Objectives Explain the importance of adequate muscular strength levels in maintaining good health and well-being. Clarify misconceptions about strength fitness. Define muscular strength and muscular endurance. Identify the factors that affect strength. Understand the principles of overload and specificity of training for strength development. Learn dietary guidelines for optimum strength development. Become familiar with core strength training and realize its importance for overall quality of life. Become acquainted with two distinct strength-training programs – with weights and without weights.
Benefits of Strength Training Increased muscle strength and endurance Increased power Increased muscle tone Increased tendon and ligament strength Health benefits Promotes weight loss and maintenance; Lessens the risk for injury; Prevents osteoporosis; Reduces chronic low-back pain and arthritic pain; Aids in childbearing; Improves cholesterol levels; Promotes psychological well-being; May help lower blood pressure and control blood sugar.
Muscular Strength and Aging Importance for older adult population Contributes more to independent living than any other fitness component (maintains ADLs) Sarcopenia the loss of lean body mass, strength, and function. (common as people age) helps to slow the age-related loss of muscle function.
Muscular Strength and Aging Enhanced quality of life It improves balance and restores mobility. It makes lifting and reaching easier. It decreases the risk for injuries and falls. It stresses the bones and preserves bone mineral density, thus decreasing the risk for osteoporosis. Increases muscle mass or size, known as muscle hypertrophy, thereby increasing metabolism Loss of muscle tissue as we age combined with normal eating habits results in the formation of fatty tissue Burns ~35 cal for every pound of muscle
Muscular Strength and Aging Gender differences Endocrinological differences do not allow women to achieve the same amount of muscle hypertrophy (size) as men Men produce Testosterone Men also have more muscle fibers Anabolic steroids and human growth hormones produce detrimental and undesirable side effects in women.
Change in Body Composition With Aerobic & Strength Program Changes in body composition Assess body composition regularly to monitor changes in percent body fat rather than simply measuring changes in total body weight Decreased adipose tissue is more obvious when combined with aerobic exercise.
Assessment of Muscular Strength and Endurance Muscular strength The ability of a muscle to exert maximum force against resistance Muscular strength is often determined by the maximal amount of resistance (weight) an individual is able to lift in a single effort one repetition maximum, or 1 RM Several body sites should be assessed
Muscular Strength: The Hand Grip Test When time is a factor, the Hand Grip Test can be used to roughly estimate strength An isometric test-- involves a static contraction If the proper grip is used, no finger motion or body movement is visible during the test
Assessment of Muscular Strength and Endurance Muscular endurance Submaximal force repeatedly over time Depends on muscular strength Muscular endurance is often established by the number of repetitions an individual can perform against a submaximal resistance or by the length of time a given contraction can be sustained
Muscular endurance test Upper body – modified dip (men) or modified push- ups (women) Lower body – bench jumps Midbody – bent-leg curl ups or abdominal crunches
Assessment of Muscular Strength and Endurance Muscular strength and endurance test Lift submaximal resistance as many times as possible Six strength-training exercises A strength/endurance rating is determined according to the maximum number of repetitions you are able to perform on each exercise
Factors That Affect Strength – Neural Stimulation Motor unit Motor neurons control muscle activity A motor unit is a motor neuron and all the muscle fibers it innervates As the number of fibers innervated and frequency of stimulation increase, so does the strength of muscular contraction
Factors That Affect Strength – Neural Stimulation Motor units
Factors That Affect Strength – Neural Stimulation Types of muscle fibers Slow-twitch (red fibers) Aerobic Fast-twitch (white fibers) Anaerobic Proportion is determined genetically but training can improve them Slow-twitch fibers are always recruited first. As speed and force increase, fast-twitch fibers become more important.
Factors That Affect Strength – Overload Achievement of strength gains Through increased ability of individual muscle fibers to generate a stronger contraction. By recruiting a greater proportion of the total available fibers for each contraction Overload principle demands placed on a system must be systematically and progressively increased over time to cause improvement or development Strength training is also called progressive resistance training
Factors That Affect Strength – Overload Procedures to overload in strength training Increasing the resistance, number of repetitions, speed of repetitions, and volume. Decreasing rest interval for endurance improvements or lengthening the rest interval for strength gains. Using any combination of the above.
Factors That Affect Strength – Specificity of Training Training must be specific to obtained desired effects Specific adaptation to imposed demand (SAID) training suggests that to improve specific sport skills, the strength training exercises performed should closely resemble the movement patterns used in that specific sport or activity
Principles Involved in Strength Training Mode of training Isometric training muscle contractions produce little or no movement as in pushing or pulling against an immovable object A critical component of health conditioning programs for the back Dynamic training muscle contractions produce movement as in leg extensions Strength is gained through the full range of motion Consists of two phases: Concentric (positive resistance): the muscle shortens as it contracts to overcome the resistance. Eccentric (negative resistance): the muscle lengthens to overcome the resistance, allowing us to lower weights in a smooth, gradual, and controlled manner.
Principles Involved in Strength Training Mode of training Isokinetic training Variable-resistance or isokinetic machines equipped with mechanical devices that provide differing amounts of resistance, with the intent of overloading the muscle group maximally through the entire range of motion.
Principles Involved in Strength Training Free Weights Weight machines Require that the individual Are safer, provide some balance the resistance exercises not possible with free through the entire lifting weights, can program variable motion. resistance, isolate muscles Are cheaper, allow variety of better, require less time to use, can be transported more select weight, can limit range of easily, require balancing by motion for rehabilitation, and using stabilizing muscles, and require less skill than free fit all exercisers. weights.
