Relative intensity and energy expenditure of a Tabata workout

This study was designed to examine the relative intensity and energy expenditure of a Tabata workout in relation to ACSM guidelines. Sixteen subjects (8 males, 8 females) performed a VO2max test to determine HRmax and VO2max. An individual HR-VO2 regression equation was established for each subject based upon the treadmill test. After treadmill testing, subjects completed two identical 20-minute Tabata workouts. HR responses during each minute of Tabata were used to estimate VO2 and caloric expenditure. HR responses during Tabata averaged 86% of HRmax. Estimated VO2 during the Tabata workout averaged 74% of VO2max. Estimated caloric expenditure averaged 15 kcals/min (240-360 kcals/workout). Thus, it was concluded that Tabata training meets ACSM guidelines for exercise intensity and caloric expenditure during an exercise session. This finding solidifies the notion that Tabata may be another option for individuals looking for a quick, yet effective workout

Defensive structures influence fighting outcomes

In many animal species, individuals engage in fights with conspecifics over access to limited resources (e.g. mates, food, or shelter). Most theory about these intraspecific fights assumes that damage has an important role in determining the contest winner. Thus, defensive structures that reduce the amount of damage an individual accrues during intraspecific competition should provide a fighting advantage. Examples of such damage-reducing structures include the dermal shields of goats, the dorsal osteoderms of crocodiles, and the armoured telsons of mantis shrimps. Although numerous studies have identified these defensive structures, no study has investigated whether they influence the outcomes of intraspecific fights. Here we investigated whether inhibiting damage by enhancing an individual's armour influenced fighting behaviour and success in the giant mesquite bug, Thasus neocalifornicus (Insecta: Hemiptera: Coreidae). We found that experimentally manipulated individuals (i.e. those provided with additional armour) were 1.6 times more likely to win a fight when compared to the control. These results demonstrate that damage, and damage-reducing structures, can influence fighting success. The implications of these results are twofold. First, our results experimentally support a fundamental assumption of most theoretical fighting models: that damage is a fighting cost that can influence contest outcomes. Second, these results highlight the importance of an individual's defensive capacity, and why defence should not be ignored. A free Plain Language Summary can be found within the Supporting Information of this article.Division of Biological Infrastructure12 month embargo; first published 06 December 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Do sexually selected weapons drive diversification?

Sexual selection is often thought to promote speciation. This expectation is largely driven by the fact that sexually selected traits can influence mating patterns and contribute to reproductive isolation. Indeed, some comparative studies have shown that clades with sexually selected traits have increased rates of speciation and diversification. However, these studies have almost exclusively focused on one mechanism of sexual selection: female choice. Another widespread mechanism is male-male competition. Few empirical studies (if any) have investigated the role of this alternative mechanism in driving diversification. Nevertheless, recent reviews have suggested that male-male competition can increase speciation rates. Here, we investigated whether traits associated with precopulatory male–male competition (i.e., sexually selected weapons) have promoted speciation and diversification in insects. We focused on three clades with both weapons and suitable phylogenies: leaf-footed and broad-headed bugs (Coreidae+Alydidae; ∼2850 species), stick insects and relatives (Phasmatodea; ∼3284 species), and scarab beetles (Scarabaeoidea; ∼39,717 species). We found no evidence that weapon-bearing lineages in these clades have higher rates of speciation or diversification than their weaponless relatives. Thus, our results suggest that precopulatory male-male competition may not have strong, general effects on speciation and diversification in insects, a group encompassing ∼60% of all described species.12 month embargo; first published online 19 March 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Damage from intraspecific combat is costly

When individuals engage in fights with conspecifics over access to resources, injuries can occur. Most theoretical models suggest that the costs associated with these injuries should influence an individual's decision to retreat from a fight. Thus, damage from intraspecific combat is frequently noted and quantified. However, the fitness-related costs associated with this damage are not. Quantifying the cost of fighting-related damage is important because most theoretical models assume that it is the cost associated with the damage (not the damage itself) that should influence an individual's decision to retreat. Here, we quantified the cost of fighting-related injuries in the giant mesquite bug, Thasus neocalifornicus. We demonstrate that experimentally simulated fighting injuries result in metabolic costs and costs to flight performance. We also show that flight costs are more severe when the injuries are larger. Overall, our results provide empirical support for the fundamental assumption that damage acquired during intraspecific combat is costly.National Science Foundation12 month embargo; published: 06 August 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Trade‐offs between weapons and testes do not manifest at high social densities

