Downhill Training Research Articles

Comparison of Uphill and Downhill Training Against 100 Meter Sprint Travel Time

Short distance running or sprinting is one of the race numbers in athletics. The achievements of sprint runners can be seen from the results of the time they achieve when running on the track. This study aims to determine the effect of uphill and downhill training on the travel time of the 100 meter sprint in the MAN 7 Jombang athletic extracurricular. In addition, to find out the difference in the effect of uphill and downhill training on the travel time of the 100-meter sprint in extracurricular athletics MAN 7 Jombang. The method used in this study is a quasi-experiment with the Two group Pretest and Posttest Design research design. A total of 20 subjects were taken as participants and divided into two exercise groups, each consisting of 10 people. The instrument in this study used a 100 meter sprint test. Then the data that has been obtained will be tested using the Paired Sample Test t test to determine the effect of treatment, Independent sample test t test to analyze the average difference between the two groups. The results showed that (1) There was a significant influence on uphill training and downhill training on the 100-meter sprint travel time in MAN 7 Jombang athletic extracurriculars. (2) There was no significant difference between the uphill and downhill training groups on the 100-meter sprint travel time in the MAN 7 Jombang athletic extracurricular.

Eccentric rehabilitation induces white matter plasticity and sensorimotor recovery in chronic spinal cord injury

Experience-dependent white matter plasticity offers new potential for rehabilitation-induced recovery after neurotrauma. This first-in-human translational experiment combined myelin water imaging in humans and genetic fate-mapping of oligodendrocyte lineage cells in mice to investigate whether downhill locomotor rehabilitation that emphasizes eccentric muscle actions promotes white matter plasticity and recovery in chronic, incomplete spinal cord injury (SCI). In humans, of 20 individuals with SCI that enrolled, four passed the imaging screen and had myelin water imaging before and after a 12-week (3 times/week) downhill locomotor treadmill training program (SCI + DH). One individual was excluded for imaging artifacts. Uninjured control participants (n = 7) had two myelin water imaging sessions within the same day. Changes in myelin water fraction (MWF), a histopathologically-validated myelin biomarker, were analyzed in a priori motor learning and non-motor learning brain regions and the cervical spinal cord using statistical approaches appropriate for small sample sizes. PDGFRα-CreERT2:mT/mG mice, that express green fluorescent protein on oligodendrocyte precursor cells and subsequent newly-differentiated oligodendrocytes upon tamoxifen-induced recombination, were either naive (n = 6) or received a moderate (75 kilodyne), contusive SCI at T9 and were randomized to downhill training (n = 6) or unexercised groups (n = 6). We initiated recombination 29 days post-injury, seven days prior to downhill training. Mice underwent two weeks of daily downhill training on the same 10% decline grade used in humans. Between-group comparison of functional (motor and sensory) and histological (oligodendrogenesis, oligodendroglial/axon interaction, paranodal structure) outcomes occurred post-training. In humans with SCI, downhill training increased MWF in brain motor learning regions (postcentral, precuneus) and mixed motor and sensory tracts of the ventral cervical spinal cord compared to control participants (P < 0.05). In mice with thoracic SCI, downhill training induced oligodendrogenesis in cervical dorsal and lateral white matter, increased axon-oligodendroglial interactions, and normalized paranodal structure in dorsal column sensory tracts (P < 0.05). Downhill training improved sensorimotor recovery in mice by normalizing hip and knee motor control and reducing hyperalgesia, both of which were associated with new oligodendrocytes in the cervical dorsal columns (P < 0.05). Our findings indicate that eccentric-focused, downhill rehabilitation promotes white matter plasticity and improved function in chronic SCI, likely via oligodendrogenesis in nervous system regions activated by the training paradigm. Together, these data reveal an exciting role for eccentric training in white matter plasticity and sensorimotor recovery after SCI.

