Optimal return to bodybuilding after a cold

A scientifically sound guide to getting back into bodybuilding after a cold. Learn how a short break from illness affects muscle growth and strength, how to optimize recovery and hydration, and which strategies and mental tricks will help you return to training motivated and confident.

Every athlete knows the feeling: a mild cold or the flu forces a break from training. Many athletes worry that just a few days without training will cause hard-earned muscles to atrophy or that the loss of strength will be significant. But how serious are the effects really? And how can you best ease back into training after illness to quickly get back on track?

This article, based on current scientific studies and practical experience, sheds light on the physiological effects of taking a break from training due to illness, how much muscle mass and strength you can realistically lose (spoiler alert: significantly less than you might expect!), what to consider regarding your water and electrolyte balance, and how to optimally resume your training after a cold. Finally, we offer tips on motivation and mindset so you can use an unplanned break to your advantage – similar to a planned deload – and maintain long-term success.

1. Effects of a sick break on muscle growth and training progress

Physiological effects of a short training break: If you take a break due to an infection, your body goes through an intense recovery. Regeneration phase. Your immune system The body is working at full capacity to fight viruses or bacteria. During this time, muscle function has a secondary priority – the body primarily uses energy and nutrients for immune defense. Exercise during an infection This process would be disrupted, as intensive training demands additional resources and regenerative capacity that the body actually needs for recovery. Therefore, it is advisable (and strongly recommended by doctors) to consistently take a break if symptoms such as fever, a severe cough, or body aches occur. Otherwise, in the worst case, you risk complications such as myocarditis (inflammation of the heart muscle). trainingpeaks.com ​trainingpeaks.com.

Mild infections vs. “training hard”: In cases of very mild symptoms (z.BEven with just a slight cold (without fever), many people find it difficult to completely stop training. Many coaches advise: “Listen to your body”Gentle, low-intensity training is sometimes possible, but only if all symptoms are present. above the neck stay and feel really fit trainingpeaks.comHowever, as soon as fatigue, fever or cough occur ("below the neck"), is it [called: Take a break​ trainingpeaks.comUltimately, health takes priority, because You can't build fitness on a sick body. trainingpeaks.com.

Antibiotics and muscle growth: If your cold or infection requires the use of antibiotics, other factors come into play. antibiotics They do fight bacteria, but Side effects have features that are relevant to athletes.According to a review article, common antibiotics can be used with reduced athletic performance accompany and in some cases lead to tendon problems lead pmc.ncbi.nlm.nih.govSome antibiotics from the fluoroquinolone group (z.BCiprofloxacin is notorious for weakening tendons – strenuous physical activity should be avoided after taking it to prevent injury. Furthermore, it can be difficult to distinguish whether fatigue and weakness during illness are caused by the infection itself or by the antibiotic. However, studies indicate that certain antibiotics can indeed Fatigue and weakness This can cause: For example, 23% of subjects taking minocycline reported weakness/fatigue.pmc.ncbi.nlm.nih.gov. also the destruction of the Intestinal flora The use of broad-spectrum antibiotics is being discussed – a healthy gut flora contributes to nutrient absorption, motivation, and even performance. In a mouse study, antibiotics that drastically reduced gut bacteria led to... 21% less voluntary running in previously athletic mice; interestingly, even almost two weeks after discontinuing the antibiotics, performance was still reduced. universityofcalifornia.eduApplied to humans, this means that after a course of antibiotics you may temporarily feel a bit more tired or have less energy, even if the infection has already subsided. However, these effects are usually short-lived. temporary. Support for gut health (z.BProbiotics, a healthy diet, and above all, sufficient time for recovery will help you quickly regain full performance. pmc.ncbi.nlm.nih.gov​ trainingpeaks.com.

Recommended waiting time before re-entry: How long should one now wait after a coldBefore resuming bodybuilding training? Sports medicine experts and experienced coaches largely agree on this point: Not too early! A frequently cited rule of thumb is: At least 1–3 days symptom-free Wait and see. A good rule of thumb is, At least three days completely free of cold symptoms before the first training session. (no runny nose, cough, or sore throat). Common cold medications (z.BYou should have stopped using nasal spray and cough medicine a few days ago without any symptoms returning – this signals that your body has truly recovered. Have you had FeverBe even more careful. In the case of a real flu (influenza), even more so. two weeks break These periods may seem long to ambitious athletes, but they are an investment in their own health and performance. Renowned coaches – including international Olympic coaches – emphasize that an athlete must first recover train fully should, if he really... fully recovered It feels better to rest for a few extra days than to start too soon and risk a relapse. The good news: these few extra days of rest will hardly affect your muscles – we'll look at why in the next section.

