The Role of Sports Clothing in Thermoregulation, Comfort, and Performance During Exercise in the Heat: A Narrative Review.

The aims of this review are to (1) summarise the current research of sports clothing as it relates to thermoregulation, comfort, and performance during exercise in the heat, (2) identify methodological limitations and gaps in the knowledge base of sports clothing, and (3) provide recommendations for exercise testing protocols to accurately assess the impact of sports clothing in athletic populations during exercise in the heat. Sports clothing consists of lightweight and breathable fabrics, surface treatments, and various designs which aim to enhance sweat evaporation and comfort during exercise in the heat. Sports clothing comprised of natural, synthetic, and chemically treated fabrics has been investigated during exercise of varying durations (15-120 min), intensities (20-70% VO2 max) and types (fixed intensity, incremental, self-paced), and in an array of climatic conditions (18-40 °C, 20-60% relative humidity). To date, few studies have identified significant differences in thermo-physiological, perceptual, and performance measures between natural and synthetic fabrics or compared the effect of chemical treatments to their non-treated equivalent on such measures during exercise. Collectively, previous wearer trials have failed to replicate the upper limit of training and competition demands when assessing sports clothing in endurance-trained individuals who regularly train and compete in hot and humid climates. Clothing comfort has also been evaluated using simple scales which fail to capture intricate detail pertaining to psychological and sensorial parameters. The incorporation of protocols using hot and humid climates (≥ 30 °C, ≥ 70% relative humidity) and longer exercise durations (> 45 min) is warranted. Future research should also consider exploring the effect of sports clothing on thermal, physiological, perceptual, and performance measures between males and females, and assessing clothing comfort using a multi-dimensional approach.

The assessment of a novel lower body resistance garment as a mechanism to increase the training stimulus during running: a randomised cross-over study.

BACKGROUND: This study examined the physiological and perceived impact of wearing a novel lower body resistance garment during exercise and recovery. METHODS: Using a randomised cross-over design, 15 recreationally-active males performed 2 × 10-min steady-state runs followed by a 10-min passive recovery with concomitant monitoring of oxygen consumption (V̇O2), heart rate (HR) and rating of perceived exertion (RPE; exercise portion only), wearing either the resistance garment (experimental) or running shorts (control). RESULTS: During exercise, there was a trend for V̇O2 and RPE to be higher (4.5% and 7.7% respectively) in experimental than control (V̇O2: r = 0.24, p > 0.05; RPE: r = 0.32, p > 0.05) and for HR to be lower (- 0.4%, r = - 0.05, p > 0.05). During recovery, V̇O2 and HR tended to be lower (4.7% and 4.3% respectively) in experimental than control (V̇O2: r = - 0.32, p > 0.05; HR: r = - 0.27, p > 0.05). CONCLUSIONS: Though effects were trivial to small, and not statistically significant, these findings provide proof of concept and suggest that this garment design may increase the training stimulus during running and aid post-exercise recovery.

The Effect of Normobaric Hypoxia on Resistance Training Adaptations in Older Adults.

ABSTRACT: Allsopp, GL, Hoffmann, SM, Feros, SA, Pasco, JA, Russell, AP, and Wright, CR. The effect of normobaric hypoxia on resistance training adaptations in older adults. J Strength Cond Res 36(8): 2306-2312, 2022-The effect of normobaric hypoxia on strength, body composition, and cardiovascular fitness was investigated after a resistance training intervention in older adults. A single-blinded, randomized control trial recruited 20 healthy adults aged 60-75 years for an 8-week resistance training intervention in normoxia ( n = 10) or normobaric hypoxia (14.4% O 2 ; n = 10). Subjects performed 2 sessions per week of upper-body and lower-body exercises at 70% of 1 repetition maximum (1RM). Pretraining and post-training, maximal oxygen uptake (V̇O 2 max), muscular endurance (30 maximal knee flexions/extensions), and 5RM were assessed, with 5RM used to calculate 1RM. Subjects underwent whole-body dual-energy x-ray absorptiometry (DXA) at pretraining and post-training for fat and lean mass quantification. Significance was set at p < 0.05. Subjects in both groups substantially improved their calculated 1RM strength for leg extension, pectoral fly, row, and squat (normoxia; 30, 38, 27, and 29%, hypoxia; 43, 50, 28, and 64%, respectively); however, hypoxia did not augment this response. Hypoxia did not enhance V̇O 2 max or muscular endurance responses after the training intervention, with no improvements seen in either group. Fat mass and lean mass remained unchanged in both groups after the intervention. In summary, 8 weeks of resistance training in hypoxia was well tolerated in healthy older adults and increased upper-body and lower-body strength. However, the magnitude of strength and lean muscle improvements in hypoxia was no greater than normoxia; therefore, there is currently no evidence to support the use of hypoxic resistance training in older adults.

