Despite the rapidly emerging evidence on the contributions of physical activity to improving cancer-related health outcomes, adherence to physical activity among young adults with lymphoma remains suboptimal. Guided by self-determination theory (SDT), the Lymfit intervention (a 12-week individualized exercise program with bi-weekly kinesiologist support and an activity tracker) aimed to foster autonomous motivation toward physical activity. This pilot randomized controlled trial aimed to evaluate the feasibility, acceptability, and preliminary effects of Lymfit. Young adults (N = 26; mean age of 32.1 years) with lymphoma who were newly diagnosed and those up to six months after completing treatment were recruited and randomly assigned one-to-one to either the intervention group (n = 13) or a wait-list control group (n = 13). All a priori feasibility benchmarks were met, confirming the feasibility of the study in terms of recruitment uptake, retention, questionnaire completion, intervention fidelity, missing data, Fitbit wear adherence, and control group design. The intervention acceptability assessment showed high ratings, with eight out of ten items receiving >80% high ratings. At post-intervention, an analysis of covariance models showed a clinically significant increase in self-reported physical activity levels, psychological need satisfaction, and exercise motivation in the intervention group compared to controls. Lymfit also led to meaningful changes in six quality-of-life domains in the intervention group, including anxiety, depression, fatigue, sleep disturbance, social roles and activities, and pain interference. The findings support Lymfit as a promising means to meet psychological needs and increase the autonomous motivation for physical activity in this group. A fully powered efficacy trial is warranted to assess the validity of these findings.

Background and objectiveTreatments of lymphoma can lead to reduced physical functioning, cancer-related fatigue, depression, anxiety, and insomnia. These side effects can negatively impact the cancer survivor's quality of life. Mounting evidence indicates that physical activities are highly therapeutic in mitigating the short- and long-term side effects of cancer treatments. Yet, lymphoma survivors' participation in physical activities remains suboptimal, which has been further exacerbated by the deleterious effects of isolation during the COVID-19 pandemic. The Lymfit intervention aims to offer motivational support, expert guidance, and a personalized exercise prescription to optimize physical activities among lymphoma survivors. This proof-of-concept study explores implementation feasibility (retention, technical and safety), and the preliminary effects of Lymfit on various health outcomes.MethodThis was a single-armed trial with a pre-and post-test design. Twenty lymphoma survivors were recruited to participate in the 12-week Lymfit intervention. Wearable activity trackers (Fitbit) were given to participants as a motivational tool and for data collection purposes. Participants received a personalized exercise prescription designed by a kinesiologist. Physiologic metrics were collected by the Fitbit monitors and were stored in the Lymfit database. Self-reported questionnaires measuring health outcomes were collected at baseline and post-intervention.ResultsThe retention rate of this trial was 70%. Minimal technical issues and no adverse effects were reported. Lymfit led to significant improvements in sleep disturbances and the ability to participate in social activities and decreased fear of cancer recurrence. It also increased daily steps and decreased sedentary time in participants who did not meet the recommended physical activity guidelines.SignificanceWith access to resources and fitness centers being limited during the pandemic, the Lymfit intervention filled an immediate need to provide physical activity guidance to lymphoma survivors. Findings provide preliminary support that implementing the Lymfit intervention is feasible and demonstrated promising results.

Traditionally, models developed to estimate resting energy expenditure (REE) in the bariatric population have been limited to linear modelling based on data from `normal' or `overweight' individuals - not `obese'. This type of modelling can be restrictive and yield functions which poorly estimate this important physiological outcome.Linear and nonlinear models of REE for individuals after bariatric surgery are developed with linear regression and symbolic regression via genetic programming. Features not traditionally used in REE modelling were also incorporated and analyzed and genetic programming's intrinsic feature selection was used as a measure of feature importance.A collection of effective new linear and nonlinear models were generated. The linear models generated outperformed the nonlinear on testing data, although the nonlinear models fit the training data better. Ultimately, the newly developed linear models showed an improvement over existing models and the feature importance analysis suggested that the typically used features (age, weight, and height) were the most important.

