8-Week Endurance and Resistance Training Effects on Stress and Coping

Study Overview: Effects of Exercise on Stress and Coping

• Study Title: "Effects of 8-week endurance and resistance training programmes on cardiovascular stress responses, life stress and coping."

• Authors: Luk
   Chovanec and Peter Gr
  pel.

• Publication: Journal of Sports Sciences, 2020, Vol. 38, No. 15, 1699–1707.

• Theoretical Context:

  • Regular physical activity (PA) is linked to preventing stress-related diseases ($Harber\,et\,al.,\,2017$; $Li\,\&\,Siegrist,\,2012$) and strengthening mental health ($Hearing\,et\,al.,\,2016$).

  • Exercise buffers physiological reactions to stress, showing lower cortisol increases and lower cardiovascular reactivity ($Rimmele\,et\,al.,\,2007$; $Klaperski\,et\,al.,\,2013$).

  • Physically active individuals typically show more rapid cardiovascular recovery to laboratory stressors compared to sedentary individuals ($Jackson\,\&\,Dishman,\,2006$).

  • While endurance training (running, biking) is well-researched, resistance training (weight lifting) has fewer studies, with unclear evidence regarding its stress-buffering benefits.

Research Hypotheses and Objectives

• Primary Objective: Investigate the effects of 8-week endurance and resistance training programmes on cardiovascular stress reactivity, cardiovascular stress recovery, perceived life stress, and coping strategies.

• Secondary Objective: Specifically examine these effects in a female sample, as women are often underrepresented in such studies and report higher psychological stress ($Kelly\,et\,al.,\,2008$).

• Specific Hypotheses:

  • Both endurance-trained (EG) and resistance-trained (RG) participants will show lower cardiovascular stress reactivity and more rapid recovery compared to controls.

  • Both training groups will report less perceived life stress.

  • Coping strategies may change (exploratory approach) in response to the training.

Methodology and Participant Characteristics

• Participant Sample:

  • Initial recruitment: $65$ female students.

  • Final sample size after dropouts: $52$

  • Mean Age: $21.02 \pm 1.65\,\text{years}$.

  • Inclusion criteria: Essentially healthy, not performing regular exercise for the last year, full-time study.

  • Exclusion criteria: Medication intake, substance abuse, smoking.

• Study Design: Randomized into three groups:

  • Endurance Training Group (EG): $n = 18$

  • Resistance Training Group (RG): $n = 21$

  • Wait-list Control Group (WCG): $n = 13$

• Testing Periods: Identical pre-test (one week prior) and post-test (one week after) assessments.

Exercise Training Intervention Protocols

• General Structure: Both training groups performed three $60\text{-min}$ supervised sessions per week ($24\,\text{total sessions}$).

• Format: $7\text{-min}$ warm-up, $45\text{-min}$ training, $8\text{-min}$ stretching cool-down.

• Endurance Training (EG):

  • Combination of low- and high-impact aerobic dance.

  • Weeks 1–4: Tempo of $130\text{--}148\,\text{BPM}$.

  • Weeks 5–8: Tempo of $148\text{--}160\,\text{BPM}$ (progression to high-impact and advanced steps).

• Resistance Training (RG):

  • Full-body programme consisting of 8 exercises: bench press, wide-grip pulldown behind the neck, lying leg curl, dumbbell biceps curl, leg extension, dumbbell side lateral raise, triceps bench dips, and sit-ups.

  • Intensity: Progressive increase from $40\%\,\text{of 1RM}$ in weeks 1–2 to $70\%\,\text{of 1RM}$ in weeks 7–8.

  • Volume: Three to five sets of $8\text{--}12\,\text{repetitions}$, with a $2\text{-min}$ recovery phase between sets.

Assessment Tools and Measurements

• Psychological Questionnaires:

  • Perceived Stress Scale (PSS): Measures frequency of feeling unpredictable, uncontrollable, or overloaded during the last month (10 items on a 5-point Likert scale).

  • Coping Orientation for Problem Experiences (COPE): 60 items assessing 15 coping strategies (\alpha > .70 for most, but lower for mental disengagement at $0.60$, denial at $0.68$, and suppression of competing activities at $0.62$).

• Cardiovascular Stress Protocol: Using iSense relaxation training software (Comesa, Austria):

  • Baseline Phase: $135\text{-s}$.

