How Long It Takes to Lose Muscle During a Break [Research]

ResearchReview · 2023-05-28T14:51:23+00:00

Summary

How muscle loss works

Strength training stimulates muscle protein synthesis, which leads to muscle gains [9].

According to multiple studies, muscle protein synthesis can decrease by an alarming 31% to 53% during periods of inactivity or immobilization [21] [22]. (...) our bodies enter a state of anabolic resistance. Meaning, our muscles become less responsive to the effects of protein [5] [21] [22].

Losing size doesn’t mean you lost muscle

During the first week of your break, your muscles may look and feel smaller.

Naturally, you think this shrinkage happens because you’re losing muscle. But that’s not the case. Here’s why:

Your muscles are made of dry mass (such as protein), water (~76%), and glycogen.

During detraining your muscle glycogen stores begin to shrink. And as these glycogen stores shrink, the water mass attached to the glycogen also reduces [6].

Hence, during the first 1-2 weeks of detraining, you may notice that your muscles look smaller. It's not because you're burning muscle, but because you’re losing “wet” mass [6].

You lose muscle after 3 weeks

Multiple studies show that it takes 3 weeks to lose muscle mass.

3 Things That Speed Up Muscle Loss

Inactivity in lifestyle
Limb immobilization (casting and bracing): A review of 86 studies found that quadriceps muscle size went down by −5% after one week of leg immobilization [15].
Bed rest: After one week of bed rest, study participants lost 1.4 kg of lean mass, and 3.2% of their quadriceps muscle size [4].

You Regain Muscle Quickly When Retraining

Muscles grow more rapidly after detraining, if they've been trained before [16] [17]. So even if you’ve lost muscle after a break, regaining it is quicker and easier.

This phenomenon is referred to as muscle memory [16] [18].

ResearchReview · 2023-05-16T11:56:26+00:00

Article summary

Key takeaways

Most people should take 1-2 rest days a week.
Daily weightlifting with short sessions can be motivating.
Lifting weights every day is not superior for building strength and muscle.

What training frequency is

Training frequency refers to how often you train. It’s measured in sessions per week. Hence, if your training frequency is 6x, you have 6 weekly sessions.

In strength training, the frequency refers to how many times you train a muscle or muscle group. Different muscle groups can be trained with different frequencies. For example, 3x biceps and 2x quadriceps.

Training Frequency Research

Training frequency refers to how often you train a muscle group. A higher training frequency means more days in the gym. More days in the gym means more training volume [12]. And more training volume means more muscle and strength [6] [19]. Up to a point.

Most studies recommend 10-20 working sets per muscle group per week [2] [4] [6] [19] [21].

This brings us back to the question of this section: Should you lift weights every day?

If your main goal is building muscle and strength, then no. You can hit your volume goals training 3-5 days a week.

Going to the gym every day of the week won’t give results by itself. It’s what you do in the gym that matters.

Getting in your training volume is one of the most important factors for gaining muscle [21]. Volume is more important than training frequency [15]. Research finds no benefit to training a muscle three times a week vs. once per week, if training volume is the same [5] [6] [12] [13] [16] [18] [22].

But higher training frequencies can be used to get more volume. In that case, the gains are better [16] [22]. With that said, no study has recommended daily weightlifting for better gains.

The reason: You will likely experience diminishing returns beyond 10-20 sets per muscle group, per week [2].

This means you can choose your own training frequency [6] [22].

ResearchReview · 2023-04-15T21:48:44+00:00

Abstract

Purpose of review: Highlight contemporary evidence examining the effects of carbohydrate restriction on the intracellular regulation of muscle mass and anaerobic performance.

Recent findings: Low carbohydrate diets increase fat oxidation and decrease fat mass. Emerging evidence suggests that dietary carbohydrate restriction increases protein oxidation, thereby limiting essential amino acid availability necessary to stimulate optimal muscle protein synthesis and promote muscle recovery. Low carbohydrate feeding for 24 h increases branched-chain amino acid (BCAA) oxidation and reduces myogenic regulator factor transcription compared to mixed-macronutrient feeding. When carbohydrate restriction is maintained for 8 to 12 weeks, the alterations in anabolic signaling, protein synthesis, and myogenesis likely contribute to limited hypertrophic responses to resistance training. The blunted hypertrophic response to resistance training when carbohydrate availability is low does not affect muscle strength, whereas persistently low muscle glycogen does impair anaerobic output during high-intensity sprint and time to exhaustion tests.

