What are the benefits of resistance exercise?

Although weight lifting has long been associated with bodybuilding and power sports such as football and field events (shot put, discus, etc.), it is more popular with the general population than ever before. Clearly, resistance training can favorably influence bone density and increase the amount of muscle attached to the skeleton. Thus resistance training include: Increased strength and powerIncreased metabolism (daily calories burned)reduced risk of bone-related disorders such as osteoporosisreduced body fat contentimproved self-imagereduced risk of injury.

 

What are options for resistance exercise?

Today there are numerous options for resistance training beyond free weights and weight machines. Today’s community gyms include free weights including dumbbells, barbells, kettlebells and other related equipment. In addition, weight-plate machines, cable equipment, bands and heavy ropes are seen as well as equipment and space allowing for body weight driving resistance exercise (e.g. pushups, pull-ups, etc). Resistance equipment can then be applied to numerous types of exercise movements including Olympic lifts such as dead lifts, squats, clean and jerk and the basic and classic resistance movements like bench, shoulder and leg press, leg and arm curls, etc. Plus, resistance equipment can applied to more dynamic movements like lunges and fireman’s carry. Body weight alone can provide enough resistance for some adaptation popular movements include squat walking and varied or walking pushups.

 

How does weight lifting increase muscle mass?

The goal of most people that lift weights or used resistance equipment is to increase the size of the muscles that are targeted. Muscle mass development through resistance training hinges on the “overload” principle. The use of weights places a greater than normal stress (load) upon the challenged muscle fibers. The overload stimulates the muscle to grow primarily by increasing the size (hypertrophy) of the overloaded muscle fibers and over time increase the number of muscle fibers. This means that the muscle fibers adapt to get stronger based on the routine resistance stimulus and as a result of the adaptations it gets bigger too. Therefore, as a biceps muscle enlarges from doing dumbbell curls it is really a reflection of an increase in size of the overloaded muscle fibers within that muscle. Although growth may occur in both Type I and Type II fibers, as mentioned, it is believed to be more significant in the challenged Type II fibers.

 

How do you know how much resistance to use to promote muscle development?

To overload a muscle you need to perform repetitions of the same movement like arm curls or bench press. Furthermore you should target the number of repetitions you will be able to do before the muscle fatigues. This is then your repetition maximum (RM) for that movement when performed using a specific resistance (e.g. weight) and at standard tempo. Using a simple guideline such as training more within the 6-12 RM which is proven to provide the most dramatic gains in muscle size. This equates to roughly 65-85% 1RM. More weight/less reps and less weight/higher reps yield more strength and endurance gains, respectively. While all three will produce size gains, but over time performing more sets in the 6-12 RM will yield the greatest gains in size. So, target more sets in the 6-12 RM range but do include some at < 6 RM to support faster strength gains which can also help your workout progress to use more weight/resistance to keep moving forward.

 

Should you increase resistance over time?

As you continue to train muscle, over time you will find it necessary to increase the level of resistance to continue to make progress in gaining strength and size. This is evident as the number of repetitions you can do before fatiguing exceeds the recommended range for muscle development and is an indicator that your muscle is adapting and getting stronger. Initially, some of this adaptation is merely your muscle becoming more efficient in the exercise. However, overall most of the improvement in performance will be because the muscle is developing more contraction machinery and support materials including water and as a result getting bigger. Try increasing the amount of resistance by 10% and determine if that puts you back in the muscle development repetition range. Improvements in strength, and in turn increased resistance applied will increase training volume without necessarily increasing your number of sets. This will keep you progressing towards your goals without increasing your time commitment.

 

How much rest do you need in between sets within the same workouts?

When you engage in resistance training you are making great demands on your muscles. Therefore, the worked muscle should be given adequate time to rest and recover after a set of repetitions (reps). Depending on the intensity of the set, muscle will need about 1 to 3 minutes to rest between sets to recover and be able to attack the next set. During an exercise set the limited stores of ATP and creatine phosphate are rapidly depleted. Giving muscle a break between sets allows for regeneration of ATP and creatine phosphate. Also as muscle contracts it temporarily pinches blood vessels and hinders blood flow within that muscle. This not only decreases nutrient and O2 delivery to working muscle fibers but also decreases the removal of waste such as lactate and CO2. The period of rest between sets allows for the blood to bring more nutrients and oxygen and remove waste and at the same time also.

