Evidence-Informed Exercise Prescription

Exercise Prescription: Review of General PrinciplesPHTH 652 Integrated Clinical Exercise Rehabilitation

Richard PreussJadranka Spahija

1Comprehensive exercise programAerobic TrainingResistance TrainingFlexibility Training+/- Neuromotor &/or Balance-Specific Training

ACSM, 1998, 2004, 2009, 2011

Aerobic training - endurance exercise, cardiorespiratory exercise, etc.RT - especially strength exercisesFlexibility Training (a.k.a. stretching exercises)+/- Balance Training (older adults)

2Benefits of exerciseEngaging in regular exercise and reducing sedentary behavior is vital for the health of adults.

Garber et al., 2011 (ACSM)Evidence category: A3Variable individual responseThere is considerable variability in individual responses to a standard dose of exercise.

Garber et al., 2011 (ACSM)Evidence category: AVariable individual responsePhysical activities should be individualized to meet the needs and preferences of each patient

American Geriatrics Society, 2002Evidence category: AS.A.I.D. PrincipleSpecific Adaptation to Imposed Demand

Progressive overloadExercises must be regularly modified to ensure continued improvementsExercise specificityExercises must be tailored to achieve specific and targeted adaptationsVariation / PeriodizationRegular modification of exercise variables may promote continued / improved adaptationWhen prescribing exercise, always ask yourself:Why am I prescribing this exercise?What is the short-term goal for this exercise?What is/are the long-term goal(s) for this exercise?

What mechanism of adaptation am I targeting with this exercise?What specific exercise variables are required to achieve the desired adaptations / goals?How / when will I modify / progress these variables in order to work towards more long-term goals?Goals of exercise (Kisner & Colby)FUNCTIONMusclePerformanceAerobic Capacity/EnduranceFlexibility/Joint MotionNeuromuscularControl & CoordinationStabilityBalance/ Postural EquilibriumMechanisms of AdaptationNeurologicalMetabolicMorphological

Mechanisms of Adaptation: NeurologicalNeurophysiological effects of exercise synthesis and release of: NeurotransmittersNeurotrophic factorsassociated with:NeurogenesisAngiogenesisSynaptogenesisSynaptic potentiationSpinal motorneuron excitabilityMotor cortex reorganization

Adkins et al., 2006; Matta Mello Portugal et al., 2013Mechanisms of Adaptation: NeurologicalFunctional effects of neurological adaptationImproved muscle coordinationImproved muscle recruitment Improved muscle activation

ACSM, 2009; Wolfe et al., 2004; Folland and Williams, 2007Mechanisms of Adaptation: MetabolicSkeletal muscle adaptations capillaries per muscle fiber blood flow surface area for gas exchange number and size of mitochondria & enzyme concentration (carbohydrate & lipid metabolism) oxidative capacity (ability to extract and use oxygen) use of glycogen stores & lactate production at a given exercise intensityRivera-Brown & Frontera, 2012Mechanisms of Adaptation: MetabolicCardiovascular adaptations plasma & total blood volume (within 7-10 days of training) lower blood viscosity & blood flow blood flow & oxygen delivery end-diastolic volume elastic recoil of left ventricle ventricular muscle mass and dilatation ejection fraction and stroke volume resting heart rate maximal cardiac output resting and submaximal systolic and diastolic BPRivera-Brown & Frontera, 2012Mechanisms of Adaptation: MorphologicalSkeletal Muscle Adaptation Muscle fibre hypertrophyMyofibrillar growth & proliferationType 2 fibres > Type 1 fibres muscle fibre / myofibril density quality of tendon & myofascia+/- modifications in muscle architecture

Folland and Williams, 2007Aerobic Exercisea.k.a. Cardiorespiratory Exercisea.k.a. Cardiovascular ExerciseMechanism of AdaptationMetabolic > Neurological & Morphological Aerobic Training Variables F.I.T.T.FrequencyIntensityTime (Duration)Type (Mode)

VolumeWhen exercising above the intensity threshold, training effects appear to be highly related to training volume (total energy cost):17Aerobic Training VolumeRecommendation:Moderate-intensity; 30 min/day; 5 days/wk or Vigorous-intensity; 20 min/day; 3 days/wk Evidence category: A

Light to moderate; 20 min/day; 3-5 days/wk may be initially beneficial for sedentary/deconditioned individualsEvidence category: B

18Aerobic Training - FrequencyDose-responseNon-linear improvement in VO2max with increased frequencyFor high-intensity trainingPlateau between 3 & 5 d/wk (ACSM, 1998) >5 d/wk Minimal added for VO2maxDisproportionate increase in injury incidenceTraining