It’s 3AM. The phone rings. Another call out. You had a lift and a high intensity interval session planned for the afternoon. So, what do you do? Do you try to squeeze it in somehow and just adapt and adjust? The unique demands of the tactical/combat athlete dictate the need for high levels of all-around fitness: strength, power, quickness, agility and extensive work capacity coupled with the ability to successfully navigate the stressful demands of the job and limited training time. While you can’t control everything, there are ways to structure training and nutrition to mitigate the deleterious effects of high levels of stress and the divergent fitness demands of the tactical athlete.

Such unique all-around fitness often requires a significant amount of concurrent training, that is, training for strength/power and aerobic capacity simultaneously, rather than in separate periodized blocks of training. The idea of concurrent training and the interference effect is not a new concept. The debate as to whether high levels of strength and high levels of aerobic capacity can be developed at the same time without sacrifices in strength and power has long been discussed. Current research however, has elucidated some of the mechanistic factors that may help explain the potential for interference. These findings lend insight into how to structure training programs and individual training sessions to reduce potential confounding factors while still developing the necessary levels of fitness.

This interference concept is most important when seeking high-level strength and power gains. The development of maximal strength and power requires the recruitment of the high-end motor units within skeletal muscle. A motor unit consists of a motor neuron and all the muscle fibers that it innervates. This is most effectively illustrated within Henneman’s size principle, as it explains the relationship between motor unit twitch force and recruitment threshold. This principle dictates that motor units are sequentially recruited based upon their recruitment thresholds and firing rates, with lower-end, larger, less fatigable motor units recruited first in most instances, followed by higher-end motor units as load and intensity increases.

With this in mind, we see that changes in skeletal muscle in response to exercise training are largely dictated by the stimulus provided. In order to elicit the desired changes, the muscle must receive a series of neural and biochemical signals that tell it how to adapt. Two important molecular signaling cascades that play a role in the changes in skeletal muscle in response to exercise are known as the mammalian target of rapamycin (mTOR) and its downstream effectors, as well as adenosine monophosphate activated protein kinase (AMPK) and its downstream effectors. These pathways are involved in mRNA translation initiation and thus have a significant impact on the end result of your training efforts.

Resistance exercise itself provides a mechanical stimulus for the activation of mTOR. This mTOR stimulation is an energy-requiring anabolic process that leads to protein synthesis. The subsequent accretion of myofibrillar proteins contributes to an increase in muscle size and strength. AMPK, on the other hand, is catabolic and because it acts as a cellular energy sensor, it can lead to adaptations such as mitochondrial biogenesis and the increased metabolic and work capacity of the muscle.
In essence, these signaling proteins represent opposite ends of the adaptation spectrum. Not only do these pathways elicit different effects on skeletal muscle, in many instances they interfere with one another because AMPK activation can block mTOR signaling. Taking these factors into account, it starts to become clear how endurance or interval-based activity can negatively affect strength and power gains. The catabolic cellular energy perturbations and metabolic by-product accumulation don’t allow the anabolic signals to go through. You can’t break down muscle and build it up at the same time.

So you may be thinking, this cellular stuff sounds well and good, but how does it apply to my ability to be strong and powerful? Well, in order to truly generate maximal force, those higher-end motor units we mentioned previously must be recruited and they must be recruited at a quick firing rate. When the ionic balance of the cellular environment is significantly disrupted (like after you perform very high intensity glycolytic intervals, for instance) the accumulation of metabolic by-products, low pH, disturbance in the Na+-K+ pump, etc., results in hyperpolarization. Hyperpolarization inhibits the neuron from firing and thus affects motor unit recruitment. As a result, it becomes difficult to recruit these high-end motor units and makes it difficult to achieve improvements in strength and power in this cellular environment.

Of course there are many athletes that are both very strong and have huge aerobic and anaerobic work capacity. And of course, it is not always necessary to separate these types of training sessions. Our focus here, however, is on the average athlete who may be experiencing a plateau in strength and power gains, or the tactical athlete who has limited training and recovery opportunities due to work, personal and other high-stress demands. Remember, the cumulative effect of your regular training program is what sets the stage for the phenotypic adaptation. Therefore, you want to construct a framework conducive to your desired long-term training goals. Fortunately, research in this area has pointed to a few strategies that can be effective.
One strategy involves leaving at least three hours between strength–focused and conditioning-focused training sessions. This three-hour window appears to be sufficient to mitigate the interference effect, provided the athlete does not remain in a negative energy balance. This can be achieved by performing two shorter training sessions per day separated by at least three hours, or by merely training the components on different days. If training must be performed in one session, performing the resistance-training portion of your training session first appears to be your best bet. This will allow you to embark on a lift prior to the resultant cellular energy depletion and accumulated metabolic by-products from interval or heavy aerobic training.

