Research Review: Leg Muscle Size and Sprint Timing in D-I Football

By Emmett Shaul

BLUF (Bottom Line Up Front)

In Division I football players, leg muscle size relates to sprint timing—stance time (foot on the ground) and swing time (leg in the air)—and the pattern differs by position group. Across all athletes, larger vastus medialis (inner quad) and soleus (deep calf) were linked to longer stance and swing times. Within each position group (Skills, Mids, Bigs), some muscles were associated with shorter times while others were associated with longer times. Findings are cross-sectional (associations, not cause-and-effect).

Purpose

Identify which specific lower-body muscles (by volume) are associated with stance and swing times during maximal sprinting, overall and by position group (Skills, Mids, Bigs).

Test Subjects

• 108 male NCAA Division I American football players
• Position groups: Skills 43 (defensive backs, wide receivers); Mids 28 (linebackers, running backs, tight ends); Bigs 37 (offensive and defensive linemen)
• Demographics: approximately early-20s (average ≈ 21.5 years; most within about 2 years either side). Body size typical of D-I rosters (BMI ≈ 29.2–29.4 kg·m⁻²; typical spread about 4–5)

Methods

• Muscle size: High-resolution MRI with automated segmentation quantified volumes of individual muscles from pelvis to ankle.
• Sprinting: Two over-ground maximal ~30 m sprints from standing starts; at least two minutes rest; best trial used. Seven body-worn sensors (sacrum, both thighs, shanks, feet) captured stance and swing times.
• Analysis: Correlations for the full sample and stepwise multiple regression within each position group identified which muscle volumes best explained stance and swing times (p ≤ .05).

Findings — All Athletes

• Athletes with longer swing also tended to have longer stance.
• The most consistent whole-group associations with longer stance and swing were larger vastus medialis (inner quad) and soleus (deep calf).
• Typical timing across groups (averages): swing ~313–315 ms (most results within about 26 ms of the average); stance ~156 ms (most results within about 22 ms of the average).

Findings — By Position

Skills (defensive backs, wide receivers)

• Stance time
  • Larger gluteus maximus (glutes) volume was associated with shorter stance time
  • Larger tibialis posterior (deep calf) volume was associated with longer stance time
• Swing time
  • Larger sartorius (hip flexor/inner thigh) and vastus intermedius (mid/deep quad) volumes were associated with shorter swing time
  • Larger vastus medialis (inner quad) volume was associated with longer swing time

Mids (linebackers, running backs, tight ends)

• Stance time
  • Larger biceps femoris long head (outer hamstring) and vastus intermedius (mid/deep quad) volumes were associated with shorter stance time
  • Larger vastus medialis (inner quad) volume was associated with longer stance time
• Swing time
  • Larger biceps femoris long head (hamstring) and piriformis (deep hip rotator) volumes were associated with shorter swing time
  • Larger semimembranosus (inner hamstring) volume was associated with longer swing time

Bigs (offensive and defensive linemen)

• Stance time
  • Larger rectus femoris (front quad/hip flexor) and sartorius (hip flexor/inner thigh) volumes were associated with shorter stance time
  • Larger tensor fasciae latae, TFL (outer hip) and tibialis anterior (shin) volumes were associated with longer stance time
• Swing time
  • Larger semimembranosus (inner hamstring) volume was associated with shorter swing time
  • Larger piriformis (deep hip rotator) and vastus lateralis (outer quad) volumes were associated with longer swing time

Practical Applications

• Program to the position’s sprint profile. Emphasize exercises that develop muscles associated with shorterstance/swing for that group, and moderate work that expands muscles associated with longer times.
• Exercise selection steers where you grow.
  • Front squats load the quadriceps more (including vastus medialis).
  • Back squats load hip extensors more.
  • Use and dose these (plus targeted assistance work) to encourage growth that supports your position group’s timing profile and limit excessive growth where larger size is linked to longer stance or swing.
• Examples:
  • Skills: build gluteus maximus, sartorius, vastus intermedius; manage vastus medialis and tibialis posterior.
  • Mids: build biceps femoris long head and vastus intermedius (stance), plus biceps femoris long head and piriformis (swing); manage vastus medialis and semimembranosus.
  • Bigs: build rectus femoris and sartorius; manage TFL, tibialis anterior, piriformis, and vastus lateraliswhen longer times are undesirable.

Limitations

• Multi-site data collection may add variability; the large sample supports generalizability.
• Team training targets muscle groups, whereas this study analyzed individual muscles to inform assistance/accessory choices.
• Only linear sprint mechanics were measured; change-of-direction relationships were not assessed.
• Muscle volume was examined; rate of force development and injury data were not directly analyzed alongside volume.

Conclusion

Leg-muscle size relates to sprint stance and swing times in Division I football, and these relationships are position-specific. Across the roster, larger vastus medialis and soleus tended to align with longer times, while, within positions, certain glute, hamstring, and hip-flexor muscles aligned with shorter times and specific quadriceps/distal muscles aligned with longer times. Practical programming is position-specific: build the muscles tied to shorter times for that group and manage development where greater size is tied to longer times—recognizing these are associations, not prescriptions of cause.

Bibliography

Metoyer CJ, Lever JR, McGinty M, Landow L, Hunt R, Hauenstein JD, Huebner A, Stone MH, Wagle JP. The Impact of Localized Muscle Mass on Sprint Mechanics During the Swing and Stance Phases of Division I Collegiate American Football Players. Journal of Strength and Conditioning Research. 2025;39(9):959–963.