© Jason Karp, Ph.D.
RunCoachJason.com
Founder/Coach, REVO2LT Running Team TM
Freelance writer & author
2011 IDEA Personal Trainer of the Year

• inadequate ATP resynthesis via aerobic metabolism
• acidosis & accumulation of metabolites
• CNS/neuromuscular?
• glycogen depletion/hypoglycemia
• dehydration
• causes decrease in plasma volume of blood, decreasing stroke volume & cardiac output
• muscle fiber damage
• results in fewer functioning actin-myosin cross-bridges
• hyperthermia
• Decreases blood flow to active muscles
• reduces mitochondrial respiration & ATP regeneration

Improve cardiac performance to increase blood flow to muscles and improve characteristics of aerobic metabolism so that reliance on O
2
independent ATP regeneration is delayed.

O
2 cost of maintaining a given pace
2
maximum volume of O
2 consumed per minute
speed above which lactate accumulates
& acidosis occurs

2
• Maximum volume of oxygen muscles consume per minute (maximum rate of oxygen consumption).
• Most often measured variable in exercise physiology.
• Expressed as liters/min or ml/kg/min.
• Although a high VO
2 max alone is not enough to attain elite-level performance, it gains one access into the club. An athlete simply cannot attain a high level of performance without a high VO
2 max.
• Largely genetically determined.
• Males have higher VO
2 max than females, primarily due to differences in cardiac output and blood hemoglobin concentration.

2
•
• Cardiac output dependent on:
• stroke volume
• heart rate
• Stroke volume determined by:
• venous return
• heart contractility
• amount of pressure in left ventricle (preload)
• amount of pressure in aorta (afterload)
• size of left ventricle

2
• Blood flow dependent on:
• redistribution of blood away from other tissues & to active muscles
• resistance of blood flow through blood vessels
• adequate dilation of blood vessels, which depends on interplay between sympathetic & parasympathetic nervous systems & associated hormones
• O 2 transport capacity of blood, which is determined by red blood cell volume & amount of hemoglobin, which transports O 2 in blood
• amount of myoglobin, which transports O 2 in muscles
• density & volume of capillaries that perfuse muscle fibers, which determines time available for diffusion into muscle mitochondria
Transporting oxygen from the heart to the muscles is a complicated matter!

2
•
2
• Dependent on mitochondrial & capillary volumes & enzyme activity.
• Reflected by difference in amount of O
2 going to muscles through a rterial circulation & amount coming out through v enous circulation (a-v O
2 difference).
• a-v O
2 difference determined by convection of O
2 through muscle capillaries and its diffusion from capillaries to mitochondria.

VO
2
= SV x HR x (a-v O
2 difference)
VO
2
= CO x (a-v O
2 difference)
Central factors
Peripheral factors
VO
2 max occurs when SV, HR (and therefore cardiac output), & a-v O
2 difference are at maximum.

• Unfit people seem to be equally limited by central & peripheral factors (they lack both high blood flow & abundant metabolic machinery)
• Highly trained endurance athletes are more centrally limited.
• Training causes a shift of limitation on sliding scale—the more fit you become, the more you move away from a metabolic limitation to VO 2 max and the closer you move to an O 2 supply limitation.
• Progressive increases in mileage improve VO 2 max by increasing muscles’ metabolic capacity. Once you have achieved a high level of mileage, intensity of training becomes more important to increase cardiac factors responsible for maximizing O 2 supply to muscles.

2
• VO
2 max of best human endurance athletes = 80-90 ml/kg/min, which equals that of pigs & rats, about half that of horses & dogs, & a third that of foxes.
• VO
2 max of thoroughbred race horse = 150 ml/kg/min. So, compared to a horse, even an Olympic champion looks like a couch potato!
• Among all animals, flying insects have highest
VO
2 max relative to their size.
• VO
2 of hummingbird flapping its wings 80 beats/min is 40 ml/gram/hour which, in human terms, equals 666 ml/kg/min!
• VO
2 of honeybee flapping its wings 250 beats/min is 6 ml/gram/min, which equals 6,000 ml/kg/min!