Behaviors and Actions of the Strength and Conditioning Coach in Fostering a Positive Coach-Athlete Relationship.

ABSTRACT: Carson, F, Blakey, M, Foulds, SJ, Hinck, K, and Hoffmann, SM. Behaviors and actions of the strength and conditioning coach in fostering a positive coach-athlete relationship. J Strength Cond Res 36(11): 3256-3263, 2022-A number of models have been developed to explain the various factors that affect coach-athlete interactions; however, they have had limited application to strength and conditioning (S&C). A systematic review of the literature was completed using the databases SPORTDiscus Full Text, MEDLINE, Global Health, Academic Search Complete, and PsychINFO, sourcing articles related to S&C coach-athlete relationships. An initial search yielded 1,364 articles, which when screened against the inclusion criteria was narrowed to 8 articles relating specifically to the S&C coach-athlete relationship. Four major themes were identified throughout the included articles: leadership styles; perceptions of leadership; coach knowledge, experience, and training; and building relationships. These themes highlighted that positive coach-athlete interactions are fostered through a mutual understanding of the S&C coach's responsibility to improve performance and reduce injury through scientific methods, with an awareness of different psychosocial behaviors of both the coach and the athlete. This will create a mutual interconnectedness whereby both parties can participate in a functional dyad. Three practical applications deduced from the findings identified the importance of building an autonomy-supportive environment, keeping knowledge and expertise at a high standard, and embracing the whole person rather than just the athlete. These teachings aim to guide S&C coaches through the necessary actions and behaviors recommended to successfully build and foster positive S&C coach-athlete relationships.

The Efficacy of the Lactate Threshold: A Sex-Based Comparison.

Hoffmann, SM, Skinner, TL, van Rosendal, SP, Osborne, MA, Emmerton, LM, and Jenkins, DG. The efficacy of the lactate threshold: A sex-based comparison. J Strength Cond Res 34(11): 3190-3198, 2020-The second lactate threshold (LT2) has previously been associated with endurance performance; however, comparisons between sexes are lacking regarding its efficacy. The aim of this study was to compare LT2 between men and women, specifically regarding its (a) relationship with endurance performance and (b) capacity to establish training and competition intensities. Competitive male (mean ± SD: age, 27.7 ± 4.7 years; V[Combining Dot Above]O2max, 59.7 ± 5.2 ml·kg·min; n = 10) and female (mean ± SD: age, 27.3 ± 6.2 years; V[Combining Dot Above]O2max, 54.5 ± 5.3 ml·kg·min; n = 12) cyclists and triathletes completed an incremental cycle trial to volitional fatigue (for determination of V[Combining Dot Above]O2max and LT2 via the modified D-max method), a constant load (±5%) exercise trial of 30 minutes at LT2 power output, and a 40-km cycle time trial. The LT2 significantly correlated with 40-km cycling performance in both men (r = -0.69 to -0.77; p < 0.01-0.05) and women (r = -0.63 to -0.75; p < 0.01-0.05). All men sustained LT2 power output for 30 minutes, compared with 82% of women. Despite LT2 reflecting a similar heart rate, V[Combining Dot Above]O2, and [La] to those elicited during a 40-km time trial in both men and women, power output at LT2 was 6% higher (p < 0.05) than mean time trial power output in women, with no significant difference in men. Based on these findings, sex-specific recommendations have been suggested in regard to the use of LT2 for establishing performance potential, prescribing endurance training intensities and setting 40-km performance intensity.

The Coach-Athlete Relationship in Strength and Conditioning: High Performance Athletes' Perceptions.

The primary purpose of this study was to investigate high performance athlete perceptions of strength and conditioning coaches, specifically, (1) their character traits, (2) the effective behaviours that display these traits, and (3) how these relationships were fostered. Using the 3+1 C's model of coach-athlete relationships as a framework (Jowett, 2007), 12 semi-structured interviews were conducted with high performance athletes (six female; six male) representing a variety of sports (i.e., freestyle wrestling, triathlon, field hockey, cycling, rowing, rugby union, netball, table tennis, and ice hockey). Participants ranged in age from 18 to 53 years (M = 29, SD = 9). Interviews took between 19-47 min and were transcribed verbatim. The transcripts equated to a total of 188 pages of data that were analyzed, coded, and further grouped into higher-order themes and general dimensions. The findings revealed 14 higher-order themes categorized under the 3+1 C's general dimensions of closeness, commitment, complementarity, and co-orientation.