2. Regeneration and realistic assessment of muscle and strength loss

Many athletes fear that even one week without training will destroy their painstakingly built-up muscles. muscles kills them or ruins their best performances.Fortunately, this fear is in most cases exaggerated. A mild infection and a short training break mean no drastic setbacks – neither in terms of muscle mass nor strength level.

What happens to the muscles during a break? During the first few days of a break, the body primarily recovers from previously built-up fatigue. Significant muscle loss It hardly sets in if the duration is short. Scientific studies show that in 3 weeks training break Almost no measurable loss of muscle thickness or strength occurs pmc.ncbi.nlm.nih.govHowever, what is unavoidable are adjustments in coordination or in the body's water balance. In a study with adolescents, both muscle mass and maximum strength remained unchanged after three weeks without training – the values ​​were still significantly above the baseline level before the start of training. pmc.ncbi.nlm.nih.gov​ pmc.ncbi.nlm.nih.govA well-known study by Häkkinen et al. reports something similar: A short Detraining phase of 3 weeks only led to minimal changes of the neuromuscular adaptations, whereas only a very long break of 24 weeks caused significant muscle atrophy and approximately 4–12% loss of strength. mdpi.comIn other words: Only after several months of inactivity do truly substantial setbacks occur – a few days or a few weeks of inactivity, on the other hand, are insignificant in the bigger picture. manageableIt is always important to take the individual training level into account.

Muscle memory and faster recovery: Even if you notice that the barbell feels a little heavier after a week of illness, that's usually no real loss of strength, rather z.BThis is due to depleted energy stores or a lack of neuromuscular coordination (more on this in a moment). Real losses Things happen slowly in muscle tissue – and what is lost, the body rebuilds thanks to Muscle Memory quickly recovered. Muscle Memory (Muscle memory) refers to the phenomenon that previously trained muscles return to their former level faster after a break than it would take to build the same gains from scratch. sciencedaily.comAmong other things, long-lasting factors are responsible. muscular cell nuclei and adaptations in the nervous system that persist even during rest. As soon as you resume training, remembers The muscle essentially returns to its previous performance level. A recent study from Finland illustrates this: Here, a group was tested after 10 weeks of training for Take a 10-week break They remained relaxed, while a control group trained intensively. Result: After another 10 weeks of training, they Muscle size and strength in BOTH groups practically the same – the break group quickly caught up in the second training phase sciencedaily.com ​sciencedaily.comThe researchers report that progress was very rapid in the first five weeks after the restart, and that The pre-break level had already been reached. sciencedaily.com.Maximum strength values ​​were even better preserved during the break than some muscle mass, but even that was quickly restored after the restart. sciencedaily.com sciencedaily.comTheir conclusion: Strength athletes don't need to worry too much about occasional training breaks of up to ten weeks, provided they otherwise train regularly and progressively. sciencedaily.com. A one- or two-week break due to a cold is therefore hardly significant in comparison.

How much energy is lost in a week? In the case of a mild infection that might keep you away from iron for 5-7 days, you will probably barely measurable losses They suffer from a loss of actual strength or muscle cross-section. What many perceive as "weakness" after a break is often due to other factors (z.B(Depleted glycogen stores or dehydration – see next section). The Maximum strength (For example, your 1-repetition maximum) remains surprisingly stable over short periods. As mentioned above, strength is largely maintained even during several weeks of rest. mdpi.com, partly thanks to neural adaptations. Even if something diminishes, it remains in the low single-digit percentage range. Interestingly, strength seems to tend to to degrade more slowly as muscle mass – in some studies, athletes still had 12% more strength after a 12-week break than before the training program, even though the gain in muscle mass during this time was completely lost. mdpi.comYour body tries to maintain function (strength) for as long as possible, even if some muscle mass is temporarily lacking. In any case, with the right strategy for re-entering training (more on that later), you can very quickly reactivate lost power.