2
Provides greatest cardiovascular load because you repeatedly reach & sustain maximum stroke volume, cardiac output,
& VO
2 max during work periods.
Purposes:
• Increase max SV, max CO, & VO
2 max
• the higher the VO 2 max, the higher the aerobic ceiling
Recommendations:
• 3-5 min work periods with 1:≤1 work-to-rest ratio
• (short intervals with very short, active recovery periods)

VO 2
(HR)
VO
2 max
(HRmax)
Work Periods
Recovery Periods
Reps

2
• Running velocity that elicits VO
2 max
(vVO
2 max)
• Fastest speed that can be maintained for
~7-10 min
• 95-100% max HR
• Slower/recreational runners:
• 1- to 1½-mile race pace
• Highly-trained/competitive runners:
• 3K (2-mile) race pace

2
• 4 x 1,000 meters @ vVO 2 max with a 1:≤1 work:rest ratio
• 6 x 800 meters @ vVO 2 max with a 1:≤1 work:rest ratio
• 16 x 400 meters @ vVO 2 max with a 1:<1 work:rest ratio
If you can run 1½ miles in 10:00 (= 6:40 mile pace):
• 4 x 1,000 meters in 4:10 with 3:00 jog recovery
• 6 x 800 meters in 3:20 with 2:30-3:00 jog recovery
• 16 x 400 meters in 1:40 with :50 jog recovery
Although tempting to run faster when intervals are shorter, pace should be same for all 3 workouts since goal is same—to improve
VO 2 max. As you progress, make workouts harder by adding more reps or decreasing recovery period rather than by running faster. Only increase speed of intervals once races have shown that you are indeed faster.

2
• While short intervals can improve VO
2 max, long intervals run at 95-100% VO
2 max are most potent stimulus.
• The more highly-trained the athlete, the more important intensity becomes to improve VO
2 max.
• The more aerobically fit the athlete, the faster the recovery both within & between interval workouts, which 1) allows athlete to complete more reps during each workout, thus enabling him/her to spend more time at vVO
2 max, & 2) allows athlete to run interval workouts more often.

• Slower/recreational runners:
• 10-15 sec/mile slower than 5K race pace (or
~10K race pace)
• 75-80% max HR
• Highly-trained/competitive runners:
• 25-30 sec/mile slower than 5K race pace (or
15-20 sec/mile slower than 10K race pace)
• 85-90% max HR
• Subjectively feel “comfortably hard”

Continuous LT Runs
3-4 miles up to 7-8 miles (or ~45 min)
LT Intervals intervals @ LT pace with short rest periods
4 x 1 mile @ LT pace w/ 1 min rest
LT+ Intervals short intervals @ slightly faster than LT pace with very short rest periods
2 sets of 4 x 1,000 meters @ 10 sec/mile faster than LT pace w/ 45 sec rest & 2 min rest between sets
LT/LSD Combo Run medium-long runs with portion @ LT pace
12-16 miles w/ last 2-4 miles @ LT pace
2 miles + 3 miles @ LT pace + 6 miles + 3 miles @ LT pace

• Best stimulus to improve LT is continuous or interval-type training performed at, or slightly faster than, current LT pace.
• Among hardest types of workouts for runners to do correctly, so monitoring by coach is essential.
• LT training is the best aerobic bang for your buck.
• LT training makes what was an anaerobic intensity before now high aerobic.
• The longer the race, the more important it is to train LT.

• High mileage (>70 miles per week) seems to improve running economy.
• optimized biomechanics
• hypertrophy of Type I skeletal muscle fibers
• greater skeletal muscle mitochondrial & capillary volumes
• greater ability for tendons to store & utilize elastic energy
• lower body mass
• optimized motor unit recruitment patterns gained from countless repetitions of running movements

• Higher intensity training (e.g., intervals & tempo runs) has been shown to improve economy.
Franch et al. (1998):
• 3.1% sig. improvement following tempo running
(20-30 min @ 90% max HR, 3 x wk for 6 wks)
• 3.0% sig. improvement following long intervals
(4-6 x 4:00 w/2:00 rest)
• 0.9% non-sig. improvement following short intervals
(30-40 x 15 sec. w/15 sec. rest)

Research has shown that weight training using near maximum loads & plyometric training can improve economy by improving muscle power.
Power = Force x Velocity
Heavy weight training (e.g., 3-5 sets of 3-6 reps @
≥ 90% 1-rep max with 5 min rest) targets the force
( strength) component of power.
Plyometric training targets the velocity (speed) component of power.

• Studies found that neither VO
2 max nor LT changed.
• suggests that improvements in economy from power training do not result from cardiovascular or metabolic changes, but rather from some other
(neural) mechanism
• Studies found increase in 1-rep max.
• Subjects didn’t gain weight.
• strength acquired through neural adaptation, rather than hypertrophy

• Improved economy may be most significant attribute gained from running high mileage.
• Adding long intervals to baseline mileage can improve economy.
• Because runners are most economical at speed at which they train the most, they should spend time training at race pace to improve economy at race pace.
• Heavy strength training & plyometrics improve economy, possibly by neural mechanism.

