Energy intake deficit and physical performance at altitude.

BACKGROUND: Physical performance of sea-level (SL) residents acutely exposed to altitude (ALT) is diminished and may improve somewhat with ALT acclimatization. HYPOTHESIS: A large reduction in lean body mass (LBM), due to severe energy intake deficit during the first 21 d of ALT (4300 m) acclimatization, will adversely affect performance. METHODS: At ALT, 10 men received a deficit (DEF) of 1500 kcal x d(-1) below body weight (BW) maintenance requirements and 7 men received adequate (ADQ) kcal x d(-1) to maintain BW. Performance was assessed by: 1) maximal oxygen uptake (VO2max); 2) time to complete 50 cycles of a lift and carry task (L+C); 3) number of one-arm elbow flexions (10% BW at 22 flexions x min(-1); and 4) adductor pollicis (AP) muscle strength and endurance time (repeated 5-s static contractions at 50% of maximal force followed by 5-s rest, to exhaustion). Performance and body composition (using BW and circumference measures) were determined at SL and at ALT on days 2 through 21. RESULTS: At SL, there were no between-group differences (p > 0.05) for any of the performance measures. From SL to day 21 at ALT, BW and LBM declined by 6.6 +/- 3 kg and 4.6 kg, respectively, for the DEF group (both p < 0.01), but did not change (both p > 0.05) for the ADQ group. Performance changes from day 2 or 3 to day 20 or 21 at ALT were as follows (values are means +/- SD): VO2max (ml x min(-1)): DEF = +97 +/- 237, ADQ = +159 +/- 156; L + C (s): DEF = -62 +/- 35*, ADQ = -35 +/- 20* (*p < 0.05; improved from day 3); arm flex (reps): DEF = -2 +/- 7, ADQ = +2 +/- 8; AP endurance (min): DEF = +1.4 +/- 2, ADQ = + 1.9 +/- 2; AP strength (kg): DEF = -0.7 +/- 4, ADQ = -1.2 +/- 2. There were no differences in performance between groups. CONCLUSIONS: A significant BW and LBM loss due to underfeeding during the first 21 d of ALT acclimatization does not impair physical performance at ALT.

Gender alters impact of hypobaric hypoxia on adductor pollicis muscle performance.

Recently, we reported that, at similar voluntary force development during static submaximal intermittent contractions of the adductor pollicis muscle, fatigue developed more slowly in women than in men under conditions of normobaric normoxia (NN) (Acta Physiol Scand 167: 233-239, 1999). We postulated that the slower fatigue of women was due, in part, to a greater capacity for muscle oxidative phosphorylation. The present study examined whether a gender difference in adductor pollicis muscle performance also exists during acute exposure to hypobaric hypoxia (HH; 4,300-m altitude). Healthy young men (n = 12) and women (n = 21) performed repeated static contractions at 50% of maximal voluntary contraction (MVC) force of rested muscle for 5 s followed by 5 s of rest until exhaustion. MVC force was measured before and at the end of each minute of exercise and at exhaustion. Exhaustion was defined as an MVC force decline to 50% of that of rested muscle. For each gender, MVC force of rested muscle in HH was not significantly different from that in NN. MVC force tended to decline at a faster rate in HH than in NN for men but not for women. In both environments, MVC force declined faster (P < 0.01) for men than for women. For men, endurance time to exhaustion was shorter (P < 0.01) in HH than in NN [6.08 +/- 0.7 vs. 8.00 +/- 0.7 (SE) min]. However, for women, endurance time to exhaustion was similar (not significant) in HH (12.86 +/- 1.2 min) and NN (13.95 +/- 1.0 min). In both environments, endurance time to exhaustion was longer for women than for men (P < 0.01). Gender differences in the impact of HH on adductor pollicis muscle endurance persisted in a smaller number of men and women matched (n = 4 pairs) for MVC force of rested muscle and thus on submaximal absolute force and, by inference, ATP demand in both environments. In contrast to gender differences in the impact of HH on small-muscle (adductor pollicis) exercise performance, peak O(2) uptake during large-muscle exercise was lower in HH than in NN by a similar (P > 0.05) percentage for men and women (-27.6 +/- 2 and -25.1 +/- 2%, respectively). Our findings are consistent with the postulate of a higher adductor pollicis muscle oxidative capacity in women than in men and imply that isolated performance of muscle with a higher oxidative capacity may be less impaired when the muscle is exposed to HH.

