Nutrition and the Scientific Principles of Strength Training

“I swear everyone is looking for a weird technique correction that adds 50lbs to their squat or a food they can eat that just zaps bodyfat, and they are going to spend lots of time in an almost completely futile effort. Train hard and smart, eat well, and try to get a bit better every month. After a while you are a completely different person, but it takes time. It doesn’t happen overnight and there are no quick tricks.” Dr Mike Israetel.


Dr. Mike Israetel of RP Strength has determined 7 fundamentals for strength training. These consist of the following:

  1. Specificity
  2. Overload
  3. Fatigue Management
  4. SRA
  5. Variation
  6. Phase Potentiation
  7. Individual Differences

These principles are taken from his book “Scientific Principles of Strength Training.” For a full and comprehensive understanding, please refer to that. The summaries below outline his principles. They are ordered into a hierarchy that places the most important principle at the top and descends in order of importance when applying the principles to your own training.  

Strength training Bk GudmundssonSource: Renaissance Periodization
BK Gudmundsson is fueled by Renaissance Periodization


“ALL body systems adapt in the direction of the training stimulus, often countering one-another’s adaptations.” Dr Mike Israetel.

What this means is that you must train for the sport that you want to get better at. Specificity often cause imbalances, as getting better at one thing may make you worse at another. For example, a triathlete would not spend the majority of their training deadlifting, whilst an elite powerlifter does not spend half their training hours on a bike.

Specificity in Practice

With powerlifting and improving strength in general, the following are important:

  • Add size to powerlifting muscles
  • Make powerlifting muscles stronger
  • Practice the technique of powerlifting lifts

These are all specific to achieving a particular goal. When it comes to CrossFit®, this concept becomes much trickier, because the idea is to be good at everything. The specificity principle is important when targeting specific programming cycles (such as strength phases) within the context of the wider arsenal of your skills.


Overload contains two parts:

  1. Training within maximal threshold
  2. Training must be harder, on average, with time

Training within your maximal threshold means that you are doing things that are challenging to your relative fitness and strength. If you have a back squat PR of 200kg, yet your strength cycle has you squatting 100kg week 1, 105 week 2 etc, then you probably are not going to get stronger. It is too easy for you.

Training must be harder, on average, with time. This involves load, reps, volume, distance, time and intensity. This means that you gradually overload your body and central nervous system with progressively harder stimulus in your training. This can be anything from max calories on the airbike in 10 mins to adding weight onto your bench press each week.

“Humans respond to training in almost identical ways qualitatively, but differ only in quantity of response. For example, ALL humans need an overload to progress and ALL humans take on muscle damage with training. HOW MUCH training is an overload and how much muscle damage occurs from any given training is different for different people, but no one on this earth can claim to experience zero muscle damage from training at any given volume.” Dr Mike Israetel.


Failure to properly manage the fatigue created from training can lead to decreased performance. If you don’t rest and allow your body to recover then you will never maximise your gains. Nutrition is absolutely vital here.


  • Hard training stimulates adaptive processes
  • Adaptation occurs DURING recovery, not training

With these two important points in mind, you must train in an intelligent way that allows you to train, adapt and recover, then train again.

Every athlete’s ability to recover is different and dependent on their previous athletic history, genetics and other factors, but if you constantly train without allowing the stimulus from training to actually take effect (in the recovery phase) then you will not progress as well as you otherwise could.

On the flipside, many athletes make the mistake (or excuse) of giving muscles too much time to recover and not training them frequently enough. The important thing to remember is that your training should be hard. If you are a committed strength athlete or Crossfitter then you probably don’t need to be reminded about this.


Variation refers to the exercise that you choose to utilise in your training. When it comes to strength training, you can’t go wrong with deadlifts, squats, bench and overhead press, but additional variations can and will strengthen your movement patterns and body in slightly different ways. For example, Romanian deadlifts or snatch grip deadlifts are great accessory exercises to improve your primary compound lift – the deadlift.

Annie in action, fueled by Renaissance PeriodizationSource: High Intensity Photography
Annie in action, fueled by Renaissance Periodization

Variation keeps things exciting, and can be a great way to focus on technical or physical weak points that you may have in other movements.