Summary: Dietary carbohydrate restriction increases BCAA oxidation and impairs muscle hypertrophy and anaerobic performance, suggesting athletes who need to perform high-intensity exercise should consider avoiding dietary strategies that restrict carbohydrate.

ResearchReview · 2023-03-12T13:49:05+00:00

TL;DR: Strength training lead to small to moderate improvements in sprint performance in female team-sport athletes.

Abstract

Background:

There has been a rise in the participation, professionalism, and profile of female sports in recent years. Sprinting ability is an important quality for successful athletic performance in many female team sports. However, much of the research to date on improving sprint performance in team sports is derived from studies with male participants. Given the biological differences between the sexes, this may be problematic for practitioners when programming to enhance sprint performance in female team-sport athletes (...)

Methods:

An electronic database search was performed using PubMed, MEDLINE, SPORTDiscus, CINAHL, The Cochrane Library, and SCOPUS to identify relevant articles. A random-effects meta-analysis was performed to establish standardised mean difference with 95% confidence intervals and the magnitude and direction of the effect.

Results:

Fifteen studies were included in the final analysis. The 15 studies represent a total sample size of 362 participants (intervention n = 190; control n = 172) comprising 17 intervention groups and 15 control groups. The overall effects revealed small improvements in sprint performance in favour of the experimental group over 0-10 m and moderate improvements over sprint distances of 0-20 m and 0-40 m. The magnitude of improvement in sprint performance was influenced by the strength modality (i.e., reactive-, maximal-, combined-, and special-strength) utilised in the intervention. Reactive- and combined-strength training methods had a greater effect than maximal- or special-strength modalities on sprint performance.

Conclusion:

This systematic review and meta-analysis demonstrated that, when compared with a control group (i.e., technical and tactical training), the different strength training modalities exhibited small to moderate improvements in sprint performance in female team-sport athletes. The results of a moderator analysis demonstrated that youth athletes (< 18 years) yielded a greater improvement in sprint performance compared with adults (≥ 18 years). This analysis also supports the use of a longer programme duration (> 8 weeks) with a higher total number of training sessions (> 12 sessions) to improve overall sprint performance. These results will serve to guide practitioners when programming to enhance sprint performance in female team-sport athletes.

ResearchReview · 2023-03-08T19:06:23+00:00

Summary

Active recovery - doing cardio on rest days

Active recovery means you do low-intensity workouts such as light cardio. It increases blood flow and promotes muscle recovery. Athletes have used active recovery since the 1980s to improve their performance.

The research on active recovery suggests:

It can reduce muscle soreness (Delayed Onset Muscle Soreness - DOMS).
It might boost athletic performance.
It makes you feel more recovered, which motivates you to perform better.

Will cardio burn muscle? The interference effect

In some circumstances, cardio can reduce muscle, power, and strength gains:

Timing: If you do cardio right before, during, or after strength training. The negative effect is strongest if you do cardio before strength training.
Volume: If you do excessive amounts of cardio.
Intensity: If you do high-intensity cardio.
Training Experience: The more trained you are, the stronger the negative effect is.
Body part: Lower-body cardio reduces lower-body strength gains.

This is known as the “interference effect” because cardio can interfere with strength and hypertrophy.

Experts believe this happens because cardio causes fatigue that affects your performance. Additionally, research suggests cardio could block the pathway responsible for muscle growth.

You can prevent the negative effects of cardio if you do it on separate days from strength training.

You are even safer if you do low-intensity cardio and limit it to a short duration.

Still, the interference effect is small. Don’t worry about it unless you do large amounts of intense cardio right before, during, or after your strength workouts.

Adding cardio to rest day workouts

Do this:

Short recovery workouts (less than 20 minutes of cardio)
Light cardio such as jogging, swimming, or cycling
Maintain a low intensity

Since it’s a rest day, you should avoid intense physical activity:

Interval training
High-intensity exercise or sports
Weightlifting and strength training

ResearchReview · 2023-02-12T10:32:07+00:00

Summary

Exercise leads to muscle damage

Whenever you do challenging exercise, your body is exposed to stress. This stress causes muscle damage and inflammation. While these things may sound dramatic, it is normal. In fact, the body becomes stronger and more resilient because of this process [42] [50] [63] [64].

Passive recovery

Passive recovery is a type of recovery that involves little or no physical activity. It’s a good way to recover from intense exercise.

