To Örebro University

While physical activity (PA) may counteract age-related functional decline and loss of independence at old age, to what extent physical function is influenced by past or present PA behaviors is currently unclear. Therefore, the aim of the study was to examine relationships between both past and present PA behaviors and components of physical function in older women. A physical function score based on the 6-minute walk test, squat jump, and single-leg-stance balance was aggregated in 60 older women (65-70 years). Present PA behavior was assessed by accelerometry (Actigraph) and past leisure-time PA was self-reported, where times in sports-related activities and in walking were analyzed separately. Analysis of differences in physical function across tertiles of PA behaviors was adjusted by DXA-derived fat mass. Physical activity level at present age and engagements in sports-related activities before retirement age, excluding walking, were both associated (P < 0.05) to physical function. Time spent in PA of at least moderate intensity was associated with physical function (P < 0.05), whereas no corresponding relationships to either sedentary time or time in light intensity PA were observed. In conclusion, PA behaviors at present age and engagement in sports-related activities performed during adulthood are both related to physical function in older women. Being physically active at old age infers beneficial effects on physical function, even in individuals with a past or present sedentary lifestyle, which supports public health efforts aiming at increasing daily time in PA of at least moderate intensity to preserve physical function in older women.

The delivery of efficient nonpharmacological treatment to prevent the loss of muscle mass in older adults is a major challenge, and information on the combined effects of training and diet is particularly important. Here we aimed to evaluate the effects of 24 wk of resistance training combined with a healthy dietary approach (n-6/n-3 ratio < 2) in a population of healthy and physically active older women (65-70 years). The three-armed randomized controlled trial included a resistance training + healthy diet group (RT-HD), a resistance training group (RT), and controls (CON). All subjects included in the study were physically active and had low levels of serum inflammatory markers. In accordance with the dietary goals, the n-6/n-3 ratio dietary intake significantly decreased only in RT-HD by 42%. An increase in 1 repetition maximum in leg extension occurred in RT (+20.4%) and RT-HD (+20.8%), but not in CON. Interestingly, leg lean mass significantly increased only in RT-HD (+1.8%). While there were no changes in serum C-reactive protein and IL-6 levels, a significant decrease in serum level of the pro-inflammatory precursor arachidonic acid (-5.3 +/- 9.4%) together with an increase in serum n-3 docosahexaenoic acid (+8.3%) occurred only in RT-HD. Altogether, this study demonstrates that the effects of resistance training on muscle mass in healthy older adults can be optimized by the adoption of a healthy diet.

The effects of 24 wk of resistance training combined with a healthy diet on lower limb explosive strength capacity were investigated in a population of healthy elderly women. Participants (n = 63; 67.5 ± 0.4 yr) were randomized into three groups; resistance training (RT), resistance training and healthy diet (RT-HD), and control (CON). Progressive resistance training was performed at a load of 75-85% one-repetition maximum. A major adjustment in the healthy dietary approach was an n-6/n-3 polyunsaturated fatty acid (PUFA) ratio below 2. Lower limb maximal strength, explosive force capacity during dynamic and isometric movements, whole body lean mass, and physical function were assessed. Whole body lean mass significantly increased by 1.5 ± 0.5% in RT-HD only. Isometric strength performance during knee extension as well as the performance in the five sit-to-stand and single-leg-stance tests increased similarly in RT and RT-HD. Improvements in dynamic peak power and time to reach peak power (i.e shorter time) during knee extension occurred in both RT (+15.7 ± 2.6 and -11.0 ± 3.8%, respectively) and RT-HD (+24.6 ± 2.6 and -20.3 ± 2.7%, respectively); however, changes were significantly larger in RT-HD. Similarly, changes in peak force and rate of force development during squat jump were higher in RT-HD (+58.5 ± 8.4 and +185.4 ± 32.9%, respectively) compared with RT (+35.7 ± 6.9 and +105.4 ± 22.4%, respectively). In conclusion, a healthy diet rich in n-3 PUFA can optimize the effects of resistance training on dynamic explosive strength capacity during isolated lower limb movements and multijoint exercises in healthy elderly women.

NEW & NOTEWORTHY Age-related decline in lower limb explosive strength leads to impaired ability to perform daily living tasks. The present randomized controlled trial demonstrates that a healthy diet rich in n-3 polyunsaturated fatty acid (n-3 PUFA) enhances resistance training-induced gains in dynamic explosive strength capacity during isolated lower limb movements and multijoint exercises in healthy elderly women. This supports the use of strategies combining resistance training and dietary changes to mitigate the decline in explosive strength capacity in older adults.