 

How much rest do you need between workouts? If a muscle is trained hard it is generally recommended to rest a muscle for at least forty-eight hours before working the same muscle again. This allows muscle to recover and adapt. Often people will train the same muscles on Mondays, Wednesdays, & Fridays or Tuesdays, Thursdays, and Saturdays and rest the muscle in between those sessions. If a muscle is trained very hard in a given workout by doing extra sets, that individual may train that muscle only two times a week or every five days or so but this is more extreme training including lots of sets and exercise targeting a muscle area. Surely there is a lot of variability between people, training intensity, training state etc. I good rule of thumb is that you want to time subsequent training of the same muscle at a time where strength has returned and you can have another great workout.

 

What does it take for muscle to recover and adapt after a workout? Recovery and repair processes include those that prepare muscle to perform efficiently again. This includes reestablishing the energy state of the muscle cells, managing damage and allow for adaptation. In the minutes that follow the end of a training session there is a re-establishment of more immediate energy pools like ATP and creatine phosphate and resetting the pH and buffering systems as well as replenishing of carbohydrate stores or glycogen. The latter can take a few hours to as long as a day for more extreme training sessions. Moreover, a challenging workout can result in damage to muscle membranes and protein-based contraction machinery. In response muscle launches an inflammation response to deal with clean up and repair needs. While inflammation has received a lot of negative press for a variety of degenerative diseases like arthritis and heart disease, a normalized inflammation response is important to muscle adaptation to resistance training. So clearly our goal isn’t to eliminate post-exercise inflammation but manage it in more abnormal response scenarios.

 

What does it take for muscle to recover and adapt after a workout?

Adaptation refers to those processes designed to allow the muscle to be better prepared to work again. Thus adaptation from resistance training includes a net increase in muscle proteins that will support the same muscle action moving forward. This includes proteins involved in muscle contraction like actin and myosin as well proteins that help regulation contraction like troponin and tropomyosin as pumps, transporters and enzymes. As muscle cells accumulate more protein, they will also accumulate more water. Therefore, much of muscle hypertrophy is protein and water. In addition, connective tissue providing integrity and support to the overloaded muscle will be enhanced as well. Lastly, regular resistance training will increase the level of stored glycogen by 100% or more over a period of several weeks.

 

How long does increase muscle protein production last?

A single training session can increase the potential for building muscle proteins over the 1-2 days that follow. However, in order to adapt to get bigger and stronger nutrition becomes a huge factor. During the 1-2 day period after a tough training session, ample protein must be available to muscle to help promote the increase in muscle protein production as well as provide the building blocks for building the protein.

 

Does weight training increase energy expenditure during and after? The increased energy demand of weight training depends on the intensity level and duration of a workout coupled with the energy needed for recovery and adaptation. The energy needed for a workout may be along the order of 5 to 10 calories per minute depending on the workload. Meanwhile recovery and adaptation may demand an additional 100 to 300 calories over the next 24 hours or so again depending on the workload of the training session. This additional energy expended should be calculated into your total energy expenditure.

 

What does muscle use for fuel to power weight training?

The predominant fuel powering weight training is carbohydrate, derived mostly from muscle glycogen stores and secondarily fat from fat tissue and within muscle tissue itself. One of the strongest influences will be epinephrine, which is released from the adrenal glands during intense training. Epinephrine will promote the breakdown of glycogen and fat stores, making those energy sources available to working muscle. On the other hand, both fat and carbohydrate fuel adaptive processes over the next few hours up to the next day or so.

 

Does resistance training increase general metabolism?

Absolutely. Not only will the daily caloric expenditure increased on the day you train and in the hours that follow, but also in general as you accumulate more muscle mass. As a general rule muscle will burn about 4 times as many calories as body fat on a pound for pound basis. And that’s just when it’s not doing anything. The difference between body fat and muscle metabolism is largely related to their relative protein content and the rate at which they are turned over (made vs broken down). Muscle is about 22% protein and adipose tissue is about 5-10%