THE HEAT SHOCK PROTEIN RESPONSE IN THE SKELETAL MUSCLE

OF UNTRAINED INDIVIDUALS

Shaun Guest

San Diego State University

School of Exercise and Nutritional Sciences

December 1st, 2009

Modified from Noble, 2008

INTRODUCTION

Magnitude of heat shock response to exercise: Individual characteristics

○ Training status○ Age○ Sex

Absolute workload ○ Intensity ○ Duration

Novelty of exercise stress

Noble, 2008

INTRODUCTIONExercise training with trained individuals: Maximum volume workloads induces the largest HSP

changes (Liu, 1999).

Highest levels of HSP with high intensities

(Liu 1999, 2000).

High-intensity resistance exercise and low-intensity

endurance exercise Blunted/abolished stress responses (Nething, 2003).

HSP response due to increased baseline levels of HSPs pre-exercise (Morton, 2009).

PURPOSE

Based on results from acute exercise bouts and training programs, determine whether exercise training in untrained individuals will lead to an attenuated heat shock protein response.

FINDING THE LITERATURE Data base search:

PubMed/Medline (via EBSCO)

Biosis PreviewsSPORTDiscusWeb of ScienceGoogle Scholar

Search topics: Heat shock proteinsHSP72Skeletal Muscle

PEDro Scale.Quality of Evidence Score of 5

(Maher et al, 2003) Inclusion criteria:

Male subjectsAvg Age: 18-35 yrs

Exclusion criteria:Female subjectsAge > 35 yrsMusculoskeletal abnormalityNeurologic disease

Study Subjects Exercise Protocols Results

Khassaf et al. (2000)

PEDro Scale = 6

N = 7

SedentaryMales

21 ± 2 yrs

VO2max

2.40± 0.27L/min

Modality:One-legged Cycle Ergometry Intensity:70%VO2max

Duration:45 mins

Muscle sample:Vastus lateralis

HSP70 content:Day 6 post-ex ~3000%P<0.05

Large variability 24hr and 48hr post-exslow/reduced ∆

Febbraio & Koukoulas (2000)

PEDro Scale = 7

N = 5

Untrained Males

20.6 ± 1 yrs

VO2max

2.55 ± 0.2 L/min

Modality:Cycle ErgometerIntensity:65% VO2max

Duration:186 ± 15 min

Muscle sample:Vastus lateralis

HSP72 mRNA:@ 10 min no

@ Fatigue-40 2.2x P<0.05

@ Fatigue (~186 min) 2.6x P<0.05

Study Subjects Exercise Protocols Results

Febbraio et al. (2002)

PEDro Scale = 6

N = 7

Physically active males

Modality:Two-legged knee extensor exerciseIntensity:40% Wmax

Duration:4-5 hrs

Muscle Sample:Vastus lateralis

Glycogen DepletedHSP72 mRNA:Post-ex 2x P<0.05HSP72 content:Post-ex 2x P<0.05

Control LegNo sig. ∆s

Fischer et al. (2006)

PEDro Scale = 8

N = 21

Physically active males

Control group

24.1± 0.9 yrs

Pmax= 140±6 W

Modality:Two-legged knee extensor exerciseIntensity:60 extensions/min 50% Pmax

Duration:3 hr

Muscle Sample:Vastus lateralis

HSP72 mRNA:2.5x post-ex P<0.05

HSP72 content:No sig. ∆

Increasing trend @ 0, 3, and 6 hr post-ex

Study Subjects Exercise Protocols Results

Paulsen et al.(2007)

PEDro Scale = 7

N = 11

Sedentary to physically active males

28 ± 4 yrs

Modality: Unilateral, maximal, isokinetic eccentric action Intensity:30/secDuration:30 sets x 10 reps40 minMuscle Sample:Vastus lateralis

HSP70 content:30 min post-ex2x P<0.01

24 hrs post-ex203 ± 37% P<0.05

Day 4 post-ex10x P<0.05

Tupling et al. (2007)

PEDro Scale = 7

N = 10

Untrained males

18 ± 0.47 yrs

MVC torque550 ± 36 Nm

Modality:Single-legged isometric knee extensionIntensity:60% MVCDuration:30min, 50% duty cycle: 5 s contract, 5 s relax

Muscle Sample:Vastus lateralis

HSP70 content:Day 1 post-ex 43% P<0.05

Elevated Day 3 post-ex P<0.05

Day 6 post-ex P<0.05

Study Subjects Exercise Protocols

Results

Morton et al. (2006)

PEDro Scale = 6

N = 8

Active, untrained men

24 ± 4 yrs

VO2max

54.9 ± 4 ml/kg/min

Modality:Treadmill runIntensity:69.8 ± 4.8% VO2max

11.7 ± 0.5 km/hrDuration:45 min

Muscle Sample:Vastus lateralis

HSP70 content:48 hr post-ex 179% 7 days post-ex 178%P<0.05

Peak response 48 hr post-ex:210 ± 70% (135-366%) P>0.05

Morton et al. (2008)

PEDro Scale = 5

N = 6 trained males

29 ± 4 yrs

N = 6 untrained males

28 ± 6 yrsVO2max

54.9 ± 4 ml/kg/min

Trained ParticipantsModality:Treadmill runningIntensity:75%VO2max

Duration:45 min

Muscle Sample:Vastus lateralis

Baseline HSP70: No sign. diff. btw trained vs. untrained

HSP70 content:48 hr post-ex 121 ±10%7 days post-ex118 ± 22% P>0.05

Study Subjects Exercise Protocols Results

Morton et al. (2008)

PEDro Scale = 8

N = 5 Recreationally active males

21 ± 2 yrs

VO2max Pretrained: 49.5±0.9 ml/kg/minVO2max

Posttrained: 54.2±1.8 ml/kg/min

2 x 3 day x 6 wk Modality:Continous/interval runningIntensity:Contin 70%VO2max

Int 100%VO2max

Duration:Int 6 x 4 min, 1 min @ 50% VO2max

Contin: 26-32 min

Continuous TrainingHSP72 content:72 hr post-ex38 ± 41%

Interval TrainingHSP72 content:72 hr post-ex23 ± 36%

No significant ∆s

Vissing et al. (2009)

PEDro Scale = 7

N = 14

Untrained males

23.8 ± 2.8 yrs

Bout18wkBout2Modality:Bench-steppingIntensity:60 steps/minW= 443 J/cycleDuration:1 x 30min step up 1 x 30min step downMuscle Sample:Vastus lateralis

Bout 1 eccentric legHSP70 content:7days post-ex 2.4xP<0.05HSP70 mRNA:3hr post-ex 8.9x24hr post-ex 1.8xDay7 post-ex baselineBout1-Bout23hrs post-ex 4.9xAll P<0.05

DISCUSSION

With exercise training:○ Number of physiological adaptations in human

skeletal muscle.Ex: fat oxidation, LA, muscle remodeling

○ The magnitude of the heat shock response is dependent upon: Individual characteristicsExercise TypeFrequencyIntensityDuration

CONCLUSIONS

Based on results from acute exercise bouts and training programs, it remains unclear whether exercise training will lead to an attenuated response in untrained individuals.

HSP response shown to be vary greatly between individuals.

HSP results reflect genetic variability of skeletal muscle to recover, remodel, and/or adapt to exercise specific stress.

FUTURE RESEARCH

Examine of role of HSP induction with performance.

Continue to use non-damaging exercise protocols ‘clean’ results.

Compare HSP response with training program in untrained and trained individuals.

Questions???