Moderate to Vigorous-intensity Continuous Training versus Highintensity Interval Training for Improving VO2max in Women: A Systematic Review and Meta-analysis.

Traditional continuous training and high-intensity interval training (HIIT) can increase maximal oxygen uptake (V̇O2max). However, there is conflicting evidence regarding which form of training demonstrates the greatest improvements to V̇O2max, and data in women is sparse. We conducted a systematic review and meta-analyses to assess whether moderate to vigorous-intensity continuous training (MVICT) or HIIT was superior at improving V̇O2max in women. Randomised controlled and parallel studies examined the influence of MVICT and/or HIIT on V̇O2max in women. There was no statistical difference in V̇O2max improvements after training between women in the MVICT and HIIT cohorts (mean difference [MD]: -0.42, 95%CI: -1.43 to 0.60, p>0.05). Both MVICT and HIIT increased V̇O2max from baseline (MD: 3.20, 95% CI: 2.73 to 3.67 and MD: 3.16, 95% CI 2.09 to 4.24, respectively, p<0.001). Greater improvements in V̇O2max were observed in women who participated in more training sessions in both training formats. Long-HIIT was superior to short-HIIT protocols at increasing V̇O2max. Although MVICT and long-HIIT sessions elicited greater increases in V̇O2max in younger women compared to short-HIIT protocols, these differences were negligible in older women. Our findings suggest MVICT and HIIT are equally effective strategies for improving V̇O2max and indicate an effect of age on its response to training in women.

Determining Criteria to Predict Repeatability of Performance in Older Adults: Using Coefficients of Variation for Strength and Functional Measures.

Reliable measures of muscle strength and functional capacity in older adults are essential. The aim of this study was to determine whether coefficients of variation (CVs) of individuals obtained at the first session can infer repeatability of performance in a subsequent session. Forty-eight healthy older adults (mean age 68.6 ± 6.1 years; age range 60-80 years) completed two assessment sessions, and on each occasion undertook: dynamometry for isometric and isokinetic quadriceps strength, 6 meter fast walk (6MFWT), timed up and go (TUG), stair climb and descent, and vertical jump. Significant linear relationships were observed between CVs in session 1 and the percentage difference between sessions 1 and 2 for torque at 60, 120, 240 and 360°/s, 6MFWT, TUG, stair climb, and stair descent. The results of this study could be used to establish criteria for determining an acceptably reliable performance in strength and functional tests.

Exercise training reduces arterial stiffness in women with high blood pressure: a systematic review and meta-analysis.

The acute and long-term benefits of exercise on cardiovascular health are well established, yet the optimal mode of exercise training that improves arterial stiffness in women with high blood pressure remains unclear. The aim of this systematic review and meta-analysis was to assess the influence of aerobic and resistance training on arterial stiffness in women with high blood pressure. After an extensive search of four online databases, six randomized controlled trials met the inclusion criteria and were included in meta-analyses. Data were extracted from six studies examining the influence of exercise on arterial stiffness assessed by pulse wave velocity (PWV) and were expressed as standardized mean difference (SMD). Whereas aerobic exercise significantly reduced arterial PWV in women with high blood pressure after long-term training [SMD -1.87, 95% confidence interval (CI) -2.34 to -1.40], resistance training had a more modest effect that was borderline statistically significant (SMD -0.31, 95% CI -0.65 to 0.03). These findings suggest regular long-term aerobic exercise training (i.e. 12-20 week interventions) reduces arterial stiffness in women with high blood pressure. Although not statistically significant, the modest number of included trials and lack of publication bias encourages further assessments on the efficacy of resistance exercise for improving arterial stiffness in women with high blood pressure. Given the unique benefits of aerobic and resistance training, particularly for postmenopausal women (e.g. bone health and muscular strength), both modes of training should be encouraged for women with high blood pressure to enhance arterial function and support favorable cardiovascular outcomes.

Effects of eccentrically biased versus conventional weight training in older adults.