This refers to how you structure the different blocks of training. For example, with powerlifting an athlete may work through the following:

  • Hypertrophy phase (grow more muscle)
  • Strength Phase (teach that new muscle to move heavy loads)
  • Peaking phase for competition (hit new PRs)

These phases occur in different ways in different sports, for Crossfitters this may be peaking your conditioning for The Open for example. But the general concept is that you maximse the potential from each phase in order to best achieve the specific goal of that phase.


This is the least important of all the above points, but should still be mentioned.

It is vital that when it comes to your training, you should work down the hierarchical list and sort out the most important, and influential, factors first. Individual factors are often linked to genetics, training history and the like, and will account for different ways that particular training may affect you in relation to another individual. These of course do play a role, but are fairly insignificant outside the realm of elite and professional athletes.

“The basics work for everyone. The individual differences are just a tweak” Dr Mike Israetel.


Nutrition is inextricably involved with these principles. If you do not fuel your body appropriately then you will be unable to perform to the best of your abilities. If you do not feed your body what it needs to recover then you cannot recover, adapt and grow stronger.

rp_bodycompositionSource: Renaissance Periodization
Body Composition

TIP: The first 2 points, calorie balance and Macronutrients alone will account for around 75 – 80% of your success.

Transformations using Renaissance Periodization meal templatesSource: Renaissance Periodization
Transformations using Renaissance Periodization meal templates

There are 5 different aspects of nutrition to pay attention to when it comes to maximising your performance and recovery, and achieving the goals that you are aiming for.

The magnitudes above are, in the same way as the principles of strength training, ordered in accordance with importance. If you are to achieve the results that you want, then you must first make sure that you are eating the correct calorie balance, macronutrients, nutrient timing and food composition before you start worrying about supplements for example.


1. Calorie Balance

Calorie balance is the ratio between calories taken in and calories expended in any one individual at any given time.

You can only ever be in ONE of the following states.

  • A negative calorie balance will always result in weight loss. “Even though body water alterations may occasionally mask this loss of tissue, it is always going to occur, with ZERO exceptions so far discovered.”
  • A eucalorie balance means that the athlete will not gain or lose weight because they expend as many calories as they consume.
  • A positive calorie balance means that the individual is consuming more calories than they are using.

In order to maximize your chances for muscle gain or fat loss, you must know when and how to enter a hypo, hyper, or eucaloric state.

Learn how now

2. Macronutrients

The second most important factor for transforming yourself is to consume the correct macronutrients to support your body and the goals that you are working towards. These consist of proteins, carbohydrates and fats. Having the right ratio between these three parts of your nutrition will differ depending on your exact goal, weight, sex, age, height and the way that you train.

Find the right macronutrients for your goals

3. Nutrient Timing

Nutrient timing means determining when during a day it is best for your body to consume the nutrients it needs (in accordance with your goals). This is best understood when it is split into meal frequency and timing in relation to activity.

4. Food Composition

This refers to the quality of the food, and the way that you combine foods to create meals.

For proteins this relates to the bioavailability of the nutrients, for carbohydrates it refers to the fibre quality and the Glycemic Index. With fats a good rule of thumb is to try and stay away from Tran Saturated fats (fast food etc) and consume Monosaturated (Avocado, nuts and their butters, olive oil) and Healthy Saturated fats (Coconut/macadamia nut oils, grass fed animal fats) wherever possible.

5. Supplements

Supplements are the final point to consider. Many athletes will prioritise this aspect of nutrition over others, however using supplements incorrectly will not help you to achieve your goals. For example, if an individual consumes 50g of protein powder daily, yet does still not achieve the overall caloric intake that will help them to achieve their goals, then their efforts are wasted and the results will not be achieved.

It is important to understand supplements as they really are, products to supplement a nutrition plan, and something to help achieve the desired outcomes from the more important steps above.


“Only science could be the surest path to the truth”

Renaissance Periodization work with many of the best athletes in the Game such as Rich Froning, BK Gudmundsson and Annie Thorisdottir. They provide nutrition templates that are specific to the exact requirements of the individuals involved, including your own. They help elite athletes to win The CrossFit Games® right through to everyday people reach the weight, size and aesthetic they desire.

Renaissance Periodization meal templateSource: Renaissance Periodization
A single page from a meal template

If you want to build muscle, lose fat, improve your health, optimise your performance and recovery, then RP Strength will help you to achieve that goal based on your own personal metrics. Stop making excuses and become the person that you are meant to be.

Achieve your goals now!

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