model relies significantly upon income generated through their supplement line, and both the P90X and Insanity programs prominently feature supplement sales. In the interest of time, this discussion will focus upon the P90X’s Nutrition Plan, which is both extensive and controversial. Although Carrie Latt Wiatt, author of various nutritional books, is featured and appears to endorse the P90X nutrition plan (on DVD #1), this diet does deviates significantly from current 2010 USDA Dietary Guidelines.

P90X contains a three-phase nutrition plan (approximately 30 days each) and allows the user to choose the most suitable timing and plan. Each phase is significantly different and some research does support the notion of changing one's diet composition and caloric intake on a regular basis as a means to induce metabolic stress and possibly assist in weight loss.

Phase 1: Fat Shredder

Macronutrient composition: 50 percent protein, 30 percent carbohydrate, 20 percent fat

Claim: High-protein diet designed to strengthen muscle will rapidly shred fat from the body

Concerns: The 2010 USDA Dietary Guidelines suggest that 45 percent to 65 percent of total calories should originate from carbohydrate sources, yet this dietary phase targets 30 percent, an amount considered carbohydrate-restricted.

One stated objective behind this phase is to shed fat, but realistically much of the initial and rapid weight loss will stem predominantly from the loss of water rather than true fat loss. After all, carbohydrate-restricted diets gradually deplete the quantity of stored carbohydrates (glycogen) within the body, and for every gram of glycogen stored, 2.4–2.7 g of water are stored. Therefore, as these stores deplete, much of the weight lost is simply the release of water mass (e.g., sweat, urine), but this mass will return once a healthy, non-carbohydrate-restricted diet is resumed. Additionally, restricted carbohydrates diets tap energy reserves, increasing fatigue and decreasing exercise performance.

As carbohydrates stores are depleted, the body attempts to spare the remaining carbohydrates and burn more fats. However, without adequate dietary carbohydrates, the body will utilize available proteins to manufacture glucose (carbohydrate). While this may spare any attacks upon existing muscle, the process of metabolizing proteins for energy or conversion to glucose exacts a toll on both the liver and kidneys, increases urine output and possible dehydration, and, as some research suggests, may potentially increase bone calcium losses.

Following the example provided on page 5 of the nutrition plan (180-pound male classified in Level II aiming for 2,400 kcal/day), 50 percent of kcal from protein would amount to 1,200 kcal, or 300 g/day of protein. By contrast, the Recommended Dietary Allowance (RDA) for this same individual is 65.5 g/day, and leading fitness organizations suggest that a resistance-trained 180-pound male should consume 115 to 147 g/day of protein. In fact, the highest level of protein intake considered to be safe for this individual is 164 g/day, which is considerably less than the P90X guideline suggests.

Furthermore, a high-protein intake makes even less sense given that little muscle growth actually occurs during the first four to six weeks. Rather, initial strength gains are associated primarily with neurological changes that do not require mega amounts of protein to achieve that outcome.

Recommendation: Skip this phase. Be smart and follow the current USDA Dietary Guidelines. Do not restrict carbohydrates below 45 percent of total calories consumed. Keep your protein intake between 10 percent and 35 percent of total caloric intake (meets current guidelines) and not at the 50 percent this phase recommends. If you have specific needs or possess a strong desire to follow this phase, talk to a registered dietitian first.

Phase 2: Energy Booster

Macronutrient composition: 40 percent protein, 40 percent carbohydrate, 20 percent fat

Claim: A balanced mix of carbohydrates and protein with lower amounts of fat will supply additional energy for performance

Concerns: This phase is referred to as an energy booster, and individuals should probably experience greater energy levels because near-normal levels of carbohydrates are being reintroduced. Following this diet during the second month of training, when additional protein is needed for muscle building, does merit good protein intake. However, the recommendation to consume 40 percent protein and 40 percent carbohydrates is still outside of recommended guidelines for active individuals.

Recommendation: In terms of protein and carbohydrate intake, Phase 2 is considerably better than Phase 1.

Phase 3: Endurance Maximizer

Macronutrient composition: 20 percent protein, 60 percent carbohydrate, 20 percent fat

Claim: An athletic diet of complex carbohydrates, lean proteins and lower fat is the necessary combination to get the most out of this final training block.