Principles Involved in Strength Training Resistance A resistance of approximately 80 percent of the maximum capacity (1 RM). 80 percent of 1 RM varies by repetitions according to type of exercise (Table 7.4). Once the person can lift the resistance more than 12 times, the resistance is increased by 5 to 10 pounds and the person again should build up to 12 repetitions. This is referred to as progressive resistance training .
Principles Involved in Strength Training Sets Number of repetitions performed for a given exercise 1 to 3 sets for the starting exerciser Recovery time Needed to replenish ATP-CP system Usually 3 minutes for strength training. About 2 minutes for health-fitness training Circuit training Alternating exercises by performing them in a sequence of three to six or more exercises
Principles Involved in Strength Training Frequency Strength training can be done through a total body workout two or three times a week or more if a split body routine (upper body one day, lower body the next) is used The muscles should be rested for about 2-3 days after a maximum workout to allow recovery If not, the person may be overtraining and not reaping the full benefits of the program Eight consecutive weeks of training are required to obtain significant strength gains
Guidelines for Various Strength-Training Programs
Training Volume Sum of all repetitions multiplied by the resistances during a training session Used to quantify the amount of work performed in a given training session Sets x Reps x Weight High training volumes and low intensities are used to achieve muscle hypertrophy. Low volumes and high intensities are used to increase strength and power.
Training Volume Periodization Used by athletes to achieve peak fitness and prevent overtraining. Involves cycling of ones training objectives (hypertrophy, strength, and endurance). With each phase of the program lasting 2–12 weeks. Increases the volume no more than 5 percent from one phase to the next.
Plyometrics Explosive jump training incorporating speed and strength training to enhance explosiveness Objective Generate the greatest amount of force in the shortest time Requires a solid strength base Higher risk for injuries than the conventional modes of progressive resistance training
Strength Gains How quickly can strength gains be observed? Studies reveal that most strength gains are seen within the first 8 weeks of training Improvement is related to previous training status 40% in individuals with no previous strength- training experience 16% in previously strength-trained people 10% in advanced individuals
Strength Training Exercises Strength training without weights (Exercises 1– 14, pages 256–260). Strength training with weights (Exercises 15–37, pages 261–270). Exercises 15–27 are recommended for a complete workout. Exercises 28–37 are supplemental or can substitute for certain exercises numbered 15–27. Stability ball exercises (Exercises 38–46, pages 270–273) Can be used to complement your workout.
Strength Training Exercises Changing exercises should be done to continue to challenge the muscles Can vary range of motion Create difficulty of exercise Avoiding monotony of doing the same exercises over and over and over…
Dietary Guidelines for Strength Development During periods of intense strength training Increase protein intake from 0.8 g/kg body weight to 1.5 g/kg body weight/day Additional 500 calories/day – complex carbohydrates Snacks: carbohydrates + protein Pre-exercise (30-60 minutes before exercise) Immediately following strength training 1 hour after training Post-exercise: ratio of 4-to-1 g carbohydrate to protein
Core Strength Training The "core" of the body includes the trunk (spine) and pelvis. Core muscles include muscles of the abdomen, hip, and spine. Many of the major muscle groups of the legs, shoulder, and arms attach to the core. A major objective of core strength training is to exercise the abdominal and lower back muscles in unison.
Pilates Exercise System A training program that uses exercises designed to help strengthen the body’s core by developing pelvic stability and abdominal control coupled with focused breathing patterns Originally developed in the 1920s by Joseph Pilates Exercises are performed either on a mat (floor) or with specialized equipment to increase strength and flexibility of deep postural muscles Intended to improve muscle tone and length, instead of muscle hypertrophy Pilates training should be conducted by certified instructors with extensive Pilates teaching experience
Stability Exercise Balls and Elastic-Band Resistive Exercise Stability exercise balls Exercises are designed to develop abdominal, hip, chest, and spinal muscles by addressing core stabilization while the exerciser maintains a balanced position over the ball Emphasis is placed on correct movement and maintenance of proper alignment Primary objective is core strength and stability
Elastic-Band Resistive Exercise Elastic bands and tubing can be used as constant-resistance training Help increase strength, mobility, functional ability, aid in rehab in injuries Advantages include Low-cost Versatility - use at almost all angles/directions of range of motion Large number of exercises to work all joints Can be packed in a suitcase Add variety to routine
Exercise Safety Guidelines Select exercises to involve all major muscle groups Select exercises to strengthen the core Never lift weights alone Use proper lifting technique Maintain proper body balance while lifting Exercise larger muscle group before smaller muscle groups
Exercise Safety Guidelines Exercise opposing muscles Breathe naturally Avoid holding your breath while straining to lift Allow adequate recovery time Pay attention to any discomfort or pain
Exercise Safety Guidelines Use common sense Stretch after any strength-training workout Consult physician before you start
Real Life Stories Critical Thinking Questions 1. What mistakes did Nathan make with his strength-training program? 2. Have you mastered proper technique in all of your strength- training exercises? Are there mistakes in form you have seen others make in the weight room? Can you list potential pitfalls of using improper form during strength training? 3. Discuss your personal feelings regarding strength training, including benefits and possible drawbacks for you from such a program.