Performance Flashcards
Rep Ranges and Purpose
Power: 1-5
Strength: 2-8
Hypertrophy: 8-15
Endurance: 15-20
Types of Periodization
Linear/Classic
Non-linear/undulating
Block
Linear Periodization
Planning based on time phrases: macro cycle (12 month), mesocycle (3-4 months), micro cycle (1-4 weeks). Work on skills in stepwise fashion. Each phase usually only works on one training parameter.
Non-linear Periodization
Volume and load are altered more frequently (daily, weekly, biweekly) to allow the neuromuscular system longer periods of recovery as lighter loads are performed more often. Several training parameters can be addressed at the same time.
Block Periodization
Highly concentrated, specialized workloads. Each step has a large volume focused on specific training abilities to maximize adaptation. If something like endurance isn’t need for the sport then it isn’t done. the blocks are usually 2-4 weeks (usually longer for linear/non-linear).
Phases:
1. Accumulation: Builds work capacity
2. Transmutation: Specific exercises with greater loads, 75-90% 1 RM
3. Realization: Even more specific movements than transmutation with loads 90% of 1RM or greater
What factors are correlated with increases in force production.
The mechanism proposed for this increase in force as a result of strength work has been attributed to increased muscle cross-sectional area and changes in neural drive (neural recruitment and firing rates)
Phases of plyometrics
Eccentric Pre-Stretch: stretches the muscle spindle of the muscle-tendon unit and non-contractile tissue within the muscle (parallel and serial elastic components)
Amortization: From eccentric pre-stretch to concentric portion. Time delay between overcoming negative work to generating force production and elastic recoil. The short the phase the more effective and powerful the movement. Longer phase = wasted energy and stretch reflex not activated.
Concentric: Facilitation of the power.
The Elftman proposal
Simply states the force production of muscle is eccentric creates the most force, then isometric, then concentric. Concentric muscle contractions are the weakest of the 3 modes. Eccentric generates 10-40 percent more force than concentric contractions.
What phase of plyometrics generates the most force?
Concentric. Because of the pre-stretch and short amortization phase. Usually concentric is weakness.
Why does eccentric muscle action generate more force?
- Cross bridges are broken down more slowly and thy is allows for a greater number of cross-bridges to be formed
- Passive tension: while being lengthened it puts a stretch on the muscle fibers and elastic components and this passive tension can contribute to force production
- They’ve been shown to recruit more fast-twitch fibers and more motor units
How long does DOMS last/resolve
Within 7-10 days
Order of muscle fiber recruitment
1.Slow twitch recruited at submaximal intensities.
2. Fast twitch IIa fibers rectuired from 30-80 intensity
3. Fast twitch IIa and IIb fibers both recruited around 70-80%
How can you recruit fast twitch fibers? Why is it important?
- Maximum intensity effort
- E-Stim
- Fast movements
RTC biopsies showed these muscles are 55-60 percent FT fibers and have shown that patients with RTC injuries are most effected in FT fibers.
Muscle spindle role
Primary role is to detect changes in muscle length and rate of change. When it is stretched there is increase in afferent nerve firing. The strength of the signal is dependent on rate of stretch (faster=stronger). The stronger the signal, the greater the efferent muscle contraction.
Role of the GTO
Located in the tendon near the attached to muscle fibers. It detects tension/force to provide information about the strength of a muscle contraction. It can regulate muscle tension and provide a “reverse stretch reflex” where the muscle is relaxed to prevent over contraction. Plyometric training tries to desensitize this.
Most important considerations for plyometrics
- Needs to be done at 80-100% MVC
- Rate of stretch more important than length of stretch
- If quality deteriorates, fatigue is being experienced and need to stop set
- More rest time
Recommended contacts for beginner, intermediate, and advanced with low-intensity, moderate, and high intensity plyometrics?
