Today, We’ll cover: ACSM training guidelines Determining intensity Central CV adaptations Peripheral CV adaptation

ACSM Guidelines for CR Endurance Training 6th Ed

Mode: prolonged activity using large muscle groups, rhythmic nature

Intensity:40/50% to 85% VO2R or HRR

Duration: 20-60 minutes continuous or intermittent

Frequency: 3-5 workouts per week

 

Determining intensity:

Target VO₂ = [%intensity(VO₂max–VO₂rest)]+VO₂rest

Example: moderately active female college student: 70%VO₂R

VO₂max = 45.0 ml•kg•min^-1; VO₂rest = 3.5 ml•kg•min^-1

Target VO₂ ml•kg•min^-1 = [0.70(45.0 - 3.5)] + 3.5

Target VO₂ = 34.6 ml•kg•min^-1

METS = 32.6/3.5 = 9.3 METS

Target HR = [%intensity(HR_max – HR_rest)] + HR_rest

Example: moderately active female college student: age 22, resting HR 60, choose 70% HRR

Target HR = [0.70(220-22-60)] + 60

Target HR = 156.6 beats/min

We did a participation point activity in class. This type of question is highly likely to appear on your second exam!

We reviewed a VO2 max test. We determined it was a good max test, as RER exceeded 1.15 and age-predicted max HR was achieved. I asked the class to do the following.

1. Calculate a Target VO2 based on 70%VO2R

2. How many METS would that be?

3. What activities can you recommend based on the MET calculation?

 

Central and peripheral adaptations which may facilitate the well-documented increase in VO2 max with training

Heart Size adaptations to endurance training

• weight and volume increase
• LV wall thickness increases
• End diastolic diameter increases

Heart morphology may be altered with heavy resistance training as well, but the effect is less clear. Available studies are cross-sectional and may not have controlled for drug use in resistance trained athetes. A moderate amount of LVH has been reported in heavy resistance trained individauls, but it in NO WAY approaches the extreme pathological LVH observed is chronic systemic hypertension. We should call it a physiological hypertrophy. One study comparing endurance trained to resistance trained, showed no absolute differences in heart volume or wall thickness between the two broups, but when these valiables were expressed relative to body mass, the differences were clear. Endurance athletes had significantly greater EDD and wall thinckness when expressed relative to kg body mass.

Heart Rate adaptations to endurance training

Resting HR decreases:

Mechanism: Increased parasympathetic tone. May also be due to decreased sympathetic activity and/or adjusted intrinsic rate.

Submax HR at a given workrate decreases

Max HR…NO CHANGE...age determined

Recovery HR . We observe there is a more rapid reduction of HR with endurance training.

Stroke Volume adaptations to endurance training

Stroke Volume (EDV-ESV)

Resting SV increases

Submax SV increases

Max SV increases

Does SV increase because contractility increases w/ training? Or because other factors enhance the Frank-Starling mechanism?

We revieved this study. Ehsani, et al. Exercise Improves LV Function in Older Men. Circulation, 1991.
After 1 yr training @ 60-80%VO₂max with intervals @ 90% SV and ejection fraction were enhanced. Ehsani argues that an enhancement in contactility caused this greater EF. Could it be that an increase in blood volume with training, and an increase in LV diastolic filling could cuase this phenomenon? In order for use to say contractility was enhanced. We would need to see what happened an the SAME End-Diastolic volume. Wouldn't we?

I distributed a clinical case study dealing with anemia in a male athlete. Please read and be prepared to discuss.