Study guide
6.1 Grip Strength & Vertical Jump Peak Power Protocols
CSEP Certified Personal Trainer CSEP-CPT
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1 Introduction: CSEP-CPT Certification & Theory Exam Overview
Introduction: CSEP-CPT Theory Exam Facts & Certification Pathway
2 Chapter 1: Anatomy & Biomechanics in Exercise
1.1 Musculoskeletal Anatomy & Major Muscle Actions 1.2 Planes of Motion & Joint Kinematics 1.3 Biomechanical Levers, Torques & Postural Forces 1.4 Neuromuscular Mechanics & Motor Unit Recruitment
3 Chapter 2: Exercise Physiology & Energy Metabolism
2.1 Bioenergetics & Metabolic Pathways 2.2 Cardiorespiratory Responses to Acute Exercise 2.3 Chronic Physiological Adaptations to Training 2.4 Fatigue Mechanisms & Excess Post-Exercise Oxygen Consumption 2.5 Dose-Response, Sedentary Behaviour & Age and Sex Differences
4 Chapter 3: CSEP-PATH & Pre-Participation Screening
3.1 The CSEP-PATH Framework & 6-A Process 3.2 Get Active Questionnaire (GAQ) & Reference Document Protocols 3.3 Pre-Assessment Screening: Resting Heart Rate & Blood Pressure Cut-Offs 3.4 Pre-Assessment Instructions, Medical Clearance & Contraindications 3.5 PASB-Q, Stages of Change, AAL-Q & Screening in Pregnancy
5 Chapter 4: Anthropometry & Body Composition Assessment
4.1 Body Mass Index (BMI) & Height/Weight Measurement Protocols 4.2 Waist Circumference Protocols & Health Risk Stratification 4.3 Body Composition Methods: Percent Fat Techniques vs. CSEP-PATH Anthropometry 4.4 Body Composition Interpretation & Sensitive Client Communication
6 Chapter 5: Aerobic Fitness Assessment
5.1 Principles of Submaximal Aerobic Testing & Heart Rate Monitoring 5.2 Modified Canadian Aerobic Fitness Test (mCAFT) Protocols 5.3 Ebbeling Treadmill & Rockport 1-Mile Walk Protocols 5.4 Submaximal Cycle Ergometer (YMCA) Test & Aerobic Calculations
7 Chapter 6: Musculoskeletal Fitness Assessment
6.1 Grip Strength & Vertical Jump Peak Power Protocols 6.2 Push-Up Test & Muscular Endurance Protocols 6.3 Sit-and-Reach & Flexibility Assessment Protocols 6.4 Back Extension (Biering-Sorensen) & Static Balance Protocols 6.5 Forearm Plank, Y Balance Test & Predicted 1-RM Protocols 6.6 Validity, Reliability, Objectivity & Measurement Error in CSEP-PATH Assessments
8 Chapter 7: Exercise Prescription & Aerobic Training Design
7.1 Canadian 24-Hour Movement Guidelines for Adults & Youth 7.2 FITT-VP Principles for Cardiorespiratory Fitness 7.3 Training Heart Rate Calculations & RPE Scales 7.4 Aerobic Progression Strategies & Periodization Models 7.5 Canada's Food Guide, Weight Management & Health vs. Performance Goals
9 Chapter 8: Muscular Fitness & Resistance Training Programming
8.1 Resistance Training Principles, Intensity & Repetition Ranges 8.2 Program Design: Exercise Selection, Order & Structural Splits 8.3 Flexibility & Neuromotor Training Programming 8.4 Warm-Up, Cool-Down & Recovery Strategies 8.5 Exercise Instruction, Spotting, Technique Correction & Self-Monitoring
10 Chapter 9: Exercise Prescription for Special & Chronic Populations
9.1 CSEP-CPT Scope for Clients with One Stable Chronic Condition 9.2 Exercise Modifications for Hypertension & Cardiovascular Risk 9.3 Exercise Considerations for Type 2 Diabetes & Metabolic Health 9.4 Exercise Modifications for Osteoporosis, Osteoarthritis & Older Adults 9.5 Asthma, Cancer & Mental Health: Precautions and Signs of Decline 9.6 Recognizing & Responding to Adverse Events During Exercise
11 Chapter 10: Behavior Change & Lifestyle Coaching
10.1 Transtheoretical Model (TTM) Stages of Change & Processes 10.2 Motivational Interviewing Principles & OARS Techniques 10.3 Collaborative Goal Setting (SMART) & Action Planning 10.4 Overcoming Barriers, Relapse Prevention & Self-Efficacy 10.5 Theory of Planned Behaviour, HAPA & Brief Action Planning 10.6 Communication, Empathy & Instructional Techniques for Individual Clients
12 Chapter 11: Professional Practice, Scope & Risk Management
11.1 CSEP Scope of Practice Boundaries & Referral Pathways 11.2 Informed Consent, Liability Waivers & Client Documentation 11.3 Legal Liability, Negligence & Privacy Legislation (PIPEDA) 11.4 Emergency Action Plans, Facility Safety & Certification Maintenance 11.5 The CSEP Code of Conduct & Ethical Professional Practice
6.1 Grip Strength & Vertical Jump Peak Power Protocols
Key Takeaways Explain This Topic AI
Handgrip dynamometry serves as an objective, validated biomarker of total-body isometric muscular strength, showing powerful inverse associations with sarcopenia, frailty, cardiovascular disease, and all-cause mortality.
