The International Olympic Committee framework on fairness, inclusion and nondiscrimination on the basis of gender identity and sex variations does not protect fairness for female athletes.

The International Olympic Committee (IOC) recently published a framework on fairness, inclusion, and nondiscrimination on the basis of gender identity and sex variations. Although we appreciate the IOC's recognition of the role of sports science and medicine in policy development, we disagree with the assertion that the IOC framework is consistent with existing scientific and medical evidence and question its recommendations for implementation. Testosterone exposure during male development results in physical differences between male and female bodies; this process underpins male athletic advantage in muscle mass, strength and power, and endurance and aerobic capacity. The IOC's "no presumption of advantage" principle disregards this reality. Studies show that transgender women (male-born individuals who identify as women) with suppressed testosterone retain muscle mass, strength, and other physical advantages compared to females; male performance advantage cannot be eliminated with testosterone suppression. The IOC's concept of "meaningful competition" is flawed because fairness of category does not hinge on closely matched performances. The female category ensures fair competition for female athletes by excluding male advantages. Case-by-case testing for transgender women may lead to stigmatization and cannot be robustly managed in practice. We argue that eligibility criteria for female competition must consider male development rather than relying on current testosterone levels. Female athletes should be recognized as the key stakeholders in the consultation and decision-making processes. We urge the IOC to reevaluate the recommendations of their Framework to include a comprehensive understanding of the biological advantages of male development to ensure fairness and safety in female sports.

Effect of Unstable Loads on Stabilizing Muscles and Bar Motion During the Bench Press.

ABSTRACT: Lawrence, MA, Ostrowski, SJ, Leib, DJ, and Carlson, LA. Effect of unstable loads on stabilizing muscles and bar motion during the bench press. J Strength Cond Res 35(2S): S120-S126, 2021-Unstable loads are anecdotally used to increase muscle stabilizer strength and utilization; however, there is little evidence to support these claims. Twelve male powerlifters (age 28.6 ± 5.2 years, body mass 105.6 ± 14.5 kg, lifting experience 9.8 ± 6.0 years, and bench press 5 repetition maximum [5RM] 133.6 ± 30.9 kg) pressed their 5RM in one stable condition with a standard barbell, and 3 unstable conditions using a flexible barbell with weights suspended from elastic bands. Mean integrated muscle activity for each repetition of the stabilizers and prime movers were measured. A Lyapunov exponent and sample entropy indicated unstable loads were less predictable and more variable in the superior/inferior direction, thus more challenging to control, despite decreased loads. The main finding was increased bicep activity in all unstable conditions (light bands and plates, +57%; mini bands and plates, +67%; and mini bands and kettlebells, +88%). Although less weight was used in the unstable 5RMs, most stabilizer muscle activity was not different between conditions, suggesting that the amount of weight used during unstable load training (up to 32.3% less load) may be limited by the ability of stabilizer muscles to control the load.

Activity of Trunk and Lower Extremity Musculature: Comparison Between Parallel Back Squats and Belt Squats.

The back squat is widely used in strength training programs. Alternatively, the belt squat has been gaining popularity since it loads the weight on the hips, as opposed to the shoulders and spine. The purpose of this study was to determine whether using a belt squat would result in less lumbar extensor activation while providing similar excitation of other prime mover and stabilizer musculature. Ten participants (9 males, 1 female; age 29.3 ± 4.9 years; body mass 96.2 ± 17.8 kg) who regularly trained both belt squats and back squats performed three sets of 5 repetitions with 100% bodyweight for each exercise. Peak and integrated muscle activity was calculated and normalized to a maximum voluntary isometric contraction. A one-way ANOVA (p < 0.05) was used to compare conditions. Belt squatting decreased lumbar erector impulse (45.4%) and peak (52.0%) activation as compared to the back squat. Belt squatting did not alter activation of the lower extremities except for a decrease in the gluteus maximus (35.2% impulse and 32.1% peak), gluteus medius (54.1% impulse and 55.2% peak). Furthermore, belt squatting reduced activation of the rectus abdominus (44.3% impulse; 31.1% peak), and external obliques (45.8% impulse; 53.7% peak) as compared to back squatting. Our results suggest belt squatting provides similar muscular demands for the quadriceps, hamstrings, and plantar flexors, but is less demanding of trunk stabilizers, and gluteual muscles. Belt squats may be a suitable alternative to back squats in order to avoid stressing low back or trunk musculature.

