Koral, J, Oranchuk, DJ, Herrera, R, and Millet, GY. Six sessions of sprint interval training improves running performance in trained athletes.J Strength Cond Res32(3): 617–623, 2018—Sprint interval training (SIT) is gaining popularity with endurance athletes. Various studies have shown that SIT allows for similar or greater endurance, strength, and power performance improvements than traditional endurance training but demands less time and volume. One of the main limitations in SIT research is that most studies were performed in a laboratory using expensive treadmills or ergometers. The aim of this study was to assess the performance effects of a novel short-term and highly accessible training protocol based on maximal shuttle runs in the field (SIT-F). Sixteen (12 male, 4 female) trained trail runners completed a 2-week procedure consisting of 4–7 bouts of 30 seconds at maximal intensity interspersed by 4 minutes of recovery, 3 times a week. Maximal aerobic speed (MAS), time to exhaustion at 90% of MAS before test (Tmax at 90% MAS), and 3,000-m time trial (TT3000m) were evaluated before and after training. Data were analyzed using a paired samplest-test, and Cohen's (d) effect sizes were calculated. Maximal aerobic speed improved by 2.3% (p= 0.01,d= 0.22), whereas peak power (PP) and mean power (MP) increased by 2.4% (p= 0.009,d= 0.33) and 2.8% (p= 0.002,d= 0.41), respectively. TT3000m was 6% shorter (p< 0.001,d= 0.35), whereas Tmax at 90% MAS was 42% longer (p< 0.001,d= 0.74). Sprint interval training in the field significantly improved the 3,000-m run, time to exhaustion, PP, and MP in trained trail runners. Sprint interval training in the field is a time-efficient and cost-free means of improving both endurance and power performance in trained athletes.

Instagram (IG) reaches millions of people, sharing personal content and all kinds of information, including those related to exercise and health. However, the scientific quality of the posted information is questionable. Thus, this study aimed to analyze whether exercise and health information posted by popular Brazilian IG influencers has technical-scientific accuracy. A personal IG account was created to identify Brazilian IG profiles. The inclusion criteria of the accounts were: (1) having 50% of all the shared posts related to topics about exercise and health, such as nutrition, health and wellness, medicine, or physical fitness; and (2) having over 100,000 followers. Qualitative analysis revealed a low quality percentage (38.79 ± 25.43%) for all analyzed posts. Out of all the posts, only 13 (~2.7%) cited a reference endorsing the information. Moreover, the higher quality-ratio score of the posts was not directly associated with the higher educational qualification of the influencers (r = 0.313; p = 0.076). Nevertheless, the number of followers was inversely correlated with the educational qualification of the influencers (r = −0.450; p = 0.009), but not with the quality-ratio score of the posts (r = −0.178 p = 0.322). We conclude that prominent Brazilian IG influencers disseminate low-quality information about exercise and health, contributing to the wide-spreading of misinformation to millions of followers.

Oranchuk, DJ, Mannerberg, JM, Robinson, TL, and Nelson, MC. Eight weeks of strength and power training improves club head speed in collegiate golfers. J Strength Cond Res 34(8): 2205–2213, 2020—Club head speed (CHS) is a major determinant of drive distance, a key component of golf performance. The purpose of this study was to determine the indirect effects of an 8-week strength and power program on CHS. Twelve (6 men, 6 women) NCAA Division II golfers (20.3 ± 1.5 years) randomly assigned to an intervention or control group underwent either a periodized strength and power program consisting of high-load barbell movements or a bodyweight and rotational movement focused resistance training program. Outcomes were CHS, countermovement jump (CMJ) height, and 1RM back squat (BS), power clean (PC), and deadlift (DL). Dependent t-tests were used to assess differences in outcome variables pre-to-post for each group, independent t-tests were used to assess differences between groups, and Pearson correlations were used to assess associations between CHS and outcome variables. On average, the intervention group experienced improvements in all outcome variables except peak CHS (p = 0.60); the control group displayed no changes in any outcome variable except a decrease in average CHS (p = 0.028). Compared with the control group, the intervention group experienced greater improvements in average CHS, BS, PC, and average and peak CMJ height (p ≤ 0.05). Additionally, CHS had large associations with PC (r = 0.70, p = 0.012), BS (r = 0.64, p = 0.025), DL (r = 0.54, p = 0.068) and CMJ (r = 0.73, p = 0.007). These results suggest that improving muscular strength and power by increasing PC, BS, and CMJ is associated with increased CHS in collegiate golfers. Integrating a high-load, barbell-focused strength and power program may be beneficial for improving CHS and indirectly, golf performance.