The standardized CSEP-PATH grip strength protocol requires an alternating bilateral sequence across two trials per hand, recording the highest score for each hand to the nearest 1 kg and summing both values to produce the combined grip strength score.
The vertical jump assessment evaluates lower-body peak anaerobic muscular power, measuring net vertical displacement ( M 2 − M 1 M_2 - M_1 M 2 − M 1 ) to the nearest 0.5 cm using a countermovement dip without an approach step.
Lower-body peak anaerobic power is calculated from vertical jump height and body mass using the validated Sayers Peak Power Equation: Peak Power (Watts) = 60.7 × ( jump height in cm ) + 45.3 × ( body mass in kg ) − 2055 \text{Peak Power (Watts)} = 60.7 \times (\text{jump height in cm}) + 45.3 \times (\text{body mass in kg}) - 2055 Peak Power (Watts) = 60.7 × ( jump height in cm ) + 45.3 × ( body mass in kg ) − 2055 .
Peak muscular power declines earlier and more precipitously with advancing age than static muscular strength due to the preferential atrophy and denervation of fast-twitch Type II motor units, making power appraisal essential for functional fall risk screening.
Last updated: October 2026
6.1 Grip Strength & Vertical Jump Peak Power Protocols
Important
Within the CSEP-PATH assessment battery, musculoskeletal fitness testing provides objective diagnostic data regarding functional capacity, neuromuscular integrity, and chronic disease risk. Muscular strength and muscular power are distinct physiological traits that require standardized testing methodologies to ensure valid, reproducible results.
Musculoskeletal fitness encompasses the integrated functional status of the muscular and skeletal systems, determining an individual's capability to perform daily occupational tasks, engage in recreational physical activity, and resist physical injury. In the CSEP Physical Activity Training for Health ( CSEP-PATH ) framework, the assessment of muscular strength and muscular power is anchored by two foundational protocols: the isometric handgrip dynamometry test and the countermovement vertical jump test . For candidates preparing for the CSEP-CPT Theory Exam, mastering the exact standard operating procedures, biomechanical foundations, equipment adjustments, safety considerations, and mathematical power derivations is required for both examination success and safe clinical practice.
Isometric Muscular Strength: Handgrip Dynamometry
Muscular strength is defined as the maximal external force that a muscle or muscle group can generate against a resistance in a single maximal voluntary contraction (MVC). In clinical exercise physiology and physical fitness appraisals, measuring maximal dynamic strength through 1-repetition maximum (1RM) barbell lifts (such as the squat or bench press) often introduces prohibitive injury risks, requires extensive technical proficiency, and demands specialized facility equipment. Consequently, the CSEP-PATH framework utilizes isometric handgrip dynamometry as an efficient, highly reliable surrogate index of total-body muscular strength.
Physiological Foundations & Biomarker Status
Handgrip strength does not merely reflect localized forearm flexor capacity; it serves as a robust biomarker of overall systemic muscular development, biological aging, and physiological reserve. Large-scale global epidemiological investigations, notably the Prospective Urban Rural Epidemiology ( PURE ) study published in The Lancet , found that grip strength predicted all-cause and cardiovascular mortality more strongly than systolic blood pressure (Leong et al., 2015).
At the cellular level, handgrip force production reflects:
Motor Unit Recruitment: The capacity of the central nervous system to maximally recruit high-threshold Type IIx and Type IIa motor units in the forearm and hand musculature according to Henneman's size principle .
Rate Coding (Firing Frequency): The temporal frequency of motor action potentials that drive individual muscle fibers into fused tetanic contraction.