Agility and Vertical Jump Performances Are Impacted by Acute Cool Exposure.

Carlson, LA, Fowler, C, and Lawrence, MA. Agility and vertical jump performances are impacted by acute cool exposure. J Strength Cond Res 33(6): 1649-1653, 2019-Outdoor sports teams may be exposed to acute cold stress during competition, which may affect performance. Limited research has explored the effects of cold exposure on athletic components. The purpose of this study was to examine the effects of an acute whole-body cool exposure on pro-agility, vertical jump, and sprint performances. Eleven lightly clothed (∼0.3 clo) and not cold acclimatized volunteers (10/1 women/men: age 20.5 ± 0.5 years; height 1.65 ± 0.09 m; mass 63.3 ± 8.9 kg; body fat 21.3 ± 7.6%) completed performance tests in both thermoneutral (17.2° C, 36% relative humidity, Biddeford, ME, USA) and cool (6.1° C, 72% relative humidity, Thorsmörk, Iceland) ambient temperatures. Before completing the performance tests, subjects engaged in a 5-minute stretching routine and were subsequently exposed to either a thermoneutral or cool ambient environment for 15 minutes. Performance tests included 3 trials of maximal vertical jumps, and 2 trials of both the 36.6-m sprint and pro-agility tests. Mean performance and lactate values were compared via paired t-tests. Pro-agility completion time was significantly (p ≤ 0.05) slower in the cool (5.63 ± 0.33 seconds) than thermoneutral (5.43 ± 0.26 seconds) environment. Vertical jump was significantly (p ≤ 0.05) lower in the cool (0.36 ± 0.07 m) than thermoneutral (0.41 ± 0.10 m) environment. Sprint performance and lactate values were unaffected by the cool exposure. Brief cool exposure seems to influence agility and vertical jump performances. Our results suggest that it would be prudent for athletes and coaches to consider the ambient environment when preparing for competition.

Influence of Exercise Time of Day on Salivary Melatonin Responses.

BACKGROUND: Sleep deprivation negatively affects cognition, pain, mood, metabolism, and immunity, which can reduce athletic performance. Melatonin facilitates sleepiness and may be affected by the proximity of exercise to sleep. PURPOSE: To evaluate the influence of exercise time of day on salivary melatonin (s-melatonin) responses. METHODS: Twelve regularly exercising men (age 20.75 [0.62] y, height 1.75 [0.04] m, mass 73.63 [10.43] kg, and maximal oxygen consumption 57.72 [6.11] mL/kg/min) participated in a randomized, crossover design. Subjects completed 3 protocols-morning exercise (09:00 h), afternoon exercise (16:00 h), and no exercise (CON)-at least 5 d apart. Exercise sessions consisted of 30 min of steady-state running at 75% of maximal oxygen consumption. Saliva was collected via passive drool at 20:00, 22:00, and 03:00 h following all sessions. RESULTS: Repeated-measures analysis of variance revealed significant time (P = .001) and condition (P = .026) effects for melatonin. Levels of s-melatonin were significantly increased at 03:00 h compared with 20:00 and 22:00 h for all conditions. Post hoc analyses revealed that s-melatonin at 22:00 h was significantly higher after morning exercise (16.5 [7.5] pg/mL) compared with afternoon exercise (13.7 [6.1] pg/mL) sessions (P = .03), whereas neither exercise condition significantly differed from the control (P > .05). CONCLUSIONS: It appears that exercising in the afternoon may blunt melatonin secretion compared with morning exercise. If sleep is an issue, morning exercise may be preferable to afternoon exercise.

Effects of the Safety Squat Bar on Trunk and Lower-Body Mechanics During a Back Squat.