Excessive downhill training leads to early onset of knee osteoarthritis

Increased levels of pro-inflammatory cytokines are associated with the release of degradative enzymes leading to osteoarthritis (OA) development. Although physical exercise (PE) is generally recognized as beneficial for OA symptoms, excessive training workload and eccentric muscular exercise have increased OA risk. Here, we investigated the effects of excessive exercise workload and exercise type on systemic inflammation and knee joint OA. Mice were divided into five groups: sedentary (SED), uphill training (TRU), downhill training (TRD), excessive uphill training (ETU), and excessive downhill training (ETD) for an 8-week training intervention protocol. ETD group had increased pro-inflammatory cytokines in serum, vastus lateralis (VL), and vastus medialis (VM) muscles, while ETU group mice had increased cytokine levels in the VL and VM. Total knee joint OARSI score were more significant in ETD group compared to SED and TRU groups. They were also more meaningful for the medial tibial plateau of ETD group compared to SED group. MMP-3 and cleaved Caspase-3 were higher in the ETD group than the SED and TRU group, while Adamts-5 was higher in the ETD group than the SED group. TRU group had increased PRG-4 levels compared to ETU and ETD group. ETD group had decreased total bone volume, trabecular bone volume, and cortical thickness compared to SED group. Excessive downhill training induced a chronic pro-inflammatory state in mice and was associated with early signs of cartilage and bone degeneration that are clinical indicators of knee OA.

Modifiability of residual force depression in single muscle fibers following uphill and downhill training in rats.

Following active muscle shortening, steady‐state isometric force is less than a purely isometric contraction at the same muscle length and level of activation; this is known as residual force depression (rFD). It is unknown whether rFD at the single muscle fiber level can be modified via training. Here we investigated whether rFD in single muscle fibers is modifiable through downhill and uphill running in the extensor digitorum longus (EDL) and soleus (SOL) muscles in rats. Rats were run uphill or downhill 5 days/week for 4 weeks. After muscles were dissected and chemically permeabilized, single fibers were tied between a length controller and force transducer, transferred to an activating solution, with ATP and pCa of 4.2 for mechanical testing. rFD was quantified after active fiber shortening from an average sarcomere length (SL) of 3.1–2.5 µm at a relative speed of 0.15 fiber lengths/s (slow) and 0.6 fiber lengths/s (fast). rFD was calculated as the difference in force (normalized to cross‐sectional area) during the isometric steady‐state phase following active shortening and the purely isometric contraction. In addition to rFD, mechanical work of shortening and stiffness depression were also calculated. rFD was present for both the EDL (6–15%) and SOL (1–2%) muscles, with no effect of training. rFD was greater for the EDL than SOL which closely corresponded to the greater stiffness depression in the EDL, indicating a greater inhibition of cross‐bridge attachments. These results indicate that while rFD was observed, training did not appear to alter this intrinsic history‐dependent property of single muscle fibers.

The effects of training with high-speed interval running on muscle performance are modulated by slope.

We examined changes in selected muscle performance parameters after 8 weeks of interval training using two opposite running inclinations. We hypothesized that the uphill training will affect endurance muscle performance outcomes, whereas the downhill training will affect power muscle performance outcomes. Fourteen physically active volunteers were randomly assigned into either the Uphill group (UG; n = 7; uphill interval running at +10% incline) or the Downhill group (DG; n = 7; downhill interval running at −10% incline) and completed 16 training sessions. Each session consisted of ten 30 s treadmill runs at 90% of maximum aerobic speed (MAS) with a work to rest ratio of 1:2. Vertical jump performance, isometric (MVC) and isokinetic torque of knee extensors and flexors, and fatigue of knee extensors were evaluated pre and post‐training. Moreover, body composition (via bioimpedance) and vastus lateralis muscle architecture (via ultrasonography) were assessed pre and post‐training. Relative lean tissue mass, relative fat mass, and squat jump (cm) significantly (p < .05) changed from baseline values by +4.5 ± 4.0%, −11.5 ± 9.6%, and +9.5 ± 11.7%, respectively, only in the DG. Similarly, DG improved absolute values of knee extension rate of torque development and impulse (p < .05), whereas knee flexion peak torque angle significantly decreased in both groups (p < .05). On the other hand, the UG increased the number of repetitions achieved during the fatigue protocol and total work by 21.2 ± 32.6% and 13.8 ± 21.2%, respectively (p < .05). No differences were found between groups in muscle architecture. Introducing variations in slope during HIIT could be used to induce specific improvements toward muscle endurance or power performance characteristics.