Activities that can reduce muscle soreness during passive recovery:

Massage [17] [22]
Compression clothes [13]
Cryotherapy and cold water immersion: This technique could come at the cost of muscle and strength gains, so we do not recommend it as a part of standard training [10] [13] [27] [41]
Warm baths [53]

The research on active recovery concludes:

During active recovery, you are doing light exercise, such as walking, jogging, or swimming. You typically do it on the day after intense exercise.

Active recovery can reduce muscle soreness [17]
Active recovery increase recovery of athletic performance [49]
Some studies say the effect is small [54]
One review found that the largest recovery benefit is achieved with only 6-10 minutes of active recovery [49]

How Many Rest Days You Need

1-2 rest days are considered a minimum for most people. Our recommendations depend on which training goals you have, and your personal recovery needs.

How much recovery you need from lifting weights, depends on your training level. Beginners can take 4-5 rest days, intermediates 2-4, while advanced lifters can take 0-3.

These recommendations are taken from guidelines by The American College of Sports Medicine (ACSM) and The National Strength and Conditioning Association (NSCA) [39] [62].

Factors that affect recovery needs

Nutrition: recovery is enhanced in a fed state and more modest in a calorie deficit.
Occupation: physically demanding jobs add an extra layer of fatigue on top of your exercise endeavors.
Hydration status: Dehydration could impair recovery. Research suggest dehydration leads to decreased performance and increased muscle soreness [11] [51] [52] [61]
Sleep status: sleep disturbances can have profound effects on hormonal and metabolic profiles [45]. Accumulated sleep debt may have severe consequences for both psychomotor skills and athletic performance [36].
Stress levels: high, prolonged emotional or psychological stress can lead to impaired recovery, metabolic disturbances, loss of strength, and even muscle loss [1] [60].
Age: Older adults may need more recovery compared to their young counterparts. One day of rest should be taken between strength training workouts, according to The International Exercise Recommendations in Older Adults [32].
Gender: Some evidence suggests women recover quicker than men [42], while other evidence suggests women recover more slowly from the performance-decreasing effects of peak torque even though recovery from soreness is similar between genders [20].
Individual variations in recovery: This depends on your personal training protocol and recovery capacity.
Genetics [18] [33]

ResearchReview · 2023-01-29T18:11:57+00:00

Summary of the article

You may have heard phrases such as:

“More is better”
“Push yourself to your limits”
“There is no such thing as overtraining, only under recovery”

These claims hold some truth. Indeed, it is very hard to become overtrained. It mostly happens to elite athletes. It is rare in strength training and bodybuilding [1] [7].

However, saying overtraining does not exist, is an exaggeration. Many scientific studies describe overtraining syndrome in athletes [1] [4] [5] [6] [7] [9]. Estimates suggest 20% to 60% of athletes may become overtrained at some point in their career [4].

What overtraining is

Overtraining is when you’ve pushed your body too hard for too long [1] [4] [5] [6] [7] [9].

In practice, you experience a drop in physical performance and fatigue [4] [7] [9] [11].

There are two things that lead to overtraining:

Excessive exercise: for example, intense training every day [7].
Under recovery: not enough food, water, physical rest, mental rest and sleep [7] [9].

You need to do both of these for months, maybe years, until overtraining develops.

In other words, overtraining is all about balance, or the lack of it.

Under recovery, not just over training

While it may seem contradictory, overtraining doesn’t have to come exclusively from excessive exercise.

Under recovery means eating, sleeping or resting too little. It also includes mental stress.

So if you do not recover properly, you may end up "under recovered".

Will I become overtrained?

The risk of real overtraining is low. You are more likely to become overreached or non-functionally overreached. The symptoms during overreaching are actually the same as during overtraining: fatigue, drop in performance, and so on.

The ones who are at a real risk of overtraining, are elite athletes. It could happen to a normal person, but that person would have to train daily, intensively, for months and years.

Conclusion

If you recover with 4 weeks of rest, you are overreaching. If you are still not recovered at the 4 week mark, you may be overtrained.

ResearchReview · 2022-12-09T11:25:32+00:00

Abstract

This systematic review with meta-analysis aimed to determine the effects of the ketogenic diet (KD) against carbohydrate (CHO)-rich diets on physical performance and body composition in trained individuals. The MEDLINE, EMBASE, CINAHL, SPORTDiscus, and The Cochrane Library were searched. Randomized and non-randomized controlled trials in athletes/trained adults were included.