Concerns: This training block is simply block 1 and block 2 repeated (weeks 9 & 11 = Block 1, week 10 & 12 = Block 2). While this phase matches the current dietary recommendations and most closely resembles the traditionally dietary plans of endurance athletes, a 60 percent carbohydrate intake may not be suitable or palatable for all.

Recommendation: If more cardio and endurance is the goal, then shifting toward this diet is logical. Furthermore, 45 percent to 55 percent carbohydrates, 20 percent to 25 percent protein and 20 percent to 30 percent fat is healthy and will satisfy almost all individuals.

Finally, a word about Beachbody’s supplement upsale: Arguably, supplements have value for some individuals, but are they necessary when one’s goal is to simply improve overall health and fitness? Not if a well-balanced and healthy diet is followed. However, those who sell or endorse supplements will necessarily take a different stand. Supplements should always be considered a complement to diet rather than a replacement for proper nutrition.

Beachbody’s recommendation to consume 4 to 8 ounces of fluid every 15 minutes during exercise is alarming given that leading health and fitness guidelines suggest 7 to 10 ounces every 15 minutes during exercise.


Programs like Rushfit, Insanity and P90X aim to offer a comprehensive program that will help consumers successfully reach their health, fitness and weight-loss goals. There is no question that these are ambitious goals, particularly when you consider how many variables are involved, such as diet, exercise (activity and non-exercise activity) and behavioral change. After all, these are the foundational principles for achieving that elusive physical metamorphosis so many desire, but they must never be offered at the expense of good science and safe programming appropriateness. 

While each of these programs possesses both merits and drawbacks, it is important to consider the bigger picture. What happens after the immediate workout that leaves a person out of breath and lying flat on his or her back? Or after the short-term extreme diet that promotes unhealthy weight loss? How do these experiences change the way people think and feel about their health and well-being, and how will it influence their choices in the future? A program that leaves an experienced exerciser exhausted and elated at the notion that muscle soreness is merely a forthcoming adaptation means something completely different to an individual who has been told by his or her physician to get into shape. 

To that end, we hope this evaluation provided greater insight into the strengths and weaknesses of these popular programs. If this review helps you serve the needs and desires of your clients and the public with whom you engage in fitness dialogue more effectively, then we have accomplished our primary goal with this endeavor.



Fabio Comana, M.A., M.S., is an exercise physiologist and spokesperson for the American Council on Exercise, and an adjunct professor at San Diego State University (SDSU) and the University of California San Diego (UCSD), teaching courses in exercise science and nutrition. He holds two master’s degrees, one in exercise physiology and one in nutrition, as well as certifications through ACE, ACSM, NSCA and ISSN.

Search This Issue
Keeping You Posted

Support Our Military & Grow Your Client Base

ACE has aligned with Joining Forces—a national initiative that encourages Americans to give back to service members and their families. Our goal is to provide 1 million fitness-service hours to members of activated National Guard, reservists and their families and we need your help! Take advantage of this opportunity to give back to the military personnel and their families in your community.
Read More »

All-new Group Fitness Instructor Manual: 20% Discount for ACE Pros

This all-new manual written by industry experts Lawrence Biscontini, Shannon Fable, Caroline Kennedy-Armbruster, James H. Rimmer and many others, comes with a companion DVD revealing practical strategies, cueing techniques and observational assessments every group fitness instructor should know.
Read More »

New ACE Group Fitness Workshop

Whether you’re an industry veteran or just breaking into the exciting world of group fitness, discover essential steps and strategies to unlock the critical elements for group-fitness success in ACE’s new live workshop debuting at the Zumba Conference on July 6.
Read More »

Sneak Peek: Symposium Speaker Line-Up

This year’s Symposium features world-renowned fitness industry leaders, including Len Kravitz, Todd Durkin, Jonathan Ross and many others! Sign up today to get the latest fitness information available from the industry’s most sought-after veterans. See who you'll have a chance to meet with this exciting sneak peek!
Read More »

Ace Certified News

ACE's Certified News is produced 12 times per year by the American Council on Exercise. No material may be reprinted without permission.

Publisher: Scott Goudeseune
Technical Editor: Cedric X. Bryant, Ph.D.
Editor In Chief: Christine J. Ekeroth
Art Director: Karen F. McGuire