Building an Engine by kyle ruth

Every year at the end of the Open we sit down with our athletes to review the season and start planning for the coming year. During the review process, we ask them to identify what we did right, what we did wrong, and what held them back. Invariably, in the majority of these discussions, the athlete cites “engine” as one of their biggest obstacles. They attribute various reasons for this: “I just gassed out early”, “I couldn’t move fast enough”, or “my double-unders didn’t hold up under fatigue”. The problem with this is that engine is an ambiguous term and doesn’t help us to define what an athlete’s limiters are nor does it help us create a plan for addressing them. This blog is going to define what “engine” means, help you to assess the underlying reason for engine issues, and finish by briefly covering how to address each of the potential limiters.

Defining the problem

In my post-open discussions I try to define “engine” for my athletes as the ability to perform at high levels of power output for extended periods of time in whatever movements are required by the test. An athlete with a good engine in CrossFit™ will be able to perform equally well on a 10min Assault Bike time trial, Open 17.1 and Open 17.5. This requires the athlete to not only be fit (capacity) but also move well (economy) in squatting, bending, pressing, bounding, and a host of other complex movement patterns. In our discussions it starts to become clear that fixing engine problems is more complex than just “going harder” in training. (which tends to be the knee-jerk reaction anytime someone says they need to develop their engine)

Once we’ve defined engine more narrowly, we are typically able to better understand why their engine limitation occurs. Some perform well on erg tests of pure capacity yet struggled with a workout like 17.5 which tested their ability to use that capacity in a combination of complex movements like thrusters and double-unders. Others find that they lacked the capacity to keep-up regardless of the movements that were tested. Knowing that there are two qualities that need to be trained in order to develop an "engine" gives us better training direction than just “going harder”.

The best athletes in the world have developed the right combination of capacity and the ability to use that capacity efficiently in the movements required in the sport.

Assessing your engine:

Determining the optimal balance between capacity and movement economy in order develop an athlete’s engine can be a challenge. This is made even more challenging in a sport like CrossFit™ where there are dozens of possible movements that athletes must not just be able to perform, but rather perform efficiently. The process of assessing an athlete is extraordinarily complex and far too deep of a topic for me to cover in one blog. However I do want to provide an overview of how I would approach the assessment of an athlete’s engine coming out of the Open season.

Capacity ---->> Combo <<---- Economy

Most athletes who feel that their engine needs development fall into one of three categories: (1) they have good movement economy but lack capacity and need to spend more time developing their energy-systems and physiological limiters (2) they are inefficient at some or all of the movement patterns required for the sport and therefore cannot express the capacity they do have or (3) they are missing some combination of both capacity and economy and need general development. Identifying which category an athlete falls into can be tricky, partially because most people likely fall somewhere on the spectrum, and partially because most athletes have some “good” and “bad” movement patterns that don’t always get tested in the Open. To get a feel for the nuance involved in placing athletes into these categories, I’ve expanded them further below:

(1) Good movement economy, poor capacity - athletes who fall into this category likely perform poorly on cyclical or erg-based tests of pure aerobic power or aerobic endurance (our VO2 or Threshold energy-system training categories). On the other hand these athletes tend to be “good movers” allowing them to move efficiently in the vast majority of the elements tested in the sport. Their movement quality allows them to perform well in tests that typically bottleneck other athletes (high skill movements or chippers for example). When a high level of power output is required (like 17.1 or 17.5) they are either unable to “move fast enough” to hit their desired score, or they burn-out quickly, exceeding the capacity of their energy-systems. We can identifying these athletes by their ability to maintain movement quality under fatigue and poor absolute scores on cyclical capacity tests.

(2) Poor movement economy, good capacity - Athletes who fall into this category likely have good scores on erg-based tests of pure capacity, and some mixed tests with a dominant cyclical component (Jackie or Open 15.5 come to mind). These athletes tend to be overly tight, lacking the freedom of movement necessary to be efficient in more complex or loaded mixed movements. Couplet style tests which require athletes to move through large ranges of motion whether loaded or unloaded gas them out due to fighting against their mobility restrictions making each movement “cost more” energy. Additionally we often see significant compensation patterns, like an over-extended lumbar spine in overhead movements, that lead to a loss in efficiency. The result of these compensations is that they fatigue locally without ever fully taxing their capacity. The two biggest things to look for here are movement quality and associated compensation patterns in movement that the athlete tends to struggle with coupled with good absolute scores on cyclical erg tests.