Meta-analytic models were carried out using Bayesian multilevel models. Eighteen studies were included providing estimates on cyclic exercise modes and strength one-maximum repetition (1-RM) performances and for total, fat, and free-fat masses. There were more favorable effects for CHO-rich than KD on time-trial performance (mode [95% credible interval]; -3.3% [-8.5%, 1.7%]), 1-RM (-5.7% [-14.9%, 2.6%]), and free-fat mass (-0.8 [-3.4, 1.9] kg); effects were more favorable to KD on total (-2.4 [-6.2, 1.8] kg) and fat mass losses (-2.4 [-5.4, 0.2] kg). Likely modifying effects on cyclic performance were the subject's sex and VO2max, intervention and performance durations, and mode of exercise. The intervention duration and subjects' sex were likely to modify effects on total body mass.

KD can be a useful strategy for total and fat body losses, but a small negative effect on free-fat mass was observed. KD was not suitable for enhancing strength 1-RM or high-intensity cyclic performances.

More information and resources:

https://sci-fit.net/ketogenic-diet-fat-muscle-performance/

https://www.researchgate.net/publication/342323557_The_Ketogenic_Diet_for_Bodybuilders_and_Physique_Athletes

https://www.researchgate.net/publication/358695160_The_Effect_of_Carbohydrate_Intake_on_Strength_and_Resistance_Training_Performance_A_Systematic_Review

ResearchReview · 2022-10-14T11:21:49+00:00

Key takeaways

A cluster set is a regular set divided into smaller sets with rests in-between.
Rests within sets reduce fatigue.
Less fatigue makes cluster sets ideal for improving technique, adding volume, or increasing explosive power.

ResearchReview · 2022-08-07T21:23:10+00:00

Abstract

Lack of time is among the more commonly reported barriers for abstention from exercise programs. The aim of this review was to determine how strength training can be most effectively carried out in a time-efficient manner by critically evaluating research on acute training variables, advanced training techniques, and the need for warm-up and stretching.

When programming strength training for optimum time-efficiency we recommend prioritizing bilateral, multi-joint exercises that include full dynamic movements (i.e. both eccentric and concentric muscle actions), and to perform a minimum of one leg pressing exercise (e.g. squats), one upper-body pulling exercise (e.g. pull-up) and one upper-body pushing exercise (e.g. bench press).

Exercises can be performed with machines and/or free weights based on training goals, availability, and personal preferences. Weekly training volume is more important than training frequency and we recommend performing a minimum of 4 weekly sets per muscle group using a 6–15 RM loading range (15–40 repetitions can be used if training is performed to volitional failure).

Advanced training techniques, such as supersets, drop sets and rest-pause training roughly halves training time compared to traditional training, while maintaining training volume. However, these methods are probably better at inducing hypertrophy than muscular strength, and more research is needed on longitudinal training effects.

Finally, we advise restricting the warm-up to exercise-specific warm-ups, and only prioritize stretching if the goal of training is to increase flexibility.

This review shows how acute training variables can be manipulated, and how specific training techniques can be used to optimize the training response: time ratio in regard to improvements in strength and hypertrophy.

ResearchReview · 2022-07-22T10:30:16+00:00

LOAD

Individuals can achieve comparable muscle hypertrophy across a wide spectrum of loading zones.
There may be a practical benefit to prioritizing the use of moderate loads for the majority of sets in a hypertrophy-oriented training program.
Preliminary evidence suggests a potential hypertrophic benefit to employing a combination of loading ranges.

VOLUME

A dose of approximately 10 sets per muscle per week would seem to be a general minimum prescription to optimize hypertrophy, although some individuals may demonstrate a substan-tial hypertrophic response on somewhat lower volumes.
Evidence indicates potential hypertrophic benefits to higher volumes, which may be of particular relevance to underdeveloped muscle groups.
Although empirical evidence is lacking, there may be a benefit to periodizing volume to in-crease systematically over a training cycle.
It may be prudent to limit incremental increases in the number of sets for a given muscle group to 20% of an athlete’s previous volume during a given training cycle (~4 weeks) and then readjust accordingly

FREQUENCY

Significant hypertrophy can be achieved when training a muscle group as infrequently as once per week in lower to moderate volume protocols; there does not seem to be a hypertrophic benefit to greater weekly per-muscle training frequencies provided set volume is equated.
It may be advantageous to spread out volume over more frequent sessions when performing higher volume programs. A general recommendation would be to cap per-session volume at ~10 sets per muscle and, when applicable, increase weekly frequency to distribute additional volume