An investigation of the psychological characteristics of stalkers: empathy, problem-solving, attachment and borderline personality features.

This study examined the psychological characteristics of a sample of self-reported stalkers in comparison with a control group, on measures of empathy, problem-solving skills, attachment, and borderline personality features. Stalkers were identified by their endorsement of specific behavioral items, consistent with a widely adopted definition of stalking, denoting behaviors that: (a) are repeatedly directed toward an identified target; (b) are intrusive and unwanted; and (c) evoke fear in the victim. Stalkers scored significantly higher than controls on measures of insecure attachment and borderline personality features, suggesting that the stalking group demonstrates a general pattern of inadequate interpersonal attachment, has limited abilities to form and maintain appropriate relationships, is emotionally labile and unstable, and experiences ambivalence regarding their interpersonal relationships. Treatment implications are discussed herein.

Dating violence: a critical review of the literature.

The investigation of dating violence has previously been underrepresented in the interpersonal violence literature. Within the past 2 decades, however, researchers have significantly advanced our knowledge of the variables associated with dating violence. This critical article provides a comprehensive review of the current body of literature on dating aggression. Research on dating violence is presented, progressing from prevalence rates and types of violence to an exploration of victim and perpetrator characteristics. There is an emphasis on the necessity to establish a theoretical model of typology to allow investigation of the distinct subgroups of violent individuals. The deficits in the present body of literature are presented and include sampling methods, dependent measures, and data analyses. Finally, implications for future research and prevention are provided.

Reproducible voluntary muscle performance during constant work rate dynamic leg exercise.

During constant intensity treadmill or cycle exercise, progressive muscle fatigue is not readily quantified and endurance time is poorly reproducible. However, integration of dynamic knee extension (DKE) exercise with serial measurement of maximal voluntary contraction (MVC) force of knee extensor muscles permits close tracking of leg fatigue. We studied reproducibility of four performance indices: MVC force of rested muscle (MVC(rest)) rate of MVC force fall, time to exhaustion, and percentage of MVC(rest) (%MVC(rest)) at exhaustion in 11 healthy women (22+/-1 yrs) during identical constant work rate 1-leg DKE (1 Hz) on 2 separate days at sea level (30 m). Means+/-SD for the two test days, and the correlations (r), standard estimate errors and coefficients of variation (CV%) between days were, respectively: a) MVC(rest)(N), 524+/-99 vs 517+/-111, 0.91, 43.0, 4.9%; b) MVC force fall (N x min(-1)), -10.77+/-9.3 vs -11.79+/-12.1, 0.94, 3.6, 26.5 %; c) Time to exhaustion (min), 22.6+/-12 vs 23.9+/-14, 0.98, 2.7, 7.5 %; and d) %MVC(rest) at exhaustion, 65+/-13 vs 62+/-14, 0.85, 7.8, 5.6%. There were no statistically significant mean differences between the two test days for any of the performance measures. To demonstrate the potential benefits of evaluating multiple effects of an experimental intervention, nine of the women were again tested within 24hr of arriving at 4,300 m altitude using the identical force, velocity, power output, and energy requirement during constant work rate dynamic leg exercise. Low variability of each performance index enhanced the ability to describe the effects of acute altitude exposure on voluntary muscle function.

Slower fatigue and faster recovery of the adductor pollicis muscle in women matched for strength with men.

In previous gender comparisons of muscle performance, men and women rarely have been closely matched, absolute force has not been equalized, and rates of fatigue and early recovery have not been determined. We compared adductor pollicis muscle performance at a similar absolute force development in healthy men and women (both n=9) matched for adductor pollicis maximal voluntary contraction (MVC) force (132 +/- 5 N for women and 136 +/- 4 N for men, mean +/- SE, P > 0.05). Subjects repeated static contractions at a target force of approximately 50% of MVC force of rested muscle (68 +/- 3 N or 51.9 +/- 1.0% MVC for women and 72 +/- 2 N or 53.0 +/- 2.0% MVC for men, P > 0.05) for 5 s followed by 5 s rest until exhaustion, i. e. inability to maintain the target force for 5 s. MVC force was measured following each minute of exercise, at exhaustion, and after each minute for 3 min of passive recovery. For women compared with men: MVC force fell less after 1 min of exercise (to 93 +/- 1% vs. 80 +/- 3% of MVC force of rested muscle, respectively, P < 0.05); MVC force (N min-1) fell approximately 2-fold slower (P < 0.05); and endurance time to exhaustion was nearly two times longer (14.7 +/- 1. 6 min vs. 7.9 +/- 0.7 min, P < 0.05). After declining to a similar level of MVC force of rested muscle at exhaustion (56 +/- 1% for women and 56 +/- 3% for men), MVC force rose faster in women than in men (to 71 +/- 2% vs. 65 +/- 3% of MVC force of rested muscle, respectively; P < 0.05) during the first minute of recovery. The findings are consistent with the hypothesis that slower adductor pollicis muscle fatigue in women is linked with differences between men and women both in impairment of force generating capacity, per se, and in rates of recovery between contractions.