Training Induced Changes to Skeletal Muscle Passive Properties Are Evident in Both Single Fibers and Fiber Bundles in the Rat Hindlimb

Introduction: The passive mechanical behavior of skeletal muscle represents both important and generally underappreciated biomechanical properties with little attention paid to their trainability. These experiments were designed to gain insight into the trainability of muscle passive mechanical properties in both single fibers and fiber bundles. Methods: Rats were trained in two groups: 4 weeks of either uphill (UH) or downhill (DH) treadmill running; with a third group as sedentary control. After sacrifice, the soleus (SOL), extensor digitorum longus (EDL), and vastus intermedius (VI) were harvested. One hundred seventy-nine bundles and 185 fibers were tested and analyzed using a cumulative stretch-relaxation protocol to determine the passive stress and elastic modulus. Titin isoform expression was analyzed using sodium dodecyl sulfate vertical agarose gel electrophoresis (SDS-VAGE). Results: Single fibers: passive modulus and stress were greater for the EDL at sarcomere lengths (SLs) ≥ 3.7 μm (modulus) and 4.0 μm (stress) with DH training compared to UH training and lesser for the SOL (SLs ≥ 3.3 μm) with DH training compared with control; there was no effect of UH training. Vastus intermedius was not affected by either training protocol. Fiber bundles: passive modulus and stress were greater for the EDL at SLs ≥ 2.5 μm (modulus) and 3.3 μm (stress) in the DH training group as compared with control, while no affects were observed in either the SOL or VI for either training group. No effects on titin isoform size were detected with training. Conclusion: This study demonstrated that a trainability of passive muscle properties at both the single fiber and fiber bundle levels was not accompanied by any detectable changes to titin isoform size.

Effects of sprint interval training on sloping surfaces on aerobic and anaerobic power

Summary Study aim: Several sprint interval training applications with different slope angles in the literature mostly focused on sprint running time and kinematic and dynamic properties of running. There is a lack of comparative studies investigating aerobic and anaerobic power. Therefore, this study aimed to examine the effects of sprint interval training on sloping surfaces on anaerobic and aerobic power. Material and methods: A total of 34 male recreationally active men aged 20.26 ± 1.68 years and having a BMI of 21.77 ± 1.74 were assigned to one of the five groups as control (CON), uphill training (EXP 1 ), downhill training (EXP 2 ), uphill + downhill training (EXP 3 ) and horizontal running training (EXP 4 ) groups. Gradually increased sprint interval training was performed on horizontal and sloping surfaces with an angle of 4°. The training period continued for three days a week for eight weeks. The initial and the final aerobic power was measured by an oxygen analyser and anaerobic power was calculated from the results of the Margaria-Kalamen staircase test. Results: Following the training programme, an increase in aerobic power was found in all training groups (EXP 1 = 20.79%, EXP 2 = 14.95%, EXP 3 = 26.85%, p &lt; 0.01) and EXP 4 = 20.46%) (p &lt; 0.05) in comparison with the CON group (0.12%), but there were no differences among the training groups. However, significant increases in anaerobic power were found in uphill training (4.91%) and uphill + downhill training (8.35%) groups (p &lt; 0.05). Conclusion: This study showed that all sprint interval studies on horizontal and sloping surfaces have a positive effect on aerobic power, and uphill and combined training are the most effective methods for the improvement of anaerobic power.

Chronic uphill and downhill exercise protocols do not lead to sarcomerogenesis in mouse skeletal muscle

It has been suggested that eccentric contraction (EC) is associated with increases in serially arranged sarcomeres (sarcomerogenesis), while concentric contraction (CC) has been associated with serial sarcomeres decrease. Sarcomerogenesis following EC is thought to be a protective muscle adaptation, preventing muscle injury in future eccentric exercise bouts (repeated bout effect). However, the mechanisms underlying sarcomerogenesis in EC remain unknown, and the sarcomerogenic responses observed in response to EC and CC are contradictory. We measured sarcomere length, sarcomere length uniformity, serial sarcomere number, and fascicle length in gastrocnemius medialis, tibialis anterior, vastus medialis and vastus lateralis in sedentary (SED) mice, and in mice following protocols of moderate uphill (TRU) and downhill (TRD) training and uphill (OTU) and downhill (OTD) overtraining. We found pain sensitivity after the first bout of EC exercise on TRD and OTD followed by a normalized sensory response after four weeks of training, indicating a repeated bout effect. However, these findings were not associated with sarcomerogenesis, as serial sarcomere numbers did not increase in TRD and OTD skeletal muscle samples compared to controls (SED). However, we found a decrease in serial sarcomere number in VL and TA in OTU group mice, which was associated with a decrease in fascicle length and no change of sarcomere length at the tested joint configuration. We conclude that excessive concentric muscle contraction (OTU group mice), leads to a decrease in serial sarcomere number, while moderate or excessive eccentric training, did not result in sarcomerogenesis, as reported in the literature.