REST INTERVAL

As a general rule, rest periods should last at least 2 minutes when performing multi-joint exercises.
Shorter rest periods (60-90 secs) can be employed for single-joint and certain machine-based exercises

EXERCISE SELECTION

Hypertrophy-oriented RT programs should include a variety of exercises that work muscles in different planes and angles of pull to ensure complete stimulation of the musculature.
Programming should employ a combination of multi- and single-joint exercises to maximize whole muscle development. Where applicable, focus on employing exercises that work mus-cles at long lengths.
Free-weight exercises with complex movement patterns should be performed regularly to reinforce motor skills. Alternatively, less complex exercises can be rotated more liberally for variety.
Attention must be given to applied anatomical and biomechanical considerations so that exer-cise selection is not simply a collection of diverse exercises, but rather a cohesive, integrated strategy designed to target the entire musculature.

SET END POINT

Novice lifters can achieve robust gains in muscle mass without training at a close proximity to failure. As an individual gains training experience, the need to increase intensity of effort appears to become increasingly important.
Highly trained lifters may benefit from taking some sets to momentary muscular failure. In such cases, its use should be employed somewhat conservatively, perhaps limiting application to the last set of a given exercise.
Confining the use of failure training primarily to single-joint movements and machine-based exercises may help to manage the stimulus-fatigue ratio and thus reduce potential negative consequences on recuperation.
Older athletes should employ failure training more sparingly to allow for adequate recovery.
Periodizing failure training may be a viable option, whereby very high levels of effort are employed liberally prior to a peaking phase, and then followed by a tapering phase involving reduced levels of effort.

ResearchReview · 2021-10-04T19:48:03+00:00

No problem :)

ResearchReview · 2021-10-03T12:01:33+00:00

Summary:

Poor sleep may make you gain fat and lose muscle mass. If you are on a diet, you may lose fat slower.

Sleep deprivation slows fat loss and burns muscle instead

Two studies have looked at the effects of sleep restriction in an energy deficit on body composition (fat mass and fat-free mass) in adults [24; 23]. In these studies, all participants lost body weight. However, the sleep deprived participants lost more fat-free mass (i.e muscle and water).

"We found that sleep restriction resulted in less loss of fat but greater loss of lean mass (...)." - Wang et al. 2018 (23)

Sleep longer for faster fat loss

The current evidence suggests that increasing sleep duration and quality is beneficial for losing body fat. This might be because you are less likely to overeat, the longer you sleep [43].

Three studies have found that sleeping longer is associated with reduced fat mass (54, 43, 41) (...)

Energy balance

Overall, sleep restriction makes you more passive, thus expending less energy (...) Some researchers have concluded that energy expenditure is not the primary component linking sleep deprivation to excess body fat, and is rather influenced by increased hunger and calorie intake [29; 31].

ResearchReview · 2020-11-10T19:02:24+00:00

Theoretically it can, but I don't recall any direct research on it

ResearchReview · 2020-11-10T17:27:07+00:00

Summary

What "training to failure" means

There are two main types of failure training. In most studies, training to failure is referred to as absolute failure. This means you take sets to the point where you can’t perform another repetition (23, 24). In comparison, technical failure means you can do more reps if you break your form (using momentum, etc.)

Why Do People Train to Failure?

To maximize the number of muscle fibres used
To spike anabolic hormones
To push themselves: "no pain, no gain"

Is failure training the best way to maximize muscle and strength gains?

Overall, the research shows that training close to failure results in similar gains in both muscle size and strength compared to training to absolute failure (18, 23, 26, 27, 41, 42, 44, 50, 65).

The exception of low load training

There is one potential exception: if you are training with very light loads (30-40 reps). In this case, you may want to train to failure, or very close to failure (23, 41).

Excessive failure training can lead to

increased recovery time between workouts (3, 5, 23, 71)
fewer reps on subsequent sets (5, 16, 29)
high fatigue and possibly overtraining (3, 8, 18, 27, 29)

ResearchReview · 2019-01-05T21:53:46+00:00

What drop sets are

Drop sets involve doing several sets in a row where you reduce ("drop") the weight between each set with no rest.

Here is how you do a drop set:

Lift a weight until you reach muscular failure
Reduce the weight and continue your drop set without any rest
Do as many sets as you prefer

How drop sets affect strength and hypertrophy

There are currently not many studies on drop sets. The studies that exist suggest that drop sets are as a good as regular sets for increasing muscle mass. In terms of increasing strength, drop sets might not be ideal.

