Influence of Increased Duration or Intensity on Training Load as - - PowerPoint PPT Presentation

Influence of Increased Duration or Intensity on Training Load as evaluated by EPOC and TRIMPS

Heikki Rusko Department of Biology of Physical Activity, University of Jyväskylä, and KIHU - Research Institute for Olympic Sports Jyväskylä, FINLAND

Training Effect - Training Effect - Disturbance of Homeostasis Disturbance of Homeostasis

VO2max of beginner exercisers increases 10-20% during the first 10-20 weeks and thereafter levels off. VO2max of endurance athletes increases for ~1-3 years and thereafter only small changes occur. Why? Because disturbance of homeostasis induced by training is necessary to obtain training effect for both athletes and beginners Do we know when our homeostasis is disturbed and is longer duration at lower intensity better than shorter duration at higher intensity?

How to measure Disturbance of How to measure Disturbance of Homeostasis - Training Load? Homeostasis - Training Load?

 Heart rate: time at diff. intensities, not enough?  Blood lactate: invasive, time consuming,

momentary?

 Stress hormones: invasive, expensive, time

consuming, requires laboratory analysis?

 RPE: feelings of fatigue, need for recovery  TRIMP: Training Impulse (Bannister 1991):

• Time x relative intensity x multiplying factor (blood

lactate vs. relative exercise intensity)

• Accumulates also during low intensity recovery

exercise

• Not totally physiological index

E.g. Brooks & Fahey, EXERCISE PHYSIOLOGY, John Wiley & Sons Inc 1984:  ”In reality, the cause of Excessive Postexercise Oxygen Consumption (EPOC) is the general disturbance to homeostasis brought on by exercise”  ”EPOC integrates the effects of increase in body temperature, changes in stress hormone and metabolite levels, changes in intracellular ion concentrations, etc… after exercise”  EPOC could be a physiological measure for

• disturbance of homeostasis,
• exercise induced fatigue accumulation and
• recovery time needed after exercise

EPOC:

Excess Postexercise Oxygen Consumption

Purpose Purpose

To evaluate the effect of increased duration or intensity of exercise on training load as evaluated by EPOCmeas, EPOCpred and TRIMP To evaluate the differences between EPOCmeas, EPOCpred and TRIMP

Subjects

 8 males  Age 28  4 years (mean  SD)  Weight 81  15 kg  Height 180  4 cm  BMI 25  4 (%Fat 17  5)  VO2max 52  8 ml/kgmin-1

• vVO2max

13,6  2,1 km/h

• vRCT

10,8  2,2 km/h

• vLT

8,1  1,5 km/h

• (3% slope)

Three treadmill running exercises

(3% slope)

 Normal: CV21/68%

• 21 min at 9,3 km/h, 68%

vVO2max

 Increased Intensity:

CV21/79%

• 21 min at 10,8 km/h, 79%

vVO2max

 Increased Duration:

CV40/68%

• 40 min at 9,3 km/h, 68%

vVO2max

Measurements: VO2 (Sensor Medics), RR-Intervals (Polar RR- recorder), blood lactate concentration (EBIO 6666), RPE

Methods Methods

EPOC EPOCmeas

meas and

and TRIMP TRIMP

 EPOCmeas: 15-min recovery VO2 – resting VO2

(sitting)

 TRIMP: = t x %HRR x 0.64e1,92(%HRR)

• = duration x relative intensity x multiplying factor
• Bannister E.W. 1991: Modelling Elite Athletic
• Performance. In: MacDougall, J.D., Wenger, H.A. &

Green, H.J. (Eds.) Physiological Testing of High- Performance Athlete 2nd ed. Human Kinetics, Champaign, Illinois.