The Effect of Uphill and Downhill Exercise Training on Myogenic Mechanism of Wnt/BMP Signaling in the Skeletal Muscle of Aged Rats

PURPOSE The purpose of this study was to determine the effect of exercise types on the Wnt/BMP signaling and the response to myogenic mechanism by downhill and uphill training in the aged rat skeletal muscles. METHODS Young and old rats were randomly assigned to control groups; young (YC) and old (OC), and two types of running training groups: old downhill exercise (ODE) and old uphill exercise (OUE). Training was progressively carried out on a treadmill at a speed of 21 m/min with a slope of +10° for uphill training vs 16 m/min with a slope of -16° for downhill training: 60 min/day, 5 days/week for 8 weeks respectively. RESULTS Downhill and uphill training significantly increased the protein levels of Wnt3a, β-catenin and LEF-1 in aged rats. On the contrary, GSK3β was reduced by running training. In addition, the expression patterns of Wnt7a, Fzd7, PKC, p-AKT, and p-mTOR in extensor digitorum longus (EDL) and soleus (SOL) muscle were significantly increased in both ODE and OUE groups. Expression patterns of BMP-2, BMP-7, and p-Smad-1/5/8 in EDL and SOL muscles were significantly increased in both ODE and OUE groups. Especially, ODE group showed more increased expression pattern than OUE group. The expression patterns of MyoD, Myf5, and Myogenin were significantly increased in both DOE and OUE groups. Myf5 and Myogenin showed more increased expression pattern in ODE group than OUE group. CONCLUSIONS The downhill and uphill exercise training may play a mediating role in increasing the expression of these reduced myogenesis related factors. Furthermore, the formation process and hypertrophy of skeletal muscle weakened due to aging can be improved and maintained. 색인어: ë ¸í™” 마우스, 내리막과 오르막 운동, GSK3β, BMP-2, BMP-7 Keywords: Aged muscles, Downhill and uphill exercise, GSK3β, BMP-2, BMP-7

PO-050 Effects of Exercise on Gene Expression Correlative to Bone Metabolism in Peripheral Blood Mononuclear Cells

Objective To examine the gene expression pattern of Peripheral Blood Mononuclear Cells （PBMCs）and to explore exercise-sensitive genes correlative to bone metabolism in PBMCs. Thus to provide a theoretical basis for exercise intervention to prevent and treat osteoporosis. &#x0D; Methods Uphill (+8° ) and downhill (-8° ) training were used for the exercise loading in two-month-old male Sprague-Dawley rats. The exercise method performed at 25 m/min, training 50 min/d, 5 d/wk, for 12 wk, respectively. Bone mineral density of distal femurs was measured using dual X-ray absorptiometry, and the expressed gene profile of PBMCs was examined using Gene Chip IVT Labeling Kit (Affymetrix). &#x0D; Results Compared with control (CON) group, the BMD of the femur in the downhill (DOWN) group was significantly increased. Compared with the uphill （UP）group, the BMD and BMC of the femur in the DOWN group were significantly increased. There were 38 genes detected differentially expressed between two exercise groups together with CON group. The expression of genes modified by running involved in immunity, cell proliferation，Rheumatoid arthritis，Cell adhesion molecules and Tnf signaling pathway. There were 105 differently expressed genes between the DOWN group and the UP group which were mainly enriched in biological processes and pathways such as response to hydrogen peroxide，lipopolysaccharide，cell factor and mechanical stimulus，Cell adhesion molecules，cell migration，collagen biosynthetic process and Tnf signaling pathway. Tnf, Cxcl2, Ccl2, Jun and Mmp9 as the key nodes of protein interaction network were identified as candidate genes related to bone metabolism and sensitive to exercise. &#x0D; Conclusions With weight gaining，age increasing and training time prolonging, long-term and high-intensity exercise will be harm for bone. At the same time and same running speed, downhill running conduces to increase bone density more than uphill running. It may be associated with differential expression of exercise-sensitive genes involved in bone metabolism in PBMCs.