How quickly can one return to their previous level? Experience and research show: Very fast. Often just a few are enough Training sessionsto counteract the perceived slump after a cold. Due to the aforementioned muscle memory effect and the return to normal nutrition/fluid intake (after possibly eating less while ill), the muscles regain their former strength. Muscle volume and performance Back quickly. After about a week of training, the body usually feels "in the groove" again. A longer break from z.BTwo to three weeks might require two to three weeks of consistent training to fully catch up – but even that is a short period in the context of a training year. Consider such a break as brief interruption, not a resetYou're not starting from scratch! This change in perspective helps enormously with motivation (see section 5). It's important that you remain patient when restarting and don't try to... missed training Trying to compensate through excessive intensity would only lead to overtraining or injury. The good news is: A mild infection does not mean a permanent loss of muscle mass or strength. Whatever minimal amount you lose, your body will quickly make up for as soon as you give it the chance.

3. Influence of water balance, electrolytes and other physiological factors

When you look in the mirror after a cold or return to the gym, your muscles may appear somewhat “flatter” or your body weight may be a few pounds lower.Don't let that worry you – in most cases it's just... not about lost muscle mass, but about water and energy balance effectsThe following physiological factors play a role:

Glycogen stores and carbohydrates: Muscle glycogen is the stored carbohydrate reserve in the muscles. It not only provides energy for intense training but also binds water in the muscle (approximately 4 g of water per 1 g of glycogen). When you're sick, you often automatically eat less – loss of appetite or skipping training (where you might otherwise consume carbohydrates) means that the Glycogen stores depleted Fever or inflammatory processes can also alter carbohydrate metabolism. The consequence: Your muscles contain less glycogen and therefore less water – you appear less efficient. “flatter” and lighter, without losing any real muscle mass. Furthermore, you feel weak because Carbohydrates are extremely important for explosive loads are already relatively moderate glycogen reductions can impair strength performance. According to a recent analysis, small decreases in muscle glycogen can have disproportionately large performance effects. strongerbyscience.comIn a study of strength athletes, the glycogen content of type II muscle fibers decreased by over 50% after a strenuous training session, while the total glycogen content decreased by only ~38%. strongerbyscience.comThis shows: Fast-action fibers are particularly susceptible to damage from depleted storage capacity. and tire more quickly. In other words: If you're not fully recovered after an illness (perhaps you ate very little for a few days or followed a low-carb diet), it can feel as if you've "lost a lot of energy." In fact, what you really need is enough energy again. carbohydratesTo give your muscles their usual fuel, focus on a carbohydrate-rich, balanced diet in the days leading up to your return to training to replenish your glycogen stores – then you'll see that the perceived loss of strength largely disappears.

Water balance and dehydration: Closely linked to glycogen is the Fluid balanceWhen you have a cold, you easily lose fluids – whether through sweating due to a slight fever, through insufficient fluid intake (you often drink less consciously when spending the day in bed), or through medication (some cold remedies dry out mucous membranes). Even a mild cold can lead to fluid loss. Dehydration of ~1–2% of body weight This can lead to measurable performance losses. Studies have shown that approximately... 1.5% fluid loss(z.B(Caused by sauna use) significantly reduced maximum bench press strength – on average, the 1RM decreased by around 5–6%. pubmed.ncbi.nlm.nih.govThe good news: After two hours of rest and rehydration with water, his strength was fully restored. pubmed.ncbi.nlm.nih.govIn other words: If you do something after your sick leave dehydrated If you are, you might feel weaker, but you are not permanentDrink enough fluids and replenish your electrolytes – then your performance will return to normal. Electrolytes (Sodium, potassium, magnesium, etc.) are important because they are involved in muscle contractions and fluid balance.A cold, especially when accompanied by sweating or z.BDiarrhea can cause an imbalance. Make sure to consume enough electrolytes through food (or isotonic drinks if needed) after recovery. Sodium (salt), in particular, along with fluids, helps rehydrate the cells. If you feel hydrated and z.BOnce your morning body weight is back within the usual range, these temporary losses are over.