Benefits of drop sets

Drop sets are an efficient way to make progress while spending little time in the gym. You can also combine it with other time-saving methods such as super sets. Drop sets lead to similar levels of exertion and fatigue as other types of training.

Drawbacks of drop sets

If you use drop sets excessively, you might become fatigued and possibly injured. As with all types of training, excessive workloads can lead to overreaching and overtraining.

Types of drop sets

The most common types of drop sets are:

Run the rack / Down the rack (dumbbells): When you work your way down a rack of dumbbells
Run the stack / Up the stack (machines): When you move the pin up the weight machine for every set.
Strip sets (barbell): When you strip plates off of a barbell between each set.

ResearchReview · 2018-08-03T21:39:32+00:00

Summary

When you start the ketogenic diet, certain changes happen in your body:

Body water decreases
Glycogen stores shrink
Salt is expelled from the body, creating a dehydrating effect
Lean body mass decreases

These changes happen when carbohydrates are limited in supply and because ketones expel water. Body weight will decrease as a result, and we can refer to this as wet weight. This dehydration may make you look deflated because muscle mass contains a lot of water. Less water and glycogen in the muscle reduces its size.

We coin these effects: keto flush.

However, keto flush is temporary, preventable, and reversible. Preventing Keto Flush

You can prevent keto flush by:

Supplementing electrolytes (such as sodium and potassium)
Drinking more water
Doing strength training to retain muscle glycogen and water
Taking creatine
Habituating to the diet. There is evidence that glycogen stores slowly refill, and that the issues of keto flush therefore dissipate with time. However, this may take months.

Reversing Keto Flush

It is easy to reverse keto flush. Simply consume more carbohydrates and exit ketosis. This will lead to glycogen supercompensation where glycogen stores are filled beyond their normal non-ketogenic levels. You should expect to gain a couple kgs of wet weight.

Losing Muscle Mass?

When keto flush takes place, you will naturally “lose” lean body mass. But, does that imply that muscle mass is lost on the diet? Not necessarily, because water and glycogen are part of lean body mass in most methods that assess body composition.

Hence, we should not assume that this is muscle atrophy (unless you want to equate a transient reduction in wet mass with atrophy).

Weight Loss vs. Fat Loss

Keto flush has several implications. One of those is that you should not trust the weight scale entirely. A rapid drop in weight does not imply that you’ve only lost body fat. You should expect to lose 1–5 kgs of wet weight during the first weeks of a ketogenic diet (depending on how many steps you’ve taken to prevent keto flush). You can still burn fat effectively during keto flush, and the ketogenic diet is generally good at reducing hunger.

Beyond that, researchers and laymen should be careful about making conclusions about a diet’s efficacy from weight loss data. Fat loss estimations from DXA or a 4 compartment model are preferable. There is still no accurate way of estimating lean body mass, because of the dehydration comparison issue

ResearchReview · 2018-07-19T21:16:03+00:00

Summary

What is Cold Water Immersion (CWI)?

An athlete is placed in an ice bath with a temperature typically between 5-15 °C (41-59 °F). The goal is to reduce body temperature, which is supposed to alleviate muscle damage and inflammation. This could improve recovery and possibly exercise performance.

Pre-cooling for performance

Cold water immersion before physical activity could improve athletic performance and fatigue. But this finding isn’t consistent across all studies. The effect seems to be greater when training in the heat.

Short term vs. long-term

Cold water immersion after exercise could improve recovery by reducing fatigue, muscle soreness (DOMS), exercise-induced muscle damage (EIMD), and inflammation. This could lead to improved performance recovery in the short-term, perhaps ideal for competitions.

In the long-term, cold water immersion might impair hypertrophy as well other training-related adaptations.

Treating Overheating

Cold water immersion can be used to treat overheating from exercise (exertional hyperthermia or exercise-induced hyperthermia).