Objective: To estimate, among people with multiple sclerosis, the extent to which a personally tailored exercise programme (MSTEP©) resulted in greater improvements in exercise capacity and related outcomes over 12 months in comparison with general exercise guidelines. Design: Two-group randomized trial. Subjects: Ambulatory and sedentary. Interventions: MSTEP©, a personally adapted exercise regimen done on most days including two days of high intensity exercise; guidelines recommending 30 minutes of moderate intensity aerobic and strength training two times per week. Main measures: Primary outcome was peak oxygen consumption (VO2peak) at 12 months; secondary outcomes were composite measures of physical function, fatigue, and health-related quality of life. Results: In total, 137 people were randomized, 66 were lost over 12 months leaving 71 with outcome data, 34 in MSTEP© group, and 37 in the Guideline group. Exercise enjoyment and confidence and exercise-induced fatigue predicted retention. There were no differences between groups on the proportion making a 10% increase in VO2peak (27.1% MSTEP© vs 29.6% Guidelines; OR: 0.83; 95% CI: 0.23–3.08) by the 12 month assessment. The effect on fatigue was larger in the MSTEP© group than the Guideline groups (OR: 1.59; 95% CI: 0.93–2.74), the effect on physical function was more modest (OR: 1.35; 95% CI: 0.80–2.25), and null for health-related quality of life outcomes. Conclusions: The disappointing exercise retention suggests that people with multiple sclerosis may not consider exercise important to their brain health. Either type of exercise resulted in stable exercise capacity over 1 year in those sticking with the programme.

Fat free mass index (FFMI) in an athletic female population is computed as (bone mineral content + lean mass / height2). It has been associated with performance and training status in their relevant sport, collegiate female athletes need to optimize bone mineral density (BMD), and lean mass as multiple factors impact their levels, including: the type of sport, nutrition, menstrual cycle, training program variation, lifestyle habits, and genetics. PURPOSE: To compare FFMI and lower body BMD across female collegiate athletes and sedentary control considering their desired sport-specific performance and training. METHODS: A sample of 68 women (Mean±SD; Age: 20.89±1.91 yrs, Height: 1.65±0.07 m, and Weight: 62.25±10.11 kg) including 43 females collegiate athletes (n= 23 hockey players, n= 20 synchronize swimmers) and 25 sedentary university students received a scan using dual-energy x-ray absorptiometry (DEXA). ANOVA was used to evaluate differences in: FFMI, and regional BMD in the spine and the femur. RESULTS: The FFMI of hockey players (18.11±1.33 kg/m2), was significantly (p<.05) higher than both the synchronized swimmers (15.43±1.25 kg/m2) and the controls (14.99±1.45 kg/m2). Hockey players, compared to synchronized swimmers and the control group, have a higher BMD of the spine, F(2, 65) = 13.391, p<.05, FFMI, F(2, 66)=37.06, p<.05. BMD of the total femur in the hockey players was great than the controls, F(2, 65)=4.06, p<.05. Total lean mass of synchronized swimmers (40.77±3.67 kg,) was greater (p<.05) than the control group (36.65±5.30kg). CONCLUSION: BMD and FFMI of the control group compared to female athletes show how sports’ demands influence bone’s health in a female collegiate population. BMD and FFMI of hockey players compared to synchronized swimmers may demonstrate the importance of percussive activities for bone health in female athletes. Differences in FFMI between female hockey players and synchronize swimmers suggest that establishing sport-specific norms in this new measure may help coaches and strength specialists better tailor training programs to optimize performance and bone health in varsity athletes.

Sleep duration improves short-term following bariatric surgery; however, little is known about its association with bodyweight medium- to long-term post-surgery. The purpose of this study was to describe sleep duration and its relationship with BMI and body composition. Forty-nine individuals, with a BMI of 36.6 ± 9.8 kg/m2, regained 26.4 ± 17.8% of their lost weight 9.5 ± 3.3 years post-surgery (range 3–16 years). Sleep logs and ActivPAL3 accelerometers were used to assess sleep duration. Participants averaged 7.9 ± 1.6 h/day and 8.5 ± 1.7 h/day of sleep for weekdays and weekends, respectively (P < 0.01). A positive association between delta weekend-weekday sleep timing midpoint with BMI (β = 0.03, 95% CI = 0.01, 0.06; P = 0.01) was noted in the multivariable-adjusted model. On average, this sample achieved recommended sleep durations medium- to long-term post-surgery. Having an earlier sleep timing midpoint during the weekend may be associated with lower BMI.