Hecker, KA, Carlson, LA, and Lawrence, MA. Effects of the safety squat bar on trunk and lower-body mechanics during a back squat. J Strength Cond Res 33(7S): S45-S51, 2019-The purpose of this study was to determine whether the safety squat bar (SSB) alters the mechanics and muscle activity of a back squat compared with a standard barbell (ST). Motion and muscle activation of the trunk and lower extremity were measured while 12 competitive powerlifters (8 males, 4 females, age 31.5 ± 6.3 years, body mass 88.1 ± 20.7 kg, competitive lifting experience 3.3 ± 2.8 years) squatted 3 sets of 5 repetitions at 75% of their 3 repetition maximum (3RM). Mean muscle activity and peak joint flexion angles were measured for the trunk and one lower extremity. A repeated-measures analysis of variance (p = 0.05) revealed an 11.3% decrease in 3RM when using the SSB. When using the SSB, there was a decrease in trunk and hip flexion (7.3 and 5.7° respectively) and a 50.3% increase in lower trapezius activation. However, using the SSB decreased activation of the rectus abdominis (46.3%), medial hamstring (17.1%), lateral hamstring (15.1%), vastus lateralis (9.3%), and medial gastrocnemius (18.8%). Squatting with the SSB resulted in a more upright trunk angle, which places less stress on the lower back, a commonly injured area when squatting. Decreases in lower-extremity muscle activation are likely due to the decreased load used, suggesting that the SSB may not be as effective as a standard bar to increase lower-extremity strength. However, the increase in the lower trapezius with the lighter load suggests that midback musculature may be challenged more by the SSB than a standard barbell.

Hydration Status and Thermoregulatory Responses in Drivers During Competitive Racing.

Carlson, LA, Lawrence, MA, and Kenefick, RW. Hydration status and thermoregulatory responses in drivers during competitive racing. J Strength Cond Res 32(7): 2061-2065, 2018-Stock car drivers are exposed to high ambient temperatures, further complicated by the fact that they are encapsulated in protective clothing; however, the hydration status of these drivers has not been determined. This study quantified the degree of fluid losses during a competitive event in hot conditions. Nine male stock car drivers (29.6 ± 9.4 years, 177.8 ± 3.0 cm, 81.5 ± 18.5 kg) were studied during a Pro Series Division NASCAR race. Sweat rate (SR) and dehydration was determined through nude body weights (BWs). Prerace BW was 81.5 ± 18.5 kg and decreased to 81.1 ± 18.5 kg after race (p = 0.001). Body weight loss after race was 0.77 ± 0.3% and mean SR was 0.63 ± 0.4 L·h. Intestinal core temperature increased from 38.0 ± 0.4 to 38.5 ± 0.4° C after race (p = 0.001). Skin temperature increased from 35.8 ± 0.8 to 36.9 ± 0.8° C after race (p = 0.001), whereas the core-to-skin temperature gradient narrowed from 2.2 ± 0.9 to 1.6 ± 0.9° C, before race to after race (p = 0.001). Heart rates after race were 89 ± 0.0% of the drivers' age-predicted maximum heart rate (HR). Fluid losses during competitive racing can be significant. Without a fluid replacement strategy, fluid losses may exceed 3% of BW and could negatively impact driving performance in longer races.

Effect of an Unstable Load on Primary and Stabilizing Muscles During the Bench Press.

Ostrowski, SJ, Carlson, LA, and Lawrence, MA. Effect of an unstable load on primary and stabilizing muscles during the bench press. J Strength Cond Res 31(2): 430-434, 2017-Unstable resistance exercises are performed to increase activity of stabilizing muscles. The premise is that this increase in activity will yield greater strength gains than traditional resistance exercises. The purpose of this study was to determine if an unstable load increases muscle activity of stabilizing muscles during a bench press as compared with a standard bench press with a typical load. Fifteen resistance-trained males (age 24.2 ± 2.7 years, mass 84.8 ± 12.0 kg, height 1.77 ± 0.05 m, weight lifting experience 9.9 ± 3.4 years, and bench press 1 repetition maximum [1RM] 107.5 ± 25.9 kg) volunteered for this study. Subjects pressed 2 sets of 5 repetitions in both stable (75% 1RM) and unstable (60% 1RM) conditions using a standard barbell and a flexible Earthquake bar, respectively. Surface electromyography was used to detect muscle activity of primary movers (pectoralis major, anterior deltoid, and triceps) and stabilizing musculature (latissimus dorsi, middle and posterior deltoid, biceps brachii, and upper trapezius). Muscle activity was compared using a multivariate analysis of variance to determine significant (p ≤ 0.05) phase and condition differences. The right and left biceps and the left middle deltoid were significantly more active in the unstable condition. Some of the stabilizing muscles were found to be significantly more active in the unstable condition with 15% less weight. Therefore, bench pressing with an unstable load appears promising in activating stabilizing musculature compared with pressing a typical barbell.

