Temporal summation of heat pain modulated by isometric exercise.

BACKGROUND: Little is known about the effects of isometric exercise on temporal summation of heat pain. Thus, the purposes of study 1 and study 2 were to examine the influence of exhaustive and non-exhaustive isometric exercise on temporal summation of heat pain in men and women. METHODS: Forty-four men and 44 women (mean age = 20 years) completed an informed consent document and a packet of questionnaires. Ten heat pulses were applied to the thenar eminence of the dominant hand using a standardized temporal summation protocol. Participants rated the intensity of the heat pulses using a 0-100 pain rating scale before and following isometric exercise consisting of squeezing a hand dynamometer at 40% of maximal voluntary contraction (MVC) to exhaustion (exhaustive exercise, study 1) and at 25% MVC for 3 min (non-exhaustive exercise, study 2). Muscle pain and perceived exertion were rated every 30 s during exercise using validated rating scales. The data were analysed with repeated measures analysis of variance. RESULTS: The results indicated there were no sex differences (p > 0.05) in time to exhaustion (study 1), muscle pain or perceived exertion (studies 1 and 2). There was a significant reduction (p < 0.05) in temporal summation ratings following isometric exercise for men and women in both study 1 and study 2. CONCLUSION: It is concluded that exhaustive and non-exhaustive isometric exercise significantly reduced temporal summation of heat pain in men and women.

Sex differences in delayed onset muscle soreness.

AIM: There is agreement that females report greater pain in response to typical experimental pain stimuli than males. However, investigations of sex differences in the sensation of delayed onset muscle soreness (DOMS) have equivocal RESULTS: The objective of this investigation was to examine sex differences in the pain from DOMS with an adequate sample size, quantification of stimulus intensity, and 2 measures of pain. METHODS: Sixty-seven participants (52% females) completed a 2-session protocol. DOMS was induced using eccentric resistance exercises in the elbow flexors of the non-dominant arm. The intensity of the eccentric contractions was based upon concentric strength. Pain response was measured 48 hrs later. The dependent variables were pressure threshold, which was assessed using a dolorimeter, and pain intensity when the arm was moved through full active range of motion, which was assessed with a visual analog scale. RESULTS: The occurrence of DOMS was confirmed by a decrease in pressure threshold after the eccentric contractions and higher pain intensity in the arm that performed the eccentric contractions than the arm that did not. Females reported lower pain intensities (M=3.41, SD=2.13) compared to males (M=5.12, SD=2.05), but no significant sex difference was found in pressure threshold. CONCLUSION: In this investigation, females reported lower muscle pain intensity than males, but showed no sex difference in pressure threshold. These and previous findings suggest that the detection of a sex difference in muscle pain depends upon the methodology of inducing DOMS and measuring sensation.

The influence of endurance exercise on delayed onset muscle soreness.

BACKGROUND: Despite several review articles supporting the existence of exercise induced analgesia, it is unclear whether exercise reduces delayed onset muscle soreness (DOMS). The purpose of this investigation was to examine the influence of an acute bout of endurance exercise on delayed onset muscle pain. METHODS: DOMS was induced in the elbow flexors of the non-dominant arm using eccentric isotonic exercise with the intensity of the eccentric contractions based upon concentric strength. Forty-eight hours after the eccentric contractions participants were randomly assigned to a group that completed 20 min of endurance exercise at 80% of estimated maximum cardiorespiratory endurance (n=23) or a group that watched a 20 min emotionally neutral video (n=27). The dependent variables were pressure pain threshold, pain intensity during arm movement through active range of motion, a standardized pain rating that was determined from a magnitude matching procedure, and state anxiety. RESULTS: A significant decrease in pressure pain threshold and an increase in the standardized pain ratings after the DOMS procedure (p<0.05) indicated that muscle pain was successfully induced. These changes were components of significant quadratic trends for pressure threshold (p<0.05) and the standardized pain ratings (p<0.01). During the 2nd session a decrease in pain intensity approached significance (p=0.05) regardless of group assignment. However, no significant group by time interactions were detected for any of the pain measures or state anxiety. CONCLUSIONS: Cycle ergometer exercise was not found to alter delayed onset muscle pain.

The association between physical activity and quality of life in older women.