Sarcoplasmic and Myofibrillar Mass: Total physiological cross-sectional area (PCSA) of the primary flexor musculature, including the flexor digitorum superficialis , flexor digitorum profundus , flexor pollicis longus , and thenar/hypothenar intrinsic complexes .
Sarcopenia & Frailty Staging: Grip strength cut-offs (< 27 kg for men, < 16 kg for women) represent international consensus diagnostic criteria for diagnosing sarcopenia and functional vulnerability in middle-aged and older adults.
Equipment & Ergonomic Handle Calibration
The assessment is administered using an isometric handgrip dynamometer, most commonly the Smedley (spring-loaded adjustable type) or the Jamar (hydraulic sealed-system type). Accurate measurement depends entirely on correctly adjusting the dynamometer handle to match the client's hand anatomy:
Handle Adjustment Rule: The appraiser adjusts the grip handle so that the second joint (second phalanx / proximal interphalangeal joint) of the client's index and middle fingers fits comfortably underneath the handle, forming an approximate 90 ∘ 90^\circ 9 0 ∘ angle at the interphalangeal joint.
Ergonomic Rationale: If the handle is positioned too narrow or too wide, the finger flexors operate at mechanically disadvantageous positions along the sarcomere length-tension curve (falling into either active insufficiency when overly closed or excessive myofilament elongation when overly widened), which significantly underestimates peak force production.
Instrument Zeroing: Before each trial, the appraiser verifies that the indicator needle or digital display is reset to exactly 0.0 kg 0.0\text{ kg} 0.0 kg .
CSEP-PATH Handgrip Standard Operating Procedure (SOP)
Strict adherence to standardized CSEP-PATH body positioning and execution cues ensures test reliability:
Client Posture: The client stands completely erect with feet flat on the floor, spaced shoulder-width apart to provide a stable base of support.
Limb Position: The arm being tested hangs naturally down at the side or is held slightly away from the body (approximately 30 ∘ 30^\circ 3 0 ∘ to 45 ∘ 45^\circ 4 5 ∘ of glenohumeral abduction) with the elbow fully extended or slightly flexed (depending on manufacturer guidelines, but kept consistent).
Torso Clearance: The dynamometer must never make contact with the client's body, clothing, or thigh during the squeeze, as bracing the instrument against the body creates mechanical leverage that invalidates the measurement.
Motion Constraint: The client must remain static; swinging the arm, dipping the torso laterally, or flexing forward at the hip during the squeeze is strictly prohibited.
Breathing Instruction (Avoiding Valsalva): The client is instructed to exhale smoothly while squeezing maximally . Breath-holding triggers the Valsalva maneuver , generating high intra-thoracic pressure, reducing venous return to the heart, and producing sudden spikes in arterial blood pressure that present clinical risks, particularly for hypertensive or older clients.
Contraction Duration: The client applies maximal, progressive force over a continuous 3 to 5 second window, avoiding rapid, jerky, or ballistic snatching motions.
Bilateral Alternating Protocol & Scoring
To prevent unilateral neuromuscular fatigue while collecting bilateral symmetry data, CSEP-PATH mandates an alternating testing sequence across two complete rounds:
Right Hand (Trial 1) ⟶ Left Hand (Trial 1) ⟶ Right Hand (Trial 2) ⟶ Left Hand (Trial 2) \text{Right Hand (Trial 1)} \longrightarrow \text{Left Hand (Trial 1)} \longrightarrow \text{Right Hand (Trial 2)} \longrightarrow \text{Left Hand (Trial 2)} Right Hand (Trial 1) ⟶ Left Hand (Trial 1) ⟶ Right Hand (Trial 2) ⟶ Left Hand (Trial 2)
The appraiser records the maximum value achieved for each trial to the nearest 1.0 kg (or 0.5 kg depending on unit gradation, but recorded as an integer in standard CSEP-PATH reporting).
The single best score from the right hand is identified.
The single best score from the left hand is identified.
The Combined Grip Strength Score is calculated as the sum of the two highest scores:
Combined Grip Strength (kg) = Maximum Right Score (kg) + Maximum Left Score (kg) \text{Combined Grip Strength (kg)} = \text{Maximum Right Score (kg)} + \text{Maximum Left Score (kg)} Combined Grip Strength (kg) = Maximum Right Score (kg) + Maximum Left Score (kg)
Note
A substantial bilateral asymmetry (greater than a 10% to 15% disparity between the dominant and non-dominant hand) may indicate localized musculoskeletal trauma, peripheral nerve impingement (e.g., carpal tunnel syndrome, cervical radiculopathy), or asymmetric neuromuscular adaptation that warrants further qualitative functional screening.
