It is common knowledge that you can get stronger through resistance training, so today I will take you through the science behind how you get stronger including recommended training frequency for sustained results. Improving your strength has multiple health, well-being and performance benefits alongside that it may help you fight Jason Statham, or look like Linda Hamilton from T2. I know, she looks amazing.
Adaptations from resistance training
Let’s start the conversation by using a novice – someone who hasn’t trained before – as an example of how resistance training makes you stronger.
0-8 weeks after starting weight training (neural adaptations)
Depending on your health status, stress, and age, but typically when you start resistance training your newbie strength gains are unreal and even looking at weight can yield results. But Sarah Connor will still beat you in an arm-wrestling contest. So how does this happen? The exact mechanisms of neural response to weight training are unknown but it is thought to occur through a number of processes (Carson et al., 2001):
- Increase requirement of muscle fibres through an increase firing frequency – rate coding and summation – to the motor units thus, increasing muscle fibre activation and force production
- Tendon adaptions i.e. changes in the Golgi tendons organ leading to disinhibition, increasing muscular force expression
- Reduction of antagonist muscle activation i.e. when you pull a dumbbell up during a bicep curl, initially your triceps will decelerate, and eccentrically control the movement but over time your body will reduce the coactivation of the triceps
- Learn a new movement and becoming more technically efficient via motor learning
8-12+ weeks after starting strength training (structural adaptations)
Once your body has laid a foundation of neural adaptation, then it will have the capacity for structural changes. But don’t worry about turning into a walking piece of muscle (or cow) because it is very difficult to do naturally. The two-dominant mechanism of structural changes in the muscles are:
- Muscular hypertrophy – fibres increase in size via muscle protein synthesis, leading to an increase in cross-sectional area
- Muscular hyperplasia – individual muscle fibres split, increasing the number of muscle fibres
Research indicates that muscle hypertrophy is the dominant mechanism underlying the increase in muscle size, which has a very strong correlation to muscular strength (Schoenfeld, 2010). Muscular hypertrophy is triggered by resistance training (alongside nutrition) which results in the following changes in the muscles:
- Increased number and size of myofibrils per muscle fiber and protein filaments
- Increased size and strength of tendons, ligaments, connective tissue
Another benefit from resistance training that may assist in strength improvements is an increase in bone density and strength, which provides a stronger frame for your muscle to leverage from.
Recovery and ideal training frequency
Unfortunately, adaptations from resistance training don’t happen overnight, and progress in your strength and physique is seen after committing to a program and taking care of your nutrition, recovery, and stress. So how long does it take for your body to adapt after a session and what is the ideal frequency to load the same muscle groups again? Your health status, age, recovery, nutrition, training intensity, and stress will influence how you recover after each session but if you are a healthy individual who is not maxing out every session, then there is a sweet spot.
Below is a graph that depicts what happens 48-60 hours after a training session with a decline, and an increase in strength:
- Depletion: fatigue after a training session with greater protein degeneration than synthesis, either because of muscle damage or the increase in catabolic hormones
- Restitution: For a period of 24-36 hours after a training session during the recovery period, you will add muscle tissue if the amount of protein synthesis exceeds the amount of breakdown. This is why proper nutrition, rest, and recovery is so important
- Supercompensation: occurs within 36-48 hours post-workout with enhanced levels of protein synthesis which is the ideal window to train the same muscles again
- Downslope: Waiting too long to stimulate the muscles again will result in slowly losing the adaptions from the previous training session
I am sure you have heard of the saying “you are only as good as you recover” which is 100% correct with any form of training. If you train the same muscles too soon after a work-out it can lead to overtraining (B) and if you don’t train frequently enough (C) it can lead to undertraining and you may lose the adaptions from the previous session (MacDougall, 1995). In an ideal world, we are training the same muscle groups within the prior of supercompensation (48-hours post) to see a gradual and sustained improvement in strength and hypertrophy (Schoenfeld, 2010). Your recovery has a direct correlation with the intensity of your training and how you recover so if you are an advanced lifter or an athlete who trains at a high intensity, you will need a longer period to recover.
The great thing about this industry and personal training is that we are constantly evolving our methods of training, and understanding of the human body. So what I have provided today may be irrelevant in years to come but this is a brief overview of our current understanding of how the human body adapts via resistance training to improve muscular strength.
In the next article “are you training hard enough?” we’ll go through methods of resistance training to make sure you’re training hard enough to stimulate a response from your workouts. Remember, that what works for others may not work for you so your approach to resistance training should always be individualised, so please feel free to reach out if you want to discuss anything relating to your training and health.
All the best,
South Yarra & Richmond Personal Training Facilities
Carroll T.J, Riek S, & Carson R.G. (2001). Neural Adaptations to Resistance Training: Implications for Movement Control. Sports Medicine, 31(12), 829–840. https://doi.org/10.2165/00007256-200131120-00001
Lasevicius, T., Schoenfeld, B., Jozo, L., Gilberto, T., Lucas D., & Tricoli, V. (2019). Similar Muscular Adaptations in Resistance Training Performed Two Versus Three Days Per Week. Journal of Human Kinetics, 68(1), 135–143. https://doi.org/10.2478/hukin-2019-0062
MacDougall, JD, (1995). The time course for elevated muscle protein synthesis following heavy resistance exercise. Journal of Applied Physiology, 480-486.
Schoenfeld, J. (2010). The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training. Journal of Strength and Conditioning Research, 24(10), 2857–2872. https://doi.org/10.1519/jsc.0b013e3181e840f3
Schoenfeld, J., Wilson, M., Lowery, P., & Krieger, W. (2014). Muscular adaptations in low- versus high-load resistance training: A meta-analysis. European Journal of Sport Science, 16(1), 1–10. https://doi.org/10.1080/17461391.2014.989922