Cardiorespiratory characteristics and cholesterol responses to a single session of heavy leg press exercise

Abstract

The effect of resistance exercise on blood lipids is not clear yet. The purpose of this study was to examine the cholesterol responses to a heavy resistance leg press exercise emphasizing on the eccentric movement 24 and 48 hours following exercise and to quantify the cardiorespiratory responses of the exercise bout in an attempt to clarify the exercise characteristics that may be responsible for the effects of heavy resistance exercise on blood lipids. Nine healthy, untrained male volunteers aged 27.2 ± 1.1 yrs (76.2 ± 2.5 kg, 1.79 ± 0.02 m) performed a session of heavy RE emphasizing on the eccentric movement consisting of eight sets of inclined leg presses at six repetition maximum with 3-min rest intervals. Venous blood samples were obtained at rest (control) and 24 and 48 hours following exercise. Average VO2 at rest was 4.0 ± 0.4 ml·min(-1)·kg(-1), during exercise 19.6 ± 0.2 ml·min(-1)·kg(-1) and during the 180 sec recovery period between sets 12.5 ± 0.2 ml·min(-1)·kg(-1). RER values decreased with the progression of the exercise and were significantly lower during the last four sets compared with the first four sets of the exercise session. Resting heart rate was 67 ± 2 bpm, and maximum heart rate during exercise was 168 ± 1 bpm. Serum creatine kinase was significantly elevated on day 1 (1090 ± 272 U·L(-1), p < 0.03) and peaked on day 2 (1230 ± 440 U·L(-1) p < 0. 01). Total cholesterol, HDL cholesterol and calculated LDL cholesterol concentration did not change significantly following with exercise. This protocol of heavy resistance exercise has no effect on TC or cholesterol sub-fraction concentration 24 and 48 hours following exercise which may be due to the low energy expenditure of the exercise and/or to the gender of the participants. Key pointsRepeated sets of heavy resistance exercise significantly increase oxygen uptake both during exercise and the following recovery period.Even though exercise was of low volume (8 sets x 6 repetitions) the elevated oxygen uptake during the rest intervals in combination with the total exercise session duration (26 min) resulted in aerobic energy expenditure that is equivalent to low to moderate intensity cycling.Leg press resistance exercise emphasizing on the eccentric movement that caused muscle damage had no effect on total cholesterol, HDL-C and LDL-C during the two days following exercise in young healthy male subjects.

Keywords: HDL; Muscle damage; energy expenditure; oxygen uptake.; total cholesterol.

Figure 1.

Average energy expenditure during the eight sets of exercise (pure exercise), the subsequent eight 3 min recovery periods and exercise + recovery. Values are means (± SE). (n = 9).

Figure 2.

Average oxygen consumption and metabolic equivalents (MET) during rest, the 8 sets of exercise (pure exercise), the subsequent 3 min recovery periods and exercise + recovery. Values are means (±SE). (n = 9).

Figure 3.

Average VO₂, VCO₂ and RER during the exercise session. Vertical bars show exercise periods. Values are means ± SE. (N=9), **P < 0.01 from the first four sets (RER).

Figure 4.

Average heart rate (bpm) during the exercise session. Values are means (± SE). (n = 9).

Figure 5.

TC, HDL-C and calculated LDL-C concentration in the control condition and 24 and 48 h post-exercise. Values are means (± SE). (n = 9).