Beginner: Low 80-100, moderate 60, high 40
Intermediate: Low 100-150, moderate 80-100, high 60-80
Advanced: Low 140-200, moderate 100-120, high 80-100
For moderate you want to do warm up of 40-100 warm up low intensity jumps
For high intensity you want to do warm up of 60-120 low intensity jumps
Sprint speed and plyometrics
Plyometrics increases sprint speed but when you combine it with weight training there doesn’t seem to be added benefit for the weight training. Is beneficial for the first 10-40 meters (no research showing beyond 40 m)
Requirements for LE plyometrics
- No pain, swelling, ROM loss
- Single leg balance (eyes open/closed 30 seconds)
- No pain with single leg half squat
- Squat 1.5-2.5 body weight
- Squat 60% body weight 5 times within 5 seconds
UE Plyometric Recommendations
- 5-10 reps/set
- 1-3 sets per exercise
- 2x/week
- 60 sec rest
- Minimum 6 different exercises
Plyometrics: General Contraindications
- Cartilage/ligament injuries
- Arthritis
- Bone bruises/tendon injuries not fully healed
Phases of Selye’s General Adaptation Syndrome
- Alarm/Reaction Phase: athlete experiences stiffness, soreness, or a small drop in performance from fatigue immediately after training session
- Resistance phase: body responds to the stress by adapting to the new stress with less soreness, stiffness, and tolerance to activity, and improved performance
- Exhaustion: occurs if the stressor goes on longer than the organism can adapt and athlete may experience staleness in training or deal with symptoms of overtraining
Are Olympic lifts safe for youth athletes?
These are safe as long they have the coordination and skill to perform properly
Are plyometrics safe for youth?
The contention that plyometric training is unsafe or that you need a predetermined amount of strength is not supported by research. They have been found to improve performance and decrease sport-related injuries.
Resistance training and growth/maturation for children/adolescents?
No research that it will negatively impact growth and maturation. WB physical activity is essential for bone formation/growth and bone mineral density is higher in adolescents who are doing activity (year long sports, resistance training, etc)
Total strength gains for children, adolescents, and adults.
In terms of absolute strength gains, adults make greater gains than adolescents and adolescents > children.
Is 1 RM testing safe in children/adolescents?
If done properly they are safe.
Strength gains/muscle mass for pre-adolescents?
It appears that training-induced strength gains are more related to neural mechanisms than hypertrophic factors (due to lack of inadequate circulating testosterone)
Recommended reps for power exercises with youth?
Due to the relatively intense nature of power exercises, fewer than 6-8 reps are typically recommended so fatigue does not interfere with quality. Not performed to failure.
Resistance Training Risk
Carries some risk but none greater than sport or other recreational activities.
Resistance Training and Damage to Growth Cartilage
In a pre-adolescent child, the growth cartilage may actually be stronger and resistant to sheering forces.
Effectiveness of youth resistance training
Youth athletes can significantly increase strength beyond growth and maturation levels. Children as young as 5-6 have benefited from participation in strength training.
Warm up for resistance training in youths
Acute bouts of static stretching create a negative impact on strength and power. Dynamic movements that elevate body temperature, enhance motor unit excitability, maximize ROM, and improve kinesthetic awareness recommended.
Training intensity/volume for youths?
1-2 sets of 10-15 when developing technique. Progress to additional sets with heavier loads (6-10 RM) on large muscle groups and with power exercises fewer than 6-8 reps.
What are the yo-yo tests?
2 markers are placed at a distance of 20 m. You use a CD in a CD player and the athletes run back/forth between markers at a given speed controlled by the CD. The speed is regularly increased and the test ends when the individual can no longer maintain the speed. The test result is determined as the distance covered.
Yo-Yo Endurance Test: Lasts 5-15 min
- Continuous
- Good for distance runners
Yo-Yo Intermittent Endurance Test: 10-20 min
- 5-18 sec of running with 5 sec rest periods
- Good for athletes in interval sports (tennis, soccer)
Yo-Yo Intermittent Recovery Test: 2-15 min
- Looks at ability to recover after intense exercise
- After each exercise period (5-15 sec) there is 10 sec pause
- Good for sports with intense bursts (basketball, hockey, football)
Central/Peripheral Changes From Aerobic Training
Central: Heart and blood changes
Peripheral:
1. Increased capillaries
2. Elevation of mitochondrial enzymes
3. Elevation of lactate dehydrogenase activity
4. Elevated mitochondrial volume
These peripheral effects enhance oxidation of lipids and sparing of glycogen, as well as lowered lactate production.
How is VO2 Max Changed (Central Change)
Max oxygen uptake increases with exercise intensities between 80-100% VO2 Max
How are peripheral factors trained to improve with endurance related exercise?
