Presentation on theme: "Building Muscular Strength and Endurance"— Presentation transcript:
1Building Muscular Strength and Endurance Chapter 4
2Muscular Strength and Endurance Resistance training may be the only type of exercise capable of slowing and maybe reversing loss of muscle mass, bone density, and strengthThe “Use it or lose it” axiom applies to the 600-plus muscles in the bodyDeclining stimulation of the muscles results in progressive shrinking and weakening of the musclesMost aerobic activities provide little stimulation of the upper body musclesDisuse atrophy- explains the loss of muscle mass and strength because of a sedentary lifestyle that is personified by low-level muscle stimulation well below the threshold for developing and maintaining muscle massHeavy resistance training and circuit weight training have the potential to produce a high enough volume of work to improve cardiorespiratory endurance by as much as 5-10 percent
3Health Benefits of Resistance Training Strength training increases muscle mass and decreases the amount of fat tissueIncreased muscle mass means your body burns more calories – even at restThe functions of daily life can be performed with less effortSymptoms of arthritis are reducedStronger legs improve balance and reduce the risk of falling
4Health Benefits of Resistance Training (2) Risk of osteoporosis is reducedPeople can live independently and with dignity longerAt least 50% of the disability associated with aging is due to disuseReaction time is improved and people may sleep more restfullySome additional health benefits of strength training are:increases basal metabolic ratecontributes to more restful sleepimproves body image, self-esteem, and self-confidenceimproves the effectiveness of the body’s use of insulinaids in weight loss and weight managementincreases HDL cholesterol
5Anaerobic Exercise Anaerobic means “without oxygen” In anaerobic exercises the body demands more oxygen than can be suppliedAnaerobic exercises are high intensityAnaerobic exercises can be sustained for only a few seconds
6Muscular Strength the maximum force a muscle or muscle group can exert with one contraction Muscular strength is best developed by high-intensity exercise—lifting more weight fewer timesTo increase strength, select a weight of 80% to 90% of your one-repetition maximum that cannot be lifted more than 10 timesMuscular strength is developed best through progressive resistance exercise.Free weights or machine weights work very well.Machine weights are best for beginners.A repetition (rep) is one complete lift of an exercise. For example, 10 complete lifts equals 10 reps.In this case 10 reps equals 1 set.Conventional weight training employs 3 sets of each exercise.One repetition maximum (1RM) is the heaviest load that can be lifted a single time.
7Static Training—Isometrics Isometric contractions occur when muscles produce tension but do not change in lengthPushing against a door or other immovable object is an isometric contractionIsometrics increase exercise arterial blood pressureStrength development is joint-angle specificIsometric contractions should be held for 6-10 seconds at maximum force.In isometric training, maximal contractions produce better results than submaximal contractions.
8Dynamic Exercise—Isotonic Training Isotonic contractions occur when muscles shorten and move the bones to which they are attachedIsotonic movements consist of concentric and eccentric contractionsDelayed muscle soreness (24 to 48 hours after exercise) from isotonic exercise is caused by microscopic tissue damageStretching, light exercise, or rest can alleviate sorenessConcentric contraction- occurs when a muscle shortens as it develops the tension to overcome an external resistance. Example-dumbell curl in the flexion phaseEccentric contraction- when the muscle lengthens and the weight is slowly returned to a starting position. Example- dumbell curl in the extension phase
9Dynamic Exercise—Variable Resistance Training Isotonic exercises do not maximally stress muscles throughout their full range of motionVariable resistance equipment is designed to provide maximum resistance throughout the full range of motionUniversal Gym and Nautilus equipment vary the resistance, although the actual resistance is impreciseThis type of equipment was developed because isotonic exercises do not maximally stress muscles throughout their full range of motion.
10Dynamic Exercise Free-Weight Training Free-weight training uses dumbbells and barbells to increase strengthFree weights allow flexible movements, and the equipment is versatileMaximum resistance throughout the full range of motion does not occur, and spotters are needed for some exercisesFreeweights are inexpensive and space effiecient
12Dynamic Exercise Isokinetic Training Isokinetic training uses equipment that adjusts resistance to accommodate the force applied by the exerciserIsokinetic exercises use preselected speeds that remain constantMaximum resistance is met throughout the full range of motionThis type of training is quite often used in rehabilitation settings.
13Dynamic Exercise Circuit Resistance Training CRT develops several fitness dimensions simultaneouslyA circuit usually consists of 8 to 15 exercise stationsCircuits are repeated 2-3 times for a 30- to 50-minute workoutExercisers work at 40% to 55% of maximum ability, performing as many repetitions as possible at each stationOptimal gains are difficult to achieve
14Muscular EnduranceMuscular endurance is the repeated application of muscular force against a submaximal resistanceUsually done over anextended period (15-45 sec. for 8-20 repetitions)If exercises are performed to maximum fatigue they may also build strength
15Principles of Resistance Training A minimum of eight to ten exercises involving the major muscle groups should be performed two to three days per week. A minimum of 1 set of 8 to 12 RM or to near fatigue should be completed by most participants; however, for older and more frail persons, 10 to 15 repetitions may be more appropriate.American College of Sports Medicine (ACSM)
16Principles of Resistance Training IntensityDurationFrequencyOverloadProgressionSpecificityVarietyIntensity should be 70% - 80% of 1 RM.Duration (Time)- meeting ACSM guidelines takes about 20 minutes.Frequency- resistance training exercises should be used no more than 3 days per week for beginners.Overload- muscles are subjected periodically to greater resistance as they adapt to the previous resistance.Progression- dictates how much and when and increase in resistance, reps, or sets should occur.Specificity- type of training dictates the type of muscle development.
17Ergogenic AidsErgogenic aids are substances, techniques, and treatments that theoretically improve physical performance in addition to the effects of normal trainingSome of the more well-known aids include:Protein supplementsCreatineGinsengAnabolic-androgenic steroidsProtein supplements- suggested amount for those in weight training is g/kg of body weight ( normal protein requirement is 0.8 g/kg)Creatine- evidence indicates that supplementation is safe in the short-term, but long-term data are lacking.Chromium picolinate- no evidence to support the use of this drugSteriods- hormones that build muscle tissue, 80% - 90% of all steroids are purchased through the black market
18Building Muscular Strength and Endurance Chapter 4