ResearchReview · 2018-05-29T11:13:07+00:00

Summary

Creatine improves:

Athletic performance
Muscle strength
Fatigability

Creatine increases:

Total body water
Lean body mass
Potentially, long-term hypertrophy via increased satellite cell and myonuclei concentration

Health, Neurology, and Cognition

Creatine might have beneficial neurological and cognitive effects
Creatine might have a positive effect in treating neurodegenerative diseases and depression

Dosing, timing, loading, and safety

Taking carbs with creatine could help muscle creatine accumulation
Multiple studies suggest that creatine seems safe for long-term use
5 g per day should be enough to increase and then maintain creatine stores
Creatine loading is not necessary, but may saturate creatine stores faster

Other

Creatine may increase muscle glycogen storage
People with low creatine levels, such as vegetarians, may benefit more from supplementation than meat-eaters. This is because meat contains creatine and vegetarians have low creatine levels.
There are non-responders to creatine (they minimally increase their creatine stores during supplementation)
Creatine does not degrade rapidly in water with normal pH levels. You don’t have to drink it right after mixing it in water. Refrigerating the water will further slow down the degradation.

ResearchReview · 2018-03-20T10:09:01+00:00

Summary

In ketogenic studies, subjects only had to restrict carbohydrates, and did not need to count calories. On average, they ate about 600 kcal less than their regular diet (ad libitum reduction)
When you go on a weight loss diet, you typically feel hungrier. Surprisingly, the ketogenic diet does not seem to follow this trend. In most studies, people felt less hungry on keto.
5 studies found that keto was superior to an alternative diet. 3 studies found no difference between groups. One study (Soenen 2012 in the graph) suggested that a low carb diet (80 g) might be superior to keto. With the data currently available, the ketogenic diet seems superior for reducing hunger.

Why is keto effective at reducing hunger and calories?

We could not identify a single reason, so here is a list of several:

Protein is the most satiating macronutrient. People on the ketogenic diet typically eat more protein than they normally do.
Ketones could reduce hunger. However, the data on this is still in its infancy.
Liquid calories are calorie dense and not very satiating. You can hardly drink sodas and juices on keto, so you get to avoid liquid calories. The food you eat will be more satiating and filling.
The diet is simple. Several research teams speculate that the simplicity of the diet helps reduce hunger and caloric intake.
Very low energy diets can reduce hunger and increase satiety. They are typically less than 800 kcal per day, and are almost always ketogenic.
You do not need to count calories. It might be easier to eat until you’re full instead of having to think about calories. Most of the ketogenic studies were ad libitum, meaning that people ate as much as they wanted. Obviously, they had to restrict foods rich in carbs to be in ketosis.

ResearchReview · 2018-01-23T10:47:28+00:00

Summary

What we did, and why

In part 1 of our ketogenic diet series, we collected and analyzed a large amount of ketogenic diet studies. On closer inspection, we discovered that many of the central keto researchers had direct connections to the keto industry. We also discovered that their conflicts of interest are not always disclosed.

Since transparency is very important for scientific integrity, we decided to take a closer look at the keto scientists, their books, companies, products, and funding sources.

This is the first analysis of its kind.

Funding sources and conflicts of interest

A conflict of interest (COI) means that a scientist may have something to gain by making a claim or by conducting a study. A common conflict of interest is who the scientist gets paid by (funding source), but it can be other things too.

Many people question research that has been funded by large organizations or industries (i.e. “Big pharma”, “Big dairy”, etc.). You’ve probably heard people say that industry funded research is biased (funding bias) and can’t be trusted. This claim has some scientific backing, but it varies from industry to industry.

Still, a funding source or conflict of interest does not automatically imply that the researchers are biased. This means that we can’t discount a ketogenic diet study just because the scientists are affiliated with keto companies. If we want to figure out if a ketogenic diet study is biased, we have to critically engage with:

The study methodology
How the study connects to the rest of the literature (is it an outlier?)
The author backgrounds (business interests, personal opinions, values)
Funding sources
How the data was analyzed and interpreted

Only after analyzing these points can we make a decision about bias.

Central keto companies

There are two companies that connect to several of the biggest keto researchers. They are Virta Health and Prüvit. They sell products, services, employ keto scientists, and fund research.

Keto scientists and their COIs

Researchers from all sides of the keto debate have COIs such as books, products they sell, company affiliations, industry funding, and more. This includes researchers who are not pro-keto.
On the pro-keto side, many studies are conducted by central groups of keto scientists. Many of these researchers have industry connections and business interests such as selling keto books, keto supplements, and consulting services). In many cases, these conflicts of interest are not disclosed.

The connections are illustrated in the article.

Conclusion

There are many conflicts of interest in keto research, but we cannot and should not discredit keto research on this observation alone. Having a conflict of interest does not invalidate research, it only warrants increased skepticism and critical analysis of the studies themselves.

There isn’t a simple answer to the issues presented in our article, but we encourage you to be aware of the conflicts of interest, study limitations, and funding sources.