Extended training appears to be essential and needs intensity <80% VO2 Max
Intensity Ranges For Aerobic Training
Low = 50-80% HR max
Moderate = 65-90 HR max
High = 80-100 HR max
HR Max is estimated by subtracting age from 220
Energy systems from anaerobic training
- High rate of creative phosphate utilization
- Lactate-producing energy system (glycolysis)
Cooper Test
Run at far as you can in 12 minutes. Can estimate VO2 Max (mL/kg/min)
ML of oxygen
Participants body weight
Per minute
Wingate anaerobic 30 cycle test
The participant cycles for 30 seconds at a fixed resistance (usually 7.5% of individuals body weight) as hard as they can and look at:
1. Peak power
2. Mean power output
3. Fatigue index (decline in power over the course of the test)
How to calculate total energy expenditure?
Basal metabolic rate (BMR) + Thermic effect of food (TEF) + Thermic effect of activity (TEA)
Technologies to assess athlete body composition?
- DXA (dual energy x-ray absorptiometry)
- This is best - Hydrodensitometry
- Air displacement plethismography
- Skin fold measurements
- Highest standard of error - Single and multi-frequency bio electrical impedance analysis
Protein requirements for athletes and when going for slight energy deficit?
Usually 1 g/kg each day but if restricting calories and want to maintain muscle you’d go up to 2.3 g/kg. Would probably do this for about 2 weeks.
Performance and weight loss.
Fat-free mass and performance is better preserved when weekly weight loss is <1% per week.
Recommended weekly changes in calories for athletes if trying to lose weight
~250-500 kcal/day while maintaining or slightly increasing energy expenditure
Energy pathways for athletes
- Non-Oxidative
- Phosphagen (ATP and CP; energy for ~10 sec)
- Glycolytic (glucose and mm glycogen; high intensity exercise for 5-60 seconds) - Aerobic (Exercise >2 minutes; major substrates = muscle and liver glycogen; intramuscular lipid; adipose tissue triglycerides; AA from mm/blood/liver/gut; body uses more of this as oxygen becomes available)
-fat
-carbohydrates
Carbohydrates vs fat
Carbs are the master fuel for athletes. Carbs can be metabolized faster than fat to more quickly provide energy. There is more energy produced with fat metabolism and less metabolic cost needed to convert fat to energy though.
Daily carbs based on exercise intensity
Light/skill-based activities = 3-5 g/kg
Moderate (1 h/day) = 5-7 g/kg
High (Endurance program 1-3 h/day; mod/high intensity) = 6-10 g/kg
Very high (>4-5 h/day; mod/high intensity) = 8-12 g/kg
- Carb Refeuling With <8 hours between 2 events
- Pre-Event Fueling
- During Endurance Sports (1-2.5 hours)
- During Ultra-Endurance Sports (2.5-3 hours)
- 1-1.2 g/kg/hour for 1st 4 hours
- 1-4 g/kg consumed 1-4 before exercise
- 30-60 g/h
- Up to 90 g/h
Protein sensitivity after resistance exercise
There is an upregulation of muscle protein synthesis for at least 24 hours after resistance training with increased sensitivity to the intake of dietary protein over this period.
Daily protein and protein RDA
There is good rationale for recommending daily protein intakes that are well above RDA to maximize metabolic adaptation to training.
Recommended protein for athletes
1.2-2.0 g/kg/day. May need higher if restricting energy. Newer research says 0.3 g/kg after key exercise sessions and every 3-5 hours over multiple meals.
Protein after exercise
MPS is optimized after exercise when a high biological value protein is consumed within 0-2 hours. Recommended intake of 0.25-0.30 g/kg body weight or 15-25 g across the typical range of athlete body sizes. Higher doses (>40 g) have not shown further MPS. Longitudinal training studies currently suggest strength/mm mass increases are greatest with immediate post-exercise protein.
Energy from alcohol
7 kcal/g
Alcohol’s effects on recovery
May interfere with it by impairing glycogen storage, slowing rate of rehydration via its suppressive effect on anti-diuretic hormone, and impairing the MPS desired for adaptation and repair. Want to minimize or avoid alcohol in post-exercise period when recovery and injury repair are priority.