The purpose of this investigation was to examine the association between physical activity and quality of life in older women. Women over the age of 60 years, living independently or in assisted-care facilities, answered a number of questions pertaining to their health status, physical activity levels, and quality of life. Results indicated that the women living independently had significantly (P <.05) higher physical activity levels compared to the women living in assisted-care facilities. In addition, overall quality of life and the domains of physical health, social relationships, and environment were found to be significantly (P <.05) higher in the women living independently compared to the women living in assisted-care facilities. Correlational analyses revealed that physical activity levels correlated significantly (P <.05) with overall quality of life and the physical health domain. It is concluded that there is an association between physical activity levels and quality of life in older women.

Effect of isometric exercise on pain perception and blood pressure in men and women.

PURPOSE: To examine the influence of isometric handgrip exercise (ISO EX) on pain perception and blood pressure in men and women. METHODS: Fifteen men and 16 women completed max and submax ISO EX consisting of squeezing a hand dynamometer with the right hand as hard as possible for the max session, and squeezing between 40% and 50% of max for 2 min for the submax session. Pain thresholds (PT), pain ratings (PR), blood pressure (SBP and DBP), and heart rate (HR) were assessed while a noxious pressure stimulus was applied to the right forefinger for 2 min before and after ISO EX. Data were analyzed with a 2 (gender) x 2 (trials) ANOVA. RESULTS: Results indicated a significant trials effect and a significant gender by trials interaction (P < 0.05) for PT for the max and submax sessions. Women had lower PT before ISO EX in comparison with the men. In addition, PT for the women increased significantly after ISO EX but did not change for the men. There were significant gender and trials effects (P < 0.05) for SBP for the submax session. Women had lower SBP before ISO EX, and SBP increased after ISO EX. DBP was also found to be lower (P < 0.05) in women before max and submax ISO EX, with DBP increasing after submax ISO EX in men and women. PR were found to be lower after max ISO EX in men and women, whereas PR were found to be lower in women after submax ISO EX. CONCLUSION: It is concluded that: 1) men and women differed in PT, SBP, and DBP before ISO EX; and 2) analgesia after ISO EX is observed more consistently in women.

Analgesia following exercise: a review.

Over the past 20 years a number of studies have examined whether analgesia occurs following exercise. Exercise involving running and cycling have been examined most often in human research, with swimming examined most often in animal research. Pain thresholds and pain tolerances have been found to increase following exercise. In addition, the intensity of a given pain stimulus has been rated lower following exercise. There have been a number of different noxious stimuli used in the laboratory to produce pain, and it appears that analgesia following exercise is found more consistently for studies that used electrical or pressure stimuli to produce pain, and less consistently in studies that used temperature to produce pain. There is also limited research indicating that analgesia can occur following resistance exercise and isometric exercise. Currently, the mechanism(s) responsible for exercise-induced analgesia are poorly understood. Although involvement of the endogenous opioid system has received mixed support in human research, results from animal research seem to indicate that there are multiple analgesia systems, including opioid and non-opioid systems. It appears from animal research that properties of the exercise stressor are important in determining which analgesic system is activated during exercise.

Experimentally induced pain perception in men and women in the morning and evening.

The literature regarding whether or not there are diurnal differences in pain perception in men and women is equivocal. The purpose of this study was to examine the influence of time of day on experimentally induced pain threshold in men and women. A secondary purpose was to measure selected psychological and physiological responses. Pressure (3000 gm force) was applied to the middle digit of the left forefinger for 2-min with the Forgione-Barber pain stimulator. Twenty-nine volunteers (women = 14; men = 15) completed two randomly assigned sessions between 6.00-8.00 in the AM and PM. Selected psychological variables (STAI,POMS) and physiological variables (BP, HR, TEMP) were assessed before application of the pressure stimulus. Data were analyzed with a 2x2 ANOVA. Results indicated that men had significantly higher (p<.05) systolic blood pressure and pain thresholds than women however, there was not a significant time of day effect for pain threshold. Significant time of day effects (p<.05) were found for systolic blood pressure and tympanic temperature. Heart rate, and tympanic temperature were found to be significantly higher (p<.05) in women in comparison to men. It is concluded that pain threshold did not differ in the AM and PM. Furthermore, men were found to have higher pain thresholds compared to the women.

Influence of resistance exercise of different intensities on state anxiety and blood pressure.

