Muscular Strength and Endurance

Benefits of Muscular Strength and Endurance

A.  Improved performance of physical activity-If you have a moderate to high level of muscular strength and endurance, you can perform everyday tasks with ease.

B.  Prevention of injuries-Increases in muscular strength can protect you from injury by helping you maintain good posture and appropriate body mechanics.

C.  Improved body composition-Strength training helps you improve your body composition by increasing lean body mass and decreasing fat.

D.  More positive self-image-You look good and feel good as a result of your accomplishments and resulting improvements in your muscular strength and endurance.

Definitions

Muscular strength – the ability to exert maximum force against resistance; 1 RM (Repetition Maximum)

Muscular Endurance – the ability of a muscle to exert submaximal force repeatedly over a period of time

Factors affecting Strength

A. Neural stimulation – all or none; more fibers innervated and frequency of stimulation increases.

B. Types of fibers

1. slow-twitch or red – person with a predominance of slow-twitch muscle fibers is likely to excel in endurance or aerobic activities.

2. fast–twitch or white - person with a predominance of fast-twitch muscle fibers is likely to excel in anaerobic activites. Fast twitch muscle fibers can also mimic slow twitch muscle fibers.

C. Overload Principle – 2 Ways to improve strength or endurance

1. Increased ability of individual muscle fibers to generate a stronger contraction.

2. By recruiting a greater proportion of the total available fibers for each contraction. (adding resistance)

D. Specificity of Training

Principles Involved in Strength Training

A. Mode of training

B. Resistance

C. Sets

D. Frequency

Types of Weight Training Exercises (Mode of training)

A. Isometric (static) exercise – applying force without movement. (worst for basic weight training to improve one’s total fitness)

B. Isotonic (dynamic) exercise – applying force with movement. (most frequently used)

A concentric muscle contraction occurs when the muscle applies force as shortens.
An eccentric muscle contraction occurs when the muscle applies force as it lengthens. (eccentric phase should be twice as long as concentric phase)
Constant resistance exercises uses a constant load (weight) throughout a joint’s range of motion (e.g., free weights, universal machines).
Variable resistance exercise uses a load (weight) that changes to provide maximum load throughout a joint’s range of motion (e.g., weight machines, nautilus).

C. Isokinetic exercise – applying force at a constant speed against an equal force exerted by a special strength training machine. (the best method for improving strength and endurance but machines expensive)

Creating a Successful Weight Training Program

Choose appropriate equipment – free weights of weight machines; Select exercises – 8 to 10 different exercises to work all major muscle groups: neck, upper back, shoulders, arms, chest, abdomen, lower back, thighs, buttocks, calves

Select resistance and number of repetitions and sets

Strength

Resistance: 80% of 1 RM

Repetitions: 1-5

Sets: 1-3

Endurance

Resistance: 50% of 1 RM

Repetitions: 20-25

Sets: 1-3

General fitness

Resistance: 70% of 1 RM

Repetitions: 8-12

Sets: 1-3

Increase resistance 3% for upper body and 5% for lower body when you reach the maximum for sets and repetitions. (Ex: When you reach 3 sets of 5 repetitions for muscular strength training, you should increase resistance either 3% or 5% based on whether it is an upper or lower body lift)

Choose frequency of exercise – two to four days per week. It depends on what you want to achieve with your program. The more you want to focus on strength and endurance, the more days a week you should workout focusing on strength or endurance

Warm up and cool down – do both a general warm-up and a warm-up for each training exercise; cool down after weight training by relaxing for 5-10 minutes and stretching. Your first set for any lift should be no where close to your training resistance (Ex: If you are working on building strength and your workout resistance is 160, your first set should be somewhere around 100-120 to get that muscle group warmed up for actual strength training)