Iron and athletes
Sometimes can be an issue with:
1. Periods of rapid growth
2. Training at high altitudes
3. Menstrual blood loss
4. Frequent blood donation
5. Vegetarians
6. Distance runners
Reversing IDA can take 3-6 months. Heme iron or non-heme iron + vitamin c foods works best. Some evidence that iron supplementation can improve performance for those with iron depletion that are not anemic but not recommended to do this without monitoring (can cause GI distress).
Vitamin D
Regulates calcium and phosphorus absorption and metabolism. Plays keep role in maintaining bone health. Studies have documented relationship between vitamin D status and injury prevention, rehab, improved neuromuscular function, increased type II muscle fiber size, decreased inflammation, decreased risk of stress fracture.
Calcium
Important for growth, maintenance, and repair of bone tissue; regulation of muscle contraction; nerve conduction; and normal blood clotting
Do Supplementing With Micronutrients Help Performance
Intake of vitamin and mineral supplements does not improve performance unless reversing a deficiency.
HGH
Released by pituitary gland. Promotes growth and cell development. HGH is converted to IGF-1 in the liver. Increases production of muscle and bone growth. Main purpose is to spur growth in childhood. Very little evidence it helps with performance but does increase lean body mass.
Steroids
Steroids are a kind of fat molecule. Body makes corticosteroids (produced by adrenal glands; helps with stress, immune response, and controlling inflammation) and androgenic anabolic steroids (main one is testosterone
EPO
Increases red blood cells in the body.
Sliding filament theory
Myosin as ADP and phosphate molecules attached at the heads. Actin, tropomyosin, and troponin. Calcium is released from sarcoplasmic reticulum and bind with troponin and causes tropomyosin molecules to move, revealing myosin attachment sites. The single phosphate gets released as the myosin heads attach to actin and forms a cross bridge. The ADP is expended for the power stroke to pull actin inwards. Once the ADP is expended, ATP attach themselves to the myosin heads and trigger the release from actin and are immediately broken down into ADP and phosphate as the heads move back into their resting position. If calcium is still present the cycle will continue and the sarcomere will short until calcium is transported back into the sarcoplasmic reticulum and the muscle relaxes.
Dietician
Someone who went to college, anyone can call themselves a nutritionist.
Percentages of macronutrients in diet?
Protein: 10-35%
Fat: 25-35%
Carbs: 45-65% (ultra endurance athletes 70-75%)
Glycogen Depletion and Replenishment
Glycogen is the limiting factor for prolonged human performance. Pre-exercise and after exercise is when you get your muscle and liver glycogen loaded/replenished. During exercise the carbs only replace your blood glucose.
Calories Stored in the body for 150 pound male
About:
- 1400 calories in mm glycogen
- 320 in liver glycogen
- 80 calories in blood glucose
Vs 60,000-150,000 calories of stored fat
Exercise intensity and fuel sources used?
<60% VO2 max almost entirely aerobic
Mixed aerobic/anaerobic is greater breakdown of mm glycogen
>80% VO2 max almost entirely mm glycogen (most athletes train >70% VO2 max)
Perception of fatigue and glycogen
As you start exhausting muscle glycogen and get into liver glycogen your perceived fatigue increases
High protein/high fat diets for athletes
Negatives to this. If not taking in enough carbohydrates then decreased storage of glycogen and lack of fatigue resistance. Breakdown of fat into ATP is a slow process and requires more oxygen.
Protein For Athletes
1.4-2.0 g/Kg usually suggested (no evidence supporting >2.0)
Amino acids for athletes
No research supporting AA supplementation when adequate, good quality protein is consumed.
Best Fats
Monounsaturated:
- Avocado, nuts, oils (avocado, canola, olive, peanut)
Polyunsaturated:
- fish, margarine (trans free), seeds
Nutrient Timing
Pre-Workout:
- Carbs: 1-4 g/kg 1-4 before exercise
- Fluid: 16-20 oz 2- hours before; another 10 oz 20 min before
During Workout
- Carbs: 30-60 g/hr
- Fluid: 4 oz per 15 min
Post Workout:
- Carbs: 1-1.5 g/kg
- Protein: 0.1-0.2 g/kg
- Fluid: 24 oz per pound of body weight lost (Generally 7-10 oz every 10-20 min and AT LEAST within 2% of body weight reduction and try to replenish within 2 hours after)
Fat/Water Soluble Vitamins
Fat Soluble: A,D, E, K (doesn’t dissolve in water and can be stored in fat tissues; higher potential for toxicity)
Water Soluble: B and C (excess excreted in urine)
Minerals female athletes are deficient in?