(3) Capacity & economy combination limiter - Athletes who fall into this category tend to be relatively balanced in terms of their engine limitations, however they can fall all over the performance spectrum. These athletes tend to have decent capacity and decent movement quality, but when a workout requires them to utilize both together the compensation in one quality exposes the hole in the other. This is typically characterized by a well-balanced athlete who just needs to be able to move faster and move better in order to be more competitive in “engine” based workouts.

What to do about it

These categories are oversimplifications of the complexity that is involved in a complete assessment of an athlete. However they provide some general guidance regarding the engine training qualities that should dominate a program depending on which category they fall into. In this section we will look at an example training session for each of the categories previously discussed.

(1) For athletes falling into the first category (poor capacity / good movement) implementing appropriately targeted energy-system training protocols should result in significant improvements in engine-based metcons. Common limitations can be related to cardiac delivery, local utilization, or respiratory endurance. Below is a basic example session of a combined cyclical and mixed training session for an athlete with limited capacity.

AB - 2min @ 60% effort

AB - 2min @ 70% effort

AB - 2min @ 80% effort

AB - 2min @ 90% effort

AB - 5min @ 60% effort


AB - 30cals (10 easy / 10 moderate / 10 hard)

10 DB Thrusters @ 45#

10 Burpees to 6” touch

30 Double-unders

Rest = work

x6-8 sets


Choice cyclical - 20min @ easy recovery pace

*note that this session is designed to target cardiac delivery limitations - this is just one possible capacity limitation and wouldn’t adequately target respiratory endurance or local muscular endurance.

(2) Athletes falling into the second category (good capacity / poor movement) would likely benefit from identifying their specific movement restrictions and compensations and addressing them. As a coach, identifying particular patterns that athletes consistently struggle with (i.e. front loaded squatting, or cycling a barbell overhead) and digging into what specifically holds them back can be one of the best ways to address their movement economy. Common limitations include postural strength or postural endurance, flexibility restrictions, and breathing mechanics restrictions. Below is another basic example session targeting improvements in movement economy for an athlete with limitations in front loaded squatting.

Thoracic Movement

A. Lax Ball t-spine crunches - 2 passes

B1. Assisted Thoracic Bridge Press-ups - 2 x 3-4 slow/controlled reps w/ 2sec pause at the top; rest as needed

B2. Quadruped Position Cat-Cow - 2 x 5-6 slow/controlled reps; rest as needed (inhale on flexion / exhale on extension)


Squatting Postural Endurance / Strength-endurance

A. Front Squat w/ empty BB @3030 - accumulate 60 reps NOT for time (work continuous sets stopping before (1) significant fatigue sets in and (2) technique or mechanics deteriorate)

B. Sandbag Bearhug Front Squat @3030 - accumulate 30 reps NOT for time (work continuous sets stopping before (1) significant fatigue sets in and (2) technique or mechanics deteriorate)


Thrusters AMRAP w/ perfect mechanics & breathing @ 75/55#

2min AB @ easy recovery pace

x3 sets


Thrusters AMRAP w/ perfect mechanics & breathing @ 105/75#

2min AB @ easy recovery pace

x3 sets

(3) Athletes falling into the final category (need development of both training qualities) need a carefully planned blend of energy-system training protocols and improvements in movement economy to allow them to advance in the sport. Their training weeks should be a balance between these two training qualities (in addition to their other training priorities). For these athletes the overdevelopment of capacity without improvements in movement quality will often lead to marginal improvements in mixed workouts and the opposite is true as well. Engine targeted sessions for these athletes can be a blend between the two example sessions provided above or more traditional mixed-modal work. Below is an example of a blended session designed to create awareness of movement quality under fatigue for a squatting limited athlete.

As many rounds as possible before hitting "the wall" at Competition pace / effort:

9 Thrusters @ 95#

9 BF Burpees

Rest to recovery (active on AB @ 100-120W)

x2 Rounds

**go AS FAST as you can for as long as you can each time, don't pace. Stop when you feel fatigue accumulation or movement quality deteriorate


As many rounds as possible before hitting "the wall" at Competition pace / effort:

9 Overhead Squats @ 115#

35 Double-unders

Rest to recovery (active on AB @ 100-120W)

x2 Rounds

**go AS FAST as you can for as long as you can each time, don't pace. Stop when you feel fatigue accumulation or movement quality deteriorate


Feeling limited by your engine can be extremely frustrating. However too often people fall into the trap of thinking that the only solution is to train harder. In my experience identifying the specific limitations to an athlete’s engine results in faster progress than aimless increases in training intensity or volume. Inappropriately prescribed training protocols that simply ask athletes to work harder year after year can at best lead to stagnated progress and at worst lead to injury and burnout. I believe that taking a more intentional approach to training is always your best option.

~ Kyle

Created By
Kyle Ruth

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