Obesity can negatively influence walking cadence, reducing the overall intensity of daily activities and increasing the risk of weight gain. Objectively describe the walking cadence of individuals’ long-term post-bariatric surgery. Fifty-eight participants, 51.2 ± 8.9 years old, with a BMI of 34.6 ± 10.1 kg/m2, 10.0 ± 3.1 years post-surgery wore an activPAL accelerometer for 7 consecutive days. Data was analyzed using participants’ current BMI, dichotomized by obesity status, < or ≥ 30 kg/m2. On average, participants walked 5124 ± 2549 steps/day on weekdays and 6097 ± 2786 steps/day on weekend days (p = .003). Participants spent the majority (75%) of their daily steps at a slow-walking average cadence (non-obese: week = 65.3 ± 5.0 steps/min and weekend = 63.8 ± 6.7 steps/min; obese: week = 67.8 ± 8.2 steps/min and weekend = 63.3 ± 6.9 steps/min), with no difference between groups for week or weekend days (p = .153 and .774). The cadence of participants with obesity was significantly lower on weekends compared to weekdays for walking events > 30 s (p = .002) and > 60 s (p = .008) in duration. Weekday cadence of participants without obesity was similar to weekend day cadence across all walking event durations. The majority of walking events occurred below 30 s in duration for all participants. Long-term post-bariatric surgery, movement occurs in short duration bouts at a slow-walking cadence for the majority of movement. Individuals without obesity had similar movement patterns from week to weekend days while participants with obesity significantly lowered their cadence on weekend days.

A collegiate athlete’s body composition can fluctuate due to factors such as nutrition, sleep, and training load. As changes in body composition can affect an athlete’s level of performance, it may be beneficial if athlete’s can accurately predict these changes throughout a season. The purpose of this study was to determine how well a group of 23 male collegiate hockey players (age = 22.44 ± 1.16 years, height = 181.30 ± 6.99 cm, weight = 86.41 ± 8.32 kg) could predict their regional and total body lean and fat tissue mass throughout a hockey season (September to March). Total body, trunk, lower body, and upper body compositional changes were measured at the beginning and at the end of the competitive season using dual energy X-Ray absorptiometry (DXA). At the end of the season, a questionnaire was completed by each participant to explore how they perceived their body composition changes (losses or gains in lean tissue and fat mass) throughout the season. Overall, players had a difficult time identifying actual changes in lean tissue and fat mass throughout the season. Upper body fat and lean tissue changes were perceived most accurately, while perceptions of body fat were related to android adiposity but not visceral adiposity. These findings suggest that some regional areas of body composition changes may happen without being noticed. For strength and conditioning coaches, if athletes are made aware of these changes before they become exaggerated, proper dietary, and training adaptations can be made to enhance performance.

Inactivity and weight regain are serious problems post-bariatric surgery. Nearly half of waking time is spent at work, representing an opportunity to accumulate physical activity and help avoid weight regain.