Calcium
Iron
Zinc
Notoriously deficient in these
Water:
- How much loss to be dehydrated
- Effect on HR
2% loss = dehydrated
1% loss makes heart beat an additional 3-5x/min
Water or Sports Drinks?
Fluid should be given regularly but if going more than 60-90 minutes then you want to start using sports drinks
How many extra calories to gain weight?
500-1000 extra calories/day to gain 1-2 pounds/week
BMI
18.5-24.9 is normal
25-29.9 is overweight
<18.5 is underweight
Muscle vs Bone Healing
Muscle is a reparative process, bone is regenerative. Muscle heals with a scar (replaces original tissue) and bone heals with tissue identical that that which existed before.
Muscle contusion/strain grades and symptoms?
Grade 1: tear of only a few muscle fibers with minor swelling and discomfort with no/mild decrease in ROM/strength
Grade 2: Clear loss of function (ROM/strength)
Grade 3: Tear extending across entire cross-section of muscle with nearly complete loss of muscle function
Muscle Healing Rest?
Immobilization for the first few days only (this allows scar tissue to gain strength), should be no more than a week.
When to start sport specific training after muscle injury?
- Ability to stretch the muscle like the uninjured side
- Pain-free use during basic movements
NSAIDS and Corticosteroids For Muscle Injuries
Short term NSAID’s fine and no negative effects. Steroids show:
1. Decreased elimination of hematoma/injured tissue
2. Delayed muscle repair
3. Reduced biomechanical strength of injured tissue
Myositis ossifications
- Suspected if pain/swelling not clearly subsiding after 10-14 days or if healing not progressing (despite proper conservative treatment)
- If symptoms intensify weeks or months after the trauma, especially if site hardens and displays reduced ROM
- Radiographs can sometimes pick up ectopic bone formation within 18-21 days but usually this lags behind symptoms by weeks
How to check hydration status
Measure weight compared to waking in the morning
Urine specific gravity and osmolarity
Hydration ranges
Hydration kept within very narrow range:
1% hyper hydration
3% hypo hydration
Hypohydration Ranges and effects
Mild = 1-5%
Moderate = 5-10%
Severe = >10% deficit
Mild to moderate effects on athletic performance from 2-5% and severe >5% (difficult to replace, even with extended recovery)
How to distinguish hyper/hypohydration
Hypo: thirst, cramping, heat sensations
Hyper: Extremity swelling, altered mentation, mood changes, seizure
Caffeine and Exercise/Fluid Loss (Recommendations)
Caffeine may increase short-term urine production at rest but does not induce dieresis during exercise. No reason to discourage mild/moderate caffeine consumption before and every 30 minutes during exercise based on diuretic effects.
Best time to measure urine for hydration status
In the a.m. during first void. Spot urine samples can be confounded by fluid intake, exercise, and food intake and may not be accurate indicators of hydration status.
Thirst as hydration assessment
Thirst increases when 2% hypohydration is approached and decreases when fluid balance restored to a loss of less than 2%. 1st thing thirst is strongly correlated with hypohydration.
Measuring body mass for hydration
Body mass is considered a valid measure of hydration status only when losses are acutely observed (pre/post practice) or compared with a valid euhydrated baseline.
Looking at urine color for hydration status
Body mass assessment gives more reliable information. First morning assessment is the most stable assessment. Urine volume and concentration stability is affected by the following variables: activity, diet, and fluid intake. Not accurate looking at it in the toilet, it’s diluted with the toilet water now.
Recommended measurements for hydration status?
- 1st morning urine color
- Thirst sensation
- Body mass
Vegetarian athletes and deficiencies
At risk for low intakes of:
Protein
Fat
Iron
Calcium
Vitamin D
Riboflavin
Zinc
B12
Sweat Rate Equation
Sweat Loss:
Body mass before exercise (kg) - body mass after exercise (kg) + volume of fluid consumed during exercise (L) - Urine volume (L) = Sweat Loss
Rate is sweat loss / hours
When should sodium chloride be considered?
- Inadequate meals or meals not eaten
- Physical activity >4 hours
- During initial days of hot weather
Urine specific gravity and urine color
USG normal is 1.005 - 1.030 (should aim for equal/less than 1.020 or urine color less than or equal to 4)
Urine color goes from 1-8 (7-8 is severely dehydrated)
Calories from the different macronutrients?