PURPOSE: The purpose of this investigation was to examine selected psychobiological responses to acute bouts of resistance exercise (RE) of different intensities. METHODS: Eighty-four participants were classified as experienced or inexperienced and then randomly assigned to three conditions: 1) 50% of one repetition maximum(1RM), 2) 80% 1RM, or 3) control condition. RE consisted of performing three sets of four exercises between 12 to 20 reps in the 50% 1RM condition and four to eight reps in the 80% 1RM condition. Dependent variables consisted of state anxiety (SA), mood states (POMS), systolic BP (SBP), diastolic BP (DBP), and heart rate (HR). These variables were assessed before as well as 1, 20, 60, 120, and 180-min following the conditions. Data were analyzed with a 2 (experience) x 3 (conditions) x 6 (trials) mixed model ANOVA and Tukey post-hoc tests. RESULTS: Results indicated that SA decreased significantly (P < 0.05) 180 min following the 50% 1RM condition. A significant decrease (P < 0.05) in vigor occurred immediately following the 50% IRM condition and persisted for 20 min. SBP increased significantly (P < 0.05) immediately following the 80% 1RM condition. HR increased significantly (P < 0.05) following both RE conditions. No significant differences were found between the experienced or inexperienced participants. CONCLUSIONS: An acute bout of RE at 50% 1RM is associated with an immediate reduction in vigor followed by a significant decrease in SA that emerged 180 min following exercise.

Perception of pain after resistance exercise.

OBJECTIVES: The main objective was to assess the influence of resistance exercise on pain threshold and pain ratings. Secondary objectives included measuring state anxiety, body awareness, systolic blood pressure, diastolic blood pressure, and heart rate responses. METHODS: Pressure (3 kg force) was applied to the middle digit of the left hand for two minutes using a Forgione-Barber pain stimulator before and after (five minute and 15 minutes) resistance exercise and quiet rest. Resistance exercise consisted of 45 minutes of lifting three sets of 10 repetitions at 75% of an individual's one repetition maximum. Quiet rest consisted of sitting quietly in a room free from distractions. RESULTS: Data were analysed by repeated measures analysis of variance for multifactor experiments. Pain threshold was significantly higher (p<0.05) and pain ratings were significantly lower (p<0.05) five minutes after resistance exercise. Changes in pain perception were accompanied by changes in heart rate, systolic blood pressure, and body awareness after exercise. CONCLUSION: A single bout of resistance exercise is capable of modifying the sensation of experimentally induced pain.

Psychological responses to brief exhaustive cycling exercise in the morning and the evening.

The purpose of this investigation was to examine whether psychological responses to exhaustive exercise would vary if the exercise was performed in the AM or PM. Sixteen men completed the State-Trait Anxiety Inventory and the Profile of Mood States before and following two exhaustive exercise sessions in the AM (0630-0930h) and the PM (1700-2000h). Data were analyzed with a 2 (condition = incremental, constant) x 2 (time of day = AM, PM) x 2 (trial = pre, post) repeated measures ANOVA. Results indicated that there was a significant time of day effect (P<0.05), as well as a significant condition by trial interaction (P<0.05) for vigor. Vigor was found to he higher in the PM before the constant power exhaustive exercise session, and decrease significantly following the session. There was also a significant trial effect (P<0.05) for fatigue. Fatigue was found to increase following the constant power exhaustive exercise sessions in the AM and PM. There were no significant changes in state anxiety, tension, depression, anger confusion or the composite measure of mood following exhaustive exercise in the AM or the PM. It is concluded that anxiety and mood responses to brief exhaustive cycling exercise are similar whether the exercise is performed in the morning or evening.

Influence of acute physical activity and relaxation on state anxiety and blood lactate in untrained college males.