Nonlinear Analysis of an Unstable Bench Press Bar Path and Muscle Activation.

Lawrence, MA, Leib, DJ, Ostrowski, SJ, and Carlson, LA. Nonlinear analysis of an unstable bench press bar path and muscle activation. J Strength Cond Res 31(5): 1206-1211, 2017-Unstable resistance exercises are typically performed to improve the ability of stabilizing muscles to maintain joint integrity under a load. The purpose of this study was to examine the effects of an unstable load (as provided by a flexible barbell and a load suspended by elastic bands) on the bar path, the primary musculature, and stabilizing musculature while bench pressing using nonlinear analyses. Fifteen resistance-trained men (age 24.2 ± 2.7 years, mass 84.1 ± 12.0 kg, height 1.77 ± 0.05 m, 9.9 ± 3.4 years of lifting experience, and bench press 1 repetition maximum (RM) 107.5 ± 25.9 kg) volunteered for this study. Subjects pressed 2 sets of 5 repetitions in both stable (total load 75% 1RM) and unstable (total load 60% 1RM) conditions using a standard barbell and a flexible Earthquake bar, respectively. Surface electromyography was used to detect muscle activity of primary movers (pectoralis major, anterior deltoid, and triceps) and bar stabilizing musculature (latissimus dorsi, middle and posterior deltoid, biceps brachii, and upper trapezius). During the unstable condition, the bar moved in more ways and was less predictable in the mediolateral and anteroposterior directions. However, the muscle activation patterns of all muscles were more constrained with the unstable barbell. These findings suggest that the unstable condition was more challenging to control, but subjects controlled the instability by contracting their muscles in a more stable pattern or "staying tight" throughout the exercise.

Salivary Lymphocyte Responses Following Acute Anaerobic Exercise in a Cool Environment.

Carlson, LA, Lawrence, MA, LeCavalier, K, and Koch, AJ. Salivary lymphocyte responses following acute anaerobic exercise in a cool environment. J Strength Cond Res 31(5): 1236-1240, 2017-The purpose of this study was to examine the impact of anaerobic training on salivary lymphocytes (s-LYMPH), and further determine whether these responses differ between cool vs. thermoneutral environments. Nine lightly clothed (∼0.3 clo) volunteers (7/2 women/men: age, 21 ± 1 years; height, 168.7 ± 7.3 cm; weight, 66.4 ± 8.4 kg; body fat, 20.6 ± 7.6%) completed speed, agility, and quickness (SAQ) sessions in both warm (18.9° C; Biddeford) and cool (10.4° C; Thorsmörk) temperatures. The SAQ sessions consisted of 3 trials of 20-m sprints, 40-m sprints, t-tests, and box drills, and two 300-yd shuttle runs in both conditions. Saliva samples via passive drool were collected at baseline, immediately postexercise, and after 2 hours of recovery. The s-LYMPH increased (p < 0.001) immediately postexercise, followed by a decrease (p < 0.001) below baseline values after 2 hours of recovery in both environments. The s-LYMPH counts were lower (p < 0.001) for the cool environment than for the thermoneutral environment. The s-LYMPH counts increased postexercise, followed by a decrease after 2 hours of recovery regardless of environment. Acute anaerobic exercise induced transient changes in s-LYMPH counts similar to that observed in peripheral blood. Compared with baseline measures, changes in s-LYMPH were of a smaller magnitude after exercise in the cool environment compared with thermoneutral environment. In summary, there is no indication that exercise in the cool environment presented a greater challenge to the subjects' immunity. Rather, these data indicate exercise in a cool environment produces smaller fluctuations in salivary immune cells compared with resting levels.