PO-261 The acute and long-term effects of KAATSU downhill walking training on muscle growth

Objective As a new training method, KAATSU Training has become a popular training method because of its obvious training effect, short period and high safety. In this paper, the acute and long-term response of the KAATSU downhill walking Training is discussed to explore its effect on muscle growth, and to provide a theoretical basis for the scientific pressurization of athletes, rehabilitation groups and fitness groups.&#x0D; Methods (1) acute effects: 8 healthy male subjects received pressure and non-pressure slow downhill walking training at the same time and in good physical condition. Pressure in the pressure group was 240mmhg, and pressure bands were tied in the non-pressure group but no pressure. The downhill slope is 16%, the speed is 3km/h, and stride slow walk on the treadmill. Forearm venous blood was taken 15 minutes before training and 15 minutes after training. The concentration of growth hormone (GH), insulin (In), cortisol (C), blood testosterone (T), creatine kinase (CK) and UREA in blood samples were tested respectively. The fingertip blood lactate (Lac) was taken 2 minutes after training, and the subjects' subjective fatigue feelings (RPE) were recorded immediately after training. The changes of surface electromyography (EMG) during training were recorded, and changes of heart rate were recorded every 2 minutes. The thigh and calf circumference were measured before and after exercise.&#x0D; (2) long-term effects: 14 healthy male subjects were randomly divided into the experimental group (KAATSU group 240mmhg, n=8) and the control group (no KAATSU group, n=6), with a slope gradient of 16% and a speed of 3km/h. 2 weeks for 10 days from Monday to Friday. The first week of Monday and the second week of Friday is the same as the acute effects test. At other times, the circumference of the thigh and the calf before and after the training were measured, the heart rate and the subjective fatigue feeling immediately after the exercise were recorded.&#x0D; Results (1)The muscle circumference increased immediately after exercise in both groups. The change of thigh circumference after exercise in the KAATSU group was significantly higher than that in the non- KAATSU group (P&lt;0.05).&#x0D; (2) There were no significant changes in growth hormone, insulin, cortisol, testosterone, creatine kinase and blood urea before and after exercise (P&gt;0.05), and no changes in creatine kinase 24 hours after training.&#x0D; (3) The exercise heart rate of the pressure group was slightly higher than that of the control group ,and the surface electromyography of the KAATSU group was significantly higher than that of the non- KAATSU group (P&lt;0.05).&#x0D; (4) There was no significant difference in subjective fatigue and blood lactic acid between the two groups (P&gt;0.05).&#x0D; (5) After two weeks of KAATSU downhill training walking, the muscle circumference of the leg in the KAATSU group was significantly higher than that of the control group (P&lt;0.05).&#x0D; Conclusions (1) One-time downhill walking training can increase muscle circumference and the KAATAU group was more obvious.&#x0D; (2) KAATSU downhill walking training can increase muscle without causing muscle damage.&#x0D; (3) KAATSU downhill walking training can collect more muscle fiber.&#x0D; (4) Under the KAATSU downhill walking training, the concentration of lactic acid is low, the subjective feeling is easy. The heart rate is slightly higher than the quiet level, which will not cause fatigue and will not affect the blood sugar level.&#x0D; (5)Long-term KAATSU downhill walking training can promote muscle growth.&#x0D;

The effects of downhill and uphill exercise training on osteogenesis-related factors in ovariectomy-induced bone loss.