Lower-Body Muscular Power: The Vertical Jump Assessment
While muscular strength measures the peak force produced regardless of time, muscular power is the rate of performing work, mathematically defined as the product of force and velocity:
Power (Watts) = Force (Newtons) × Velocity (m/s) = Work (Joules) Time (seconds) \text{Power (Watts)} = \text{Force (Newtons)} \times \text{Velocity (m/s)} = \frac{\text{Work (Joules)}}{\text{Time (seconds)}} Power (Watts) = Force (Newtons) × Velocity (m/s) = Time (seconds) Work (Joules)
In functional human movement, athletic competition, and fall avoidance, force must be exerted rapidly. The CSEP-PATH vertical jump test measures explosive lower-body leg power within the immediate phosphagen (ATP-PC) bioenergetic domain.
Motor Unit Dynamics & The Stretch-Shortening Cycle
Vertical jump execution depends on neuromuscular activation and the stretch-shortening cycle (SSC) :
Stretch-Shortening Cycle Mechanics: When a client dips rapidly into a countermovement semi-squat, the quadriceps, gluteus maximus, and gastrocnemius-soleus complex undergo rapid eccentric pre-stretch . This active lengthening phase stores potential elastic energy within the muscle tendons and aponeuroses (predominantly the Achilles and patellar tendons) while concurrently stimulating muscle spindle primary ( I a Ia I a ) afferents. The spindle discharge triggers a reflexive concentric motor facilitation ( myotatic stretch reflex ), augmenting concentric force production during the subsequent upward propulsion.
Rate of Force Development (RFD): Peak power in the vertical jump occurs within the initial 200 to 300 milliseconds 200\text{ to }300\text{ milliseconds} 200 to 300 milliseconds of propulsion. Because maximal isometric force typically requires 400 to 600 milliseconds 400\text{ to }600\text{ milliseconds} 400 to 600 milliseconds to manifest, vertical jump height is primarily limited by the client's RFD and synchronization of high-velocity Type II motor units.
CSEP-PATH Vertical Jump SOP
The assessment is administered using a calibrated wall-mounted measuring board, marked wall tape with chalked fingertips, or a mechanical vane apparatus (such as a Vertec). [Wall / Vertec Scale]
- │
- Phase 1: Standing Reach (M1) │ Phase 2: Peak Jump Apex (M2)
- │
- O [Arm Raised] │ O [Apex Touch]
- /|\ ───────► M1 │ /|\ ───────► M2
- | │ |
- / \ [Feet Flat] │ / \ [In Air]
- ───────────────────────────── │ ─────────────────────────────
- Net Jump Displacement = M2 - M1 (measured to nearest 0.5 cm)
- Step 1: Determining Standing Reach Height ( M 1 M_1 M 1 )
The client stands completely flat-footed, with the side of their dominant arm positioned adjacent to the wall or directly beneath the Vertec apparatus.
The client reaches up as high as possible with their dominant hand, keeping their feet flat on the floor, heels in contact with the ground, and knees and hips fully extended.
The client touches the measuring board or vanes with chalked fingertips or pushes the highest reachable vane.
The appraiser records this baseline standing reach height as M 1 M_1 M 1 to the nearest 0.5 cm .
Step 2: Executing the Countermovement Jump ( M 2 M_2 M 2 )
The client steps out approximately 15 cm (6 inches) away from the wall to allow sufficient clearance for unobstructed arm swinging and body displacement.
The client prepares by lowering their arms, bending the knees and hips into a rapid semi-squat countermovement dip (typically 90 ∘ 90^\circ 9 0 ∘ of knee flexion), swinging the arms back, and explosively driving vertically upward.
At the absolute apex of the vertical trajectory, the client reaches overhead with the dominant arm and slaps the measuring surface or displaces the highest vane with the fingertips to establish M 2 M_2 M 2 .
Critical Technique Restrictions:
No Run-Up or Stutter-Steps: The jump must initiate from a stationary, bilateral stance. The client cannot take a step, shuffle, or gather-hop into the jump.
Simultaneous Take-Off: Both feet must leave the floor simultaneously.
Landing Safety: The client must land bilaterally with knees bent to absorb ground reaction forces across the kinetic chain.