Type I Type IIA Type IIB
Slow-Twitch Fast-Twitch A Fast-Twitch B
1) Change characteristics of each fiber type
2) Change area taken up by fiber type
3) Conversion of fiber types?
• Increasing % of ST fibers would increase aerobic power & capacity because ST fibers contain more mitochondria & aerobic enzymes.
We combat fatigue by making muscles act as much like ST fibers as we can by causing 1, 2, &/or 3.

Changes in Muscle Fiber Type Before and After Training
% Type I Fibers
Pre-training
45.8 (6.9)
Post-training
36.2 (4.3)*
% Type II Fibers
Avg. Diameter Type I (  m)
Avg. Diameter Type II (  m)
54.2 (6.9)
50.7 (0.8)
57.9 (2.0)
63.8 (4.3)*
52.7 (1.0)
57.8 (3.8)
% Area Type I Fibers
% Area Type II Fibers
43.0 (6.6)
57.0 (6.6)
34.4 (4.0)*
65.6 (4.0)*
Data from Dawson et al. (1998). *Significantly different from pre-training values (p<0.05).
Training consisted of sprint intervals (
20-40 x 30-80m @ 90-100% max speed w/1:6 work:rest ratio, decreasing to 1:4 ratio as training progressed) 3 x week for 6 weeks.

Workouts that use anaerobic glycolysis as predominant energy system and repeatedly cause acidosis to improve acidosis tolerance, muscle buffering capacity, and anaerobic capacity.

• Intervals from 45 seconds to ~2 min (300-
800 meters) w/ either short or long recovery
• short recovery keeps acidosis level high throughout workout
• long recovery allows for even greater degree of acidosis
• 6-8 x 400 meters @ mile race pace w/1:1 work:rest ratio
• 2 sets of 5 x 300 meters @ 800m race pace w/1:2 work:rest ratio & 5:00 between sets
H + + HCO
3-
 H
2
CO
3
 CO
2
+ H
2
O

To get the most out of plyometric training, try to spend as little time on the ground as possible between hops/bounds/jumps. Do exercises on a soft surface, such as grass, a track, or a gymnastic mat. Begin with two sessions per week of two sets of ten repetitions (2 x 10) with full recovery between sets.
Week
3
4
1
2
5
6
Single leg hops
2 x 10
2 x 10
2 x 10
2 x 10
2 x 10
2 x 10
Bleacher hops
2 x 10
2 x 10
2 x 10
2 x 10
2 x 10
2 x 10
Double leg bound
2 x 10
2 x 10
2 x 10
2 x 10
Alternate leg bound
2 x 10
2 x 10
2 x 10
2 x 10
Squat jumps
2 x 10
2 x 10
2 x 10
Depth jumps
2 x 10
2 x 10
Box jumps
2 x 10
2 x 10
Single leg hops: 1) On one leg, hop up and down; 2) hop forward and back; 3) hop side-to-side.
Bleacher hops: Standing at the bottom of the bleacher steps on one leg, hop up the steps. Walk back down and hop up again on the other leg.
Double leg bound: From a squat position with both legs, jump forward as far as you can.
Alternate leg bound: In an exaggerated running motion, bound (which looks like a combination of running and jumping) forward from one leg to the other.
Squat jumps: With hands on hips in a squat position, jump straight up as high as you can. Upon landing, lower back into a squat position in one smooth motion, and immediately jump up again.
Depth jumps: From a standing position on a one-foot tall box, jump onto the ground and land in a squat position.
From this squat position, jump straight up as high as you can.
Box jumps: From the ground, jump with two feet onto a box about one foot high, and then immediately jump into the air and back down to the ground. As you get experienced with the exercise, try jumping with one foot at a time.

•
• long runs (>2 hrs) & LT/LSD combo runs to deplete muscle glycogen
• causes greater synthesis & storage
• causes greater reliance on fat
• stimulates liver gluconeogenesis
•

• Dehydration
• drink fluids w/sodium during marathon
• Muscle Fiber Damage
• do long runs on pavement
• Hyperthermia
• acclimatize (~14 days) by running in heat

References & Recommended Readings
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References & Recommended Readings
Daniels, J. (2005). Daniels’ Running Formula . Champaign, IL: Human Kinetics.
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References & Recommended Readings
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