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Physiological comparison of concentric and eccentric arm cycling in males and females.

Beaven CM, Willis SJ, Cook CJ, Holmberg HC - PLoS ONE (2014)

Bottom Line: In contrast, delta efficiency (ηΔ), as previously defined by Coyle and colleagues in 1992, demonstrated a sex difference (men>women; p<0.05).Sex differences were also apparent in arteriovenous oxygen difference and heart rate during CON.We suggest delta efficiency as a sensitive measure of efficiency that allowed the identification of sex differences.

View Article: PubMed Central - PubMed

Affiliation: Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.

ABSTRACT
Lower body eccentric exercise is well known to elicit high levels of muscular force with relatively low cardiovascular and metabolic strain. As a result, eccentric exercise has been successfully utilised as an adaptive stressor to improve lower body muscle function in populations ranging from the frail and debilitated, to highly-trained individuals. Here we investigate the metabolic, cardiorespiratory, and energy costs of upper body eccentric exercise in a healthy population. Seven men and seven women performed 4-min efforts of eccentric (ECC) or concentric (CON) arm cycling on a novel arm ergometer at workloads corresponding to 40, 60, and 80% of their peak workload as assessed in an incremental concentric trial. The heart rate, ventilation, cardiac output, respiratory exchange ratio, and blood lactate concentrations were all clearly greater in CON condition at all of the relative workloads (all p<0.003). Effect size calculations demonstrated that the magnitude of the differences in VO2 and work economy between the ECC and CON exercise ranged from very large to extremely large; however, in no case did mechanical efficiency (η(MECH)) differ between the conditions (all p>0.05). In contrast, delta efficiency (ηΔ), as previously defined by Coyle and colleagues in 1992, demonstrated a sex difference (men>women; p<0.05). Sex differences were also apparent in arteriovenous oxygen difference and heart rate during CON. Here, we reinforce the high-force, low cost attributes of eccentric exercise which can be generalised to the muscles of the upper body. Upper body eccentric exercise is likely to form a useful adjunct in debilitative, rehabilitative, and adaptive clinical exercise programs; however, reports of a shift towards an oxidative phenotype should be taken into consideration by power athletes. We suggest delta efficiency as a sensitive measure of efficiency that allowed the identification of sex differences.

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Arterial pressure and systemic vascular resistance plots responses to eccentric and concentric arm cycling.Values are reported as mean ± standard deviation. *p<0.05 vs concentric exercise modality. A: Systolic Arterial Pressure; B: Mean Arterial Pressure; C: Systemic Vascular Resistance; Inset: relationship between VO2 (x-axis: L min−1) and Systemic Vascular Resistance (y-axis: dyn·s·cm−5).
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pone-0112079-g006: Arterial pressure and systemic vascular resistance plots responses to eccentric and concentric arm cycling.Values are reported as mean ± standard deviation. *p<0.05 vs concentric exercise modality. A: Systolic Arterial Pressure; B: Mean Arterial Pressure; C: Systemic Vascular Resistance; Inset: relationship between VO2 (x-axis: L min−1) and Systemic Vascular Resistance (y-axis: dyn·s·cm−5).

Mentions: Using multiple regression to control for between subject variation, VO2 was significantly related to QC (R2 = 0.84; p<0.0001) and HR (R2 = 0.87; p<0.0001), but not SV (R2 = 0.31; p = 0.24). Plotting VO2 against absolute work output resulted in distinct slopes for the CON (0.0173) and ECC (0.007) conditions (Figure 5). These linear relationships revealed that the oxygen requirement was 206% greater in the CON compared to ECC condition at the wattage corresponding to the lowest VO2 observed (26.8 W; 0.36 L min−1), a value that increased to 235% at the highest VO2 observed (152.2 W; 2.91 L min−1). When individual plots of VO2 against absolute work output were plotted the slopes for the CON (0.0198; range: 0.0158 to 0.0245) and ECC conditions (0.008; range 0.004 to 0.0160) were similar to the grouped data (Figure 5). Finally, it was apparent that, despite higher systolic arterial pressure in the CON trials (all p<0.0015; Figure 6A), the mean arterial pressure was not different between the conditions (all p>0.4; Figure 6B). This observation was explained by greater systemic vascular resistance in the ECC condition compared to the CON condition at all workloads (all ES >2.50; all p<0.0001; Figure 6C) with a decrease in vascular resistance as workload (VO2) increased (Figure 6 inset).