Stress hormones and lack of sleep: Illness puts stress on the body. The body often releases more substances. Cortisol This releases a stress hormone that, in high concentrations, can have a catabolic (breakdown) effect. At the same time, sleeping becomes difficult with a blocked nose or cough, thus impairing this crucial function. Sleep as regeneration time is shortened. Insufficient sleep, in turn, increases cortisol and lowers anabolic hormones such as testosterone and growth hormone. This combination is unfavorable for muscle building. But: It is a short-term effect during the acute illness. Once you're sleeping soundly again and the infection has cleared up, your hormone levels will return to normal. It's important to... Catching up on sleep And pay attention to good sleep quality once you're feeling better – this will support the complete regeneration of your muscles. Many people notice that they recover rapidly after a full night's sleep. So, after an illness, treat yourself to 8-9 hours of sleep to make up for any deficits.

Additionally, it should be mentioned that cortisol causes increased water retention under the skin, which can lead to rapid and clearly visible deteriorations in body composition, thus making one's physique appear much worse very quickly.

Nutrition and muscle protein synthesis: During illness, you often have less appetite and therefore consume fewer calories and protein. If this persists, it can slow down muscle growth or contribute to slight muscle loss, because your muscles constantly need amino acids for maintenance. Protein intake This is therefore particularly important during the regeneration phase. In fact, studies suggest that High protein intake can reduce muscle loss during inactivity. pmc.ncbi.nlm.nih.govTherefore, make sure you consume enough protein during your rest period (approximately 2.5–3 g per kg of body weight, depending on the recommendation), even if you're not training. Overall, your calorie intake shouldn't be drastically reduced – some people make the mistake of eating less during their rest period for fear of gaining weight. But remember: your body needs energy for the immune system and to repair damage. A moderate calorie level with plenty of micronutrients (fruits, vegetables) and protein will help you... Muscle protein breakdown to minimize and regain resilience more quickly pmc.ncbi.nlm.nih.gov. Short: Meet your protein and nutrient needs, to give your muscles, immune system, substrate for maintenance and regeneration.

Bottom line – no reason to panic: The factors mentioned can explain why you feel weaker after the illness or why the scale shows a lower number. None of these changes are permanent. They can be quickly reversed with the right measures (fluids, electrolytes, food, sleep).Your Muscle tissue Even in a mild infection, the body remains largely intact – and what about… Performance was temporarily restricted, is Normalized within a few daysIf you treat your body sensibly, you'll be fine. Avoid additional diuretics during the cold phase (don't force excessive sweating) and ensure you're getting enough nutrients – then you'll be almost there. without loss of substance from the break.

4. Optimal strategies for returning to training

After you've fully recovered, it's finally time to get back under the barbell. Now the question is: How do I structure the first training sessions after the break? Here, a smart and systematic approach pays off. The following: Strategies for re-entry have proven their worth:

Gradual increase instead of full throttle: As tempting as it is to pick up right where you left off before your illness, a gradual approach is more sensible and effective in the long run. Many experienced coaches recommend: In the first few sessions, train as if you were a beginner. Specifically, this means Reduced intensity and volume to choose. Why all this? Your body – muscles, joints, cardiovascular system, and nervous system – needs to readjust to the strain. After a week without training, you're largely recovered, but you may experience unusually strong symptoms. Sore muscles This happens when you immediately give 100% again. By doing that Reduce your training volume by ~20–30% And if you use slightly less weight, you'll prevent excessive muscle soreness and overexertion. Consider the first week as Transition phase, to restart the engine.

Example for the first units: If you're following a push/pull/legs routine, you could do 1-2 fewer sets than usual for each exercise in your first workout after the break. Leave the workout feeling like you could do more, rather than pushing yourself to complete exhaustion. Pyramid up the weight slowlyListen to your body. Many athletes also like to do this. a light full-body workout The very first workout back – with moderate weights for all major muscle groups. This stimulates blood flow and gives you a sense of where you stand without immediately putting maximum strain on any one area.

Increase in training volume: After the careful reintegration week, you can... Gradually increase training volumeIf everything went well (no abnormal pain, no more symptoms of illness), increase the volume in week 2 to approximately 90–100% of your pre-break volume. You can also bring the weights back to their previous level. Many even report that they are particularly efficient after a recovery break – so you might be pleasantly surprised. Nevertheless: Prioritize technology and a moderate pace of progress. about short-term maximum performance. After two, at the latest three weeks, you should be back in your normal training rhythm. This gentle Ramp-up is comparable to a planned re-entry after a deload or the off-season. Professional coaches often handle it the same way with their athletes: first lay the foundations, then build intensity.

