METABOLIC AND BIOMECHANICAL VARIABLES OF 2 INCLINE CONDITIONS DURING DISTANCE RUNNING

The purpose of this experiment was to examine the effects of an inclin e during distance running on selected metabolic and biomechanical vari ables. Six (4 males? 2 females) trained distance runners (age 27.2 +/- 7.8 yr; (V) over dot O-2max 63.7 +/- 7.5 mL.kg(-1).min(-1)) performed three 35-min runs at speeds corresponding to each individual's anaero bic threshold. The first run (Control) was performed at 0% grade. The remaining two runs were randomly assigned and included a 5% incline du ring min 5-15 (Run A) or 20-30 (Run B). Heart rate via telemetry (HR), and oxygen consumption ((V) over dot O-2max), minute ventilation ((V) over dot(E)), RER, and tidal volume (TV) were measured by indirect ca lorimetry. High speed videography was used to measure time in support phase, time in swing phase, step length, trunk lean, vertical oscillat ion of the hip, knee flexion in support, shank angle during toe-off, a nd ankle flexion at heel strike during the runs. Significant increases (P less than or equal to 0.05) were found during the incline conditio ns of Run A for (V) over dot O-2 (+18%) HR (+11%), (V) over dot(E) (+2 4%), and RER (+8%) and Run B for (V) over dot O-2 (+19%) HR (+10%), an d (V) over dot(E) (+25%) compared with the Control. No significant dif ferences (P > 0.05) were noted between Run A and Run B during incline running in the physiological variables. No significant differences (P > 0.05) were observed in any of the biomechanical variables among the runs. These data indicate that the energy expenditure required during incline running is the same regardless of incline location during a 35 -min run, and running mechanics are not significantly altered during a 5% incline lasting 10 min. In addition, following a 5% incline for 10 min, runners experience no significant physiological or biomechanical changes during subsequent level running at anaerobic threshold pace.