The effects of resistance training prioritization in NCAA Division I Football summer training

Effects of Resistance Training on Spasticity in People with Stroke: A Systematic Review

Resistance training induces neuromuscular adaptations and its impact on spasticity remains inadequately researched. This systematic review (PROSPERO: CRD42022322164) aimed to analyze the effects of resistance training, compared with no treatment, conventional therapy, or other therapies, in people with stroke-related spasticity. A comprehensive search was conducted up to October 2023 in PubMed, PEDro, Cochrane, Web of Science, and Scopus databases. Selection criteria were randomized controlled trials involving participants with stroke-related spasticity intervened with resistance training. The PEDro scale was used to evaluate the methodological quality. From a total of 274 articles, 23 full-text articles were assessed for eligibility and nine articles were included in the systematic review, involving 225 participants (155 males, 70 females; mean age: 59.4 years). Benefits were found to spasticity after resistance training. Furthermore, studies measuring spasticity also reported benefits to function, strength, gait, and balance. In conclusion, resistance training was superior to, or at least equal to, conventional therapy, other therapies, or no intervention for improving spasticity, as well as function, strength, gait, and balance. However, the results should be taken with caution because of the heterogeneity of the protocols used. Further research is needed to explore the effects of resistance training programs on people with stroke.

No Changes in Body Composition in NCAA Division I Collegiate Football Players because of COVID-19 Restrictions

ABSTRACT

Czeck, MA, Roelofs, EJ, Evanoff, NG, and Dengel, DR. No Changes in body composition in NCAA Division I Collegiate Football Players due to COVID-19 restrictions. J Strength Cond Res 36(6): 1749-1752, 2022-The purpose of this study was to explore the impact of coronavirus disease 2019 (COVID-19) restrictions on body composition, assessed by dual x-ray absorptiometry (DXA), between the 2020 postseason (pre-COVID-19 restrictions) and the 2021 postseason (post-COVID-19 restrictions) in collegiate football players (n = 50). In addition, a subset of athletes (n = 23) was used to explore body composition variables across 4 postseason time points. Body composition variables assessed were total and regional body fat percent, total mass, lean mass, fat mass, bone mineral content, bone mineral density, and visceral adipose tissue mass. Paired t-tests were used to determine differences between the 2020 postseason and the 2021 postseason in body composition variables. Analysis of variance with Tukey HSD post hoc tests assessed significant differences in total and regional body composition across 4 years while adjusting for multiple comparisons. There were no significant differences (p > 0.05) between postseason 2020 and postseason 2021 for all measures of body composition. In a subset of athletes, body composition was analyzed over a 4-year period of time. There were no significant differences between all 4 time points for all measures of body composition. In conclusion, body composition variables in this study's subjects were not affected because of coronavirus disease 2019 restrictions or over 4 years of their collegiate football career.

Position-Specific Physical Workload Intensities in American Collegiate Football Training

ABSTRACT

MamonJr, MA, Olthof, SBH, Burns, GT, Lepley, AS, Kozloff, KM, and Zernicke, RF. Position-specific physical workload intensities in American collegiate football training. J Strength Cond Res 36(2): 420-426, 2022-Quantifying player training loads allows football coaching staff to make informed adjustments to the volume and intensity of training. Physical workload intensity in American football practices have not been extensively quantified. The current study examined physical workload intensities across positions in American collegiate football during training. Data from player tracking technology (Catapult Vector) were collected from 72 American football players (National Collegiate Athletic Association Division I) during in-season practices. Players were involved in individualized skill (indy), team playbook (team), and special team (ST) drills during practice and analyzed for their specialist offensive or defensive role (e.g., linebacker or wide receiver). Player running (i.e., high-speed running and sprint) and accelerations (i.e., high-intensity PlayerLoad and high-intensity inertial movement analysis) per minute were of interest. Drill type and practice day had significant effects on all workload intensity metrics (p < 0.01), but not position. Greater running intensities were seen in ST drills compared with other drill types. Tuesday practice sessions had greater overall intensities compared with other days. Interaction effect of position and drill type was significant (p < 0.001) for all intensity metrics, indicating that position groups exhibited unique workload responses to the drill types. Drill type and practice day interaction effect was significant for all intensity metrics (p < 0.01). The findings may be informative for coaches to tailor physical workloads of practice drills for positional roles in preparation for games and practices. Player tracking technology can add value for strength and conditioning coaches to adjust training programs based on position-specific on-field demands of players.

