Every athlete may encounter a time in their career when they stop lifting, this could be due to injury, temporary loss of love/motivation for the gym, or even a forced resignation due to something like a job/moving/vacation.
In my opinion, one of the toughest parts of being a strength athlete is watching your strength and muscle gains wither away. With a recent knee surgery (ruptured quad), I’ve been doing a good amount of research on this topic, mostly for the mental struggle that comes with a forced leave under the bar (you’re not alone).
[Lacking motivation? Check out 5 Underappreciated Benefits of Lifting Weights.]
If you’re an avid strength athlete, then I have good and bad news. The good news, when you return to lifting you’ll re-coop faster and return to a similar point where you left off compared to a non-athlete with less previous muscle/neural adaptation. Conversely, the higher your training status, the faster it will decline due to lack of stimulus.
Below includes six things that happen to body when you stop lifting.
1. Loss of Strength
This factor is dependent on your lifestyle, previous training history, age, muscle composition (i.e.: fast:slow twitch ratios), and much more. For those who train at higher intensities, or have achieved the status of “elite”, they’ll unfortunately, lose strength faster than the non-lifter.
Why? It’s harder to maintain higher levels of strength without a continued stimulus. Think about it this way, elite status lifters are pushing new strength limits, which the body doesn’t naturally possess without that style of training.
Cessation of Training Completely
A study published in the Journal of Strength and Conditioning compared two groups of 46-healthy individuals who followed a 16-week training program. They followed the program with either 4-weeks of a tapered program, or the complete cessation of training. Researchers found that the group who completely stopped training lost around 6-9% of their maximal strength and their power output decreased by 14-17%.
The dropping of frequency or intensity, also known as detraining, will also cause strength loss, but to a much lesser extent. In 2011, researchers analyzed two groups of healthy individuals that followed either an endurance or resistance training program. Both groups performed their respective workouts for 24-weeks, then followed with a 24-week period of detraining.
Researchers found that body weight, body size, and cardiovascular fitness all returned to their baseline values (what individuals possessed at beginning of the study). Yet, the resistance training group maintained slightly elevated levels of strength and lean mass. This amount was very small, but it suggests that resistance trained individuals have a better chance of maintaining what they built before detraining (rejoice!).
Changes Due to Injury
From a research paper published in 2002, an overview was performed on three studies that looked at strength loss following skeletal muscle injuries. From the research, they looked at a total of 824 different muscles and drew conclusions from averaged data of the studies. Researchers suggested that muscular strength loss following an injury is due to three different categories including: damage to force generating mechanisms, failure to activate currently attached mechanisms, and a loss of force generating structures.
Their speculated timeline of strength loss shows that within the first couple days (1-2) of injury a muscle can lose around 50% of its previous strength. After, it steadily inclines as the muscle rebuilds and repairs. Additionally, contractile protein content declined by roughly 20% from 7-14 days of injury. As these two factors decrease, the protein degradation rate increases inversely by around 50% within the first week of injury. Although, from their studies the protein degradation returns to baseline around 14-days post-injury.
Two points to keep in mind from the above injury study. First, it was performed on rats, so the data may be different for human musculature. Second, there are multiple types of skeletal muscular injuries, so take this data with a grain of salt. It’s incredibly difficult to predict a specific individual’s suggested rate of strength loss/recovery.
2. Loss of Muscle Size (Muscular Atrophy)
The rate at which you’ll lose the hypertrophy, or size of your muscles, will also be heavily determined by the above physiological factors. From the study mentioned above in the detraining section, we can gather an idea of what to expect from muscular mass and body size when we experience a prolonged detraining periods.
In a 2015 study, researchers split 32 men into two age groups (23 +/- 1 & 68 +/- 1) and put them in a knee immobilizer for 6-weeks to track decreases in their leg strength, work capacity, lean mass, muscle fiber composition, and capillary supply. They found that the younger men lost around 30% of their strength after a 2-week period compared to 25% in the older group.
This study does an adequate job at suggesting the more muscle/physical fitness you have, the faster you’ll lose it. Additionally, the younger men lost roughly 485 grams of their muscle’s mass, while the older group averaged 250 grams.
3. Hormone Changes (Testosterone, Human Growth Hormone, and More)
Hormones like testosterone and human growth hormone increase with the onset of heavy resistance training. The larger compound movements (squat, deadlift, etc) are said to produce the most of these hormones naturally. After detraining and cessation of training, elevated hormones will decrease and may eventually end up back at their baseline (as referenced in the above study mentioned in the cessation of training section).
Yet, if you detrain, or have to limit your training (train 1-2 times a week), then these results may be completely different. Researchers that followed kayak athletes post-season in 2009 showed that their detraining experimental group saw an increase in their testosterone:cortisol ratio, when compared to the cessation of training group. Thus, suggesting that even a little training can be beneficial for hormones and the body to avoid catabolic states.
If it seems odd that testosterone:cortisol levels would increase with less training, then think about a deload. Athletes do this to give their nervous system and muscles a break, which in return, promotes favorable anabolic responses (decreases cortisol).
4. Muscle Fiber Composition
When we lift we alter our muscle fiber composition to adapt to the training stimulus, so it only makes sense that there’s an opposite relationship when we stop exercising. Research still can’t provide you with a definitive answer in how much your composition will shift, but it’s suggested that after 3-weeks of detraining cross-sectional areas of muscle fibers can change by +/- 6%.
[Learn how to train for fast and slow twitch muscle fibers, plus what makes them different.]
In terms of long-term fiber change, a case study from 1981 (which is a VERY old study) showed that after a 7-month detraining period, a powerlifter experienced a fiber atrophy change of around 37%. It’s also suggested that fast twitch muscles are the first to change, or convert to a slower twitch muscle fiber.
The rate at which our muscle fiber composition changes is very individualized, so like the muscular atrophy section, take these studies with an open mind. Everyone’s body will change at different rates due to age, hormones, lean mass, training history, and so forth.
5. Mood, Memory, and Concentration
Exercise increases our mood by releasing feel good endorphins such as dopamine and serotonin. Not to mention, as you hit new PRs and strength feats your mood will boost naturally due to an increase in self-confidence. Our memory also improves from exercise due to increased blood flow to the hippocampus. Research is conflicted on the exact mechanisms behind this, but it’s suggested that on the opposite spectrum when we have lessened blood flow to this area of the brain we’ll experience varied levels of cognitive impairment.
Our mental sharpness also increases with regular exercise. In 2015, researchers analyzed differences in ten sets of twin’s brains, in each pair, one was physically active and the other was not. They found the physically active twin to have more gray matter. Increased gray matter will make your brain more efficient at reacting to stress and aging.
6. Neural Adaptation Loss
Heavy weight and intense lifting requires higher amount of synapses to fire. As we taper off of previous training intensities, our nervous system’s excitation will also decrease. The degree of this will be subject to the individual, but from the study above in the cessation section, a 4-week leave from training caused a 14-17% decrease in power output.
Sometimes breaks from the weight room are inevitable, but that’s life. The above points will all be influenced by multiple characteristics that make up our body and previous training. One of the toughest parts of strength training is coping mentally as we see an uncontrollable decline strength and mass.
Yet, if you’re someone who’s a weathered gym rat, then fear not, we have the ability to bounce back quicker, even though we tend to lose our gains more rapidly.