Social conditions can alter the allocation of resources to reproductive traits. For example, an increase in social density during development is frequently associated with an increase in the testes mass of males. Sperm competition theory assumes that increased investment in testes should come at the expense of investing into precopulatory traits, such as sexually selected weaponry. However, much remains unknown about the role of the social context on the concurrent, relative investment in both testes and weapons. We found that the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae), grew nearly 20% larger testes when raised in high social densities. In addition to manipulating social density, we used autotomy (limb loss) to limit investment in their hindlimb weapon during development. At low densities, we found that those that lost a weapon during development grew larger testes by adulthood, supporting previous work demonstrating a weapons–testes trade-off. However, at high social densities, males that dropped a hindlimb did not grow larger testes, though testes were already large at this density. These results underscore the importance of the social context to resource allocation patterns within the individual. © 2021 European Society for Evolutionary Biology12 month embargo; first published: 18 April 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Weapon performance drives weapon evolution

Many sexually selected traits function as weapons, and these weapons can be incredibly diverse. However, the factors underlying weapon diversity among species remain poorly understood, and a fundamental hypothesis to explain this diversity remains untested. Although weapons can serve multiple functions, an undeniably important function is their role in fights. Thus, a crucial hypothesis is that weapon diversification is driven by the evolution of weapon modifications that provide an advantage in combat (e.g. causing more damage). Here, we test this fighting-advantage hypothesis using data from 17 species of coreid bugs. We utilize the fact that male-male combat in coreids often results in detectable damage, allowing us to link different weapon morphologies to different levels of damage among species. We find that certain weapon morphologies inflict much more damage than others, strongly supporting the fighting-advantage hypothesis. Moreover, very different weapon morphologies can inflict similarly severe amounts of damage, leading to a weapon performance landscape with multiple performance peaks. This multi-peak pattern could potentially drive different lineages towards divergent weapon forms, further increasing weapon diversity among species. Overall, our results may help explain how sexually selected weapons have evolved into the diversity of forms seen today.12 month embargo; published: 27 January 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Data set for Joseph, Emberts, Sasson, and Miller 2017 Evolution

This file includes data from two experiments, 1) investment in testes and nearby traits when a weapon is autotomized during development versus when a weapon is not autotomized 2) offspring production for males with and without autotomy. A "READ ME" tab is included in the file that explains all the headers

Data from: Males that drop a sexually-selected weapon grow larger testes

Costly sexually-selected weapons are predicted to trade off with post-copulatory traits, such as testes. Although weapons can be important for achieving access to females, individuals of some species can permanently drop (i.e. autotomize) their weapons to escape danger. We capitalized on this natural behavior to experimentally address whether the loss of a sexually-selected weapon leads to increased testes investment in the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae). In a second experiment, we measured offspring production for males that lost a weapon during development. We found that those that dropped a hind limb during development grew significantly larger testes than the control treatments. Hind-limb autotomy did not result in the enlargement of other nearby traits. Our results are the first to show that males may compensate for natural weapon loss by investing more in testes. In a second experiment we found that females paired with males that lost a hind limb had 40% lower egg hatching success. Yet, in those cases where viable offspring were produced, males missing a hind limb produced 42% more offspring than males with intact limbs. These results suggest that the loss of a hind-limb weapon can, in some cases, lead to greater fertilization success

The Effects of BungeeSkate[superscript]TM Training on Measures of On-Ice Acceleration and Speed

Color poster with text, photographs, figures, tables, and graphs.Previous research has stated that dry land sled pulling trains first step quickness in hockey players. Further research has demonstrated that off-ice horizontal training (sled pull, parachute, etc.) relates well to on-ice acceleration and speed. However, there is limited literature pertaining to on-ice resistance training that aims to enhance speed and acceleration in hockey players. The purpose of the present study was to determine if on-ice BungeeSkate training will improve on-ice speed and acceleration in youth hockey players.University of Wisconsin--Eau Claire Office of Research and Sponsored Programs