Resistance Training Load Effects on Muscle Hypertrophy and Strength Gain: Systematic Review and Network Meta-analysis

PURPOSE

This study aimed to analyze the effect of resistance training (RT) performed until volitional failure with low, moderate, and high loads on muscle hypertrophy and muscle strength in healthy adults and to assess the possible participant-, design-, and training-related covariates that may affect the adaptations.

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science databases were searched. Including only studies that performed sets to volitional failure, the effects of low- (>15 repetitions maximum (RM)), moderate- (9-15 RM), and high-load (≤8 RM) RTs were examined in healthy adults. Network meta-analysis was undertaken to calculate the standardized mean difference (SMD) between RT loads in overall and subgroup analyses involving studies deemed of high quality. Associations between participant-, design-, and training-related covariates with SMD were assessed by univariate and multivariate network meta-regression analyses.

RESULTS

Twenty-eight studies involving 747 healthy adults were included. Although no differences in muscle hypertrophy between RT loads were found in overall (P = 0.113-0.469) or subgroup analysis (P = 0.871-0.995), greater effects were observed in untrained participants (P = 0.033) and participants with some training background who undertook more RT sessions (P = 0.031-0.045). Muscle strength improvement was superior for both high-load and moderate-load compared with low-load RT in overall and subgroup analysis (SMD, 0.60-0.63 and 0.34-0.35, respectively; P < 0.001-0.003), with a nonsignificant but superior effect for high compared with moderate load (SMD, 0.26-0.28, P = 0.068).

CONCLUSIONS

Although muscle hypertrophy improvements seem to be load independent, increases in muscle strength are superior in high-load RT programs. Untrained participants exhibit greater muscle hypertrophy, whereas undertaking more RT sessions provides superior gains in those with previous training experience.

Periodization: Variation in the Definition and Discrepancies in Study Design

Over the past several decades, periodization has been widely accepted as the gold standard of training theory. Within the literature, there are numerous definitions for periodization, which makes it difficult to study. When examining the proposed definitions and related studies on periodization, problems arise in the following domains: (1) periodization has been proposed to serve as the macro-management of the training process concerning the annual plan, yet research on long-term effects is scarce; (2) periodization and programming are being used interchangeably in research; and (3) training is not periodized alongside other stressors such as sport (i.e., only resistance training is being performed without the inclusion of sport). Overall, the state of the literature suggests that the inability to define periodization makes the statement of its superiority difficult to experimentally test. This paper discusses the proposed definitions of periodization and the study designs which have been employed to examine the concept.

Fat-Free Mass Index in NCAA Division I and II Collegiate American Football Players

Fat-free mass index (FFMI) is a height-adjusted assessment of fat-free mass (FFM), with previous research suggesting a natural upper limit of 25 kg·m in resistance trained male athletes. The current study evaluated upper limits for FFMI in collegiate American football players (n = 235) and evaluated differences between positions, divisions, and age groups. The sample consisted of 2 National Collegiate Athletic Association Division I teams (n = 78, n = 69) and 1 Division II team (n = 88). Body composition was assessed via dual-energy x-ray absorptiometry and used to calculate FFMI; linear regression was used to normalize values to a height of 180 cm. Sixty-two participants (26.4%) had height-adjusted FFMI values above 25 kg·m (mean = 23.7 ± 2.1 kg·m; 97.5th percentile = 28.1 kg·m). Differences were observed among position groups (p < 0.001; η = 0.25), with highest values observed in offensive linemen (OL) and defensive linemen (DL) and lowest values observed in offensive and defensive backs. Fat-free mass index was higher in Division I teams than Division II team (24.3 ± 1.8 kg·m vs. 23.4 ± 1.8 kg·m; p < 0.001; d = 0.49). Fat-free mass index did not differ between age groups. Upper limit estimations for FFMI seem to vary by position; although the 97.5th percentile (28.1 kg·m) may represent a more suitable upper limit for the college football population as a whole, this value was exceeded by 6 linemen (3 OL and 3 DL), with a maximal observed value of 31.7 kg·m. Football practitioners may use FFMI to evaluate an individual's capacity for additional FFM accretion, suitability for a specific position, potential for switching positions, and overall recruiting assessment.

