Maximizing strength and muscle has many benefits, such as increased metabolism and bone mass. It’s essential for maintaining health, wellness, and fitness – all good reasons for trying to stay physically fit.
However, many people find it difficult to stay committed to a fitness program. This is why your fitness program should be as efficient as possible.
Maybe you’re not satisfied with the results you’re getting from your resistance training, or you want to optimize your workout for maximum results.
Either way, you can increase the success of your training program and start maximizing strength and muscle, whether you’re a beginner or an advanced athlete.
How? By following these 8 keys to optimizing the muscle clocks in your skeletal muscle.
1. Understanding muscle clocks for optimal performance
Timing Resistance Training (Human Kinetics Publishers, 2020) by Amy Ashmore, reveals that scientists have discovered that muscles have clocks. These clocks are genes inside your muscles that regulate physiological and environmental stimuli around a 24 hour period.
Your muscle clocks prepare your body for upcoming changes in your daily routine, and they communicate with your brain (the master clock) and other organs in your body.
During resistance training, muscles produce myokines (or proteins) that tell your body what’s happening. Exercising gives cues to your muscle clocks in order for them to perform optimally.
The time of day when you do resistance training, the frequency of training, type of exercise, and rest all condition your muscles and organs to self-regulate. This is why you can negatively affect your circadian rhythms by making frequent changes to your exercise schedule. (1)
Your muscle clocks look for and need consistency in your exercise routine to be able to prepare for upcoming training sessions.
There are actually times of the day when your body is better suited for different kinds of exercises:
- Resistance training: Your body temperature peaks between 4pm and 6pm, and it’s believed to be the reason pliability, speed, and strength peak during this time frame. Therefore, the optimal time for resistance training is 4pm to 6pm to start maximizing strength and muscle.
- Cardiovascular exercises: Muscle stamina and endurance peak around early to mid morning, meaning this is the best time for cardiovascular exercises.
- Sports specific exercises: As mental acuity peaks around the middle of the day, sports specific exercises should be done during this timeframe.
2. Avoid muscle interference and confusion
You may be surprised to know that cardiovascular exercise and resistance training conflict with each other at the molecular level. When they are done in the same session, gains in muscle mass (hypertrophy) and strength are adversely affected.
A lot of people in the gym are doing workouts that are counterproductive and sub-optimal because they’re performing resistance training and cardiovascular exercise in the same session.
As Ashmore points out in her book, skeletal muscles are not beasts of burden. They are perceptive and can tell the difference between cardiovascular and resistance exercises.
Your skeletal muscles can also detect subtle differences between exercises that are biomechanically similar and for the same muscle, like a bench press and dumbbell fly. These two exercises activate different bundles of fibers within the pectoralis muscle, which results in a more extensive workout which is key to optimizing and maximizing strength and muscle training.
Muscles use their internal clocks to look for consistency. The cues muscles receive from different modes of training tell them which molecular mechanisms to activate.
When your workout is chaotic, muscles get confused and the outcome of your workout is adversely affected.
The molecular mechanisms in the muscles involved in strength gains need approximately 3 hours to reset. (2) This is why you should do cardiovascular exercise and resistance training at least 3 hours apart.
Additional research has shown that you need between 6 hours and 24 hours to avoid having cardiovascular exercise interfere with gains in strength and muscle mass. (3)
Cardiovascular exercise should be limited to 20-40 minutes to avoid interference with gains in strength, muscle mass, and power (the ability to move weight with speed). (2, 4, 5)
When cardiovascular exercise interferes with resistance training progress, you can experience adverse side effects, such as:
- Decreased muscle contractility (the muscles’ ability to contract)
- Increased Delayed Onset Muscle Soreness (DOMS), which products microscopic tears in the muscle and reduces the contractility of muscles
- Increased protein breakdown
- The depletion of glucose, adenosine triphosphate (ATP), and phosphocreatine (PCr) which are all used for energy
- Decreased testosterone levels
- Increased blood lactate and cortisol levels that negatively affect strength, hypertrophy, and power outcomes
- Decreased muscle glycogen (a multibranched polysaccharide of glucose)
Doing cardiovascular exercise immediately before resistance training elevates your cortisol and blood lactate and interferes with the contractility of your muscles.