The psychological impact of stalking on female undergraduates.

This study examined the psychological impact of stalking upon female undergraduates, a population previously determined to experience a surprising stalking prevalence rate. Despite common understanding that stalking has deleterious effects, there have been no previous efforts to systematically assess them with standardized measures. Thirty-six female stalking victims were compared with 43 females who had been harassed and 48 controls. Psychological impact was assessed with the Posttraumatic Stress Disorder Scale, the Symptom Checklist-90-R, and the Self-Report Interpersonal Trust Scale. Stalked subjects endorsed significantly more PTSD symptoms and with greater severity than the harassed or control subjects. Stalked subjects also had significantly higher scores on several subscales of the SCL-90, and had significantly higher positive symptom totals and distress indices.

Cardiovascular and neuroendocrine responses to exercise in hypoxia during impaired neural feedback from muscle.

Reflex mechanisms from contracting skeletal muscle have been shown to be important for cardiovascular, neuroendocrine, and extramuscular fuel-mobilization responses in exercise. Furthermore, because hypoxia results in exaggerated metabolic changes in contracting muscle, the present study evaluated whether enhancement of cardiovascular and neuroendocrine responses by hypoxia during exercise is influenced by neural feedback from contracting muscle. Seven healthy males cycled at 46% maximal O(2) uptake for 20 min both during normoxia and at 11.5% O(2), and both without and with epidural anesthesia (EA; 20 ml 0.25% bupivacain, resulting in cutaneous hypesthesia below T10-T12 and 25% reduction in maximal leg strength). Exercise to exhaustion was also performed at 7.8% O(2). The exercise-induced increases in heart rate; cardiac output; leg blood flow; plasma concentrations of growth hormone, adrenocorticotropin, cortisol, and catecholamines; renin activity; glucose production and disappearance; norepinephrine spillover [2, 190 +/- 341 ng/min (exercise at 11.5% O(2)) vs. 988 +/- 95 ng/min (exercise during normoxia)]; lactate release from and glucose uptake in the leg; and the decreases in plasma insulin and free fatty acids were exaggerated in hypoxia (P < 0.05). In muscle, concentrations of lactate, creatine, and inosine 5'-monophosphate were higher, and those of phosphocreatine were lower after exercise in hypoxia compared with normoxia. The exercise-induced increase in mean arterial blood pressure was not affected by hypoxia, but it was reduced by EA [108 +/- 4 mmHg (control) vs. 97 +/- 4 mmHg (EA); P < 0.05], and the reduction was more pronounced during severe hypoxia compared with normoxia. Apart from this, time to exhaustion at extreme hypoxia, circulatory responses, concentrations of neuroendocrine hormones, and extramuscular substrate mobilization were not diminished by EA. In conclusion, in essence the hypoxia-induced enhancement of systemic adaptation to exercise is not mediated by neural feedback from working muscle in humans.

Transdermal nicotine replacement for hospitalized patients: a randomized clinical trial.

BACKGROUND: This study was undertaken to assess the safety and efficacy of a treatment involving brief counseling and the nicotine patch among hospital inpatients and to identify variables associated with long-term smoking cessation following hospitalization. METHODS: One hundred eighty-five patients were randomly assigned to one of three smoking cessation interventions: (1) A Minimal Care (MC) condition, consisting of a brief physician-delivered motivational message to stop smoking, (2) a Counseling + Active Nicotine Patch (CAP) condition in which patients received the motivational message, a 6-week supply of nicotine patches, and extended bedside and telephone counseling, and (3) a Counseling + Placebo Patch (CPP) condition identical to the CAP condition except the supplied patches contained no nicotine. RESULTS: At 6-month follow-up, abstinence rates for the three treatments were 4.9, 6.5, and 9.7% for the MC, CPP, and CAP treatments, respectively. These differences were not statistically significant. Patients admitted for respiratory disease were more likely to quit than patients with any other diagnosis. The nicotine patch was well tolerated by hospital inpatients. CONCLUSIONS: The initiation of nicotine patch therapy during hospitalization appears to be safe when used among patients carrying a wide range of diagnoses. Our study provided no evidence of the superiority of nicotine patches versus placebo, but this does not preclude the possibility that future research using larger samples might detect differences between patch groups. Hospital interventions for smoking cessation may be most effective among patients hospitalized for a smoking-related illness such as respiratory disease.