Comparison of Knee Moments and Landing Patterns During a Lateral Cutting Maneuver: Shod Vs. Barefoot.

Noncontact anterior cruciate ligament (ACL) injuries often occur during lateral cutting maneuvers, in which extension, adduction, and external rotation create high loads on the ACL. The aim of this study was to examine knee moments and foot strike patterns during lateral cutting when shod (SD) and barefoot (BF). Fifteen NCAA Division III athletes (7 female and 8 male; age 20.2 ± 1.5 years; mass 71.5 ± 11.3 kg; height, 1.7 ± 0.06 m) without lower limb pathologies were analyzed during 5 trials of 45° lateral cutting maneuvers for each limb in both BF and SD conditions with the approach speed of 4.3 m·s. Kinetic and kinematic data were collected using an 8-camera motion capture system and a force plate with collection rates at 240 Hz and 2400 Hz, respectively. Paired t-tests were used to determine differences conditions. The SD condition produced a significantly (p ≤ 0.05) greater peak adduction moment and cutting, whereas BF caused more anterior foot strike. Lateral cutting when BF places no more stress on the ACL than when SD. Our findings suggest that lateral cutting maneuvers when BF will not increase stress on the ACL.

Effects of an Unstable Load on Force and Muscle Activation During a Parallel Back Squat.

Stability training has become commonplace in the strength and conditioning field. Although unstable surface training has been investigated, little is known regarding the efficacy of performing resistance exercises with an unstable load. The purpose of this study was to determine if performing a parallel back squat with an unstable load (weights suspended from the bar by an elastic band) produces greater ground reaction forces (GRFs) and muscle activation in the trunk and lower extremities than a stable condition (a normally loaded barbell). Fifteen resistance-trained males (age: 24.2 ± 3.4 years, mass: 83.4 ± 18.7 kg) completed 10 repetitions of the back squat, with 60% of their 1 repetition maximum in both stable and unstable conditions. Peak vertical GRF and the integrated muscle activity of the rectus femoris, vastus lateralis, vastus medialis, biceps femoris, soleus, rectus abdominis, external oblique, and erector spinae muscles on the right side of the body were determined The unstable load resulted in a small (3.9%) but significant decrease in peak vertical GRF. The unstable load also produced greater muscle activation in the rectus abdominis, external oblique, and soleus. The findings of this study suggest that squatting with an unstable load will increase activation of the stabilizing musculature; and while force decrements were statistically significant, the decrease was so small it may not be relevant to practitioners.

Physiological strain of stock car drivers during competitive racing.

Heat strain experienced by motorsport athletes competing in National Association for Stock Car Automobile Racing (NASCAR) may be significant enough to impair performance or even result in a life-threatening accident. There is a need to carefully quantify heat strain during actual NASCAR race competitions in order to faithfully represent the magnitude of the problem and conceptualize future mitigation practices. The purpose of this investigation was to quantify the thermoregulatory and physiological strain associated with competitive stock car driving. Eight male stock car drivers (29.0±10.0yr; 176.2±3.3cm, 80.6±15.7kg) participated in sanctioned stock car races. Physiological measurements included intestinal core (Tc) and skin (Tsk) temperatures, heart rate (HR), blood pressure, and body mass before and after completion of the race. Pre-race Tc was 38.1±0.1°C which increased to 38.6±0.2°C post-race (p=0.001). Tsk increased from 36.1±0.2°C pre-race to 37.3±0.3°C post-race (p=0.001) whereas the core-to-skin temperature gradient decreased from a pre-race value of 2.0±0.3°C to 1.3±0.3°C post-race (p=0.005). HRs post-race were 80±0.1% of the drivers' age-predicted maximum HR. Physiological Strain Index (PSI) post-race was 4.9, which indicates moderate strain. Drivers' thermal sensation based on the ASHRAE Scale increased from 1.3±0.5 to 2.8±0.4, and their perception of exertion (RPE) responses also increased from 8.4±1.6 to 13.9±1.8 after competition. Heat strain associated with competitive stock car racing is significant. These findings suggest the need for heat mitigation practices and provide evidence that motorsport should consider strategies to become heat acclimatized to better meet the thermoregulatory and cardiovascular challenges of motorsport competition.