[Purpose]Recent evidence suggests that regular exercise training plays a decisive role in maintaining homeostasis and promoting muscle and skeletal formation. However, the effect of downhill exercise training on osteogenesis-related factors is not well understood.[Methods]Thus, we investigated the effect of uphill and downhill training on ovariectomy (OVX)-induced bone loss. After ovary removal, the exercise method performed included uphill (16 m/min, +15°) and downhill training (16 m/min, –15°) for 60 min/day and 5 days/week, respectively, for 8 weeks.[Results]Our results showed that both uphill and downhill training significantly decreased the body weight, total cholesterol, and creatine kinase (CK) levels in the context of OVX-induced bone loss. On the contrary, levels of an osteogenesis indicator, osteocalcin and alkaline phosphatase were elevated. Consequently, the uphill and downhill training reduced OVX- induced bone loss in the distal femoral metaphysis. Likewise, the bone microstructure in OVX-induced bone loss was enhanced upon training. In particular, the inhibition of RANKL-induced osteoclast formation and osteoclast-specific gene expression improved upon downhill training compared to uphill training.[Conclusion]These results suggest that the uphill and downhill exercise types appeared to positively affect the expression of osteogenesis-related factors along with bone density and microstructure. Particularly, the downhill training has more beneficial effects on the maintenance of homeostasis during bone formation.

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OBJECTIVES/SPECIFIC AIMS: Incomplete spinal cord injury (iSCI) is a life-long disability that typically results in a profound loss of locomotion capability. Current rehabilitation methods rarely restore full community ambulation, which in turn limits quality of life. Most individuals with iSCI exhibit persistent deficits in eccentric muscle control and reach recovery plateaus below the levels necessary for independent community ambulation. Eccentric motor control is essential during the weight acceptance phase of gait, which is emphasized during downhill walking. METHODS/STUDY POPULATION: The overground locomotion of subjects with chronic iSCI was analyzed both prior to and following a 12-week downhill body-weight-supported treadmill training regimen and compared to that of matched healthy controls in terms of kinematics, kinetics, and EMG activation. RESULTS/ANTICIPATED RESULTS: We expect to find significant differences between the controls and subjects with iSCI, with deficits in eccentric motor control accounting for some of these differences. In addition, we expect the downhill training to yield significant improvement in eccentric muscle control that translates into improvements in functional, overground walking for the subjects with iSCI. DISCUSSION/SIGNIFICANCE OF IMPACT: The goal is to determine if downhill training can improve eccentric motor control and extend recovery beyond established plateaus. OpenSim modeling of the experimental data will help quantify changes in eccentric control of individual muscles to clarify where specific gains are made.

Effect of downhill sprint training on speed of school boys

The aim of this study was to examine the downhill sprint training on the speed of school boys. Thirty healthy school boys were selected to experimental (n = 15) and control (n = 15) groups. They carried out 8 weeks downhill training. Speed was measured before and immediately after a training period. The data collected from the two groups prior to and post experimentation were statistically analyzed by analysis of covariance (ANCOVA). The result of the study found that due to the eight weeks of downhill training the speed of the subjects was increased.

Gradual downhill running improves age-related skeletal muscle and bone weakness: implication of autophagy and bone morphogenetic proteins.

What is the central question of this study? Exercise training by running has an effect on age-related muscle and bone wasting that improves physical activity and quality of life in the elderly. However, the effect of downhill running on age-related muscle and bone wasting, and its mechanisms, are unclear. What is the main finding and its importance? Gradual downhill running can improve skeletal muscle growth and bone formation by enhancing autophagy and bone morphogenetic protein signalling in aged rats. Therefore, downhill running exercise might be a practical intervention to improve skeletal muscle and bone protection in the elderly. Recent evidence suggests that autophagy and the bone morphogenetic protein (BMP) signalling pathway regulate skeletal muscle growth and bone formation in aged rats. However, the effect of downhill running on muscle growth and bone formation is not well understood. Thus, we investigated the effect of downhill and uphill running on age-related muscle and bone weakness. Young and late middle-aged rats were randomly assigned to control groups (young, YC; and late middle-aged, LMC) and two types of running training groups (late middle-aged downhill, LMD; and late middle-aged uphill, LMU). Training was progressively carried out on a treadmill at a speed of 21mmin-1 with a slope of +10deg for uphill training versus 16mmin-1 with a slope of -16deg for downhill training, both for 60minday-1 , 5 daysweek-1 for 8weeks. Downhill and uphill training increased autophagy-related protein 5, microtubule-associated protein light chain, Beclin-1 and p62 proteins in aged rats. In addition, superoxide dismutase, haem oxygenase-1 and the BMP signalling pathway were elevated. Phosphorylation of mammalian target of rapamycin and myogenic differentiation were increased significantly in the LMD and LMU groups. Consequently, in the femur, BMP-2, BMP-7 and autophagy molecules were highly expressed in the LMD and LMU groups. These results suggest that both downhill and uphill training appear to have a positive effect on expression of autophagy molecules and BMPs. In particular, these physiological adaptations from gradual downhill exercise have an effect on bone morphological changes and muscle quality similar to gradual uphill training interventions in ageing.