The purpose of this investigation was to evaluate the acute effects of physical activity and relaxation on state anxiety and blood lactate. Thirty male Ss performed resistance exercise (N=15) or cycling (N=15) for 50 min at 70% of maximum, while 30 additional male Ss practiced autogenic relaxation (N=15) or rested quietly (N=15) in a sound chamber for 50 min. Assessment of state anxiety and blood lactate was performed before, 5-10 min and 60 min following treatments. The data were analyzed with a repeated measures ANOVA for multifactor experiments, and results indicate a significant group by trial interaction for state anxiety (p<0.0001) and lactate (p < 0.0001). Post-hoc analysis revealed that: 1. lactate increased (p<0.001) immediately following resistance exercise and fell to baseline levels 60 min post exercise; 2. state anxiety was decreased (p < 0.01) at 5-10 min following autogenic relaxation and quiet rest; and 3. a reduction (p < 0.001) in state anxiety was noted at 60 min following cycling. It is concluded that: 1. comparable anxiolytic effects occur following aerobic exercise (cycling), autogenic relaxation and quiet rest, but the effect persists for a longer period of time following aerobic exercise; and 2. accumulation of lactate does not influence state anxiety in normal individuals.

Influence of wet suit wear on anxiety responses to underwater exercise.

The purpose of this investigation was to evaluate the effect of wearing a wet suit on selected psychological and physiologic variables. Certified divers (n = 13) finned underwater at 0.52 m/s for 20 min with and without a wet suit. Order was randomly assigned and performed on separate days. Heart rate, respiration rate, use of compressed air, ratings of perceived exertion, and breathing ratings increased significantly (P < 0.05) for both conditions, and increases in heart rate, use of compressed air, and breathing ratings were significantly greater for the wet-suit condition. Rectal temperature increased significantly (P < 0.001) for the wet-suit but not the bathing-suit condition. State anxiety and body awareness increased (P < 0.001) following the wet-suit condition. Furthermore, state anxiety decreased significantly (P < 0.001) by 15 min after exercise in the bathing-suit condition. It is concluded that wet suit wear can result in elevated anxiety when performed at a water temperature and exercise intensity sufficient to produce increased core temperature.

Psychological effects of an aerobic exercise session and a rest session following pregnancy.

BACKGROUND: Mood changes have been reported to occur in many women following pregnancy. It is well documented that exercise is associated with reductions in state anxiety and depression. The purpose of this study was to assess mood changes in the postpartum period in women who exercised compared to women who did not exercise. METHODS: All of the women who volunteered for this study had delivered a baby within the past year (mean = 12 wks; SD = 4 wks). Twenty women volunteered to complete the State-Trait Anxiety Inventory and the Profile of Mood States before and following either an exercise session (N = 10) or a quiet rest session (N 10). Exercise consisted of 60 min of low-impact aerobic activity at an intensity between 60-70% of maximal heart rate reserve. Quiet rest consisted of sitting quietly in a room free from distractions for 60 min. Data were analyzed with 2 x 2 ANOVA. RESULTS AND CONCLUSIONS: Results indicated that state anxiety and depression decreased significantly (p < 0.05) following exercise and quiet rest. Furthermore, exercise was associated with significant decreases (p < 0.05) in total mood disturbance, as well as significant increases (p < 0.05) in vigor in physically active postpartum women.

Perception of pain following aerobic exercise.

The literature regarding the effect of exercise on pain is equivocal. The purpose of this investigation was to quantify the influence of an acute bout of exercise on pain threshold (PT) and pain ratings (PR). A secondary purpose was to measure heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and state anxiety (SA) responses. Pressure (3000-g force) was applied to the middle digit of the right forefinger for 2 min with the Forgione-Barber pain stimulator before and following (5 min of cycling at 75% VO2max. Quiet rest consisted of sitting quietly for 30 min in a sound-dampened chamber. Order was counterbalanced, randomly assigned, and performed on different days. Data was analyzed with a repeated measures ANOVA for multifactor experiments. PT was significantly higher (P < 0.05) and PR were significantly lower (P < 0.05) in the exercise condition 5 min post-exercise in comparison with quiet rest. Changes in pain perception were accompanied by lower SBP (P < 0.03) and higher HR (P < 0.0001). in the exercise condition. It is concluded that an acute bout of exercise is associated with changes in pain perception.

Influence of weight training on state anxiety, body awareness and blood pressure.

The primary purpose of this investigation was to evaluate the effect of one session of recreational weight training on state anxiety and related constructs. State anxiety, body awareness and blood pressure were evaluated before and within 5-min following 50-min of self-selected weight training activity in a group of 25 subjects, and following 50-min of non-activity for 25 control subjects. Repeated measures ANOVA revealed that state anxiety did not change (p > 0.05) significantly following weight training or quiet rest. However, there was a significant (p < 0.05) increase in body awareness in the weight training group, as well as a significant (p < 0.05) trials by conditions interaction in systolic blood pressure. The control group experienced a decrease in systolic blood pressure of 5 mmHg, whereas the exercise group had an increase in blood pressure of 5 mmHg. It is concluded that state anxiety is not altered immediately following one session of recreational weight training activity, but this activity does produce increases in body awareness and systolic blood pressure.