Pay attention to warning signs: Pay special attention to your body during the first few training sessions. Certain Signals You should take this seriously and react accordingly:

• Elevated resting heart rate: Miss z.BCheck your resting heart rate in the morning. If it's unusually high (10+ beats above normal), this could be a sign that your body hasn't fully recovered. In that case, caution is advised – perhaps take an extra day of rest or keep your training very easy until your heart rate returns to normal.

• Unusual heart palpitations or shortness of breath during training: If you suddenly experience a significantly increased heart rate or shortness of breath during activities that used to be easy, don't overexert yourself. Your cardiovascular system may simply need more time to adjust. Take longer breaks between sets and avoid pushing yourself to the point of gasping for breath.

• Persistent cough or chest pain: If you experience coughing fits or tightness in your chest during exercise, stop training. This could mean that your airways are still irritated – if necessary, consult your doctor before continuing.

• Excessive muscle soreness or joint pain: A little muscle soreness after your first workout is normal. However, if you have such severe muscle soreness that movement is very painful or your joints hurt, you may have [a condition/condition]. got involved too intensivelyIt's better to give yourself an extra day to recover and start again more gently. Extreme muscle soreness can also put a strain on the immune system; you want to avoid that after a recent illness.

• General feeling of illness: If you feel unwell again after training (chills, general malaise), it was clearly too soon or too much. Then you should stop and recover. There's no point in forcing anything – you'll only be out of action longer than if you were patient for a few days.

Adjust training plan: It may be useful to Training split or order to modify something in the first few weeks. For example, you can do more Incorporate rest daysInstead of training 6 days a week, perhaps spread it out over 3-4 days with rest days in between. This gives your body enough time to adapt to the strain between sessions. You could also initially focus more on Basic exercises Focus on stimulating the entire body with a few exercises and reduce isolation exercises to avoid unnecessary fatigue. Some coaches recommend training with higher repetitions and moderate weights after illness before returning to maximum weights – because injury-prone structures (tendons, ligaments) benefit from well-circulated, moderate training before they have to withstand maximum tension again. Even light Cardio can be integrated at the beginning to boost overall fitness – but also moderately (z.B. Walks, leisurely cycling), especially if the infection has affected endurance.

5. Motivation and mental aspects

A break due to illness can be mentally draining. You feel like you're losing valuable time, and some athletes become impatient or even anxious about their progress.Here it is important to... mental perspective to adjust.

A one-week break is insignificant in the long run: Be aware that a training break from z.B. one week In the long timeline of your training, it hardly makes a difference. With 52 weeks in a year, 1-2 weeks of rest are perfectly normal – even top athletes have off-time. Your body doesn't forget what you've "taught" it over months and years of training just because you take a few days off. Imagine your training journey like a long road: a short construction zone will only slightly delay your trip, but it won't affect your final destination. This realization takes the pressure off. In fact, a week's rest can even be beneficial. positive be (see comparison with Deload below). Keep in mind: Long-term success in bodybuilding comes from consistency and sustainability.Not by forcing daily workouts without a break. So, if you take a break due to illness, you're ultimately doing the right thing for long-term progress – you're preventing things from getting worse and you'll come back stronger.

Stay positive – it's not the end of the world: Everyone catches a cold now and then. The important thing is, avoid negative thinkingto fall apart (“Now everything is ruined, I’m losing my muscles!”). Remember the facts from this article: Your body hardly loses any substance in such a short time, and what it does lose, it quickly regains. sciencedaily.com sciencedaily.comSome athletes even report that they return to training with even more energy and renewed enthusiasm after forced breaks. Growth phase returned. This effect is comparable to the principle of SupercompensationRecovery leads to a rapid increase in performance beyond the initial level. In the aforementioned Finnish study, the group without a break tended to stagnate after 10 weeks, while the group with a break was able to improve again in the last 10 weeks and catch up. sciencedaily.comThis shows that the body needs occasional rest in order to recover afterwards. to grow optimallySo, feel free to view your sick leave as a kind of... unplanned deload A deload is a period of reduced stress that allows your body to repair and recover. Many successful bodybuilders already schedule a deload week every few weeks to prevent overtraining and ensure long-term progress. Your cold has essentially taken over this role. In this light, the break isn't negative, but rather an integral part of the training process.