So, if strength and muscle mass are your goals, then you should limit your cardiovascular exercises to less than 3 days per week. (5)
Running and jogging appear to interfere with resistance training progress more than cycling.(3, 5) The reason seems to be that cycling does not involve eccentric contractions (muscle contraction while lengthening), which cause microscopic muscle damage.
The intensity of cardiovascular training can also adversely affect your progress related to strength, muscle mass, and power. Your cardiovascular training should be limited to 40% to 50% of your maximum heart rate to avoid interference.
You can find your maximum heart rate by subtracting your age from 220. If you’re 37, for example, your maximum heart rate is 220 – 37 = 183.
After a high intensity resistance training session, your muscles need at least 48 to 96 hours to recover, and detraining sets in after 96 hours.
Since high intensity interval training (HIIT) has become popular, you may be wondering what the effects of concurrent HIIT are on resistance training.
While HIIT reduces resistance training outcomes, it appears that HIIT training sessions that are shorter than cardiovascular training sessions seem to have less adverse effects on strength, muscle mass, and power outcomes than cardiovascular exercise. (7)
There is also evidence that lower body sprint interval training can have negative effects on your upper body strength and muscle mass progress. (8)
3. Maximizing strength and muscle with testosterone and HGH
Resistance training stimulates the release of testosterone. Compound exercises, such as a squat, involve the movement of more than one joint and stimulate more testosterone than an isolation exercise such as a dumbbell curl. (9, 10)
Like testosterone, your body releases HGH (human growth hormone) during exercise. One study showed that doing a slow velocity bench press stimulates more HGH than a fast velocity bench press. (11)
The greater the intensity of your exercise, the more HGH, testosterone, and cortisol your body releases.
Timing your resistance training is also important in regard to rest periods, specifically intraset rest, or rest within a set of repetitions. Intraset rest can range from 10 to 120 seconds.
One study demonstrated that rest within sets was more effective at improving strength and power outcomes than traditional rest between sets, which can last up to 5 minutes. (12)
If you find that you can’t finish a set of repetitions, rest 15 to 30 seconds, and then complete the rest of the set. You will be maximizing strength and muscle this way. For example, if you’re trying to do 10 repetitions, but can only get 8, rest and then finish your last 2 repetitions.
4. Optimize your workout with biomechanics
Your muscle clocks seek out exercises which are biomechanically similar because it provides clues and they know what to anticipate.
By doing exercises that are biomechanically similar, your muscle clocks are conditioned and learn to activate molecular mechanisms at the appropriate time.
Combining exercises that have similar joint movement, such as a knee extension and a leg press, lets the muscles know what to expect within a 24 hour period.
5. Designing effective resistance training programs
Creating an effective training program that is maximizing strength and muscle means you are training your muscles to anticipate workouts. Your muscles will know to make physiological changes necessary for the upcoming workout.
Motor learning plays a significant part in designing effective resistance training. It develops specific motor skills through repetition and practice so that the skills become automatic.
By conditioning your central nervous system with motor learning, your motor skills become refined and developed, allowing you to perform the skill automatically on a long-term basis.
Performing biomechanically similar exercises contributes to the proper motor learning, memory, and performance of the exercises.
It’s imperative to correctly structure your workout so that you provide your muscles the proper cues to prepare for upcoming workouts.
If your workout is not properly structured, or if you’re using poor exercise technique, motor learning will be poorly developed. The outcome is that your muscles aren’t able to anticipate and make the necessary physiological changes for the upcoming workout.
Consistently timed exercise improves the performance of your muscles, coordinates function with other body systems, and facilitates good recovery and sleep.
A resistance training program that is chaotic and complex confuses your muscles, and they won’t know how to make the proper responses.
Whereas, a simplified training program cues your muscles to know what to expect so they can make the proper physiological changes at the molecular level. This way you can avoid a decline in performance or a lack of improvement.
When your muscles can anticipate types of exercises at a consistent time, you can see improvements in the following areas:
- Body composition (lean to fat ratio)
- Muscle mass
In regard to resistance training, it can take your muscles anywhere from weeks to months to learn to anticipate a training program and the specific exercises. And as we age, our ability to anticipate upcoming exercise only declines. (13)
By age 70, your body’s ability to motor plan, or anticipate training, falls to the level of children. This is why a training regimen should be simplified with exercises that are biomechanically paired.