The combined athletic and academic demands place a significant burden on collegiate hockey players. Numerous cross-sectional studies have been conducted with professional hockey players assessing body composition and skeletal fitness; yet, no research has investigated the longitudinal physiologic changes among elite collegiate athletes. PURPOSE: To examine changes in body composition and physiologic tests across a player’s collegiate hockey career. METHODS: Over three seasons, six elite male Canadian university hockey players (age = 21.35 ± .28 years, weight = 84.53 ± 7.26 kg , height = 179.48 ± 7.60 cm, body fat percentage = 15.55 ± 1.68% at baseline) participated in the study at the beginning of their hockey seasons. All participants underwent physical testing (as outlined in the 2016 NHL combine) and a day after testing, one total body dual energy x-ray absorptiometry (DXA) scan to measure body composition. RESULTS: A repeated measures ANOVA was used to track body composition and physiologic performance variables over a three-year period. Players gained body weight (1.66 ± 1.96 kg), total body fat percentage (2.83 ± 1.91%), visceral adiposity (.16 ± .15 kg), upper fat mass (1.57 ± 1.20 kg), and lower fat mass (.52 ± .36 kg) (p < .05 for all comparisons). Total and regional lean tissue mass stayed relatively constant throughout their careers. There were no significant changes in agility scores, left grip strength, long jump distance or impulse generated in the vertical jump as all of these assessments stayed relatively consistent throughout the seasons. As players progressed through their careers, they achieved significantly more bench press repetitions, pull-ups, and had higher Wingate peak power scores (p < .05 for all comparisons). CONCLUSIONS: Pilot findings suggest that as players progress through their collegiate hockey careers, they gain weight, total and regional body fat, and are typically stronger in respects to some fitness tests. With this knowledge, strength and conditioning coaches can work in tandem with food scientists and nutritionists to optimize meal plans in an effort to prevent weight and adipose tissue gain which may enhance on-ice play and player health across their three-year university careers.

The aim of this study was to elucidate the physiological mechanisms of exertional dyspnea relief following weight loss for severe obesity. To this end, we compared detailed physiological and perceptual responses to symptom-limited incremental cycle exercise testing in 6 adults (3 W) mean±SE aged 44±3 yrs before (PRE) and 3-mo after Roux-en-Y gastric bypass surgery (POST), which decreased body mass by 24 kg (129±6 vs.106±6 kg), body mass index by 9 kg/m2 (47±2 vs. 38±2 kg/m2) and fat mass by 19 kg (62±5 vs. 43±5 kg). Peak power output was similar in POST vs. PRE (154±21 vs. 133±11 W). With few exceptions, heart rate, oxygen uptake and ventilation (V̇E) were lower during exercise in POST vs. PRE. Inspiratory capacity (IC) decreased by 0.13 L and increased by 0.21 L from rest to peak exercise in PRE and POST, respectively. Inspiratory reserve volume (IRV) was lower at any given V̇E during exercise in POST vs. PRE, reflecting the combination of differences in the behavior of dynamic IC and adoption of a relatively deep and slow breathing pattern during exercise in POST. Dyspnea ratings were lower during exercise at standardized submaximal power outputs greater than 75W in POST vs. PRE, whereas dyspnea-V̇E relationships were superimposed. Dyspnea-IRV relationships were rightward shifted during exercise in POST vs. PRE, such that dyspnea ratings were lower at any given IRV during exercise in POST vs. PRE. In conclusion, relief of exertional dyspnea following bariatric surgery could not be explained by improved dynamic breathing mechanics, but reflected the awareness of reduced V̇E during exercise.

Purpose: The primary aim was to assess the accuracy of common prediction equations, the Harris-Benedict (HB) and the Mifflin St. Jeor (MSJ) equations, for estimating resting energy expenditure (REE) among people with spinal cord injury (SCI) against actual REE measurements. The secondary aim was to cross-validate the Buchholz et al. energy prediction equation created for people with SCI. Methods: A metabolic cart with canopy was used to measure the actual REE. The HB, MSJ, and the Buchholz et al. equations were used for the prediction of REE. Results: Thirty-nine participants (31 males and 8 females) were enrolled in this cross-sectional study. The REEs significantly differed from one another, F(1.52, 57.68) = 52.04, P < 0.001, where both the HB (M = 1703.06, SD = 265.1) and the MSJ (M = 1628.92, SD = 233.8) energy predictions were significantly higher (P < 0.001) than the measured REE (M = 1394.05, SD = 298.7). In contrast, the Buchholz et al. equation did not differ from the measured REE. Conclusions: Our data show that the HB and MSJ equations do not accurately predict the energy needs of this community. Using a SCI-specific equation would improve estimates of REE, such as the Buchholz et al. equation. More research into energy equations for this population may help health care professionals better tailor dietary requirements for weight management.