  • Preparatory Phase: $50\text{-s}$.

  • Stress Stimulus: $15\text{-s}$ visual/acoustic cues (pictures of spiders/snakes + unpleasant noise).

  • Relaxation Phase: $70\text{-s}$.

• Cardiovascular Metrics:

  • Heart Rate Reactivity (AUCI): Area under the individual response curve with respect to the increase.

  • Heart Rate Recovery: Time (in seconds) taken for post-stress values to reach baseline.

• Fitness Test: 2-km UKK walk test to estimate maximum oxygen uptake ($\text{VO}_2\text{max}$).

Results: Physiological Changes and Fitness

• Body Mass Index (BMI):

  • Significant Group $\times$ Time interaction: $F(2, 49) = 12.18$, p < .001, $\eta_p^2 = 0.33$.

  • Decrease in EG: $t(17) = 4.10, p = .001, d_z = 0.96$.

  • Decrease in RG: t(20) = 5.01, p < .001, d_z = 1.09.

• Fitness (VO2max):

  • Significant Group $\times$ Time interaction: $F(2, 49) = 24.85$, p < .001, $\eta_p^2 = 0.50$.

  • EG improvement: Pre-test $35.30 \pm 0.77$ to Post-test $39.25 \pm 0.73\,\text{ml/kg/min}$ ($d_z = 2.95$).

  • RG improvement: Pre-test $35.91 \pm 0.72$ to Post-test $37.82 \pm 0.60\,\text{ml/kg/min}$ ($d_z = 0.96$).

Results: Stress Responses and Coping

• Heart Rate Reactivity:

  • No significant differences in AUCI between groups ($p = .171$ pre-test; $p = .962$ post-test).

  • Interaction effect: $p = .222, \eta_p^2 = 0.06$.

• Heart Rate Recovery:

  • Significant Group $\times$ Time interaction: $F(2, 49) = 3.47$, $p = .04$, $\eta_p^2 = 0.12$.

  • Significant group difference in post-test recovery: $F(2, 49) = 6.23, p = .004, \eta_p^2 = 0.20$.

  • EG recovery time: Decreased from $23.44 \pm 5.23\,\text{s}$ to $10.00 \pm 2.97\,\text{s}$ ($d_z = 0.66$).

  • RG recovery time: Decreased from $14.71 \pm 3.68\,\text{s}$ to $5.24 \pm 1.59\,\text{s}$ ($d_z = 0.53$).

  • Wait-list Control Group: Showed no significant change ($16.62\,\text{s}$ to $22.92\,\text{s}$).

• Perceived Life Stress (PSS):

  • Significant interaction: $F(2, 49) = 5.93$, $p = .01$, $\eta_p^2 = 0.20$.

  • Significant reduction in EG ($d_z = 0.65$) and RG ($d_z = 1.26$).

• Coping Strategies (COPE):

  • No significant Between-Group differences occurred for any of the 15 tested strategies.

  • Within-group significant changes in the Resistance Training Group: Report of higher Positive Reinterpretation ($t(20) = 2.14, p = .045$) and Active Coping ($t(20) = 2.21, p = .04$).

Discussion and Practical Implications

• Recovery Efficiency: Both endurance and resistance training resulted in the same health-related benefit of faster heart rate recovery from acute stress, supporting that exercise training improves stress regulation regardless of type.

• Reactivity vs. Recovery: The lack of reactivity effects might be due to the stressor intensity. The study protocol induced a change of approximately $+15\,\text{bpm}$, whereas stronger stimuli like the Trier Social Stress Test (TSST) induce $+20\,\text{bpm}$. Lower reactivity might be masked by the less stressful protocol.

• Stable Coping traits: The study suggests that coping strategies are trait-like and stable ($Powers\,et\,al.,\,2002$; $Nielsen\,\&amp;\,Knardahl,\,2014$). An 8-week period appears too short to significantly alter these behaviors, as they may require longer durations of physical activity to become malleable.

• Subjective Stress: Participation in group exercise ( broadened social networks) and progressive physical demands (increased stress tolerance) may lead to reduced perceived stress.

• Conclusion: Both endurance activities (aerobic dance, jogging) and resistance activities (weight lifting) can effectively improve stress regulation competence in healthy young women.