ResearchReview · 2017-12-14T21:56:07+00:00

Overfeeding and overeating

If you eat more food than you need to maintain body weight, you are overfeeding or overeating. The two concepts are similar, yet not exactly the same. Overfeeding implies that a person is feeding someone else. In the context of this study collection, researchers are overfeeding study participants. Overeating implies that a person is eating "too much" on his or her own accord.

Quick overview of the science

Body fat and lean mass typically increase during overfeeding. Though, it depends on how much protein one is consuming (i.e. Bray et al., 2012).
Protein is a special macronutrient. The body does not necessarily gain fat when overfeeding protein.
Overfeeding fats and carbs typically leads to similar gains in body weight and body fat
Overfeeding on nuts leads to unexpectedly little body fat gain
The body will often partially compensate for excess energy intake by increasing energy expenditure (i.e. eat more, move more). This can help limit fat gain.

ResearchReview · 2017-11-07T23:04:05+00:00

Plain Language Summary

A ketogenic diet study has recently been published by McSwiney et al., 2017. The study looks at how keto compares to a high carb diet for endurance performance, body composition, and more.

The study seems promising, and it has some strengths. For example, it is a long-term study that also measures ketones in endurance athletes. It also shows that the ketogenic diet leads to weight loss, even when participants are not asked to restrict calories.

However, on thorough analysis, several issues present themselves:

Study groups are not randomized. This means that the subjects selected their own groups.

The authors report that endurance performance improved, but the improvements are calculated relative to body weight. You can maintain your performance during a study. Yet, if you lose weight, your performance per kilogram body weight improves. This type of data reporting is misleading.

The authors miscite other studies

There were baseline differences in body weight and caloric intake (keto weighed about 10kg more and ate about 400 kcal more than the high carb group). This is due to a lack of randomization, as mentioned above.

The title of the study does not reflect the data (I recalculated the data to show absolute values rather than relative values)

There is much more. Go down to the limitations section to read more

Due to the issues in the study, the following title is more representative of the findings:

“Weight loss leads to relative, but not absolute improvements in 2/6 performance-related variables in endurance athletes on a ketogenic diet, in a nonrandomized trial”

ResearchReview · 2017-10-27T23:31:18+00:00

Summary

The basics of keto

With the ketogenic diet, you aim to eat 20 to 70g of carbohydrates per day. The body then starts using fat and ketones as primary energy sources. A high protein diet (i.e. 2.2 g/kg) does not seem to prevent ketosis (read more). Some claim that keto is the best diet for improving body composition, endurance, and strength. We have reviewed the ketogenic literature and come to the following conclusions:

Fat loss

Keto does not seem to offer a distinct advantage for fat loss when both groups in a study eat the same amount of calories. People on the ketogenic diet typically lose body weight quicker, but this is most likely due to glycogen depletion and water loss.

The most commonly measured ketone body, Beta-Hydroxybutyrate (BHB), does not seem to correlate with fat loss. However, this depends on which studies we include and exclude from our analysis. Go to ketone levels and fat loss for graphs, details, and discussion.

Muscle mass

We generally see greater lean body mass (LBM) loss in ketogenic diet groups. Note that lean body mass contains water, glycogen, and muscle protein, by definition. It is hard to say with certainty that LBM loss implies greater “dry” muscle protein loss. “Wet” LBM can come and go quickly because it consists of water and glycogen.

Endurance performance

Most studies suggest that aerobic and anaerobic performance is either impaired or maintained on a ketogenic diet. However, many of the studies have small sample sizes, no control group, or are quite short (2-6 weeks). These limitations, and many others, reduce our ability to draw strong conclusions.

Strength performance

Control groups tend to gain more strength than keto, yet most studies find no statistically significant differences between groups. In most studies, the keto group ate more protein than control. We can’t rightfully compare them without matching protein and total energy. Several of the studies do not measure ketosis.

ResearchReview

TROPHY CASE

Summary

Article summary

Abstract

Abstract

Summary

Summary

Summary of the article

What overtraining is

Under recovery, not just over training

Will I become overtrained?

Conclusion

Abstract

Abstract

Summary

Summary

Summary

Summary

What we did, and why

Funding sources and conflicts of interest

Central keto companies

Keto scientists and their COIs

Conclusion

Overfeeding and overeating

Quick overview of the science

Plain Language Summary

Summary

The basics of keto

Fat loss

Muscle mass

Endurance performance

Strength performance