Physiological comparison of concentric and eccentric arm cycling in males and females.

Beaven CM, Willis SJ, Cook CJ, Holmberg HC - PLoS ONE (2014)

Arterial pressure and systemic vascular resistance plots responses to eccentric and concentric arm cycling.Values are reported as mean ± standard deviation. *p<0.05 vs concentric exercise modality. A: Systolic Arterial Pressure; B: Mean Arterial Pressure; C: Systemic Vascular Resistance; Inset: relationship between VO2 (x-axis: L min−1) and Systemic Vascular Resistance (y-axis: dyn·s·cm−5).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221259&req=5

pone-0112079-g006: Arterial pressure and systemic vascular resistance plots responses to eccentric and concentric arm cycling.Values are reported as mean ± standard deviation. *p<0.05 vs concentric exercise modality. A: Systolic Arterial Pressure; B: Mean Arterial Pressure; C: Systemic Vascular Resistance; Inset: relationship between VO2 (x-axis: L min−1) and Systemic Vascular Resistance (y-axis: dyn·s·cm−5).
Mentions: Using multiple regression to control for between subject variation, VO2 was significantly related to QC (R2 = 0.84; p<0.0001) and HR (R2 = 0.87; p<0.0001), but not SV (R2 = 0.31; p = 0.24). Plotting VO2 against absolute work output resulted in distinct slopes for the CON (0.0173) and ECC (0.007) conditions (Figure 5). These linear relationships revealed that the oxygen requirement was 206% greater in the CON compared to ECC condition at the wattage corresponding to the lowest VO2 observed (26.8 W; 0.36 L min−1), a value that increased to 235% at the highest VO2 observed (152.2 W; 2.91 L min−1). When individual plots of VO2 against absolute work output were plotted the slopes for the CON (0.0198; range: 0.0158 to 0.0245) and ECC conditions (0.008; range 0.004 to 0.0160) were similar to the grouped data (Figure 5). Finally, it was apparent that, despite higher systolic arterial pressure in the CON trials (all p<0.0015; Figure 6A), the mean arterial pressure was not different between the conditions (all p>0.4; Figure 6B). This observation was explained by greater systemic vascular resistance in the ECC condition compared to the CON condition at all workloads (all ES >2.50; all p<0.0001; Figure 6C) with a decrease in vascular resistance as workload (VO2) increased (Figure 6 inset).

Bottom Line: In contrast, delta efficiency (ηΔ), as previously defined by Coyle and colleagues in 1992, demonstrated a sex difference (men>women; p<0.05).Sex differences were also apparent in arteriovenous oxygen difference and heart rate during CON.We suggest delta efficiency as a sensitive measure of efficiency that allowed the identification of sex differences.

View Article: PubMed Central - PubMed

Affiliation: Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.

ABSTRACT
Lower body eccentric exercise is well known to elicit high levels of muscular force with relatively low cardiovascular and metabolic strain. As a result, eccentric exercise has been successfully utilised as an adaptive stressor to improve lower body muscle function in populations ranging from the frail and debilitated, to highly-trained individuals. Here we investigate the metabolic, cardiorespiratory, and energy costs of upper body eccentric exercise in a healthy population. Seven men and seven women performed 4-min efforts of eccentric (ECC) or concentric (CON) arm cycling on a novel arm ergometer at workloads corresponding to 40, 60, and 80% of their peak workload as assessed in an incremental concentric trial. The heart rate, ventilation, cardiac output, respiratory exchange ratio, and blood lactate concentrations were all clearly greater in CON condition at all of the relative workloads (all p<0.003). Effect size calculations demonstrated that the magnitude of the differences in VO2 and work economy between the ECC and CON exercise ranged from very large to extremely large; however, in no case did mechanical efficiency (η(MECH)) differ between the conditions (all p>0.05). In contrast, delta efficiency (ηΔ), as previously defined by Coyle and colleagues in 1992, demonstrated a sex difference (men>women; p<0.05). Sex differences were also apparent in arteriovenous oxygen difference and heart rate during CON. Here, we reinforce the high-force, low cost attributes of eccentric exercise which can be generalised to the muscles of the upper body. Upper body eccentric exercise is likely to form a useful adjunct in debilitative, rehabilitative, and adaptive clinical exercise programs; however, reports of a shift towards an oxidative phenotype should be taken into consideration by power athletes. We suggest delta efficiency as a sensitive measure of efficiency that allowed the identification of sex differences.

Show MeSH
Related in: MedlinePlus