Author(s): WILSON, B., JAFRI, M., GREYVENSTEIN, D., NEWBOLD, J.P., PHILLIPS, S.M. , Institution: MCMASTER UNIVERSITY, Country: CANADA, Abstract-ID: 1172

INTRODUCTION:
Resistance exercise training (RET) leads to increases in muscular size/mass (hypertrophy) and strength changes. Lean mass (LM), of which skeletal muscle mass is a sub-component, plays a role in strength and, in many cases, it is positively correlated with sports performance. However, it is proposed that there is an upper limit to the amount of LM attainable by an individual. Previous research suggests that the greatest increase in whole-body LM occurs in the first year of structured resistance training, with a steep decrease in adaptation after this time. For competitive football athletes, altering body composition to meet the physical demands of their sport is common practice. High-level athletes undertaking monitored, prescribed, progressive intense RET are a valuable population to observe rates of LM adaptation and also assess the potential upper limits of muscular hypertrophy with increasing training status (from novice – 1 year – to experienced – 5+ years).
METHODS:
137 University North American football players between the ages of 18 and 25 took part in the study, producing 382 DXA assessments. Collections were placed at relevant points around the competitive season during pre-, post-, and off-season timeframes. All DXA assessments were collected under identical controls: no food, water, or vigorous exercise for at least 8 hours, voided bladder and bowels, and rehydration with 500mL of water followed by 15 minutes of quiet laying in advance of scan start. All athletes were following a structured and supervised RET routine designed by a certified strength and conditioning specialists 2-4 times per week during the study involvement period.
RESULTS:
Linear mixed-effects modeling revealed no significant interaction between resistance training status (novice through experienced) and the amount of LM adaptation (p > 0.05). All training status groups (1 through 5+ years) exhibited similar relative changes in lean mass accumulation of ~1.5kg per year, indicating that training age was not a primary driver of lean mass changes in this cohort.
CONCLUSION:
The present findings suggest that university-level football athletes continue to show improvements in lean mass throughout their collegiate playing careers, regardless of prior resistance training experience. The absence of a significant “plateau” in LM accretion indicates that structured, supervised resistance training remains an effective stimulus for hypertrophy even in athletes with 5 or more years of experience.