Effects of sled towing on sprint starts.

Sled towing is a popular method of sprint training. Researchers have struggled to identify a loading scheme that is most appropriate to improve sprint performance in the acceleration phase. The purpose of this study was to determine if loads of 10% body weight (BWT) or 20% BWT produced significantly greater propulsive ground reaction force (GRF) impulse, peak propulsive GRF, or a greater propulsive rate of force development (RFD) than an unweighted sprint start. Seventeen healthy court and field athletes (10 men, 7 women; 20.9 ± 1.1 years) completed 5 starts of each condition (unweighted, 10% BWT, 20% BWT). Participants began each start in an upright staggered stance. Propulsive GRF impulse was greater in the 20% BWT condition than the unweighted condition in both limbs and greater in the 20% BWT condition than the 10% BWT condition in the front leg only, and vertical GRF impulse was greater in the 20% BWT than the unweighted condition. In summary, our results suggest that a 10% BWT load is not sufficient to increase propulsive GRF impulse. A loading scheme of 20% BWT is sufficient to increase propulsive GRF impulse. Coaches seeking to improve sprint starts may observe improvements using a load of 20% BWT during training while towing a sled.

Influence of the Flo-Dynamics Movement System intervention on measures of performance in older persons.

BACKGROUND: Fall-related injuries associated with aging are a serious clinical and economic problem. The Flo-Dynamics Movement System (FDMS), which consists of eight movements with a water-filled device, may be a useful low-impact exercise suited for older persons. This study investigated the effects of the FDMS regimen with the Wun-Jo trainer on measures of strength, flexibility, and balance in older individuals. METHODS: In a quasi-experimental study, 15 healthy subjects aged 61-79 years participated in an FDMS exercise program with the Wun-Jo trainer, consisting of three weekly 30-minute sessions. The following measures were assessed pretraining and after 8 weeks of training: knee flexor and extensor isokinetic strength; grip strength; the Short Physical Performance Battery; functional reach; and low back and hamstring flexibility. Data were analyzed using repeated measures analysis of variance, with statistical significance set at the P ≤ 0.05 confidence level. RESULTS: Sit and reach test scores significantly increased (+21%) from baseline to week 8 (P < 0.001). Forward-left functional reach testing significantly increased (P = 0.012), while forward-right functional reach testing did not change (P = 0.474). Both left-lateral (P = 0.012) and right-lateral (P = 0.036) functional reach scores improved. Grip strength increased in both the left (+11.9%) and right (+14.5%) hands (P < 0.001 for each). Isokinetic knee extension at 60° per second increased for the left (+15.6%) and right (+17.6%) significantly (P = 0.001 for each). Isokinetic knee flexion at 60° per second significantly increased for both the left (+43.2%, P = 0.010) and right (+41.7%, P < 0.001). Time to complete the ten-repetition chair stand decreased significantly (-31%, P = 0.004). The 8-feet walk time also significantly decreased (-21.6%, P < 0.001). CONCLUSION: Participating in the FDMS with the Wun-Jo device may improve balance, low back and hamstring flexibility, walking speed, and knee extensor/flexor and grip strength in older individuals. FDMS training provides an alternative to traditional exercise and offers an effective strategy to increase functional ability in the elderly.

Influence of carbohydrate ingestion on salivary immunoglobulin A following resistance exercise.