Magnesium kinetics in adolescent girls determined using stable isotopes: effects of high and low calcium intake.

Magnesium kinetics were measured in five adolescent girls who were participating in a calcium balance study. Two calcium levels were fed in a randomized crossover design. After an acclimation period, 26Mg was consumed orally and 25Mg was given intravenously, and then blood, urine, and feces were collected for 14 days. Total magnesium and percent enrichment were determined, and data were fitted to a eight-compartment model. There was no significant difference between high and low calcium intakes for any of the parameters examined. Mean values for control (800 mg/day) and high (1,800 mg/day) calcium intake were as follows: Mg intake, 305 +/- 30 and 286 +/- 9 mg/day; absorption (percent), 44 +/- 7 and 39 +/- 9; absorption (mg/day), 134 +/- 35 and 110 +/- 28; urinary excretion, 96 +/- 22 and 101 +/- 31 mg/day; fecal excretion, 175 +/- 32 and 200 +/- 11 mg/day; and magnesium balance, 13 +/- 35 and -34 +/- 48 mg/day, respectively. In conclusion, high calcium intake did not alter magnesium kinetics or balance in adolescent girls.

Muscle fatigue and exhaustion during dynamic leg exercise in normoxia and hypobaric hypoxia.

Using an exercise device that integrates maximal voluntary static contraction (MVC) of knee extensor muscles with dynamic knee extension, we compared progressive muscle fatigue, i.e., rate of decline in force-generating capacity, in normoxia (758 Torr) and hypobaric hypoxia (464 Torr). Eight healthy men performed exhaustive constant work rate knee extension (21 +/- 3 W, 79 +/- 2 and 87 +/- 2% of 1-leg knee extension O2 peak uptake for normoxia and hypobaria, respectively) from knee angles of 90-150 degrees at a rate of 1 Hz. MVC (90 degrees knee angle) was performed before dynamic exercise and during < or = 5-s pauses every 2 min of dynamic exercise. MVC force was 578 +/- 29 N in normoxia and 569 +/- 29 N in hypobaria before exercise and fell, at exhaustion, to similar levels (265 +/- 10 and 284 +/- 20 N for normoxia and hypobaria, respectively; P > 0.05) that were higher (P < 0.01) than peak force of constant work rate knee extension (98 +/- 10 N, 18 +/- 3% of MVC). Time to exhaustion was 56% shorter for hypobaria than for normoxia (19 +/- 5 vs. 43 +/- 7 min, respectively; P < 0.01), and rate of right leg MVC fall was nearly twofold greater for hypobaria than for normoxia (mean slope = -22.3 vs. -11.9 N/min, respectively; P < 0.05). With increasing duration of dynamic exercise for normoxia and hypobaria, integrated electromyographic activity during MVC fell progressively with MVC force, implying attenuated maximal muscle excitation. Exhaustion, per se, was postulated to related more closely to impaired shortening velocity than to failure of force-generating capacity.

Screening sigmoidoscopy. Factors associated with utilization.

Although screening sigmoidoscopy (SS) reduces colorectal cancer mortality, surveys indicate that fewer than half of primary care physicians routinely recommend SS and less than 10% of eligible patients receive this test. The purpose of this study was to explore barriers to compliance with SS through a cross-sectional survey of general medicine patients. Clinician advice, perceived benefit of the test, and having a family member who has had the test are associated with SS, while perceived pain is a barrier to compliance and can negate the positive effects of clinician advice. These factors can be targeted as part of efforts to improve compliance with SS.

Quantitation of progressive muscle fatigue during dynamic leg exercise in humans.

