Limits...
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.

Show MeSH

Related in: MedlinePlus

Sex differences in cardiovascular measures of eccentric and concentric cycling.Values are reported as mean ± standard deviation. *clear difference vs male participants. (A-V)O2, arteriovenous difference.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4221259&req=5

pone-0112079-g004: Sex differences in cardiovascular measures of eccentric and concentric cycling.Values are reported as mean ± standard deviation. *clear difference vs male participants. (A-V)O2, arteriovenous difference.

Mentions: While no sex differences were apparent in QC (all p>0.5), the HR was consistently and substantially higher in females by 10 to 16 bpm during concentric exercise (ES 0.71 to 1.23) which corresponded to a 4.2 to 6.4% higher percentage of the maximum heart rate observed in the incremental concentric arm cycling test (Figure 4A). The cardiac index was also higher in women at all concentric workloads by 0.85 to 1.62 L min−1 m−2 (ES 0.84 to 1.12; Figure 4B). Interestingly, despite the relative loads prescribed, VO2 during concentric exercise was lower in women at all workloads by 0.30 to 0.43 L min−1 (p≤0.0172; ES: 1.40 to 1.83; Figure 4C) and thus the internally liberated metabolic power of concentric arm cycling was also lower in women (all p≤0.0182; ES: 1.49 to 1.95). A corollary of the fact that VO2 was lower in women, despite no difference between the sexes for QC, was that the (A-V)O2 was of lesser magnitude in women (all p≤0.0340; Figure 4D). Overall, the (A-V)O2 was greater during concentric than eccentric exercise at 40% (ES: 1.98±0.65), 60% (ES: 1.62±0.65), and 80% (ES: 1.45±0.65) of WPEAK (all p≤0.001). In both exercise conditions, the (A-V)O2 tended to increase with workload (CON: 102 to 106 ml O2·L−1, 4.2±4.1%, p = 0.0831; ECC: 66 to 78 ml O2·L−1, 15.4±8.3%, p = 0.0028).


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

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

Sex differences in cardiovascular measures of eccentric and concentric cycling.Values are reported as mean ± standard deviation. *clear difference vs male participants. (A-V)O2, arteriovenous difference.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0112079-g004: Sex differences in cardiovascular measures of eccentric and concentric cycling.Values are reported as mean ± standard deviation. *clear difference vs male participants. (A-V)O2, arteriovenous difference.
Mentions: While no sex differences were apparent in QC (all p>0.5), the HR was consistently and substantially higher in females by 10 to 16 bpm during concentric exercise (ES 0.71 to 1.23) which corresponded to a 4.2 to 6.4% higher percentage of the maximum heart rate observed in the incremental concentric arm cycling test (Figure 4A). The cardiac index was also higher in women at all concentric workloads by 0.85 to 1.62 L min−1 m−2 (ES 0.84 to 1.12; Figure 4B). Interestingly, despite the relative loads prescribed, VO2 during concentric exercise was lower in women at all workloads by 0.30 to 0.43 L min−1 (p≤0.0172; ES: 1.40 to 1.83; Figure 4C) and thus the internally liberated metabolic power of concentric arm cycling was also lower in women (all p≤0.0182; ES: 1.49 to 1.95). A corollary of the fact that VO2 was lower in women, despite no difference between the sexes for QC, was that the (A-V)O2 was of lesser magnitude in women (all p≤0.0340; Figure 4D). Overall, the (A-V)O2 was greater during concentric than eccentric exercise at 40% (ES: 1.98±0.65), 60% (ES: 1.62±0.65), and 80% (ES: 1.45±0.65) of WPEAK (all p≤0.001). In both exercise conditions, the (A-V)O2 tended to increase with workload (CON: 102 to 106 ml O2·L−1, 4.2±4.1%, p = 0.0831; ECC: 66 to 78 ml O2·L−1, 15.4±8.3%, p = 0.0028).

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