Quantifying echo intensity (EI), a proposed measure of muscle quality, is becoming increasingly popular. Additionally, much attention has been paid to regional differences in other ultrasonically evaluated measures of muscle morphology and architecture. However, the variability of regional (proximal, middle, distal) EI of the vastus lateralis, rectus femoris, and lateral and anterior vastus intermedius has yet to be determined. Twenty participants (40 limbs), were evaluated on 3 occasions, separated by 7 days. Intersession variability of EI with and without subcutaneous fat correction was quantified. Furthermore, the interchangeability of corrected EI across regions was evaluated. Variability of regional quadriceps EI was substantially lower with subcutaneous fat correction (intraclass correlation coefficient (ICC) = 0.81–0.98, coefficient of variation (CV) = 4.5%–16.8%, typical error of measure (TEM) = 0.13–0.49) versus raw values (ICC = 0.69–0.98, CV = 7.7%–42.7%, TEM = 0.14–0.68), especially when examining the vastus intermedius (ICC = 0.81–0.95, CV = 7.1%–16.8%, TEM = 0.23–0.49 vs. ICC = 0.69–0.92, CV = 22.9%–42.7%, TEM = 0.31–0.68). With the exception of the rectus femoris and vastus intermedius (p ≥ 0.143, effect size (ES) ≤ 0.18), corrected EI was greater for proximal and distal regions when compared with the midpoint (p ≤ 0.038, ES = 0.38–0.82). Researchers and practitioners should utilize subcutaneous fat thickness correction to confidently evaluate EI at all regions of the quadriceps. Regional EI cannot be used interchangeably for the vastus muscles, likely because of an increase in fibrous content towards the myotendinous junctions. Novelty Regional quadriceps echo intensity was reliable with and without correction for subcutaneous fat thickness. Intersession variability of regional quadriceps echo intensity was substantially improved following subcutaneous fat correction. Quadriceps echo intensity increased towards myotendinous junctions in the vastus muscles.

Ultrasonography-derived cross-sectional area (CSA) and echo intensity (EI) are increasingly utilized by investigators to study muscle size and quality, respectively. We sought to examine age, sex, and region (proximal, middle, distal) differences in vastus lateralis and rectus femoris CSA and EI, and determine whether correction for subcutaneous fat thickness influences the magnitude of EI differences. Fifteen younger men (mean age = 23 years), 15 younger women (aged 21 years), 11 older men (aged 74 years), and 15 older women (aged 70 years) participated. Clear differences were observed among age, sex, and region for vastus lateralis CSA (p ≤ 0.013, d = 0.38–0.73), whereas rectus femoris CSA was only different between younger and older participants at the proximal region (p = 0.017, d = 0.65). Uncorrected EI was greatest at the distal region of both muscles (p < 0.001, d = 0.59–1.38), with only the younger men having significantly lower EI values than the other groups (p ≤ 0.043, d = 0.37–0.63). Subcutaneous fat correction resulted in a marked increase in the magnitude of sex-specific EI differences (p ≤ 0.032, d ≥ 0.42). Additionally, subcutaneous fat correction increased the uniformity of EI throughout the thigh. These findings highlight considerable region-specific differences in muscle size and quality among younger and older men and women and highlight the need to correct for subcutaneous fat thickness when examining EI. Novelty Rectus femoris CSA is similar between younger and older adults except at the most proximal site evaluated. Age- and sex-specific differences in uncorrected EI are nonuniform across the thigh. Correction for subcutaneous fat thickness substantially increased EI in women, resulting in greater sex differences.