There is virtually no published information on muscle fatigue, defined as a gradual decline in force-generating capacity, during conventional dynamic (D) leg exercise. To quantitate progression of fatigue, we developed 1) a model featuring integration of maximal voluntary static contraction (MVC) of knee extension (KE) muscles with ongoing DKE and 2) a device that allows frequent rapid transfer between DKE isolated to the quadriceps femoris muscles and measurement of KE MVC. Eight healthy men performed graded and submaximal constant work rate one-leg DKE to exhaustion while seated. Work rate, a product of a contraction rate (1 Hz), force measured at the ankle, and distance of ankle movement from 90 degrees to 150 degrees of KE, was precisely controlled. Lack of rise in myoelectric activity in biceps femoris of the active leg during DKE and MVC was consistent with restriction of muscle action to quadriceps femoris. The slope of the linear relationship between O2 uptake and work rate was 13.7 ml O2/W (r = 0.93). This slope and the increase of heart rate relative to increasing work intensity agreed with published values for D leg exercise. Test-retest values for O2 uptake were similar (P > 0.05) for matched DKE work rates. To track fatigue, MVC (90 degrees knee angle) was performed every 2 min of DKE. After 4 min of DKE at work rates corresponding to (mean +/- SE) 66 +/- 2, 78 +/- 2, and 100% of peak DKE O2 uptake, MVC fell to 95 +/- 3, 90 +/- 5, and 65 +/- 7%* of MVC of rested muscle, respectively (*P < 0.01 from previous work rates). Virtually identical declines in MVC were observed by the end of graded work rate DKE and submaximal constant work rate DKE tests. Quantitation of progressive muscle fatigue during D leg exercise provides a framework to study the effects of a variety of interventions on the fatigue process and may permit unique insights into the involved mechanisms.

Varying nicotine patch dose and type of smoking cessation counseling.

OBJECTIVE: To compare the efficacy and safety of 22-mg and 44-mg doses of transdermal nicotine therapy when it is paired with minimal, individual, or group counseling to improve smoking cessation rates. DESIGN: An 8-week clinical trial (4 weeks double-blind followed by 4 weeks open label) using random assignment of participants to both dose (22 or 44 mg) and counseling (minimal, individual, or group) conditions. PARTICIPANTS: Daily cigarette smokers (> or = 15 cigarettes per day for at least 1 year) who volunteered to participate in a study of smoking cessation treatment. A total of 504 participants were enrolled at two sites. INTERVENTION: Four weeks of 22- or 44-mg transdermal nicotine therapy followed by 4 weeks of dosage reduction (2 weeks of 22 mg followed by 2 weeks of 11 mg). Counseling consisted of a self-help pamphlet (minimal); a self-help pamphlet, a brief physician motivational message, and three brief (< 15 minutes) follow-up visits with a nurse (individual); or the pamphlet, the motivational message, and eight weekly 1-hour group smoking cessation counseling visits (group). All participants returned weekly to turn in questionnaires and for assessment of their smoking status. MAIN OUTCOME MEASURES: Abstinence from smoking was based on self-report, confirmed by an expired carbon monoxide concentration lower than 10 ppm. Withdrawal severity was assessed by means of an eight-item self-report questionnaire completed daily. RESULTS: Smoking cessation rates for the two nicotine patch doses and three levels of counseling did not differ significantly at either 8 weeks or 26 weeks following the quit date. Among those receiving minimal contact, the 44-mg dose produced greater abstinence at 4 weeks than did the 22-mg dose (68% vs 45%; P < .01). Participants receiving minimal-contact adjuvant treatment were less likely to be abstinent at the end of 4 weeks than those receiving individual or group counseling (56% vs 67%; P < .05). The 44-mg dose decreased desire to smoke more than the 22-mg dose, but this effect was not related to success in quitting smoking. Transdermal nicotine therapy at doses of 44 mg produced a significantly greater frequency of nausea (28%), vomiting (10%), and erythema with edema at the patch site (30%) than did a 22-mg dose (10%, 2%, and 13%, respectively; P < .01 for each adverse effect). Three serious adverse events occurred during use of the 44-mg patch dose. CONCLUSIONS: There does not appear to be any general, sustained benefit of initiating transdermal nicotine therapy with a 44-mg patch dose or of providing intense adjuvant smoking cessation treatment. The two doses and all adjuvant treatments produced equivalent effects at the 26-week follow-up, and the higher patch dose produced more adverse effects. Higher-dose (44-mg) nicotine replacement does not appear to be indicated for general clinical populations, although it may provide short-term benefit to some smokers attempting to quit with minimal adjuvant treatment.

