Physical Activity and Anxiety

EPHE 348

Anxiety

• Defined as a negative emotional state– Nervousness– Worry– Apprehension– Arousal

• State vs. Trait?• 1-2% prevalence (panic) at clinical

diagnoses and up to 16% for all anxiety disorders.

Anxiety

• Billions of dollars in economic costs

• Personal and family suffering

• Predisposing factor for drug and substance abuse

Panic Attack

• A discrete period of intense fear or discomfort, in which four or more symptoms occur– Palpitations or chest pain

– Sweating

– Trembling or choking

– Shortness of breath

– Nausea/dizziness or chills/hot flushes

– Fear of losing control/going crazy

– paresthesias

Panic Disorder

• Recurrent panic attacks

• Followed by– Persistent concern of other attacks– Worry about the implications of attacks– Change in behaviour related to the attacks– Agoraphobia (with or without)

Treatment

• Medication (benzodiazepines, tranquilizers, anti-depressants)

• Psychotherapy

• Can exercise help?

Anxiety and PA

• More than 100 studies in the literature but most are correlational

• 60% of clinicians prescribe exercise to help with anxiety

• Meta-analyses show inconsistency (ES .15-.56). Safe to assume a small effect size

Types of activities

• Aerobic activities have an effect but strength activities do not (seen in self-report, EMG, HR, EEG)

• Resistance training may even increase anxiety slightly

• Intensity and duration do not seem to be overly sensitive to reducing post exercise anxiety

PA and Anxiety?

• Anxiolytic effect duration is approximately 2 hours (Landers & Petruzzello, 1994)

• PA seems as powerful a strategy as any other behavioural technique (e.g., relaxation)

• No strong evidence that it is effective compared to pharmacotherapy

UVic Study (Blacklock, Rhodes, Blanchard & Gaul, in press)

• 50 participants (cancer, control matched) randomized to days of light or moderate intensity EX (20 min)

• Measures at baseline, immediately after, and 10 min post-exercise

• Main effect but no interaction effects on state anxiety

Blacklock et al. (in press)

1.051.091.131.171.211.251.291.331.371.411.451.491.53

1 2 3

Time

Sta

te A

nxie

ty

Light Exercise

Moderate Exercise

Long-Term Effects?

• Evidence that exercise can reduce state anxiety and neuroticism

• Reduced stress reactivity

Limitations

• Little control of activity history and fitness

• Dose and mode standardization

• Testing and expectation effects

• Generalizability

Adverse Events? (Rhodes et al.)

• 8/12 studies reported events

• 6 panic attacks (< 1%) from 802 participants

PA and other mood states

• POMS is the most popular mood measure (anger, tension, fatigue, depression, confusion & vigor)

• What does a bout of PA do?

• McDonald & Hogdon (1991) meta-analysis found a trivial effect for Anger and small effects for tension, vigor, fatigue, and confusion (2-3 hour effect)

Circumplex of Mood (Tellegen, 1988)

Attraction/Pleasure(Valence)

Avoidance/Displeasure

Aroused

Calm(Intensity)

Basic Emotion States (Shaver, 1987)

• Anger – irritation, annoyance, fury, rage

• Fear – apprehension, anxiety, panic, terror

• Joy – happiness, pleasure, exhileration

• Sadness – despondency, depression, grief

What affects Affect? Watson & Clark (1994)

• Exogenous factors – e.g. rain, music

• Endogenous rhythms – i.e., biological cycles

• Traits/temperament – i.e. personality

• Characteristic variability – i.e. magnitude of mood fluctuation stability

Limits of Mood Studies

• Too many confounding variables!

• Testing effects

• Ecological validity

• No standardization

• College samples

Why does PA affect anxiety mood?Physiological Mechanisms

• Thermogenic hypothesis- increased body temp, increases relaxation. Seems plausible for anxiety

• Monoamine hypothesis – depression decreases norepinephrine & serotonin. Animal models show that PA may moderate this system

Phys Mechanisms Cont.

• Opponent-process hypothesis – fight or flight system physiological taxing and opposition. May explain depression and anxiety

Cognitive Mechanisms

• Expectancy – perhaps…some variance can be attributed to this.

• Distraction – PA was associate with larger mood gains than just time-out (limited evidence)