Step 3: Trial Sequencing & Net Jump Calculation
The client performs three trials , with a recovery interval of at least 30 to 60 seconds between attempts to permit partial phosphocreatine (PCr) replenishment and clear any acute neuromuscular fatigue.
For each trial, the net jump height is calculated:
Jump Height (cm) = M 2 − M 1 \text{Jump Height (cm)} = M_2 - M_1 Jump Height (cm) = M 2 − M 1
The appraiser records all three values to the nearest 0.5 cm , and the highest net jump height among the three trials is selected for peak power calculation and normative interpretation.
Quantifying Mechanical Power: The Sayers Peak Power Equation
Direct mechanical measurement of power historically required laboratory-grade force plates measuring three-dimensional ground reaction forces ( F z F_z F z ) coupled with optical motion capture. To enable accurate, field-accessible power quantification without expensive laboratory hardware, exercise physiologists developed predictive regression equations.
In CSEP-PATH, lower-body peak power is calculated from the best jump with the Sayers Peak Power Equation (Sayers et al., 1999). It was derived from force-platform data and is printed on the CSEP-PATH client information sheet:
Peak Power (Watts) = 60.7 × ( jump height in cm ) + 45.3 × ( body mass in kg ) − 2055 \mathbf{\text{Peak Power (Watts)} = 60.7 \times (\text{jump height in cm}) + 45.3 \times (\text{body mass in kg}) - 2055} Peak Power (Watts) = 60.7 × ( jump height in cm ) + 45.3 × ( body mass in kg ) − 2055
Step-by-Step Mathematical Calculation Example
Consider a 24-year-old female client undergoing a CSEP-PATH musculoskeletal fitness assessment:
- Body Mass ( B M BM BM ): 62.0 kg 62.0\text{ kg} 62.0 kg
- Standing Reach Height ( M 1 M_1 M 1 ): 208.5 cm 208.5\text{ cm} 208.5 cm
Trial 1 Jump Apex: 244.0 cm ⟶ Height = 244.0 − 208.5 = 35.5 cm 244.0\text{ cm} \longrightarrow \text{Height} = 244.0 - 208.5 = 35.5\text{ cm} 244.0 cm ⟶ Height = 244.0 − 208.5 = 35.5 cm
Trial 2 Jump Apex: 246.5 cm ⟶ Height = 246.5 − 208.5 = 38.0 cm 246.5\text{ cm} \longrightarrow \text{Height} = 246.5 - 208.5 = 38.0\text{ cm} 246.5 cm ⟶ Height = 246.5 − 208.5 = 38.0 cm
Trial 3 Jump Apex: 245.5 cm ⟶ Height = 245.5 − 208.5 = 37.0 cm 245.5\text{ cm} \longrightarrow \text{Height} = 245.5 - 208.5 = 37.0\text{ cm} 245.5 cm ⟶ Height = 245.5 − 208.5 = 37.0 cm
Execution Steps:
Select Best Jump Height: The highest net jump height is Trial 2: 38.0 cm 38.0\text{ cm} 38.0 cm .
Apply the Sayers Equation: Peak Power = 60.7 × ( 38.0 ) + 45.3 × ( 62.0 ) − 2055 \text{Peak Power} = 60.7 \times (38.0) + 45.3 \times (62.0) - 2055 Peak Power = 60.7 × ( 38.0 ) + 45.3 × ( 62.0 ) − 2055
Compute Intermediate Products: 60.7 × 38.0 = 2306.6 W 60.7 \times 38.0 = 2306.6\text{ W} 60.7 × 38.0 = 2306.6 W 45.3 × 62.0 = 2808.6 W 45.3 \times 62.0 = 2808.6\text{ W} 45.3 × 62.0 = 2808.6 W
Sum the Products: 2306.6 + 2808.6 = 5115.2 W 2306.6 + 2808.6 = 5115.2\text{ W} 2306.6 + 2808.6 = 5115.2 W
Subtract the Constant: Peak Power = 5115.2 − 2055 = 3060.2 Watts \text{Peak Power} = 5115.2 - 2055 = \mathbf{3060.2\text{ Watts}} Peak Power = 5115.2 − 2055 = 3060.2 Watts
Calculate Relative Peak Power: To evaluate power relative to total inertia, divide absolute power by body mass: Relative Peak Power = 3060.2 W 62.0 kg = 49.36 W/kg \text{Relative Peak Power} = \frac{3060.2\text{ W}}{62.0\text{ kg}} = \mathbf{49.36\text{ W/kg}} Relative Peak Power = 62.0 kg 3060.2 W = 49.36 W/kg
Note
Evaluating both absolute power (Watts) and relative power (Watts per kilogram) prevents misleading evaluations. An individual with larger body mass may produce substantial absolute power due to greater muscle cross-sectional area, yet exhibit low relative power because of excess non-contractile adipose tissue.