6. Avoid overtraining for maximizing strength and muscle
Overtraining is defined as a decline in performance or a lack of improvement. Overtraining can lead to loss of muscle mass and eventual injury, which is why you should moderate your training loads.
Many people fall prey to the belief that maximizing strength and muscle happens by continually increasing the volume and intensity of their resistance training. However, this eventually leads to overtraining.
Incorporating biomechanically paired exercises, timing cues, compound exercises, and contrast training methods, as well as training to subfailure, will help you avoid overtraining.
Contrast training involves using low intensity training, as opposed to moderate-to-high intensity training.
An example of contrast training is post-activation potentiation – the practice of performing a similar exercise immediately before another, making the muscle fibers more receptive to the second exercise.
Periodically changing your resistance training program, for example monthly, will also help you avoid overtraining. Avoiding DOMS will help you avoid overtraining too, since microscopic muscle tears inhibit strength gains.
7. Maximize strength by exploiting muscle clocks
For your workout to have positive strength outcomes, your muscle clocks need consistency to make the necessary physiological adaptations. Pairing biomechanically similar exercises is one way to accomplish this.
Compound exercises appear to be more effective for improving strength and oxygen uptake than single joint or isolation exercises. (14)
Compound exercises are also more advantageous for functions related to activities of daily living and athletic activities than single joint exercises.
But compound exercises have their limitations. They are more difficult to learn and require more coordination. Plus, they don’t focus, or isolate, one muscle.
Single joint exercises are effective for improving body composition and hypertrophy, and they should compliment compound exercises. One way to do this is to do a tricep extension immediately followed by tricep dips.
By doing an isolation exercise immediately before a compound exercise, you can exhaust the isolated muscle further than by just doing an isolation exercise alone.
Volume (the amount of exercise during a session) can also be used for maximizing strength and muscle mass.
One study compared three groups of men who performed 1, 3, and 5 sets of each resistance exercise. (15) The results demonstrated that increases in strength, muscle mass, and endurance were greater in the 5-set group than the 3-set group and 1-set group respectively.
For optimal muscle hypertrophy, 4-6 sets of 6 to 12 repetitions per exercise is recommended.
8. Improve flexibility by using muscle clocks
Flexibility is your muscles’ ability to stretch when lengthened and then relax. We’re told that stretching increases pliability and reduces tight muscles.
Muscle clocks look for muscle pliability as a cue and use it as a stimulus for power and strength outcomes. Muscle pliability also signals your muscle clocks information about the type of training and time of day so they know what mode of training to expect and when.
Pliable muscles, or muscles that are stretched, contract more forcefully than muscles that are tight.
Regularly scheduled resistance training helps your muscle clocks develop rhythm within a 24-hour period so that your skeletal muscles can anticipate upcoming workouts.
Flexibility training, or stretching, should be done after an exercise session. Static stretching should be held for 30 seconds without pain because stretching 30-45 seconds reduces strength outcomes.
And stretching longer than 60 seconds is detrimental to power, strength, and speed-dependent skills. (16)
One study demonstrated that dynamic stretching and warm-ups improves quadriceps strength before the activity. (17) Dynamic stretching involves frequently changing positions, and tai chi is an example of dynamic stretching.
Dynamic stretching is different from ballistic stretching, which is not advised, since it involves bouncing and jerking, and can cause injury.
Start maximizing strength and muscle mass
Programming your muscle clocks is one of the best things you can do for your workout.
Timing you resistance training by following the above guidelines will make a big difference in your workout, leading to significant increases in strength and muscle mass.
Once you program your muscle clocks and time your resistance training, you’ll notice the difference and reap the rewards.
Time waits for no one. Your muscle clocks are ticking. The time is now.
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- Calixto R, Verlengia R, Crisp A, et al. Acute affects of movement velocity on blood lactate and growth hormone responses after eccentric bench press exercise in resistance-trained men. Biol Sport. 2015;31(4):289-294.
- Oliver JM, Jagim AR, Sanchez AC, et al. Greater gains in strength and power with intra-set rest intervals in hypertrophic training. J Strength Cond Res. 2013;27(11):3116-3131.
- Stockel T, Wunsch K, Hughes CML. Age-related decline in anticipatory motor planning and its relation to cognitive and motor skill proficiency. Front Aging Neurosci. 2017;9:1-12.
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