Peripheral arterial disease (PAD) patients have reduced muscle strength and impaired walking ability. The aim of this study was to examine the effects of maximal strength training (MST) on walking economy and walking performance in PAD patients. Ten patients with mild to moderate-severe claudication, classified as Fontaine stage II PAD and with functional limitations from intermittent claudication were recruited and went through an 8-week control period followed by an 8-week, three times a week, MST period. The patients performed four sets of five repetitions dynamic leg press with emphasis on maximal mobilization of force in the concentric action and with a progressive adjusted intensity corresponding to 85-90% of one repetition maximum (1 RM). After the MST period, leg press 1 RM significantly increased by 35.0 ± 10.8 kg (31.3%). Dynamic rate of force development, measured on a force plate installed on the leg press, increased by 1424 ± 1217 N/s (102.7%). The strength improvements led to a significant increase in walking economy of 9.7% when walking horizontally, and to a significant increase in walking performance of 13.6% measured on an incremental treadmill test to exhaustion. No changes were apparent after the control period. No changes in body mass or peak oxygen uptake were observed. MST increases strength in Fontaine stage II PAD patients and leads to improved walking economy. These results suggest that application of MST could accompany aerobic endurance training as a part of the treatment of PAD patients with mild to moderate-severe claudication.

Peripheral arterial disease (PAD) patients suffer from reduced blood flow to the lower extremities, which causes impaired walking ability. Plantar flexion (PF) endurance training and maximal strength training (MST) induce distinct types of improvements in walking ability in PAD. However, the combined effects of both exercises are still not explored in these patients. This study examined whether concurrent MST and PF training would induce similar training responses as each training mode alone. Ten patients with PAD underwent 8 weeks of concurrent leg press MST and PF training, three times a week. The reference group (n=10) received recommended exercise guidelines. The training group improved treadmill peak oxygen consumption and incremental protocol time to exhaustion with 12.7 ± 7.7% and 12.6 ± 13.2%. Leg press maximal strength and rate of force development improved with 38.3 ± 3.1% and 140.1 ± 40.3%, respectively, along with a 5.2 ± 6.2% within group work economy improvement. No changes appeared in the reference group. Compared with previous studies, concurrent MST and PF training appear to induce similar training responses in PAD patients as when each training mode is executed alone, and without any adverse effects.

It has been a long-lasting debate whether the heart's stroke volume (SV) increases at high aerobic intensities or plateau. Further, sex and level of aerobic power are shown to influence the response. The purpose of this study was to investigate the SV at increasing intensities in elite female athletes and moderately trained females. 13 elite athletes and 11 moderately trained controls with maximal oxygen consumption (VO(2max)) of 67.1 ± 6.1 and 49.5 ± 2.3 mL ∙ min (- 1) ∙ kg (- 1), respectively, were recruited. SV was measured at rest, and running on a treadmill at 40%, 60%, 80% and 100% of VO(2max) using the single breath acetylene uptake (SB) technique. Both groups showed a significant (p<0.05) increase in SV from 40% of VO2max to VO(2max), with increases from 105.3 ± 19.0 to 129.1 ± 16.3 mL∙ beat(-1) for the elite females and from 68.7 ± 21.7 to 82.7 ± 14.0 mL ∙ beat (- 1) for the moderately trained. No differences were observed between groups in these increases, but the elite athletes displayed a larger (p<0.05) SV at all intensities. It is concluded that the SV increases at high aerobic intensities both in elite athlete females and moderately trained females.

Results from the single-breath method are in line with previous findings, showing a good reliability. Although thoracic bioimpedance showed a similar reliability as the single-breath method, and is easier to use, the agreement with single breath was poor, and thoracic bioimpedance seems not to be able to replace it.