Carbs and protein = 4 kcal/gram
Fat = 9 kcal/gram
Blood pressure during stress test
Max responses commonly cited as (upper limits of normal):
Systolic: Men 210, Women 190
Diastolic: Men/Women 110
However, older age is associated with increased max BP and SBP cut points may not be applicable to people aged 40+ where the BP responses of the 90th percentile exceeded these values.
How to measure an ahtlete’s head for a helmet?
Place the tape around the head at the widest point. Should be 1 inch above the eyebrow in the front and on the occipital lobe in the back. Tape should be snug (tight and then back off without it becoming loose). Compare this to caliper measurements (1 inch above eyebrow to occipital crest). Compare the measurements. Ideal head shape should have similar circumference and caliper measurements. If the head is more circular there will be smaller caliper measurement and if very long head will have greater caliper measurement. A variance of 2-3 sizes or more usually means and unusual head shape that requires special helmet.
Trying on the helmet for sizing?
- Have them wet the hair (simulate sweat)
- Frontal rim of helmet should be 1 inch or 1 finger above eyebrow
- Feel under posterior rim of helmet, padding should be firm against skin but comfortable
- Put finger in ear hold and make sure back lateral pads have firm contact with head
- Grip face mask and rotate and go up/down. Skin should move with the pads and not slide under pads
- Pull face mask towards you, a gap shouldn’t occur between front and forehead
- Keep the helmet on for 1 minute. After removing it shouldn’t be white (loss of circulation) but redness is okay.
- Cheek pads should be clearly seen from front and in contact with skin but not putting cheeks in puckered position
- Face mask clearance from front of nose should be 2-3 fingers
- Push straight down on top of the helmet and ask athlete where pressure is (should respond all over or on top, not front to back)
- Ask athlete if it’s comfortable
- Should be firm but comfortable
Never:
1. Interchange pads between different brands of helmets
2. Use the correct pad for the shell size (M, L, or XL)
3. Ne’er alter a pad by cutting it down
4.
VO2 Max Measurements (Good/Average)
In ml/kg/min
Males (Females about 10 lower)
Average - Around 50
Above average - low 50’s
High - Around 60
Very High - upper 60’s
Extremely High - 70+
How is VO2 Max Measured
- Use face mask to measure
- Use an incremental test on bike or TM
- Intensity usually increased every 30-60 seconds
- Continue to failure
- VO2 Max is measured at highest VO2 recorded over 60 sec period
Best way to increase VO2 Max
With high intensity interval training
T-Test
10 yards forward and then 5 yards to each side. Excellent is under 9.5 for males and 10.5 for females. Good is 1 second less than this for each, average 2 seconds less, poor >11.5.
Pro-Agility Test
Start in 3 point position. Cones set up 5 meters on each side of the start line.
20 meter multi-state fitness test and yo-yo tests
Beep tests with cones 20 meters apart. Keep running back and forth within beeps. If don’t hit the beep you have to get back on pace within 2 beeps.
Recommended load (%1 RM) and goal reps for different training goals?
Strength: >85% and 6 or less reps
Power: 80-90% for 1-2 reps (single effort event) and 75-85% for 3-5 (multiple effort event)
Hypertrophy: 67-85% for 6-12 reps
Endurance: 67% or less for 12 or more reps
Estimating %RM
This doesn’t match EXACTLY with the NSCA but if 1 RM is 100% then each rep added is 3% less.
2 = 97
3 = 94
4 = 91
Etc.
What is the minimum percentage MVIC needed to make strength gains?
50-60%
Muscle fiber types?
Type 1: Rich in myoglobin (protein that stores oxygen in muscles) and are fatigue resistance, they usually produce low levels of force.
Type 2A: Called fast-oxidative. They have combination of both aerobic and anaerobic mechanisms, can generate high levels of force and have moderate resistance to fatigue
Type 2B: Called fast-glycolytic. Primarily anaerobic and can generate high levels of force rapidly
How is blood pressure supposed to change during a stress test or exercise?
During exercise systolic pressure is supposed to increase by about 20 mmHg and diastolic stays relatively the same or slightly decreases (because the arteries dilate/expand in response to increased blood flow).