INTRODUCTION: We compared the effects of eccentrically biased (EB) and conventional (CONV) resistance training on muscle architecture, one-repetition maximum (1RM), isometric strength, isokinetic force-velocity characteristics, functional capacity, and pulse wave velocity in older men and women. METHODS: Twenty-eight older adults participated in the study (mean ± SD: age = 68 ± 5 yr). Of these, 13 were allocated to a waitlist control, 10 of whom progressed to training (CONV, n = 12; EB, n = 13). Training was twice a week for 16 wk. EB involved three sets of 10 concentric lifts at 50% of 1RM with the eccentric portion of repetitions performed unilaterally, alternating between limbs with each repetition. CONV involved two sets of 10 repetitions at 75% of 1RM. EB and CONV were matched for total work. Isokinetic knee extensor strength was assessed across a range of velocities (0-360°·s(-1)). Functional capacity was assessed via a 6-m fast walk test, a timed up and go test, stair climb and descent power test, and vertical jump test. Vastus lateralis and gastrocnemius medialis architecture were assessed using ultrasonography. RESULTS: Both EB and CONV improved 1RM (Δ 23%-35%, P < 0.01). Compared to the control group, both training regimens improved 6-m fast walk (Δ 5%-7%, P < 0.01) and concentric torque at 60 and 120°·s(-1) (Δ 6%-8%, P < 0.05). Significant improvements were evident in EB for isometric and concentric torque at 240 and 360°·s(-1) (Δ 6%-11%, P < 0.05), vastus lateralis thickness (Δ 5%, P < 0.05), and stair climb (Δ 5%, P < 0.01). Timed up and go (Δ 5%, P < 0.01), stair descent (Δ 4%, P < 0.05), and vertical jump (Δ 7%, P < 0.01) improved in CONV. Pulse wave velocity, pennation angle, and fascicle length remained unchanged in both training groups. CONCLUSIONS: EB seems superior to CONV at increasing torque at high contraction velocities, whereas CONV seems more effective at improving some functional performance measures and vertical jump. This has important implications for preserving functional capacity.

Aging and the force-velocity relationship of muscles.

Aging in humans is associated with a loss in neuromuscular function and performance. This is related, in part, to the reduction in muscular strength and power caused by a loss of skeletal muscle mass (sarcopenia) and changes in muscle architecture. Due to these changes, the force-velocity (f-v) relationship of human muscles alters with age. This change has functional implications such as slower walking speeds. Different methods to reverse these changes have been investigated, including traditional resistance training, power training and eccentric (or eccentrically-biased) resistance training. This review will summarise the changes of the f-v relationship with age, the functional implications of these changes and the various methods to reverse or at least partly ameliorate these changes.

Cycling efficiency and performance following short-term training using uncoupled cranks.

OBJECTIVES: Uncoupled cycling cranks are designed to remove the ability of one leg to assist the other during the cycling action. It has been suggested that training with this type of crank can increase mechanical efficiency. However, whether these improvements can confer performance enhancement in already well-trained cyclists has not been reported. METHOD: Fourteen well-trained cyclists (13 males, 1 female; 32.4 +/- 8.8 y; 74.5 +/- 10.3 kg; Vo2max 60.6 +/- 5.5 mL.kg-1.min-1; mean +/- SD) participated in this study. Participants were randomized to training on a stationary bicycle using either an uncoupled (n = 7) or traditional crank (n = 7) system. Training involved 1-h sessions, 3 days per week for 6 weeks, and at a heart rate equivalent to 70% of peak power output (PPO) substituted into the training schedule in place of other training. Vo2max, lactate threshold, gross efficiency, and cycling performance were measured before and following the training intervention. Pre- and posttesting was conducted using traditional cranks. RESULTS: No differences were observed between the groups for changes in Vo2max, lactate threshold, gross efficiency, or average power maintained during a 30-minute time trial. CONCLUSION: Our results indicate that 6 weeks (18 sessions) of training using an uncoupled crank system does not result in changes in any physiological or performance measures in well-trained cyclists.