Longitudinal Body Composition Changes in NCAA Division I College Football Players

Trexler, ET, Smith-Ryan, AE, Mann, JB, Ivey, PA, Hirsch, KR, and Mock, MG. Longitudinal body composition changes in NCAA Division I college football players. J Strength Cond Res 31(1): 1-8, 2017-Many athletes seek to optimize body composition to fit the physical demands of their sport. American football requires a unique combination of size, speed, and power. The purpose of the current study was to evaluate longitudinal changes in body composition in Division I collegiate football players. For 57 players (mean ± SD, age = 19.5 ± 0.9 years, height = 186.9 ± 5.7 cm, weight = 107.7 ± 19.1 kg), body composition was assessed via dual-energy x-ray absorptiometry in the off-season (March-Pre), end of off-season (May), mid-July (Pre-Season), and the following March (March-Post). Outcome variables included weight, body fat percentage (BF%), fat mass, lean mass (LM), android and gynoid (GYN) fat, bone mineral content (BMC), and bone mineral density (BMD). For a subset of athletes (n = 13 out of 57), changes over a 4-year playing career were evaluated with measurements taken every March. Throughout a single year, favorable changes were observed for BF% (Δ = -1.3 ± 2.5%), LM (Δ = 2.8 ± 2.8 kg), GYN (Δ = -1.5 ± 3.0%), BMC (Δ = 0.06 ± 0.14 kg), and BMD (Δ = 0.015 ± 0.027 g·cm, all p ≤ 0.05). Across 4 years, weight increased significantly (Δ = 6.6 ± 4.1 kg) and favorable changes were observed for LM (Δ = 4.3 ± 3.0 kg), BMC (Δ = 0.18 ± 0.17 kg), and BMD (Δ = 0.033 ± 0.039 g·cm, all p ≤ 0.05). Similar patterns in body composition changes were observed for linemen and non-linemen. Results indicate that well-trained collegiate football players at high levels of competition can achieve favorable changes in body composition, even late in the career, which may confer benefits for performance and injury prevention.

Effect of compensatory acceleration training in combination with accommodating resistance on upper body strength in collegiate athletes

PURPOSE

To determine the impact of inclusion of a band or chain compensatory acceleration training (CAT), in a 5-week training phase, on maximal upper body strength during a 14-week off-season strength and conditioning program for collegiate male athletes.

PATIENTS AND METHODS

Twenty-four National Collegiate Athletic Association (NCAA) collegiate baseball players, who were familiar with the current strength and conditioning program and had a minimum of 1 year of formal collegiate strength and conditioning experience, participated in this off-season training study. None of the men had participated in CAT before. Subjects were matched following a maximal effort (1-repetition maximum [1-RM]) bench press test in week 1, then were randomly assigned into a band-based CAT group or a chain-based CAT group and participated in a 5-week training phase that included bench pressing twice per week. Upper body strength was measured by 1-RM bench press again at week 6. A 2 × 2 mixed factorial (method × time) analysis of variance was calculated to compare differences across groups. The alpha level was set at P<0.05.

RESULTS

No difference (F 1,22=0.04, P=0.84) existed between the band-based CAT and chain-based CAT groups. A significant difference was observed between pre- and posttests of 1-RM bench (F 1,22=88.46, P=0.001).

CONCLUSION

A 5-week band CAT or chain CAT training program used in conjunction with an off-season strength and conditioning program can increase maximal upper body strength in collegiate baseball athletes. Using band CAT and/or chain CAT as a training modality in the off-season will vary the training stimulus from the traditional and likely help to maintain the athlete's interest.