Mountain Biking

A somewhat recent introduction to the world of fitness is mountain biking. The good news is that an actual mountain is not generally needed, so an “off road,” an old hiking trail, and even gravel roads can substitute as a mountain biking excursion. For more fit and experienced riders, however, only a true mountain will do. Either way, it allows an outdoor “getaway” and can be a great supplement to traditional workouts. BENEFITS OF MOUNTAIN BIKING The varying terrain allows for a full body workout. For example, going uphill challenges the leg muscles, whereas riding downhill engages the muscles of the arm, shoulder, chest, back, and abdomen. The uphill and downhill training also makes for a natural interval workout. Ascending will get the heart rate up, sometimes substantially — and often for several minutes if the incline is long, whereas descending or returning to level ground allows the heart rate to recover. Like all forms of biking, it induces a lower impact on the skeletal system than most activities — at least for the lower limbs. Also, because of ever-changing terrain and grade, mountain bike rides can improve coordination and proprioception and challenge decision-making skills. Most important, it’s fun. The combination of good aerobic (and anaerobic) workout, being outside, and the euphoria of traveling at fast speeds makes mountain biking a favorite activity for many. GETTING STARTED First, get fitted for a mountain bike made by a company that has a reputation of making a durable product. Don’t hesitate to buy a used bike to save some money. Next, get a helmet. And for now, don’t worry about getting the special pedals and clipless shoes that many riders have. Simply use toe clips. Because water bottles are more difficult to access during a ride, consider the hands-free drinking option that Camelbak and others provide. Once you’ve acquired the appropriate gear, team up with other riders who can show you some trails and give basic pointers along the way. Initially consider mountain biking once every week or two because commuting time and organizing a ride with others can be a laborious process. Also, start on easy trails to get used to your bike — including gear changing — and avoid extended rides that may lead to muscle soreness. MOUNTAIN BIKE TIPS Relax the upper body — Rigid and extended arms increase the chance of joint injury in the shoulder, elbow, and wrists. Allow your arms and hands to act as shock absorbers. Uphill — The focus should be on the right gear to allow a challenging, yet lighter, intensity. The goal is to make it up the hill, so pace yourself. Downhill — The main goal here is safety. One wrong turn or a fallen branch can lead to an injurious fall. Be patient — Mountain biking is a skill as much as a great form of exercise, and both take time to acquire. Stay safe — follow the safety tips presented below. Mountain biking presents a great opportunity for enjoyment, but riders must ease into it. Preparation, appropriate equipment, and good decision making can make it one of the most enjoyable activities in your fitness routine. SAFETY TIPS Start and progress slowly — Because two distinct dynamic qualities are required — fitness and skill — error on the side of caution. A combination of too much speed and some shifty terrain under the tires can make for a dangerous ride. Stay focused — A genuine respect for this activity is needed. Even a minor lapse in attention can lead to an accident on the trail. Partner up — For two main reasons. First, an unknown trail is more likely to cause an injury via a fall, so have the more experienced rider go first so he or she can give warning of upcoming obstacles and potentially dangerous turns. Second, getting lost is a real possibility. Fatigue and onsetting darkness can amplify this situation. Know the weather and trail conditions — Nothing makes a trip seem more wasted than to run into a bad storm on the trail. Furthermore, slick trails simply increase the probability of a fall.