Delisle-Houde, P, Chiarlitti, NA, Reid, RER, and Andersen, RE. Relationship between physiologic tests, body composition changes, and on-ice playing time in canadian collegiate hockey players. J Strength Cond Res 32(5): 1297-1302, 2018-Hockey player's body composition and physical fitness are suggested to influence coaching decisions regarding on-ice playing time. The purpose of this study was to explore the relationship between seasonal body composition changes, off-ice preseason testing, and on-ice metrics. Twenty-one Canadian collegiate hockey players (22.70 ± 1.30 years old, 181.0 ± 5.92 cm, 86.52 ± 6.41 kg) underwent off-ice physical testing at the beginning of their season and had one total body dual energy x-ray absorptiometry scan at the beginning and end of the season. The team's statistician tracked all on-ice metrics. Pearson correlations were used to explore relationships between off-ice tests (long jump, vertical jump, beep test, and Wingate test), change in body composition (body fat percentage, visceral adiposity, and total lean tissue mass), and on-ice performance (average time on ice, average shift length, power play time, penalty kill time, and shot differential). Long jump was correlated with shot differential (r = -0.532, p ≤ 0.05) and average shift length (r = -0.491, p ≤ 0.05) while fatigue index was correlated with average ice time (r = -0.476, p ≤ 0.05). Hockey performance is a complex interaction of player's body compositions and skeletal fitness that interact to affect on-ice playing metrics.

PURPOSE: Collegiate athletics are known to affect body composition, strength, and bone characteristics. However, it is unknown which sport is most beneficial for increased bone mineral density (BMD). To compare the BMD of female collegiate athletes (n=102) who compete in impact loading sports; ice hockey players (HP; n=24), cheerleading (CH; n=22), and ballet dancers (BD; N=10) to female athletes in active loading sports; synchronized swimmers (SS; n=20), and sedentary controls (SC; N = 26). METHODS: Participants underwent a total body, lumbar spine and femoral neck iDXA scan to evaluate BMD. Participants aged 20.5 ±1.8 years and weighed 61.3 ±9.8kg. ANCOVA compared BMD of the femoral neck, greater trochanter, total femoral, and lumbar spine (L1-L4) by sport while controlling for age. RESULTS: HP had the most regular menstrual cycles (83%), followed by SS (75%), SC (65%), CH (64%). BD had the least regular cycles (50%) and many were oligomenorrheic. BD and HP had a significantly higher BMD in the femoral neck and greater trochanter as compared to all other groups (p≤0.05; p≤0.001). However, HP had significantly higher total femoral BMD than CH, SS and SC. BD demonstrated higher femoral BMD compared to CH, SS and SC (p≤0.01). Analysis of the BMD in the lumbar spine revealed that HP and BD had significantly higher BMD as compared to the SS and SC (1.14±0.12g/cm2). Furthermore, there was no statistical difference between BD and the CH. However, CH had higher lumbar spine BMD than the SS and the SC (p≤0.00) (Table 1).Table 1: BMD by Sport TypeCONCLUSION: Although, ballet is an aesthetic sport as compared to hockey, both offer superior benefits to bone health than cheerleading, synchronized swimming, and being sedentary. The high prevalence of menstrual irregularity in the ballet dancers did not appear to negatively influence BMD. These results suggest that monitoring bone health in female athletes participating in low impact sports should be a priority.

Smokers typically exhibit lower body weights than non-smokers despite poorer metabolic and physiologic profiles. Nicotine, an appetite suppressant found in cigarettes and cigars, may play a role in weight control. Physical activity also contributes to lower body weights; however, this simultaneously reduces all-cause mortality, risk of coronary artery disease, and other chronic conditions. PURPOSE: To investigate if smoking status has an impact on weight loss and physical activity levels in patients 1-17 years after Roux-en-Y gastric bypass (RYGB). METHODS: A total of 509 individuals who had previously undergone RYGB (1-17 years post) were recruited for this study. To assess physical activity habits, participants were asked, “How many times per week do you exercise for 30 min or more at an intensity that makes you sweat or breathe hard?” Participants were also asked if they were a current smoker, ex-smoker or never smoked. RESULTS: The sample consisted of 22% smokers (114 total, 81 females), 47% never- smokers (239 total, 190 females) and 31% ex-smokers (156 total, 120 females). There were no significant differences in smoking status (p=.45) or physical activity (p=.57) between sexes. Current smokers had the highest BMI change (-21.2±.8kg/m2) compared to both never-smokers (-18.8±.6kg/m2; p=.01) and ex-smokers (-18.7±.7kg/m2; p=.02) while there was no significant difference between never-smokers and ex-smokers (p=.97). Ex-smokers reported being significantly more active (1.7±1.9bouts) compared to current smokers (1.1±1.7bouts; p=.01) while there were no differences in activity between never-smokers (1.5±1.7bouts) and current smokers (p=.07). CONCLUSIONS: Although smokers lost the greatest amount of weight post-surgery, they also reported being inadequately active. Post-surgical follow-ups should evaluate numerous health measures as indicators of surgical success, as long term weight change may also be equally affected by both healthy and unhealthy habits.