Tricarboxylic acid cycle intermediates during incremental exercise in healthy subjects and in patients with McArdle's disease.

1. The importance of the level of tricarboxylic acid cycle intermediates (malate, citrate and fumarate) for energy transduction during exercise has been investigated in six healthy subjects and in two patients with muscle phosphorylase deficiency (McArdle's disease). 2. Healthy subjects cycled for 10 min at low (50 W), moderate [130 +/- 6 W (mean +/- SEM)] and high (226 +/- 12 W) work rates, corresponding to 26, 50 and 80% of their maximal O2 uptake, respectively. Patients with McArdle's disease cycled for 11-13 min at submaximal (40 W) rates, and to fatigue at maximal work rates of 60-90 W. 3. In healthy subjects, phosphocreatine was unchanged during low work rates, but decreased to 79 and 32% of the initial level during moderate and high work rates. In patients with McArdle's disease, phosphocreatine decreased to 82 and 34% of the initial level during submaximal and peak exercise. Muscle lactate increased in healthy subjects during exercise at moderate and high work rates, but remained low in patients with McArdle's disease. 4. In healthy subjects, tricarboxylic acid cycle intermediates were similar at rest and at low work rates (0.48 +/- 0.04 mmol/kg dry weight), but increased to 1.6 +/- 0.2 mmol/kg dry weight and 4.0 +/- 0.3 mmol/kg dry weight at moderate and high work rates. The tricarboxylic acid cycle intermediate level in patients with McArdle's disease was similar to that in healthy subjects at rest, but was markedly reduced during exercise when compared at the same relative intensity. The peak level of tricarboxylic acid cycle intermediates in patients with McArdle's disease was 22% of that in healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment and diagnostic subtype in facial affect recognition in schizophrenia.

Patients with schizophrenia have been described as having deficits in the ability to recognize facial expressions of emotion. We report the results of a study on the effects of global psychopathology, positive and negative symptoms, diagnostic subtype, and antipsychotic medications, on the ability of subjects with schizophrenia to recognize facial affect. Eighteen SCID diagnosed patients with schizophrenia and ten matched controls were evaluated at a drug-free baseline for ability to identify facial expression expressed in a standardized series of photographs, with concurrent measures of global psychopathology, and positive and negative symptoms. At baseline patients were impaired in affect recognition relative to the normals, and impairment was not related to measures of psychopathology or positive or negative symptoms. Performance did not improve with antipsychotic treatment, and patients with paranoid schizophrenia had significantly better affect recognition abilities than non-paranoid patients.

Adductor pollicis muscle fatigue during acute and chronic altitude exposure and return to sea level.

Large muscle exercise performance is impaired during acute exposure to normobaric or hypobaric hypoxia, but the effects of hypoxic conditions on fatigue of isolated smaller muscle groups per se are poorly defined. We studied how acute and chronic altitude (ALT) exposure and post-ALT return to sea level (SL) affects voluntary strength and fatigue of the adductor pollicis muscle. Eight healthy men (mean age 28 yr) were studied on five separate occasions: at SL, on days 1 (acute) and 13 (chronic) at ALT (4,300 m), and on days 1 (post 1) and 3 or 4 (post 2) at SL after 20 days of residence at ALT. On each day, maximal voluntary contractions (MVCs) of the adductor pollicis were obtained before and at the end of each minute of submaximal intermittent contractions of the adductor pollicis (50% of MVC of rested muscle, 5 s of contraction/5 s of rest) until exhaustion, defined as the inability to exert or maintain 50% of rested MVC. MVC of rested muscle did not differ among days. Time to exhaustion was shorter at acute ALT [5.1 +/- 0.5 (SE) min] than at SL (7.4 +/- 0.8 min, P < 0.05) and tended to be shorter than at chronic ALT (6.6 +/- 0.7 min, P > 0.05). Compared with acute and chronic ALT, time to exhaustion was prolonged during post 1 (9.0 +/- 1.2 min, P < 0.05) but not post 2 (6.1 +/- 0.5 min, P > 0.05). We conclude that 1) MVC of rested adductor pollicis muscle is not impaired during or after ALT exposure, 2) compared with SL conditions, acute but not chronic ALT exposure leads to a more rapid decline in adductor pollicis MVC associated with submaximal contractions, and 3) time to exhaustion is prolonged for > or = 1 day after return from ALT.