Health Benefit Rating (HBR) Interpretation
CSEP-PATH interprets combined grip strength and vertical jump peak power with age- and sex-specific Health Benefit Ratings (HBR) . The data sheets list five bands (Excellent, Very Good, Good, Fair and Poor) that frame results in terms of health and function rather than athletic ranking:
Excellent: Far exceeds standard physiological requirements; associated with optimal musculoskeletal resilience, robust bone mineral density, and elite physical capacity.
Very Good: Above-average capacity; confers substantial protection against occupational strain, physical fatigue, and metabolic deterioration.
Good: Represents the target baseline threshold for health-related fitness; sufficient to independently complete all daily physical tasks and maintain long-term functional autonomy.
Fair: Borderline functional capacity; indicates emerging physical deconditioning that warrants progressive, targeted resistance and power training.
Poor: Substantial musculoskeletal deficit; associated with elevated risk of workplace injury, functional disability, accelerated sarcopenia, and fall vulnerability.
Clinical Trajectory: Power vs. Strength Loss Across Lifespan
An essential theoretical concept tested on the CSEP-CPT exam is the differential loss of muscular strength versus muscular power during the aging process:
Sarcopenia (Loss of Muscle Mass & Strength): Muscle strength declines at approximately 1.0% to 1.5% per year after the age of 50.
Dynapenia (Loss of Muscle Power): Muscular power declines at an accelerated rate of approximately 2.5% to 3.5% per year after age 50—more than double the rate of strength loss.
Neuromuscular Mechanism: Aging induces progressive motor neuron apoptosis with preferential denervation and selective atrophy of fast-twitch Type II fibers, alongside slowing of sarcoplasmic reticulum calcium release and reductions in tendon stiffness. Because reactive balance recovery requires immediate, explosive force to execute a compensatory stepping strategy, lower-body power is a superior prospective predictor of fall risk compared to isometric strength.
Muscular Strength & Power Protocol Comparison Table
- Assessment Parameter CSEP-PATH Grip Strength Test CSEP-PATH Vertical Jump Test
- Musculoskeletal Component Isometric Muscular Strength (Upper Body) Dynamic Peak Anaerobic Power (Lower Body)
Primary Musculature Tested Flexor digitorum superficialis/profundus, thenar/hypothenar Quadriceps, gluteus maximus, gastrocnemius, soleus
Standard Testing Equipment Calibrated Smedley or Jamar handgrip dynamometer Wall-mounted measuring board/tape with chalk, or Vertec
Ergonomic Calibration 2nd phalanx of index/middle finger fits under handle at 90 ∘ 90^\circ 9 0 ∘ Standing reach height ( M 1 M_1 M 1 ) measured flat-footed to nearest 0.5 cm
Execution Technique 3–5 second continuous maximal isometric squeeze; arm at side Bilateral countermovement semi-squat jump; arms swing back
Prohibited Compensations Touching body/thigh with dynamometer; breath-holding Run-up steps; gather-hops; unilateral take-off; straight knees
Breathing Control Exhale continuously during squeeze (avoid Valsalva) Natural exhalation during explosive upward propulsion
Trial Administration 2 alternating trials per hand (R1 → \rightarrow → L1 → \rightarrow → R2 → \rightarrow → L2) 3 trials with 30–60 second rest intervals between jumps
Unit of Measurement Nearest 1.0 kg (highest right + highest left = Combined Score) Nearest 0.5 cm (highest net jump height: M 2 − M 1 M_2 - M_1 M 2 − M 1 )
Mathematical Derivations Combined Score = Best Right (kg) + Best Left (kg) \text{Combined Score} = \text{Best Right (kg)} + \text{Best Left (kg)} Combined Score = Best Right (kg) + Best Left (kg) Sayers: Power (W) = 60.7 × ( cm ) + 45.3 × ( kg ) − 2055 \text{Power (W)} = 60.7 \times (\text{cm}) + 45.3 \times (\text{kg}) - 2055 Power (W) = 60.7 × ( cm ) + 45.3 × ( kg ) − 2055
Clinical / Health Implication Biomarker of systemic sarcopenia, frailty, and mortality Predictor of fall risk, rapid balance recovery, and agility