Eccentric ergometer training (EET) is increasingly being proposed as a therapeutic strategy to improve skeletal muscle strength in various cardiorespiratory diseases, due to the principle that lengthening muscle actions lead to high force-generating capacity at low cardiopulmonary load. One clinical population that may particularly benefit from this strategy is chronic obstructive pulmonary disease (COPD), as ventilatory constraints and locomotor muscle dysfunction often limit efficacy of conventional exercise rehabilitation in patients with severe disease. While the feasibility of EET for COPD has been established, the nature and extent of adaptation within COPD muscle is unknown. The aim of this study was therefore to characterize the locomotor muscle adaptations to EET in patients with severe COPD, and compare them with adaptations gained through conventional concentric ergometer training (CET). Male patients were randomized to either EET (n = 8) or CET (n = 7) for 10 weeks and matched for heart rate intensity. EET patients trained on average at a workload that was three times that of CET, at a lower perception of leg fatigue and dyspnea. EET led to increases in isometric peak strength and relative thigh mass (p < 0.01) whereas CET had no such effect. However, EET did not result in fiber hypertrophy, as morphometric analysis of muscle biopsies showed no increase in mean fiber cross-sectional area (p = 0.82), with variability in the direction and magnitude of fiber-type responses (20% increase in Type 1, p = 0.18; 4% decrease in Type 2a, p = 0.37) compared to CET (26% increase in Type 1, p = 0.04; 15% increase in Type 2a, p = 0.09). EET had no impact on mitochondrial adaptation, as revealed by lack of change in markers of mitochondrial biogenesis, content and respiration, which contrasted to improvements (p < 0.05) within CET muscle. While future study is needed to more definitively determine the effects of EET on fiber hypertrophy and associated underlying molecular signaling pathways in COPD locomotor muscle, our findings promote the implementation of this strategy to improve muscle strength. Furthermore, contrasting mitochondrial adaptations suggest evaluation of a sequential paradigm of eccentric followed by concentric cycling as a means of augmenting the training response and attenuating skeletal muscle dysfunction in patients with advanced COPD.

Consistent physical activity (PA) is one of the strongest predictors of successful long-term weight loss maintenance. However, joint pain is common among severely obese patients and is a significant barrier to regular PA. PURPOSE: Our goal was to compare the prevalence of hip, knee, and back/other pain before and after bariatric surgery and explore interrelationships among joint pain, BMI, and PA. METHODS: Data were drawn from a convenience sample of adults undergoing bariatric surgery at an urban academic center. In a phone survey, participants reported whether they had experienced knee, hip, and/or back/other pain prior to surgery, and changes in joint pain post-surgery. We compared BMI and PA by pain status (improved vs. same/worse) using t-tests and chi-square. RESULTS: The 285 participants had undergone surgery a mean (SD) of 10 (3) years earlier. At follow up [FU], participants had an average age of 51 (10), BMI of 34.4 (8.4), and change in BMI of -19.0 (9.4); 191 (68%) had a BMI≥30. Prior to surgery, 21-45% reported joint pain; at FU, 123 (43%) reported no pain; 80 (28%); 66 (23%); and 16 (6%) reported pain in 1,2, or 3 joint regions, and 62 (22%) were on NSAIDs or analgesics. Participants who reported having less joint pain had greater reductions in BMI, and a significantly larger proportion reported being more active than prior to surgery (Table 1). Those with improved knee and back pain were also more likely to meet recommended PA guidelines. CONCLUSION: Joint pain was common among bariatric surgery patients and had improved in 34-40% even 10 years later. Improvements in pain were associated with greater reductions in BMI, greater likelihood of being more active, and of meeting PA guidelines. For the >60% with similar/worse joint pain, effective pain management strategies may be needed to facilitate reaching PA goals.

