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Facilitating physical activity during the workday may help desk-bound workers reduce risks associated with sedentary behavior. We 1) evaluated the efficacy of a cycling workstation to increase energy expenditure while performing a typing task and 2) fabricated a power measurement system to determine the accuracy and reliability of an exercise cycle. Ten individuals performed 10 min trials of sitting while typing (SITtype) and pedaling while typing (PEDtype). Expired gases were recorded and typing performance was assessed. Metabolic cost during PEDtype was ∼2.5× greater compared to SITtype (255 ± 14 vs. 100 ± 11 kcal h−1, P < 0.01). Typing time and number of typing errors did not differ between PEDtype and SITtype (7.7 ± 1.5 vs. 7.6 ± 1.6 min, P = 0.51, 3.3 ± 4.6 vs. 3.8 ± 2.7 errors, P = 0.80). The exercise cycle overestimated power by 14–138% compared to actual power but actual power was reliable (r = 0.998, P < 0.01). A cycling workstation can facilitate physical activity without compromising typing performance. The exercise cycle's inaccuracy could be misleading to users. [ABSTRACT FROM AUTHOR]

The article reports on research which was conducted to investigate the effect locomotor muscle fatigue had on joint-specific power production during cycling. Researchers evaluated 10 cyclists who performed cycling time trials to evaluate changes in maximal cycling. They found that exercise-induced changes in maximal cycling power manifested with differential power loss at each joint action with ankle plantarfiexion and knee flexion exhibiting relatively greater fatigue than knee extension and hip extension and concluded that fatigue caused by cycling does not alter submaximal joint-specific powers.

The article offers information on the study conducted by researchers including Steven J. Elmer, Paul R. Barratt, and James C. Martin on submaximal and maximal cycling. It states that power production during submaximal cycling is dominated by knee extension, whereas maximal cycling is dominated by hip extension. The study aimed at determining the level of power produced by ankle, knee, and hip joint actions during cycling. It also analyzed the connection between relative joint-specific powers and net cycling powers.

Background : Previous investigators have reported that long term eccentric cycling increases muscle size and strength in a variety of populations. The joint-specific strategies used to absorb power during eccentric cycling, however, have not been identified. The purpose of this investigation was to determine the extent to which ankle, knee, and hip joint actions absorb power during eccentric cycling. Methods : Eight active males resisted the reverse moving pedals of an isokinetic eccentric ergometer (60rpm) while targeting 20% of their maximum concentric cycling power. Pedal reaction forces and joint kinematics were recorded with an instrumented pedal and instrumented spatial linkage system, respectively. Joint powers were calculated using inverse dynamics; averaged over complete crank revolutions and over extension and flexion phases; and differences were assessed with a one-way ANOVA. Findings : Ankle, knee, and hip joint actions absorbed 10 (SD 3)%, 58 (SD 8)%, and 29 (SD 9)% of the total power, respectively, with 3 (SD 1)% transferred across the hip. The main power absorbing actions were eccentric knee extension (−139 (SD 21) watts), eccentric hip extension (−51 (SD 31) watts), and eccentric hip flexion (−25 (SD 6) watts). Interpretation : Eccentric cycling was performed with a combination of knee and hip joint actions which is consistent with submaximal concentric cycling. These data support and extend previous work that eccentric cycling improves knee extensor function and hip extensor muscle cross sectional area. Such information may allow clinicians to take even greater advantage of eccentric cycling as a rehabilitation modality. [Copyright &y& Elsevier]

Introduction: Eccentric leg cycling (cycle ergometry adapted to impose muscle lengthening contractions) offers an effective exercise for restoring lower-body muscular function, maintaining health, and improving performance in clinical and athletic populations.Purpose: We extended this model to the upper body and evaluated the effectiveness of a 7-week eccentric arm cycling (ECCarm) intervention to improve upper-body muscular function. We also explored whether ECCarm would alter arterial function.Methods: Participants performed ECCarm (n = 9) or concentric arm cycling (CONarm; n = 8) 3×/week while training intensity increased (5-20 min, 60-70% upper-body peak heart rate). Maximum elbow extensor strength, upper-body concentric power, and peripheral and central arterial stiffness were assessed before and after training.Results: During training, heart rates and perceived exertion did not differ between groups (~68% upper-body peak heart rate, ~12 Borg units, both P > 0.05), whereas power during ECCarm was ~2× that for CONarm (122 ± 43 vs. 59 ± 20 W, P < 0.01). Muscle soreness for ECCarm was greater than CONarm (P = 0.02), however, soreness was minimal for both groups (<0.50 cm). Following training, ECCarm exhibited greater changes in elbow extensor strength (16 ± 10 vs. 1 ± 9%, P = 0.01) and upper-body power (6 ± 8 vs. -3 ± 7%, P < 0.01) compared to CONarm. Peripheral and central arterial stiffness did not change for either group (both P > 0.05).Conclusion: Upper-body eccentric exercise improved dynamic muscular function while training at low exertion levels. Results occurred with minimal soreness and without compromising arterial function. ECCarm findings parallel eccentric leg cycling findings and indicate that eccentric cycle ergometry offers a robust model for enhancing upper-body muscular function. ECCarm could have applications in rehabilitation and sport training. [ABSTRACT FROM AUTHOR]

Previous investigators have reported velocity-dependent strength loss for single-joint actions following acute eccentric exercise. The extent to which velocity influences recovery of multi-joint function is not well documented. Our main purpose was to compare alterations in maximal cycling power produced across a range of pedaling rates following eccentric exercise. An additional purpose was to determine the extent to which changes in rating of perceived exertion (RPE) associated with submaximal cycling reflect changes in maximal cycling power. Eighteen cyclists performed baseline trials of maximal and submaximal single-leg concentric cycling immediately before and 24 and 48 h after acute submaximal single-leg eccentric (151 ± 32 W, 487 ± 107 s) and concentric (148 ± 21 W, 488 ± 79 s) cycling trials. Maximum cycling power (apex of power-pedaling rate relationship; P (max)) was assessed using inertial-load cycling, and powers produced at 65, 110 and 155 rpm were also analyzed. Compared to baseline, P (max) was reduced (11-13%) at 24-48 h in the eccentric leg (P < 0.001). Power produced at 65, 110 and 155 rpm was reduced by similar relative magnitudes (11-15%) at 24-48 h in the eccentric leg. RPE increased (15-18%) at 24-48 h in the eccentric leg (P < 0.001). Magnitudes of relative changes in RPE did not differ from those for P (max). There were no alterations in the concentric leg. Our results indicated a global, rather than velocity-specific, reduction in neuromuscular function. Such a global reduction does not support the notion of fiber-type specific damage from eccentric exercise. The similar relative changes in RPE and P (max) suggest that increased exertion may reflect the need to recruit additional motor units to produce the same submaximal power. [ABSTRACT FROM AUTHOR]