EPOC EPOCpred

pred

 EPOCpred: EPOCt = EPOCt-1 + f(EPOCt, %HRt, Δt)

• Neural Network computational model based on the

relations between EPOC vs. intensity of exercise as the %VO2max (%HRmax), duration of exercise and On-Off information

• Saalasti S. 2003: Neural networks for heart rate time

series analysis. Ph.D. Dissertation. Department of Mathematical Information Technology, University of Jyväskylä, Finland

Rusko, H.K., Pulkkinen, A., Saalasti, S., Hynynen, E., & Kettunen, J. Pre-prediction of EPOC: A tool for monitoring fatigue accumulation during exercise? Medicine and Science in Sports and Exercise, 35: S183, 2003.

10 20 30 40 50 5 10 15 20 25 30 35 40 45 50 55 Time (min) VO2 (ml/kg/min)

CV21/68% CV21/79% CV40/68% Max RCT LT

60 80 100 120 140 160 180 200 5 10 15 20 25 30 35 40 45 50 55 Time (min) Heart Rate (bpm)

CV21/68% CV21/79% CV40/68% Max RCT LT

Description of exercises Description of exercises

VO

2 as

expected: higher with increased intensity Heart rate as expected: continued to increase with increased duration

1 2 3 4 5 6 7 8 9 10 10 20 30 40 50 60 70 Time (min) RPE

CV21/68% CV21/79% CV40/68% Max RCT LT

2 4 6 8 10 12 10 20 30 40 50 60 70 Time (min) Blood lactate (mM)

CV21/68% CV21/79% CV40/68% Max RCT LT

Which one induced a greater disturbance of homeostasis? Blood lactate as expected: higher with increased intensity RPE as expected: continued to increase with increased duration

20 40 60 80 100 120 10 20 30 40 50 Time (min) TRIMP (arb. units)

CV21/68% CV21/79% CV40/68%

50 100 150 200 250 10 20 30 40 50 60 Time (min) EPOCpred (ml/kg)

CV21/68% CV21/79% CV40/68%

Accumulation of TRIMP and EPOC Accumulation of TRIMP and EPOCpred

pred

TRIMP greater change with increased duration EPOC

pred

greater change with increased duration And decreased during recovery

150 155 160 165 170 175 180 185 190 HR Heart Rate (bpm) p<0.01 0,0 1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 RPE bLa RPE / bLa (mM)

CV21/68% CV21/79% CV40/68%

p<0.01 p<0.01

20 40 60 80 100 120 140 160 180 EPOCmeasured EPOCpred TRIMP

CV21/68% CV21/79% CV40/68% p<0.01 p<0.01 p<0.01

Intensity induced a greater change: RPE, bLa, peakHR, EPOCmeas Duration induced a greater change: EPOCpred, TRIMP

Comparison of exercises Comparison of exercises

R2 = 0,75 50 100 150 200 250 300 350 20 40 60 80 100 120 140 TRIMP (arb. units) EPOCpred (ml/kg)

High Correlation between EPOC High Correlation between EPOCpred

pred

and

and TRIMP TRIMP

Why difference between EPOCmeas vs. EPOCpred and TRIMP?

EPOCpred and TRIMP start to accumulate with time at ~50-60% HRR (over LT) Present subjects had higher VO2max, LT and RCT than ”average persons”: e.g. LT 63%HRR (78%HRmax)

30 40 50 60 70 80 90 100 %vVO2max % HRR %

LT RCT CV21/69% CV21/78% CV40/69%

Conclusions Conclusions

 Increase in training intensity from 68% to 79% vVO2max for 21 min exercise induced a greater disturbance of homeostasis (increase in training load) than increase in training duration from 21 to 40 min at 68%vVO2max based on

• Heart rate
• Blood lactate
• RPE
• Measured EPOC

 TRIMP and EPOCpred were more sensitive to increase in training duration than intensity at the present training intensities

Conclusions Conclusions

 TRIMP and EPOCpred integrated similarly the

intensity and duration of exercise

 EPOCpred and TRIMP depend very much on the %

HR and %HRR level which may differ between subjects having different training background

 Calculation of EPOCpred and TRIMP should take

into account the differences in individual ”threshold” –values

 EPOCpred can give dynamic information on the

accumulation of training load and allows calculation of time needed for recovery (decrease of EPOCpred to resting level)

Thank you for your attention Thank you for your attention