Delisle-Houde, P, Reid, RER, Insogna, JA, Chiarlitti, NA, and Andersen, RE. Seasonal changes in physiological responses and body composition during a competitive season in male and female elite collegiate ice hockey players. J Strength Cond Res 33(8): 2162-2169, 2019-Ice hockey continually overloads athletes with limited time for recovery, which may affect several physiological responses and alter body composition. The purpose of this study was to identify changes in physiological parameters and body composition profiles over the competitive season in elite collegiate ice hockey players. Forty-four players, 24 males (age = 22.7 ± 1.3 years, height = 1.82 ± 0.6 m, and body mass = 86.87 ± 6.44 kg) and 20 females (age = 19.9 ± 1.8 years, height = 1.66 ± 0.7 m, and body mass = 68.76 ± 5.91 kg) participated in 4-minute submaximal exercise tests and body composition assessments at pre-season, mid-season, and end-season. Changes in physiological parameters and body composition were analyzed using repeated-measures analysis of covariance controlling for age. Males' postexercise blood lactate concentration decreased (p ≤ 0.05) from pre- to mid-season (9.3 vs. 6.2 mmol·L) and increased (p ≤ 0.05) from mid- to end-season (6.2 vs. 8.0 mmol·L). Heart rate increased (p ≤ 0.05) after the third and fourth minute of the submaximal test in both sexes from pre- to end-season and from mid- to end-season. Males' body fat percentage decreased (p ≤ 0.05) from mid-season (17.4 vs. 16.1%), whereas increases were observed (p ≤ 0.05) in both sexes from mid- to end-season. This study produced evidence that male and female collegiate hockey athletes' physiological responses and body composition profiles change over the season. Sport scientists working with collegiate hockey teams, may need to revise annual training programs to attenuate reductions in fitness and hopefully prevent injuries.

To optimize the health and sport performance in athletes, sport scientists have recently turned to monitoring physiological variables and markers of performance. Currently, preferred types of monitoring have not been identified and past research has shown that males and females might react differently to physiological stress. PURPOSE: To compare the physiological response of male and female elite collegiate hockey players after a 4-minute submaximal cycling test performed at a predicted 75% of VO2max. METHODS: 52 elite Canadian collegiate hockey players, 28 males (age = 22.6±1.3, height =182.59 ±6.00 cm, weight = 87.12±6.43 kg, body fat = 17.3±4.28%) and 24 females (age = 19.9±1.3, height =166.97 ±7.20 cm, weight = 67.75±8.10kg, body fat = 26.3±4.68%) participated in a 4-minute submaximal cycling test at a predicted 75% of VO2max. Heart rate (HR) and rate of perceived exertion (RPE) were assessed during each stage and after the submaximal test, while blood lactate level was measured 2 minutes after the test. ANOVA was used to compare sex differences in HR, RPE and post exercise blood lactate. SUMMARY OF RESULTS: Females had higher heart rates at each stage of the exercise test: time 1 (F(1,51) = 5.914, p ≤ .05), time 2 (F(1,51) = 14.457, p ≤ .05), time 3 (F(1,51) = 15.299, p ≤ .05) and time 4 (F(1,51) = 14.628, p ≤ .05). There were no between sex differences in post exercise blood lactate and RPE at any stage of the exercise test. CONCLUSION: Under similar physiological stress, male and female athletes demonstrate similar post exercise blood lactate levels. However, submaximal heart rates at each stage of the submaximal test were higher among the female athletes. More work is needed to understand cardio-metabolic sex differences, which could help sport scientists better tailor training program for elite female athletes. This novel method of testing may be suitable for tracking physical fitness over the course of a playing season for male and female athletes.