Effect of Combined Uphill-Downhill Sprint Training on Kinematics and Maximum Running Speed in Experienced Sprinters

This study examined the effects of sprint running training on sloping surfaces (3°) in experienced sprinters using selected kinematic variables. Twelve experienced sprinters were randomly allocated to two training groups (combined uphill–downhill and horizontal). Pre- and post-training tests were performed to examine the effects of six weeks of training on maximum running speed, step rate, step length, step time, contact time, braking and propulsive phase of contact time, flight time and selected postural characteristics during a step cycle in the final steps of a 35m sprint test. In the combined uphill–downhill training group, maximum running speed was substantially greater (from 9.08 ± 0.90 m s-1 to 9.51 ± 0.62 m s-1; p &lt;0.05) after training by 4.8%; step rate, contact time, step time and concentric phase was not modified. There were no significant changes in maximal speed or sprint kinematics in the horizontal training group. Overall, the posture characteristics did not change with training. The combined uphill–downhill training method was substantially more effective in improving the maximum running speed in experienced sprinters than a traditional horizontal training method.

Specific training improves skeletal muscle mitochondrial calcium homeostasis after eccentric exercise

There is limited understanding of the mitochondrial adaptation following repeated eccentric exercise bouts, a model resulting in muscle adaptation known as the repeat bout effect. It was hypothesized that downhill training would reduce mitochondrial calcium content (MCC) post an acute eccentric bout with concurrent improvements in mitochondrial respiratory function. Thirty-four Sprague-Dawley rats were divided into four groups: control (N), control with acute eccentric exercise (N (ecc)), trained control (X) and trained with acute eccentric exercise (X (ecc)). Training for X and X (ecc) consisted of 30min per day for five consecutive days of downhill treadmill running. The acute eccentric exercise bout was a -14° treadmill exercise for 90min performed 2weeks after the training period. Animals were killed 48h post-exercise. Isolated mitochondria from the red quadriceps allowed for the measure of mitochondrial respiratory indices and MCC. Calpain activity and heat shock protein 72 expression (HSP72) were also measured. MCC dramatically increased following the acute bout of eccentric exercise in N (ecc) (p<0.001), but did not change in X (ecc). Mitochondrial respiratory function tended to be slightly depressed in N (ecc) (state 3 respiration, p=0.053; respiratory control ratio, p=0.098) and unaltered in X (ecc). Previous training altered the calpain and heat shock protein response to an acute bout of eccentric exercise. The results suggest that downhill exercise training improves mitochondrial calcium homeostasis following an acute bout of prolonged eccentric exercise and may stabilize mitochondrial respiratory function. These improvements coincide with a reduction in calpain activity and heat shock protein upregulation.

Downhill training upregulates mice hippocampal and striatal brain-derived neurotrophic factor levels

This study examined the effects of downhill treadmill exercise on brain-derived neurotrophic factor (BDNF) protein on the hippocampus and striatum of mice. Twenty-four adult mice were assigned to three groups: non-runners control, level or downhill (16 degrees decline) running exercise. The exercise schedule consisted of progressive treadmill running for 5 days week(-1) over 8 weeks. Blood lactate levels classified exercise intensity as moderate to high. Both training types increased citrate synthase activity of the soleus muscle when compared to untrained controls. While level running increased BDNF levels selectively in the hippocampus (68.5%), the eccentric running resulted in a pronounced BDNF increase in both the hippocampus (137.0%) and the striatum (49.9%). Further studies will specify whether the observed alterations in BDNF are due to downhill-induced upregulation or complex learning-induced mechanisms that influence BDNF levels in these brain regions.

Mitochondrial IV complex and brain neurothrophic derived factor responses of mice brain cortex after downhill training

Twenty-four adult male CF1 mice were assigned to three groups: non-runners control, level running exercise (0 degrees incline) and downhill running exercise (16 degrees decline). Exercise groups were given running treadmill training for 5 days/week over 8 weeks. Blood lactate analysis was performed in the first and last exercise session. Mice were sacrificed 48 h after the last exercise session and their solei (citrate synthase activity) and brain cortices (BDNF levels and cytochrome c oxidase activity) were surgically removed and immediately stored at -80 degrees C for later analyses. Training significantly increased (P<0.05) citrate synthase activity when compared to untrained control. Blood lactate levels classified the exercise intensity as moderate to high. The downhill exercise training significantly reduced (P<0.05) brain cortex cytochrome c oxidase activity when compared to untrained control and level running exercise groups. BDNF levels significantly decreased (P<0.05) in both exercise groups.