Efficacy of perceptual versus heart rate monitoring in the development of endurance.

The purpose of this investigation was to compare the effectiveness of using ratings of perceived exertion (RPE) with heart rate in the monitoring of exercise intensity during aerobic dance instruction. Thirty-eight students who enrolled in aerobic dance classes used heart rate to monitor exercise intensity while 38 additional students used RPE to monitor exercise intensity during a 14-week course. Classes met twice a week for 50 min and all outside workouts were recorded. The groups did not differ with respect to the number of outside workouts. The dependent variable was endurance performance as measured by the distance run in 15 min. Data were analysed with a repeated measures analysis of variance (ANOVA) for multifactor experiments. There were significant trials (P less than 0.0001) and interaction (P less than 0.05) effects, and both groups improved significantly in endurance performance during 14 weeks of training. However, the group using RPE to monitor exercise intensity had a significantly greater gain in endurance. The heart rate group had a mean increase of 6% (166 m) whereas the RPE group increased 11% (274 m). It is concluded that during aerobic dance the monitoring of exercise intensity with RPE is associated with greater improvement in endurance than is heart rate monitoring.

Changes in mood state following whole-body hyperthermia.

Mood states of cancer patients were assessed pre- and post-41.8 degrees C whole-body hyperthermia using the Profile of Mood States questionnaire. Results demonstrated a statistically significant increase in fatigue associated with decreased vigour which returned to baseline values by 72 h. In contrast, a significant improvement in depression was evident through 72 h following treatment. The relationship of this result to earlier studies of WBH-induced beta-endorphin is discussed.

Perception of effort in female and male competitive swimmers.

The primary purpose of this investigation was to compare 31 competitive female swimmers with 31 competitive male swimmers on their perceptual responses to submaximal swimming. A secondary purpose was to evaluate the relationship between heart rate (HR) and perceived exertion (RPE) in swimming. Each swimmer completed a 200-yd swim in his/her specialty stroke at 90% of the swimmer's current best time. Underwater and overhead pace lights were used to achieve an even pace during the swims, and HR was monitored by means of radiotelemetry. Ratings of overall and local perceived exertion were assessed immediately following each swim with Borg's 6-20 scale. ANOVA revealed no RPE differences across stroke classifications for the female or male swimmers, but local and overall RPE were lower (p less than 0.01) in the females. Mean HR, however, was significantly higher (p less than 0.05) for the female swimmers. Unlike research with other exercise modes, correlational analyses revealed that overall and local RPE were unrelated to HR (p greater than 0.05). Based on these findings, it is concluded that 1) female swimmers judged a paced swim to be less effortful than did male swimmers despite a greater objective strain in the females, and 2) HR was not correlated with perception of effort.

Air travel across four time zones in college swimmers.

Eighteen female and 22 male college swimmers were flown across four time zones in east-to-west (E-W) and west-to-east (W-E) directions. A pre- and postflight paced swim of 182.9 m at an intensity equal to 90% of the swimmers' maximal velocity was completed, and salivary cortisol, heart rate (HR), and rated perceived exertion were measured. Blood pressure, HR, muscle soreness, and mood were also assessed at rest on the day before and on the day after travel. Because training volumes for both females and males were greater (P less than 0.001) in the week before W-E than E-W travel, the W-E and E-W data were analyzed separately. Two-way repeated-measures analyses of variance revealed that pre- and postexercise cortisol decreased after E-W travel and increased after W-E travel in comparison to preflight values. Resting and exercise HR responses to air travel were small in magnitude, and their significance depended on the direction of travel. Effort sense was not altered by air travel, but significant (P less than 0.001) improvements in mood and reductions in muscle soreness were observed after E-W and W-E travel for both genders. It was concluded that 1) female and male college swimmers have similar responses to air travel and 2) air travel across four time zones during heavy swim training does not have negative physiological, perceptual, or affective consequences.