BACKGROUND: Heavy exercise stresses immune function, however carbohydrate (CHO) supplementation has been shown to attenuate the decline in some measures of immune function after exercise. The purpose of the study was to investigate the impact of CHO supplementation on salivary immunoglobulin A (s-IgA) levels, interleukin 2 (IL-2), and interleukin 5 (IL-5), following an acute bout of resistance exercise (RE). METHODS: Ten resistance trained male collegiate athletes (21±2 yr; 174±6 cm, 80±11kg, 14%±4% fat) performed RE consisting of four exercises (leg press, lat pull-downs, bench press, and leg curls). Volunteers performed four sets of 10 repetitions at 65% of 1-RM, with 2 min rest between sets for all exercises. Subjects consumed either CHO beverage (1 g•kg-1 body weight) or placebo (P) prior to, during, and after RE (randomized, double blind design). Saliva and venous blood were collected pre-, post- and 90 min post-exercise. RESULTS: No change occurred in s-IgA from rest relative to osmolality or as a secretion rate (p > 0.05). IL-2 levels were unchanged by exercise in both trials (time effect p = 0.342). IL-5 was significantly (time effect p = 0.04) decreased between rest (1.55 ± 0.07 pg•ml-1) and 90 min post-exercise (0.96 ± 0 .11 pg•ml-1), with no difference between treatments (group x time effect p = 0.610). There was no time-by-treatment interaction (p < 0.05) observed between CHO and P treatments for s-IgA or IL-5. CONCLUSION: IL-5 decreases after RE, but s-IgA and IL-2 levels remain stable. CHO ingestion prior to-, during or following RE did not appear to alter salivary immune responses.

Changes in transcriptional output of human peripheral blood mononuclear cells following resistance exercise.

Various types of exercise alter the population of circulating peripheral blood mononuclear cells (PBMCs) and change their transcriptional output. This work examines changes in PBMC populations and transcription in response to resistance exercise training (RET), and identify key transcriptional changes in PBMCs that may play a role in altering peripheral tissues in response to RET. Ten resistance-trained men (20-24 years), performed an acute bout of RET for ~30 min following a 12 h fast. Venous blood was sampled at rest, immediately following exercise, and at 2 h post-exercise and analyzed for total and differential leukocytes and global gene expression using Affymetrix Genechips. Results showed elevated leukocytes, monocytes, lymphocytes, and lactate values immediately post-exercise (P < 0.05) over baseline. At 2 h post-exercise, leukocytes, and granulocytes remained elevated (P < 0.05), whereas lymphocytes were lower than (P < 0.05) baseline values. Initial microarray results showed the greatest transcriptional changes in pathways related to immune response, inflammation, and cellular communication. The change in PBMC population (2 h time point) correlated with a dramatic decrease in the expression of CD160, and XCL1, markers of lymphocyte populations. At the 2 h recovery time point upregulation of matrix metalloproteinase 9, orosomucoid 1, dishevelled-associated activator of morphogenesis 2, and arginase 1 suggest an induction in muscle damage and repair during this time frame. These results demonstrate that an acute bout of RET disrupts cellular homeostasis, induces a transient redistribution of certain leukocytes, and results in transcriptional changes in PBMCs translating into systemic changes in response to RET.

Carbohydrate supplementation and immune responses after acute exhaustive resistance exercise.

This investigation sought to study changes in leukocyte subsets after an acute bout of resistance exercise (ARE) and to determine whether ingestion of carbohydrate (CHO) could attenuate those immune responses. Nine male track-and-field athletes (21.1 +/- 1.4 yr, 177.2 +/- 5.5 cm, 80.9 +/- 9.7 kg, 8.7% +/- 3.8% fat) and 10 male ice hockey athletes (21.0 +/- 2.2 yr, 174.3 +/- 6.2 cm, 79.6 +/-11.1 kg, 13.9% +/- 3.73% fat) participated in 2 different ARE protocols. Both experiments employed a counterbalanced double-blind research design, wherein participants consumed either a CHO (1 g/kg body weight) or placebo beverage before, during, and after a weight-lifting session. Serum cortisol decreased (p < .05) at 90 min into recovery compared with immediately postexercise. Plasma lactate, total leukocyte, neutrophil, and monocyte concentrations increased (p < .05) from baseline to immediately postexercise. Lymphocytes decreased significantly (p < .05) from baseline to 90 min postexercise. Lymphocytes were lower (p < .05) for the CHO condition than for placebo. The findings of this study indicate the following: ARE appears to evoke changes in immune cells similar to those previously reported during endurance exercise, and CHO ingestion attenuates lymphocytosis after ARE.