Psychological strategies for re-entry into the workforce: Once you're allowed to train again, it can be psychologically challenging to start with slightly less weight. Here, it helps to... Expectations To set it correctly: Allow yourself to step by step to come back. Celebrate small successes – for example, that you completed your first workout and can move again. Set short-term goals like "Complete all planned workouts this week, regardless of the weight" instead of immediately "setting a new PR." The big goals (muscle building, strength gains) remain, but the intermediate steps will adjust accordingly. Remember how bad you might have felt while you were sick – compared to that, even this is a significant achievement. can train a success.This attitude creates gratitude and reduces performance pressure.

Another trick: Train with a partner or coachEspecially when returning to training. These factors can rein you in if you become overconfident, and they also provide support if you're feeling insecure. A good coach will confirm that a short break won't cause any long-term damage – that alone is often incredibly reassuring. Document your progress Continue working in your training log after the break. This way, you can see in black and white how you're getting closer to your previous performance levels from session to session – or even surpassing them. This process can be really fun, almost like reliving your "newbie gains," only much faster.

Last but not least: Patience and self-compassion. Everyone's body is different. Some people jump right back into their old routine after a cold, others need a few days longer. That's okay. Don't judge yourself if you can't give 100% on day one after your break. Be proud that you've taken responsibility for your health. A mild infection can throw you off balance. not off trackAnd mentally strengthened, you may come back more resilient. This mental strength – the ability to endure breaks and return wisely – is a quality that distinguishes successful athletes.

Conclusion (mental): A one-week training break due to a cold caused no long-term losses – neither on your body nor on your progress timeline. See them as part of your training plan, similar to a deload, and focus on the positive effects of recoveryStay informed (z.B(with articles like this one), to replace fear with knowledge. With the right mindset, you'll find that such a break can be beneficial. mentally stronger and makes you hungrier for new successes. And the next time you catch a cold, you'll know: stay calm, listen to your body, and then... motivated and with a plan, back to the gym – long-term success will remain with you.

Bibliography

Scientific and professional sources:

1. Encarnação et al. (2023) – Effects of Detraining on Muscle Strength and HypertrophySystematic review of the training break. Reports u.a., that 3 weeks training break, only minimal changes this results in neuromuscular adaptations, while a 24-week break brings significant losses.mdpi.com.

2. Halonen et al. (2024) – A study from the University of Jyväskylä on training breaks shows that a 10-week breakIn the middle of it all are the long-term strength and muscle gains. not affectedMuscle size and strength increased after resuming training. quickly reached again (Keyword Muscle Memory) sciencedaily.com sciencedaily.com. Source: University of Jyväskylä press release​ sciencedaily.com​ sciencedaily.com.

3. Mühlbauer et al.(2020) – Study of young athletes: Three weeks of training break resulted in no loss. muscle thickness, strength, or performance pmc.ncbi.nlm.nih.gov​ pmc.ncbi.nlm.nih.govThis reinforces the idea that short breaks can be easily compensated for.

4. Close et al. (2014) – Antibiotic Precautions in AthletesA specialist article about antibiotics and sports. It states that Common antibiotics may be associated with reduced performance and tendon problems.​ pmc.ncbi.nlm.nih.gov and that certain antibiotics can cause fatigue/weakness pmc.ncbi.nlm.nih.govEmphasizes a cautious return to activity after taking antibiotics.

5. UC Riverside (2022) – Study by T. Garland et al.: Shows in mice that antibiotics the Intestinal flora damage and to 21% less endurance performance led, even almost two weeks after discontinuation universityofcalifornia.eduThis underlines the importance of gut health for motivation and performance.

6. Schoffstall et al. (2001) – Study on dehydration: Already ~1.5% weight loss due to fluid deprivation It significantly reduces 1RM strength, but this is reversible after rehydration within 2 hours. pubmed.ncbi.nlm.nih.gov. Emphasis of the Importance of hydration for strength performance.

7. Trexler, E. (2020) – Article in Stronger by Science: “Modest Glycogen Depletion…” – Discusses research showing minimal glycogen reduction which can impair performance more than previously thought strongerbyscience.comThe importance of sufficient carbohydrates for strength training.

8. Lamon && Paddon-Jones (2016) – Review: Protecting skeletal muscle during disuseRecognizes that Optimized protein intake reduces muscle loss during inactivity​ pmc.ncbi.nlm.nih.govRecommendation to pay attention to protein and nutrition during breaks.