Nutrition

Nutritional intervention can also be an effective strategy to promote recovery and reduce the interference effect of concurrent training. In a study looking at the effect of an essential amino acid (EAA) and carbohydrate (CHO) drink and exercise on molecular signaling, the researchers found that the EAA-CHO mixture actually reduced AMPK signaling post-exercise and increased mTOR signaling, thus promoting an anabolic environment conducive to protein synthesis. This is likely due to the change in the energy state of the cell with the consumption of EAA-CHO beverage and/or the effects of leucine that has been found to act not only as a substrate but also potentially as an anabolic signal as well. Previous research has indicated that peri-workout nutrition also improved the hormonal environment by reducing cortisol and utilizing insulin and amino acids to provide an anabolic stimulus favoring protein synthesis. Coconut water and branched chain amino acids (BCAAs) would work well in this instance.

Stress

Stress is another important consideration with respect to overall health as well as training program design for the tactical athlete. Cortisol increases with acute stress. Chronic stress, including sleep deprivation, can also keep cortisol levels significantly elevated. If stress is not managed, this can eventually lead to compromised adrenal function, fatigue and adverse effects on health and performance. High cortisol has a two-fold negative effect on performance. Not only does elevated cortisol reduce testosterone, it also is a potent inhibitor of mTOR’s downstream effectors. This inhibition blocks anabolic signaling and compromises protein synthesis. A reduction in testosterone and anabolic signaling means your ability to positively adapt to a resistance training stimulus is significantly compromised.

In this high-stress scenario, altering your training plan is important. Substituting a lift or a glycolytic interval session for rest, mobility training or a light active recovery workout consisting of lower intensity aerobic based activity will be more effective for overall fitness and health in the long run then gutting through a tough workout. As a guide for those of you who don’t typically train in anything but fifth gear, keeping your heart rate below 130 beats per minutes is an easy way to quantify a “lighter” workout.

The following are a few simple templates to use in order to structure training in a way that can reduce the interference effect and manage recovery for the tactical athlete.

Once a Day training session

Monday

• LSD or rest

Workout Options:
30-60 minute run, bike, swim, row or heavy bag work

OR

LSD intervals: (work/rest)

• 10min/1min
• 5min /1 min
• 2min /30s
• 1min/30s

Tuesday
Lift

Workout Options:

• Squat (4x5)
• Press (3x5)
• BSS (3x8ea)
• Push-ups (4x30)

*BSS-Bulgarian Split Squat

Wednesday
Intervals

Workout Options:

• 15s/30s (x15-20)

OR

• 5min/1min (x5) + 20s/40s (x10)

Thursday
Lift

Workout Options:

• DL (4x5)
• BOR (3x5)
• Lateral BB
• Lunge (3x8ea)
• nverted Row (3x8)

*BOR- bent-over row

Friday
Rest

Saturday
Sprints

Workout Options:

• 6-8x100m (5min+ rest )

OR

• 8-10x40yds (2-5+ min rest)

Sunday
Mixed Modal + LSD OR Lift

Workout Options:

• Power Clean (5x3)
• Front Squat (4x3)
• Pull-ups (4x8)
• Back Ext/GHD (3x10)

OR

• 4 sets of:
• Front Squat (x8)
• 400m (or 2min on treadmill at incline)

Two-a-days

Monday

AM-LSD
PM-Mobility

Tuesday

AM-Lift
Squat
Press
Push-ups

PM-Intervals (1:2)(work: rest)

Wednesday
Rest

Thursday
AM-Lift
DL
BOR
Lateral BB Lunge

PM-Intervals (2:1)(Work: rest)

Friday

AM- Lift

• Power Clean
• Front Squat
• Pull-ups

PM- Mixed Modal

OR
LSD (30min)

Saturday
Rest

Sunday
Sprints

*Based on a Monday-Friday work schedule. Adjust based upon work schedule, optimal training days and days needed for recovery. Additional rest or light long slow distance (LSD) days can be added to account for call outs and/or operation training, etc. Set and rep schemes will be dictated by phase of training and training goals. Additionally, decreasing strength training to 2 days a week and adding an additional conditioning session instead can be used for operators that need to focus on improved conditioning during a particular training phase.

Incorporating these concepts into a structured, linear or non-linear periodized training program can provide a solid quantifiable, progressive training program for a tactical athlete.